Diabetes

Are Our Healthy Years Getting Shorter?

by

What Does This Mean For You?

Author: Dr. Stephen Chaney

If you’ve ever traveled the subway system in London, you can’t have missed the “Mind the Gap” signs warning not to put your foot in the gap between the subway and the platform.

That warning is more important than ever in an age where people look at their cell phones rather than where they are walking. Of course, if they are looking at their cell phones, they might miss the sign and…

But today’s “Health Tip” is not about subway gaps. It’s about a far more important gap – the gap between our healthspan (how many years we enjoy good health) and our lifespan (how many years we live).

A recent study (L Gimeno et al, The Journals of Gerontology, Series B, 79(8), gbae113, 2024) suggesting that our healthy years are getting shorter caught my attention.

All of us imagine that our golden years will be ones of vibrant health. We’ll travel to exotic places. We’ll take long walks in the mountains. We’ll play with our grandchildren. Life will be wonderful.

But if this study is correct, none of that will happen for many young Americans. They will be too frail and sick to enjoy their golden years. They will be surviving rather than thriving.

So, in today’s “Health Tips From the Professor” I will review the study and tell you what it means for you.

How Was The Study Done?

clinical studyThe investigators used data on 114,526 adults >50 (average age = 63) from developed countries (the United States, England, and continental Europe). Specifically, they used data from people who participated in the Healthy and Retirement Study (26,939 people in the United States), the English Longitudinal Study on Ageing (14,992 people in England), and the Survey of Health, Ageing, and Retirement (72,595 people in continental Europe) between 2004 and 2018.

These surveys collected data on health-related outcomes every 2 years. The outcomes measured were:

  • Six activities of daily living (ADLs) such as eating, bathing, and walking.
  • Four instrumental activities of daily living (IADLs) related to essential tasks such as grocery shopping or preparing a hot meal.
  • Seven measures of mobility difficulties and motor coordination tasks such as walking one block, lifting 10 pounds, or picking up a small coin from a flat surface.

The assumption was that the severity of limitations was ADL > IADL > mobility difficulties. This is based on previous research showing that a person with ADL limitations is likely to have IADL limitations and mobility difficulties. And a person with IADL limitations is likely to have mobility difficulties. Based on this assumption, they classified participants in this study into 4 disability categories:

  • Mild disability: ≥1 IADL limitations and any number of mobility difficulties.
  • Moderate disability: 1-2 ADL limitations with any number of IADL limitations and mobility difficulties.
  • Severe disability: ≥3 ADL limitations with any number of IADL limitations and mobility difficulties.

The study also measured the prevalence (percent of the population) with:

  • Obesity
  • Heart disease.
  • Diabetes
  • Cancer
  • Lung disease.
  • High blood pressure.
  • High cholesterol.

Finally, the study also measured grip strength because loss of grip strength is considered an indicator of future disabilities.

The unique feature of this study is it compared the health and disability of people who were at the same age when tested but were born in different decades ranging from 1925 to 1955.

Because of the rapid change in diet and lifestyle following World War II, the health and disability of people born in the 1936-1945 decade encompassing World War II was used as the standard to which all other decades were compared.

Are Our Healthy Years Getting Shorter?

Some of you may have skipped over the previous section, so I will repeat the way these data were analyzed because it is crucial to your understanding of the study.

“The unique feature of this study is it compared the health and disability of people who were at the same age when tested but were born in different decades ranging from 1925 to 1955.

Because of the rapid change in diet and lifestyle following World War II, the health and disability of people born in the 1936-1945 decade encompassing World War II was used as the standard to which all other decades were compared.”

When looking at data from the United States, there were two distinct patterns.

The vertical line in the center of the graph represents the health and disability status of people born during World War II because all comparisons in this study were to people born in the decade encompassing World War II. A worsening of health and disabilities is indicated in red and an improvement in health and disabilities is shown in green. 

Pattern A was characteristic of a constant worsening of health and disabilities from people born in the decade starting in 1925 to people born in the decade starting in 1955.

This pattern was seen for:

  • Obesity
  • Heart disease.
  • Diabetes
  • Lung disease.
  • High blood pressure.
  • High cholesterol.
  • Severe disabilities.
  • Reduction in grip strength.

Remember, this study is measuring health and disability of people at the same age. The only difference is when they were born. It tells us people in their 50s, 60s, or 70s born in 1955 or later are in poorer health than people of the same age who were born in 1925.

And it’s not just the United States. For obesity and health parameters the pattern was the same for England and Europe. For severe disabilities the pattern was the same for England but was not as clear for Europe.

Two things should be noted for this pattern:

  • The worsening of health and the increase in severe disabilities comes despite the vast improvements in the health care systems in these countries and improved understanding of the causes of these diseases.
  • Obesity is likely a major driver of our declining health and increased disability. However, it is not the only driver. If the investigators had graphed the percentage of highly processed foods in the diet or the decline in regular exercise, the pattern would have been similar.

Pattern B shows an improvement in the period leading up to World War II and a deterioration in the period after World War II. The authors interpreted the improvement prior to World War II as due to improvements in health care and the deterioration after World War II as due to changes in diet and lifestyle.

This is the pattern seen for mild and moderate disabilities in the United States. The pattern for mild and moderate disabilities was not as clear for England and Europe.

The authors concluded, “In all regions, we found evidence for worsening health across cohorts [groups of people born in successive decades], particularly for those born after 1945.”

What Does This Study Mean For You?

QuestionsI don’t want to overinterpret this study. This study breaks new ground, but it has some limitations that I would characterize with three statements:

  • It is a very difficult study to do perfectly.
  • There are several factors that could affect the interpretation of the data and the outcome of the study.
  • The authors made a valiant effort to correct for any factors that could have affected the outcome.

For more details about the factors that might affect the outcome of the study and how the authors corrected for them, read the study.

However, this is the first study to use this approach to gauge the decrease in healthy years (healthspan) in developed countries over the past 40 years. It has its flaws, but it is consistent with several other studies documenting declining health in the current generation of young adults. For example, in a recent issue of “Health Tips From the Professor” I reviewed a study showing that colon cancer rates are increasing at an alarming rate for young adults in this country.

At the beginning of this article, I talked about the gap between our healthspan (how many years we enjoy good health) and our lifespan (how many years we live).

This study suggests that the onset of significant health issues and disabilities is occurring at a younger age today than for people born before World War II. In short, it suggests that our healthspan (the number of healthy years) is getting shorter.

This study did not look at lifespan, but numerous studies show that our lifespan is still increasing. So, the gap between healthspan and lifespan appears to be getting larger. In simple terms this means that when today’s young adults reach their “golden years”, they may spend more of those years in poor health than those of us born in the 1940’s.

But, what does this mean for you? The take home lesson should be, “This doesn’t have to be. You don’t have to be frail and sickly in your golden years. We know how to prevent this.”

  • It starts with a healthy diet – a whole food, primarily plant-based diet with lots of colorful fruits and vegetables, whole grains, nuts and seeds.
  • Add in a regular exercise program with a mixture of aerobic and resistance exercises.
  • Include an individualized supplement program.

You notice I didn’t list weight control as one of the top three prevention strategies. That’s because I don’t recommend fad diets and rapid weight loss programs. If you do the first three things well, your weight will come off naturally – a little bit at a time.

And once you have mastered all four things, you will increase your healthy years and narrow the gap between your healthspan and your lifespan. You can look forward to golden years filled with vitality and adventure.

The Bottom Line

A recent study used an innovative approach to quantify the deterioration in health and the physical ability to function well in daily activities as we age. The unique feature of this study is it compared the health and disability of people who were at the same age when tested but were born in different decades ranging from 1925 to 1955.

The study found a constant worsening of health and disabilities from people born in the decade starting in 1925 to people born in the decade starting in 1955 for:

  • Obesity
  • Heart disease.
  • Diabetes
  • Lung disease.
  • High blood pressure.
  • High cholesterol.
  • Severe disabilities.

The authors concluded, “We found evidence for worsening health across cohorts [groups of people born in successive decades], particularly for those born since 1945.”

In short, people born in recent years have fewer healthy years (a shorter healthspan) than people born before World War II. And since our lifespans are getting longer, this means the gap between our healthspan and our lifespan is increasing.

All of us imagine that our golden years will be ones of vibrant health. We’ll travel to exotic places. We’ll take long walks in the mountains. We’ll play with our grandchildren. Life will be wonderful.

But if this study is correct, none of that will happen for many of today’s young adults. They will be too frail and sick to enjoy their golden years.

For more details about this study and how you can increase your healthy years, narrow the gap between your healthspan and your lifespan, and look forward to golden years filled with vitality and adventure, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

 ______________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

_______________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Do Bad Genes Doom You To Bad Health?

by

The Influence Of Genetics And Diet On Type 2 Diabetes

Author: Dr. Stephen Chaney 

Does it ever feel like you have drawn the short straw?

Everyone in your family has succumbed to heart disease, diabetes, or cancer at a young age. Are you doomed to the same fate?

You ordered a DNA test. It sounded like fun. But when the gene report came back it said you had a “bad” genetic profile. You were told you are at high risk of diabetes, heart attack, stroke, cancer, or dementia. Are you doomed to a short and sickly life?

In both cases, you are probably wondering, “Is there anything I can do to improve my odds of a healthy life? What if I lost some of those extra pounds, exercised more, and ate a healthier diet? Would that make a difference?”

The study (J Merino et al, PLoS Medicine 19(4): e1003972, April 26, 2022) I will describe today was designed to answer these questions.

But before I describe the study, I should probably cover what I call Genetics 101: “How Genes Affect Your Health”.

Genetics 101: How Genes Affect Your Health

GeneticistIf you studied genetics in school, you probably learned about diseases like sickle cell anemia, which is caused by a single mutation in a single gene. If you get two copies of the “bad” gene, you will have sickle cell anemia. If you get one copy of the “bad” gene and one copy of the normal gene, you have sickle cell trait, which is much less severe.

Simply put, you either have the disease or you don’t. It’s dependent on your genetics, and you can’t do much about it.

If you know someone who has been treated for breast cancer, you are probably familiar with a more complex relationship between genetics and health. There are several “bad” genes that increase the risk of breast cancer. And knowing which gene is involved is important for selecting the best treatment regimen.

But most of the diseases that shorten our lives (like diabetes, heart disease, most cancers, and dementia) are what we call polygenetic diseases. Simply put, that means that there are dozens of genes that increase the risk of these diseases. Each gene makes a small contribution to the increased risk. So, we can only measure the genetic contribution to these diseases by measuring hundreds of mutations in dozens of genes, something called a polygenetic risk score.

The study I will be describing today looked at the relative effect of genetics (measured as the type 2 diabetes polygenic risk score) and diet quality (measured as the Alternative Healthy Eating Index (AHEI)) on the risk of developing type 2 diabetes.

How Was This Study Done?

clinical studyThe data for this study were obtained from 3 long-term clinical studies conducted in the United States – the Nurses’ Health Study (121,700 participants), the Nurses’ Health Study II (116,340 participants), and the Health Professionals Follow-Up Study (51,529 participants).

These studies measured lifestyle factors (including diet) every 4 years and correlated them with disease outcomes over 20+ years.

The study I will be discussing today was performed with 35,759 participants in these 3 studies for whom DNA sequencing data was available.

  • The DNA sequence data were used to generate a type 2 diabetes polygenic risk score for each participant in this study.
  • Food frequency questionnaires obtained every 4 years in these studies were used to calculate the Alternative Healthy Eating Index (AHEI) score for each participant.
    • The AHEI is based on higher intake of fruits, whole grains, vegetables, nuts and legumes, polyunsaturated fatty acids, long-chain omega-3 fatty acids, moderate intake of alcohol, and lower intake of red and processed meats, sugar sweetened drinks and fruit juice, sodium, and trans-fat).

The investigators used these measurements to estimate the relative effect of genetics and diet quality on the risk of developing type 2 diabetes.

The Influence Of Genetics And Diet On Type 2 Diabetes 

Genetic TestingThe participants were divided into low, intermediate, and high genetic risk based on their type 2 diabetes polygenic risk score.

Compared with low genetic risk:

  • Intermediate genetic risk increased the risk of developing type 2 diabetes by 26%.
  • High genetic risk increased the risk of developing type 2 diabetes by 75%.

Put another way, each 1 standard deviation increase in the polygenetic risk score:

  • Increased the risk of developing type 2 diabetes by 42%.

Simply put, bad genes can significantly increase your risk of developing type 2 diabetes. That’s the bad news. But that doesn’t mean you should think, “Diabetes is in my genes. There is nothing I can do.”

The investigators also divided the participants into those who had a high-quality diet, those who had an intermediate quality diet, and those who had a low-quality diet based on their AHEI (Alternative Healthy Eating Index) score.

Finally, they divided the participants into groups depending on their BMI, a measure of obesity.

Compared to an obese person consuming a low-quality diet, a lean person consuming a high-quality diet:

  • Reduced their risk of developing type 2 diabetes by around 43% for each category of genetic risk.
  • More specifically, a lean person consuming a high-quality diet reduced their risk of developing type 2 diabetes:
    • By 41% if they were at low genetic risk.
    • By 50% if they were at intermediate genetic risk.
    • By 38% if they were at high genetic risk.

The investigators then made a statistical adjustment to remove BMI from their calculations, so they could focus on Mediterranean Diet Foodsthe effect of diet alone on the risk of developing type 2 diabetes.

Compared to a low-quality diet, a high-quality diet:

  • Reduced the risk of developing type 2 diabetes by around 33% for each category of genetic risk.
  • More specifically, a high-quality diet reduced the risk of developing type 2 diabetes:
    • By 31% for those at low genetic risk.
    • By 39% for those at intermediate genetic risk.
    • By 29% for those at high genetic risk.

Looking at it another way:

  • When people at high genetic risk consumed a high-quality diet, their risk of developing type 2 diabetes was only 13% higher than people at intermediate genetic risk who consumed a low-quality diet (such as the typical American diet).
  • When people at intermediate genetic risk consumed a high-quality diet, their risk of developing type 2 diabetes was 5% less than people at low genetic risk who consumed a low-quality diet.

Simply put:

  • If you are at intermediate genetic risk, a high-quality diet may completely reverse your risk of developing type 2 diabetes.
  • If you are at high genetic risk, a high-quality diet can partially reverse your risk of developing type 2 diabetes.

In short, the good news is that bad genes do not doom you to type 2 diabetes.

  • The investigators did not provide similar information for the effect of an ideal weight on the risk of developing type 2 diabetes, but it is likely that the combination of diet plus weight management would result in an even more significant reduction in risk of developing type 2 diabetes for individuals in the even the highest risk category.

The authors concluded, “These data provide evidence for the independent associations of genetic risk and diet quality with incident type 2 diabetes and suggest that a healthy diet is associated with lower diabetes risk across all levels of genetic risk.”

Do Bad Genes Doom You To Bad Health?

Bad GenesAt the beginning of this article I posed the question, “Do bad genes doom you to bad health?”

Based on this study, the good news is that bad genes don’t doom you type 2 diabetes. And just because most of your relatives are diabetic doesn’t mean that must be your fate.

  • This study shows that a healthy diet significantly reduces your risk of developing type 2 diabetes at every genetic risk level.
  • And the study suggests that a healthy diet plus a healthy weight is even more beneficial at reducing your risk of type 2 diabetes.
  • While not included in this study, other studies have shown that exercise also plays a role in reducing type 2 diabetes risk.

None of this information is new. What is new is that a healthy diet is equally beneficial at reducing type 2 diabetes risk even in individuals with a high genetic risk of developing the disease. Simply put, you can reverse the effects of bad genes.

“And what is this magic diet?”, you might ask. In this study, it was based on AHEI score. Someone with a high AHEI score consumes:

  • Lots of fruits, whole grains, vegetables, nuts and legumes, polyunsaturated fatty acids, and long-chain omega-3 fatty acids.
  • Moderate or no amounts of alcohol.
  • Little or no red and processed meats, sugar sweetened drinks, fruit juices, sodium, and foods with trans-fat.

Any whole food, primarily plant-based diet from vegan to Mediterranean or DASH fits the bill.

Finally, while this study focused just on type 2 diabetes, other studies have come to similar conclusions for other diseases.

Should You Get Your DNA Tested?

If you are looking for guidance on how to reduce your risks, the answer is, “No”. In this study, the same diet and lifestyle changes lowered the risk of type diabetes at every genetic risk level. Despite what some charlatans may tell you, there is no special diet or magic potion for people with a high genetic risk for developing type 2 diabetes.

If you are looking for motivation, the answer may be, “Yes”. If knowing you are at high risk makes it more likely that you will make the diet and lifestyle changes needed to lower your risk of type 2 diabetes, a DNA test may be just what you need

The Bottom Line

If a serious disease runs in your family or if you have had your DNA tested and found out you are at high risk for some disease, you are probably wondering whether there is anything you can do or whether your bad genes have doomed you to a short and sickly life.

A recent study answered that question for type 2 diabetes. It showed a healthy diet significantly reduces the risk of type 2 diabetes even in people at high genetic risk of developing the disease.

Other studies have come to similar conclusions for other diseases. In short, bad genes don’t doom you to bad health.

For more details about the study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

_____________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

_______________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Are All Plant-Based Diets Healthy?

by

Why Are Plant-Based Diets Healthy?

Author: Dr. Stephen Chaney

Unless you are like Rip van Winkle and have been asleep for the past 30 years, you have probably heard that plant-based diets are good for you. In fact, that advice is sound. It is based on multiple long-term studies.

But you may still be hesitant to make the switch. You are probably wondering if you have to be a vegan purist to benefit from a plant-based diet. If so, you are wondering whether you can make that drastic a change in your diet. Or, you may have already decided “that is a bridge too far” and don’t want to even consider it.

So, one important question is, “Do you have to go vegan to benefit from a plant-based diet?”

On the other hand, “Big Food, Inc” has made it easier than ever to switch to more “plant-based” eating. After all, sugar comes from plants. And highly processed grains come from plants. Add a few chemicals and you can come up with an endless supply of highly processed plant-based foods.

So, another important question is, “Can a diet of highly processed plant-based foods be as healthy as a diet of whole, unprocessed plant-foods?”

The study (Y. Wang et al., Nutrition Journal, 22: 46, 2023) I am reviewing today was designed to answer these two questions. It also represents the first meta-analysis to combine data from studies on the effects of plant-based diets on diabetes, heart disease, cancer, and mortality into a single study.

How Was The Study Done?

clinical studyThe investigators performed a meta-analysis of 76 studies with 2,230,443 participants that looked at the associations of plant-based dietary patterns and the incidence of type 2 diabetes, cardiovascular disease, cancer, and mortality among adults 18 years or older.

The characteristics of study participants ranged from:

  • 25 to 87 years old.
  • BMI of 20 to 30.

And the duration of the studies within the meta-analysis ranged from 2 to 36 years.

The adherence to plant-based diets was defined as higher consumption of plant-based foods and lower consumption or exclusion of animal-based foods.

The meta-analysis also included studies looking at the effect of changing from a more animal-based to a more plant-based dietary pattern.

The meta-analysis included studies looking at the benefit of vegan and vegetarian diets. In terms of participants these studies represented just over 50% of the data in the meta-analysis. So, this meta-analysis was ideally positioned to determine whether vegan and vegetarian diets were more beneficial than other primarily plant-based dietary patterns that included some animal foods.

The methodology used to classify diets as primarily plant-based varied from study to study. But in each case the study participants were divided into quartiles ranging from consuming the most plant-based diet to consuming the least plant-based diet.

The study then compared study participants with the highest adherence to plant-based diets to those with the lowest adherence to plant-based diets with respect to type 2 diabetes, cardiovascular disease, cancer, and mortality.

Finally, the study also compared adherence to healthy plant-based dietary patterns (whole or minimally processed fruits, vegetables, whole grains, beans, nuts, and seeds) to unhealthy plant-based dietary patterns (foods and drinks with added sugar, highly processed plant foods, and starchy vegetables).

Are Plant-Based Diets Healthy?

When comparing highest to lowest adherence to plant-based dietary patterns the risk of:

  • Type-2 diabetes was reduced by 18%.
  • Cardiovascular disease was reduced by 10%.
  • Cancer was reduced by 12%.
  • Mortality was reduced by 16%.

In short, all the news was good for primarily plant-based dietary patterns.

Are All Plant-Based Diets Healthy?

Increased adherence to a healthy plant-based dietary pattern (That term is defined in the methods section above) was associated with an even better reduction in disease risk. For example:

  • Type-2 diabetes was reduced by 21%.
  • Cardiovascular disease was reduced by 15%.
  • Cancer was reduced by 13%.
  • Mortality was reduced by 14%, which was statistically indistinguishable from the reduction in mortality associated with all plant-based dietary patterns above.

Factory FarmIn contrast, increased adherence to an unhealthy plant-based dietary pattern was associated with increased risks of disease. For example:

  • The risk of type 2 diabetes increased by 8%.
  • The risk of cardiovascular disease increased by 14%.
  • The risk of cancer increased by 7%.
  • The risk of mortality increased by 16%.

In short, plant-based dietary patterns consisting of whole or minimally processed plant foods are good for you. Plant-based dietary patterns consisting of highly processed plant foods are not.

Are Vegan and Vegetarian Diets More Beneficial Than Other Plant-Based Dietary Patterns?

Mediterranean Diet FoodsTwenty seven of the studies within this meta-analysis compared vegetarian or vegan dietary patterns with animal-based dietary patterns. These studies had 1,343,967 participants, which amounts to 57% of the participants in the meta-analysis.

Thus, this meta-analysis was well positioned to determine relative benefits of vegan and vegetarian diets compared to other primarily plant-based dietary patterns that include some animal foods. The investigators reported that:

  • The risk reduction for type 2 diabetes was greater in studies with vegan and vegetarian diets than in studies with other primarily plant-based diets.
  • No other statistically significant benefits were observed for vegan and vegetarian diets compared to other primarily plant-based diets.

In short, you don’t need to become a vegan to experience the health benefits of a plant-based diet.

In contrast, increased adherence to an unhealthy plant-based dietary pattern was associated with increased risks of disease. For example:

  • The risk of type 2 diabetes increased by 8%.
  • The risk of cardiovascular disease increased by 14%.
  • The risk of cancer increased by 7%.
  • The risk of mortality increased by 16%.

In short, plant-based dietary patterns consisting of whole or minimally processed plant foods are good for you. Plant-based dietary patterns consisting of highly processed plant foods are not.

What If You Change From An Animal-Based To A Plant-Based Diet?

Food ChoicesIf you have been consuming an animal-based diet for years, you may be wondering whether it is too late to change. Has the damage already been done?

Six studies within this meta-analysis examined the effect of changing from an animal-based diet to a plant-based diet on type 2 diabetes and mortality. Changing to a more plant-based dietary pattern:

  • Reduced diabetes by 17% and mortality by 5%.

In short, it’s never too late to switch to a more plant-based dietary pattern.

Why Are Plant-Based Diets Healthy?

The short answer is that we don’t know for sure, but the authors mentioned several popular hypotheses.

  • Obesity is a risk factor for type 2 diabetes, cardiovascular disease, and certain types of cancer. And studies have shown that people consuming plant-based diets tend to weigh less.
  • The increased fiber content and higher ratio of polyunsaturated fats to saturated fats lower cholesterol levels and improve blood lipid profiles, which are associated with a lower risk of cardiovascular disease.
  • Plant-based diets are anti-inflammatory, which reduces the risk of all three diseases.
  • Plant foods are rich in polyphenols and other phytonutrients that are associated with reduced risk of cardiovascular disease, lower blood pressure, and improvements in insulin sensitivity.
  • Plant foods are metabolized by gut bacteria to metabolites that are associated with reduced risk of type 2 diabetes and cardiovascular disease.
  • Plant foods support healthy gut bacteria associated with a reduced risk of several diseases.
  • Finally, plant-based dietary patterns are associated with no or reduced consumption of red and processed meats, which increase the risk of type 2 diabetes, cardiovascular disease, and certain types of cancer.

For a more detailed discussion read the article).

What Does This Study Mean For You?

The authors of this study concluded, “Higher adherence to plant-based dietary patterns, especially from healthy sources, may be universally beneficial for the primary prevention of type 2 diabetes, cardiovascular disease, cancer, and mortality. The current study provides further evidence in support of current recommendations that emphasize consuming high-quality plant-based foods for achieving optimal health.”

“Future studies are needed to elucidate…mechanistic pathways linking plant-based diets with multiple disease outcomes.”

I would just like to emphasize a few points:

  • These are all association studies. It takes decades for diseases like diabetes, heart disease, and cancer to develop. So, it is impossible to confirm these findings with double blind, placebo-controlled studies. However, when you have 76 studies with over 2 million participants all pointing to the same conclusion, it is hard to ignore the findings.
  • The good news is that you don’t have to become a vegan to experience these benefits. There are many healthy primarily plant-based diets available. Choose the one that best fits your food preferences and lifestyle.
  • Be aware that whatever diet you choose, Big Food Inc is only too happy to provide you with highly processed foods that fit that dietary pattern. Don’t fall for that trap. Stick with whole or minimally processed plant foods.
  • If your current diet isn’t the best, it is never too late to switch to a healthier primarily plant-based diet.

The Bottom Line

A recent meta-analysis of 76 studies with 2,230,443 participants looked at the associations of plant-based dietary patterns and the incidence of type 2 diabetes, cardiovascular disease, cancer, and mortality among adults 18 years or older.

The authors of the study concluded, “Higher adherence to plant-based dietary patterns, especially from healthy sources, may be universally beneficial for the primary prevention of type 2 diabetes, cardiovascular disease, cancer, and mortality. The current study provides further evidence in support of current recommendations that emphasize consuminh high-quality plant-based foods for achieving optimal health.”

Other key points from the study are:

  • These are all association studies. It takes decades for diseases like diabetes, heart disease, and cancer to develop. So, it is impossible to confirm these findings with double blind, placebo-controlled studies. However, when you have 76 studies with over 2 million participants all pointing to the same conclusion, it is hard to ignore the findings.
  • The good news is that you don’t have to become a vegan to experience these benefits. There are many healthy primarily plant-based diets available. Choose the one that best fits your food preferences and lifestyle.
  • Be aware that whatever diet you choose, Big Food Inc is only too happy to provide you with highly processed foods that fit that dietary pattern. Don’t fall for that trap. Stick with whole or minimally processed plant foods.
  • If your current diet isn’t the best, it is never too late to switch to a healthier primarily plant-based diet.

For more details about how the authors came to these conclusions and what they mean for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

_______________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

 ______________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Can Personalized Diets Help Control Blood Sugar?

by

What Does This Study Mean For You? 

Author: Dr. Stephen Chaney 

Personalized diets are highly advertised. We are told to forget the old “one size fits all” diets of the past. We are told we are all different, so diets should be individualized to us.

We are promised that by collecting DNA samples from our tissue or bacteria in our gut, blood samples, and personal medical history, a personalized diet can be created that “fits us like a glove”.

But are those promises true, or are they hype? Diets to control blood sugar spikes should be a perfect topic for testing those claims. Millions of Americans have trouble controlling their blood sugar levels. Specifically:

  • 1 million adults (14.7% of US adults) have diabetes, mostly type 2 diabetes.
  • 6 million adults (38.0% of US adults) have prediabetes.
    • That amounts to 52% of the US population who have trouble controlling blood sugar levels.
  • Previous studies have shown that prediabetes and type 2 diabetes are largely reversible with diet and lifestyle change.
  • Recent studies have shown tremendous inter-person variability in the blood sugar response to any given food.
  • Previous studies have shown that our gut bacteria influence our blood sugar response to foods.

In theory, blood sugar control should be the perfect candidate for personalized diets. With that in mind, the authors of this study have created an algorithm called PNP (Personal Nutrition Program) that combines continuous blood glucose monitoring, HbA1c measurement (a measure of blood sugar control), personal characteristics (physical activities, sleep times, stress, and hunger), and a DNA analysis of stool samples to identify the species of gut bacteria. They also created a PNP app to allow participants to monitor and modify the foods they ate on a continuous basis.

In this study (AY Kharmats et al, The American Journal of Clinical Nutrition, 118: 443-451, 2023) the authors compared the effectiveness of their Personalized Nutrition Program algorithm with a standard, one-size-fits-all, low fat diet for improving blood sugar control in patients with prediabetes and type 2 diabetes.

Note: They used a low fat diet because, despite what you may have heard, low fat diets are better than low carb diets for diabetics. Of course, the low fat diet they used was created by dietitians. The carbohydrates came from whole foods rather than added sugars.

How Was The Study Done? 

Clinical StudyThe investigators recruited 156 participants from the NYU Langone Health Center between January 2018 and March 2021. The participants selected were overweight with prediabetes or moderately controlled type 2 diabetes. For participants with type 2 diabetes, it was managed with lifestyle alone or lifestyle plus metformin. Other characteristic of the study participants were:

  • Gender: 33.5% male, 66.5% female.
  • Race & Ethnicity: 55.7% white, 24.1% black, 16.5% Hispanic.
  • Education: 69.5% with a college degree.
  • Baseline BMI: 33 (Obese).
  • Baseline HbA1c: 5.8% (prediabetic range) with 12% of participants ≥6.5% (diabetic range).

The participants were randomly divided into two groups that were matched with respect to weight and blood sugar control. One group was put on a diet based on the investigator’s PNP algorithm. The other group was put on a standardized low fat (< 25% of calories from fat) diet that is often used with diabetic patients.

Upon admission to the study, blood samples were drawn for HbA1c, a detailed questionnaire was filled out, and stool samples were obtained for DNA analysis to identify the species of bacteria in their gut.

Each participant was given a continuous glucose monitoring device to wear during the study. This allowed the investigators to monitor the participants blood sugar control throughout the study.

All this information was used to provide individual diet recommendations for the personalized diet group using the PNP algorithm developed by the investigators.

The study lasted 6 months and measured improvements in blood sugar control as assessed by a decrease in blood sugar spikes and a reduction in HbA1c.

Both Groups were put on a registered dietitian-led behavioral intervention program targeting 7% weight loss and a calorie deficit goal of 500 calories per day. The 1-hour sessions were conducted by Webex weekly for 4 weeks and then every other week for the remaining 5 months. The sessions included:

  • Education (e.g., obesity risks, benefits of weight loss, strategies for restricting calories, protocols for aerobic exercise and strength training, and dealing with weight loss plateaus)
  • Behavioral change (e.g., importance of behavioral change, goal setting, self-reward, and problem-solving around common barriers to weight loss success)

The participants were advised to gradually build up to 150 min/week of moderate intensity exercise.

Each participant was given access to the PNP mobile app designed by the investigators. The app provided real-time feedback regarding their dietary intake relative to the target specific to their group (low fat diet or personalized diet). Participants were asked to use the app to:

  • Enter their dietary intake and self-monitor their meals (If the meal did not match the target specific to their group, the participants were trained how to substitute other foods, so their meal better matched their target.)
  • For the Standardized Low Fat Group, the PNP app provided real-time feedback regarding calorie intake and macronutrient distribution for meals and snacks logged in by the participants.
  • For the Personalized Group the PNP app scored meals as excellent, very good, good, bad, or very bad based on the PNP algorithm developed by the investigators.

Can Personalized Diets Help Control Blood Sugar? 

The results were clear-cut:

  • Weight loss was identical on both diets. This is no surprise. The study design included an exceptionally well-designed weight loss protocol for both groups.
  • The decrease in HbA1c was identical on both diets.
  • The improvement in blood sugar control was identical on both diets.

The investigators concluded, “[The] personalized diet did not result in an increased reduction in GV [blood sugar control] or HbA1c in patients with prediabetes or moderately controlled type 2 diabetes compared to a standardized diet.”

Since the investigators had designed the algorithm used to create personalized diets for this study, this was probably not the result they wanted.

So, they added, “Additional subgroup analyses may help to identify patients who are more likely to benefit from this personalized intervention.”

What Does This Study Mean For You? 

QuestionsThis first takeaway from this study was obvious:

  • The personally designed diet did not perform any better than a standard, one size fits all, diet at improving blood sugar control.

Of course, this was not any standard diet. It was a diet that has been used successfully with diabetics for years. However, a lot of research had gone into developing the personalized diet. One might have expected it to perform better.

This is not the first study in which a personalized diet has performed no better than a standard diet. It doesn’t mean that the concept behind personalized diets is faulty. It just means we don’t yet know enough to design a personalized diet that really works.

The second takeaway from this study might be less obvious:

  • Weight loss is the most important factor for improving blood sugar control. Any diet that reduces weight will improve blood sugar control. This is also true for many other health issues such as high cholesterol, high blood pressure, high triglycerides, and osteoarthritis.
  • However, this should not come as a surprise either.
    • Vegan and keto diets are polar opposites. Yet both give similar short-term weight loss and provide similar short-term health benefits.
    • Studies have shown that intermittent fasting gives no better weight loss and health benefits than any diet that cuts calories to a similar extent.
    • In other words, the diet you choose or the way you choose to restrict calories doesn’t matter. It is weight loss that provides the health benefits.
  • However, diet does appear to matter in the long term. If you look at studies ranging from 10 to 30 years, primarily plant-based diets provide better health benefits than primarily meat-based diets. And diets consisting primarily of whole, unprocessed foods provide better health benefits than diets high in processed foods.

Finally, there is an important corollary to this study showing that a personalized diet performed no better than a standardized diet at controlling blood sugar.

  • Some companies are trying to sell you expensive personalized diets with extravagant claims about the health benefits of their diet. Be wary of those diets. The science supporting their diets is premature. Their claims may be misleading.
  • And if the companies claim their diet is supported by published clinical studies, you should evaluate those studies carefully. The study I reviewed in this article was an exceptionally well-designed study. Any study that does not control for weight loss is likely to provide misleading results.

The Bottom Line 

A recent study compared the effectiveness of a personalized diet and a standardized diet in improving blood sugar control for patients with prediabetes or type 2 diabetes. The results were clear-cut:

  • Weight loss was identical on both diets. This is no surprise. The study design included an exceptionally well-designed weight loss protocol for both groups.
  • The decrease in HbA1c was identical on both diets.
  • The improvement in blood sugar control was identical on both diets.

This doesn’t mean that the concept behind personalized diets is faulty. It just means we don’t yet know enough to design a personalized diet that really works.

For more information on this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

______________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

_____________________________________________________________________

About The Author 

Dr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”.

Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

Since retiring from the University of North Carolina, he has been writing a weekly health blog called “Health Tips From the Professor”. He has also written two best-selling books, “Slaying the Food Myths” and “Slaying the Supplement Myths”. And most recently he has created an online lifestyle change course, “Create Your Personal Health Zone”. For more information visit https://chaneyhealth.com.

 

For the past 45 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

What Can Twins Tell Us About Diet?

by

What Are The Pros And Cons Of Twin Studies? 

Author: Dr. Stephen Chaney 

Why is the advice on healthy diets so confusing? One blog claims the vegan diet is best. Another says it is the keto diet is best. The Mediterranean diet is popular, but other experts claim the DASH or MIND diet might be better. Blogs champion diets ranging from the familiar to downright weird.

If you try to keep up with the science, it seems like the science is constantly changing. Each week you see headlines saying the latest study shows diet “X” is best – and “X” keeps changing. Why is that? Why do studies on healthy diets keep coming up with conflicting conclusions?

I have discussed the strengths and weaknesses of clinical studies and why they provide conflicting results in detail in previous issues of “Health Tips From the Professor”. However, one factor I have not discussed in detail is the effect of genetics on how we utilize foods, something called nutrigenomics.

Simply put, we are all genetically different. The way we utilize foods is different. The effect that foods have on our bodies is different. I have touched on that briefly in a previous article discussing individual difference in blood sugar response to various foods. But that is just one of many examples.

We do not yet know enough about gene-nutrient interactions to use genomic data to accurately predict which diets are best. Again, I have covered that topic in a previous issue of “Health Tips From the Professor”. However, we do know that genetic differences have a big influence on which diet is best for us. And most clinical studies on diets do not even attempt to take genetic differences into account.

That is where twin studies come in. Identical twins (monozygotic twins) have an identical genetic makeup and usually have an identical environment until they become adults. So, when I saw an identical twin study (MJ Landry et al, JAMA Network Open, 6(11):e2344457, 2023) comparing a vegan diet (only plant foods) with an omnivorous diet (both animal and plant foods), I wanted to review it and share it with you.

How Was The Study Done? 

Clinical StudyIdentical twins were recruited from the Stanford Twin Registry. Twenty-two identical twin pairs were chosen for this study. Their characteristics were average age = 40, BMI = 26% (moderately overweight), sex = 77% female, ethnicity = 73% white, followed by an approximately equal representation of Asian, black, multiracial, and Pacific Islander.

One unanticipated characteristic of this group of twins was that 70% of them still lived together and cooked together, so their environment was also very similar.

One twin of each pair was put on a healthy vegan diet and the other on a healthy omnivorous diet for 8 weeks. Both diets were designed by dietitians. The diets emphasized fruits, vegetables, and whole grains while limiting added sugars and refined grains.

Both diets were healthier than the diets the twins were eating prior to the study. Finally, the participants were not told how much to eat, and were not instructed to lose weight.

For the first four weeks the participants were provided with all their meals by a nationwide food delivery company. The participants were also provided with training on purchasing and preparing healthy foods for their diet. This prepared them for the last 4 weeks of the study in which they purchased and prepared their own meals.

Participants visited the Stanford Clinical and Translational Science Research Unit at the beginning of the study and at the end of weeks 4 and 8 for weight measurement and a fasting blood draw.

Adherence to the diets was measured by a series of unannounced interviews to administer a 24-hour dietary recall questionnaire. These were scheduled for the weeks they visited the clinic.

What Can Twins Tell Us About Diet? 

TwinsEven though the sample size was small, there were three statistically significant results.

  • LDL-cholesterol was reduced by 12% for the twin on the vegan diet, while it remained unchanged for the twin on the omnivorous diet.
  • The fasting insulin level was reduced by 21% for the twin on the vegan diet, while it remained unchanged for the twin on the omnivorous diet. This suggests the twin on the vegan diet was experiencing improved blood sugar control after just 8 weeks.
  • The twin on the vegan diet lost 4 pounds in 8 weeks, while weight remained the same for the twin on the omnivorous diet. This occurred even though neither twin was instructed to eat less nor to lose weight. It is most likely a consequence of the lower caloric density of the vegan diet (See my discussion of caloric density in last week’s issue of “Health Tips From the Professor”.
  • The changes in LDL-cholesterol and fasting insulin were remarkable because none of the twins in this study had elevated LDL-cholesterol or problems with blood sugar control at the beginning of the study.

The authors of this study concluded, “In this randomized clinical trial of the cardiometabolic effects of omnivorous vs vegan diets in identical twins, the healthy vegan diet led to improved cardiometabolic outcomes compared with a healthy omnivorous diet. Clinicians can consider this dietary approach as a healthy alternative for their patients.”

[Let me decipher the term cardiometabolic for you. The decrease in LDL-cholesterol is associated with heart health – the cardio portion of the term. The decrease in fasting insulin is associated with decreased risk of diabetes. Since diabetes is considered a metabolic disease, this is the metabolic portion of the term.]

Were There Any Downsides To The Vegan Diet? 

thumbs down symbolThis study also highlighted two well-known limitations of vegan diets.

  • Although the differences were not statistically significant, the authors expressed concern that vitamin B12 intake was less for twins on the vegan diet than twins on the omnivorous diet even though the vegan diet was designed by dietitians.

The authors noted that B12 deficiency among vegans is well known, and said, “Long-term vegans are typically encouraged to take a cyanocobalamin (vitamin B12) supplement.

  • Although both groups had excellent adherence to their assigned diets, those assigned to the vegan diet expressed a lower satisfaction with the diet, which suggests long-term adherence to the diet after the study ended was unlikely.

The authors said, “Although our findings suggest that vegan diets offer a protective cardiometabolic advantage compared with a healthy omnivorous diet, excluding all meats and/or dairy products may not be necessary because research suggests that cardiometabolic benefits can be achieved with modest reduction in animal foods and increases in healthy plant-based foods compared with typical diets.”

“We believe that lower dietary satisfaction in the vegan group may have been attributable to the strictness of the vegan diet…Some people may find a less restrictive diet preferable for LDL-cholesterol-lowering effects.”

I concur.

What Are The Pros And Cons Of Twin Studies? 

pros and consThe Pros are obvious. Most dietary studies cannot take genetic differences into account and have difficulty accounting for environmental differences. In this study genetics was identical for each twin pair and their environment was very similar. It offers a unique advantage over other studies.

But the strength of this study is also its greatest weakness. Because the general population is genetically and environmentally diverse, it is difficult to extrapolate the results to the general population.

If this were the only study to show cardiometabolic benefits of a plant-based diet, it would simply be an interesting observation.

  • But there are several studies showing that the vegan diet is associated with lower weight and reduced risk of heart disease and diabetes.
  • And there are dozens of studies showing that primarily plant-based omnivorous diets reduce the risk of heart disease and diabetes.

This study is fully consistent with those studies.

The Bottom Line 

A recent study put identical twins on either a healthy vegan diet (only plant foods) or a healthy omnivorous diet (both animal and plant foods) for 8 weeks. At the end of 8 weeks:

  • LDL-cholesterol was reduced by 12% for the twin on the vegan diet, while it remained unchanged for the twin on the omnivorous diet.
  • The fasting insulin level was reduced by 21% for the twin on the vegan diet, while it remained unchanged for the twin on the omnivorous diet. This suggests the twin on the vegan diet was experiencing improved blood sugar control after just 8 weeks.
  • The twin on the vegan diet lost 4 pounds in 8 weeks, while weight remained the same for the twin on the omnivorous diet. This occurred even though neither twin was instructed to eat less or to lose weight. It is most likely a consequence of the lower caloric density of the vegan diet.
  • The changes in LDL-cholesterol and fasting insulin were remarkable because none of the twins in this study had elevated LDL-cholesterol or problems with blood sugar control at the beginning of the study.

The authors of this study concluded, “In this randomized clinical trial of the cardiometabolic effects of omnivorous vs vegan diets in identical twins, the healthy vegan diet led to improved cardiometabolic outcomes compared with a healthy omnivorous diet. Clinicians can consider this dietary approach as a healthy alternative for their patients.”

For more information on the pros and cons of this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

 _____________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

_______________________________________________________________________

 About The Author

Dr. Steve ChaneyDr. Chaney has a BS in Chemistry from Duke University and a PhD in Biochemistry from UCLA. He is Professor Emeritus from the University of North Carolina where he taught biochemistry and nutrition to medical and dental students for 40 years.  Dr. Chaney won numerous teaching awards at UNC, including the Academy of Educators “Excellence in Teaching Lifetime Achievement Award”. Dr Chaney also ran an active cancer research program at UNC and published over 100 scientific articles and reviews in peer-reviewed scientific journals. In addition, he authored two chapters on nutrition in one of the leading biochemistry text books for medical students.

For the past 35 years Dr. Chaney and his wife Suzanne have been helping people improve their health holistically through a combination of good diet, exercise, weight control and appropriate supplementation.

Are All Carbs Bad?

by

Are Low Carb Enthusiasts Right About The Dangers Of Carbohydrates?

Author: Dr. Stephen Chaney 

Low carb enthusiasts have been on the warpath against carbohydrates for years.

Almost everyone agrees that sugar-sweetened sodas and highly processed, refined foods with added sugar are bad for us. But low carb enthusiasts claim that we should also avoid fruits, grains, and starchy vegetables. Have they gone too far?

Several recent studies suggest they have. For example, both association studies and randomized controlled studies suggest that total carbohydrate intake is neither harmful nor beneficial for heart health.

In addition, recent studies suggest that free sugar intake is associated with both elevated triglyceride levels and an increase in heart disease risk.

But those studies have mostly looked at free sugar intake from sugar-sweetened sodas. The authors of this study (RK Kelley et al, BMC Medicine, 21:34, 2023) decided to look more carefully at the effect of all free sugars and other types of carbohydrates on triglyceride levels and heart disease risk.

How Was This Study Done?

clinical studyThe 110,497 people chosen for this study were a subgroup of participants in the UK Biobank Study, a large, long-term study looking at the contributions of genetic predisposition and environmental exposure (including diet) to the development of disease in England, Scotland, and Wales.

The participants in this study were aged between 37 and 73 (average age = 56) on enrollment and were followed for an average of 9.4 years. None of them had a history of heart disease or diabetes or were taking diabetic medications at the time of enrollment.

During the 9.4-year follow-up, five 24-hour dietary recalls were performed, so that usual dietary intake could be measured rather than dietary intake at a single time point. The people in this study participated in an average of 2.9 diet surveys, and none of them had less than two diet surveys.

The averaged data from the dietary recalls were analyzed for the amount and kinds of carbohydrate in the diet. With respect to the types of carbohydrate, the following definitions would be useful.

  • The term free sugars includes all monosaccharides and disaccharides added to foods by the manufacturer, cook, or consumer, plus sugars naturally present in honey, syrups, and unsweetened fruit juices.
  • The term non-free sugars includes all sugars not in the free sugar category, mostly sugars naturally occurring in fruits, vegetables, and dairy products.
  • The term refined grains includes white bread, white pasta, white rice, most crackers and cereals, pizza, and grain dishes with added fat.
  • The term whole grains includes wholegrain bread, wholegrain pasta, brown rice, bran cereal, wholegrain cereals, oat cereal, and muesli.

Finally, the study looked at the association of total carbohydrate and each class of carbohydrate defined above with all heart disease, heart attacks, stroke, and triglyceride levels.

Are All Carbs Bad?

Question MarkThe study looked at total carbohydrate intake, free sugar intake, and fiber intake. In each case, the study divided the participants into quartiles and compared those in the highest quartile with those in the lowest quartile.

Using this criterion:

  • Total carbohydrate intake was not associated with any cardiovascular outcome measured (total heart disease risk, heart attack risk, and stroke risk).
  • Free sugar intake was positively associated with all cardiovascular outcomes measured. Each 5% increase in caloric intake from free sugars was associated with a:
    • 7% increase in total heart disease risk.
    • 6% increase in heart attack risk.
    • 10% increase in stroke risk.
    • 3% increase in triglyceride levels.
  • Fiber intake was inversely associated with total heart disease risk. Specifically, each 5 gram/day increase in fiber was associated with a:
    • 4% decrease in total heart disease risk.

The investigators also looked at the effect of replacing less healthy carbohydrates with healthier carbohydrates. They found that:

  • Replacing 5% of caloric intake from refined grains with whole grains reduced both total heart disease risk and stroke risk by 6%.
  • Replacing 5% of caloric intake from free sugars (mostly sugar-sweetened beverages, fruit juices, and processed foods with added sugar) with non-free sugars (mostly fruits, vegetables, and dairy products) reduced total heart disease risk by 5% and stroke risk by 9%.

Are Low Carb Enthusiasts Right About The Dangers Of Carbohydrates?

With these data in mind let’s look at the claims of the low-carb enthusiasts.

Claim #1: Carbohydrates raise triglyceride levels. This study shows:

  • This claim is false with respect to total carbohydrate intake and high fiber carbohydrate intake (fruits, vegetables, and whole grains. This study did not measure intake of beans, nuts, and seeds, but they would likely be in the same category).
  • However, this claim is true with respect to foods high in free sugars (sugar-sweetened beverages, fruit juices, and processed foods with added sugar).

Claim #2: Carbohydrates increase heart disease risk. This study shows:

  • That claim is false with respect to total carbohydrate intake and high fiber carbohydrate intake.
  • However, this claim is true with respect to foods high in free sugars.

Claim #3: Carbohydrates cause weight gain [Note: Low carb enthusiasts usually word it differently. Their claim is that eliminating carbohydrates will help you lose weight. But that claim doesn’t make sense unless you believed eating carbohydrates caused you to gain weight.] This study shows:

  • This claim is false with respect to total carbohydrate intake and high fiber carbohydrate intake.
  • Once again, this claim is true with respect to foods high in free sugars.

The data with high fiber carbohydrates was particularly interesting. When the authors compared the group with the highest fiber intake to the group with the lowest fiber intake, the high-fiber group:

  • Consumed 33% more calories per day.
  • But had lower BMI and waste circumference (measures of obesity) than the low-carbohydrate group.

This suggests that you don’t need to starve yourself to lose weight. You just need to eat healthier foods.

And, in case you were wondering, the high fiber group ate:

  • 5 more servings of fruits and vegetables and…
  • 2 more servings of whole grain foods than the low fiber group.

This is consistent with several previous studies showing that diets containing a lot of fruits, vegetables, and whole grains are associated with a healthier weight.

The authors concluded, “Higher free sugar intake was associated with higher cardiovascular disease incidence and higher triglyceride concentrations…Higher fiber intake and replacement of refined grain starch and free sugars with wholegrain starch and non-free sugars, respectively, may be protective for incident heart disease.”

In short, with respect to heart disease, the type, not the amount of dietary carbohydrate is the important risk factor.

What Does This Mean For You?

Questioning WomanForget the low carb “mumbo jumbo”.

  • Carbohydrates aren’t the problem. The wrong kind of carbohydrates are the problem. Fruit juice, sugar-sweetened sodas, and processed foods with added sugar:
    • Increase triglyceride levels.
    • Are associated with weight gain.
    • Increase the risk for heart disease.
  • In other words, they are the villains. They are responsible for the bad effects that low carb enthusiasts ascribe to all carbohydrates.
  • Don’t fear whole fruits, vegetables, dairy, and whole grain foods. They are the good guys.
    • They have minimal effect on triglyceride levels.
    • They are associated with healthier weight.
    • They are associated with a lower risk of heart disease and diabetes.

So, the bottom line for you is simple. Not all carbs are created equal.

  • Your mother was right. Eat your fruits, vegetables, and whole grains.
  • Avoid fruit juice, sodas and other sugar-sweetened beverages, and processed foods with added sugar. [Note: Artificially sweetened beverages are no better than sugar-sweetened beverages, but that’s another story for another day.]

And, if you were wondering why low carb diets appear to work for weight loss, it’s because any restrictive diet works short term. As I have noted previously, keto and vegan diets work equally well for short-term weight loss.

The Bottom Line 

Low carb enthusiasts have been telling us for years to avoid all carbohydrates (including fruits, starchy vegetables, and whole grains) because carbohydrates:

  • Increase triglyceride levels.
  • Cause weight gain.
  • Increase our risk for heart disease.

A recent study has shown that these claims are only true for some carbohydrates, namely fruit juices, sodas and other sugar-sweetened beverages, and processed foods with added sugar.

Whole fruits, vegetables, and whole grain foods have the opposite effect. They:

  • Have a minimal effect on triglyceride levels.
  • Are associated with a healthier weight.
  • Are associated with a lower risk of heart disease and diabetes.

So, forget the low carb “mumbo jumbo” and be sure to eat your fruits, vegetables, and whole grains.

For more information on this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

___________________________________________________________________________

My posts and “Health Tips From the Professor” articles carefully avoid claims about any brand of supplement or manufacturer of supplements. However, I am often asked by representatives of supplement companies if they can share them with their customers.

My answer is, “Yes, as long as you share only the article without any additions or alterations. In particular, you should avoid adding any mention of your company or your company’s products. If you were to do that, you could be making what the FTC and FDA consider a “misleading health claim” that could result in legal action against you and the company you represent.

For more detail about FTC regulations for health claims, see this link.

https://www.ftc.gov/business-guidance/resources/health-products-compliance-guidance

Are Low Carb Diets Healthier?

by

The “Goldilocks Effect”

Author: Dr. Stephen Chaney

Goldilocks EffectThe low-carb wars rage on. Low-carb enthusiasts claim that low-carb diets are healthy. Many health experts warn about the dangers of low-carb diets. Several studies have reported that low-carb diets increase risk of mortality (shorten lifespan).

However, two recent studies have come to the opposite conclusion. Those studies reported that high carbohydrate intake increased mortality, and low carbohydrate intake was associated with the lowest mortality.

One of those studies, called the Prospective Urban Rural Epidemiology (PURE) study was published a few years ago. It included data from 135,335 participants from 18 countries across 5 continents. That’s a very large study, and normally we expect very large studies to be accurate. The results from the PURE study had low-carb enthusiasts doing a victory lap and claiming it was time to rewrite nutritional guidelines to favor low-carb diets.

Whenever controversies like this arise, reputable scientists are motivated to take another look at the question. They understand that all studies have their weaknesses and biases. So, they look at previous studies very carefully and try to design a study that eliminates the weaknesses and biases of those studies. Their goal is to design a stronger study that reconciles the differences between the previous studies.

A third study published a year later (SB Seidelmann et al, The Lancet, doi.org/10.1016/S2468-2667(18)30135-X was such a study. This study resolved the conflicting data and finally answered the question: “How much carbohydrate should we be eating if we desire a long and healthy life?” The answer is “Enough”.

I call this “The Goldilocks Effect”. You may remember “Goldilocks And The Three Bears”. One bed was too hard. One bed was too soft. But one bed was “just right”. One bowl of porridge was too hot. One was two cold. But one was “just right”. According to this study, the same is true for carbohydrate intake. High carbohydrate intake is unhealthy. Low carbohydrate intake is unhealthy. But moderate carbohydrate intake is “just right”.

How Was The Study Done?

clinical studyThis study was performed in two parts. This first part drew on data from the Atherosclerosis Risk in Communities (ARIC) study. That study enrolled 15,428 men and women, aged 45-64, from four US communities between 1987 and 1989. This group was followed for an average of 25 years, during which time 6283 people died. Carbohydrate intake was calculated based on food frequency questionnaires administered when participants enrolled in the study and again 6 years later. The study evaluated the association between carbohydrate intake and mortality.

The second part was a meta-analysis that combined the data from the ARIC study with all major clinical studies since 2007 that measured carbohydrate intake and mortality and lasted 5 years or more. The total number of participants included in this meta-analysis was 432,179, and it included data from previous studies that claimed low-carbohydrate intake was associated with decreased mortality.

Are Low Carb Diets Healthier?

GravestoneThe results from the ARIC study were:

  • The relationship between mortality and carbohydrate intake was a U-shaped curve.
    • The lowest risk of death was observed with a moderate carbohydrate intake (50-55%). This is the intake recommended by current nutrition guidelines.
    • The highest risk of death was observed with a low carbohydrate intake (<40%).
    • The risk of death also increased with very high carbohydrate intake (>70%).
  • When the investigators used the mortality data to estimate life expectancy, they predicted a 50-year old participant would have a projected life expectancy of:
    • 33.1 years if they had a moderate intake of carbohydrates.
    • 4 years less if they had a low carbohydrate intake.
    • 1.1 year less if they had a very high carbohydrate intake.
  • The risk associated with low carbohydrate intake was affected by what the carbohydrate was replaced with.
    • When carbohydrates were replaced with animal protein and animal fat there was an increased risk of mortality on a low-carb diet. The animal-based low-carb diet contained more beef, pork, lamb, chicken, and fish. It was also higher in saturated fat.Beans and Nuts
    • When carbohydrates were replaced with plant protein and plant fats, there was a decreased risk of mortality on a low-carb diet. The plant-based low-carb diet contained more nuts, peanut butter, dark or whole grain breads, chocolate, and white bread. It was also higher in polyunsaturated fats.
  • The effect of carbohydrate intake on mortality was virtually the same for all-cause mortality, cardiovascular mortality, and non-cardiovascular mortality.
  • There was no significant effect of carbohydrate intake on long-term weight gain (another myth busted).

The results from the dueling meta-analyses were actually very similar. When the data from all studies were combined:

  • Both very low carbohydrate diets and very high carbohydrate diets were associated with increased mortality.
  • Meat-based low-carb diets increased mortality, and plant-based low-carb diets decreased mortality.
  • Once again, the results were the same for total mortality, cardiovascular mortality, and non-cardiovascular mortality.

The authors concluded: “Our findings suggest a negative long-term association between life-expectancy and both low carbohydrate and high carbohydrate diets…These data also provide further evidence that animal-based low carbohydrate diets should be discouraged. Alternatively, when restricting carbohydrate intake, replacement of carbohydrates with predominantly plant-based fats and proteins could be considered as a long-term approach to healthy aging.”

Simply put, that means if a low carb diet works best for you, it is healthier to replace the carbs with plant-based fats and protein rather than animal-based fats and protein.

The “Goldilocks Effect”

low carb dietThis study also resolved the discrepancies between previous studies. The authors pointed out that the average carbohydrate intake is very different in Europe and the US than in Asian countries and low-income countries.

In the US and Europe mean carbohydrate intake is about 50% of calories and it ranges from 25% to 70% of calories. With that range of carbohydrate intake, it is possible to observe the increase in mortality associated with both very low and very high carbohydrate intakes.

The US and European countries are affluent, which means that low-carb enthusiasts can afford diets high in animal protein.

White rice is a staple in Asian countries, and protein is a garnish rather than a main course. Consequently, overall carbohydrate intake is greater in Asian countries and very few Asians eat a truly low carbohydrate diet. High protein foods tend to be more expensive than high carbohydrate foods. Thus, very few people in developing countries can afford to follow a very low carbohydrate diet, and overall carbohydrate intake also tends to be higher.

Therefore, in Asian and developing countries the average carbohydrate intake is greater (~61%) than in the US and Europe, and the range of carbohydrate intake is from 45% to 80% of calories. With that range of intake, it is only possible to see the increase in mortality associated with very high carbohydrate intake.

Both the studies that low-carb enthusiasts quote to support their claim that low-carb diets are healthy relied heavily on data from Asian and developing countries.ARIC Study

In fact, when the authors of the current study overlaid the data from the PURE study with their ARIC data, there was an almost perfect fit. The only difference was that their ARIC data covered both low and high carbohydrate intake while the PURE study touted by low-carb enthusiasts only covered moderate to high carbohydrate intake.

[I have given you my rendition of the graph on the right. If you would like to see the data yourself, look at the paper.]

Basically, low-carb advocates are telling you that diets with carbohydrate intakes of 30% or less are healthy based on studies that did not include carbohydrate intakes below 40%. That is misleading. The studies they quote are incapable of detecting the risks of low carbohydrate diets.

What Does This Study Mean For You?

QuestionsThere are several important take-home lessons from this study:

  • All major studies agree that very high carbohydrate intake is unhealthy. In part, that reflects the fact that diets with high carbohydrate intake are likely to be high in sodas and sugary junk foods. It may also reflect the fact that diets which are high in carbohydrate are often low in plant protein or healthy fats or both.
  • All studies that cover the full range of carbohydrate intake agree that very low carbohydrate intake is also unhealthy. It shortens the life expectancy of a 50-year-old by about 4 years.
  • The studies quoted by low carb enthusiasts to support their claim that low-carb diets are healthy don’t include carbohydrate intakes below 40%. That means their claims are misleading. The studies they quote are incapable of detecting the risks of low carbohydrate diets.
  • Meat-based low-carb diets decrease life expectancy while plant-based low carb diets increase life expectancy. This is consistent with previous studies. For more details on those studies, see my article, “Are Any Low-Carb Diets Healthy?”, in “Health Tips From The Professor” or my book, “Slaying The Food Myths”.

The health risks of meat-based low-carb diets may be due to the saturated fat content or the heavy reliance on red meat. However, the risks are just as likely to be due to the foods these diets leave out – typically fruits, whole grains, legumes, and some vegetables.

Proponents of low-carb diets assume that you can make up for the missing nutrients by just taking multivitamins. However, each food group also provides a unique combination of phytonutrients and fibers. The fibers, in turn, influence your microbiome. Simply put, whenever you leave out whole food groups, you put your health at risk.

The Bottom Line

The low-carb wars are raging. Several studies have reported that low-carb diets increase risk of mortality (shorten lifespan). However, two studies published a few years ago have come to the opposite conclusion. Those studies have low-carb enthusiasts doing a victory lap and claiming it is time to rewrite nutritional guidelines to favor low-carb diets.

However, a study published a year later resolves the conflicting data and finally answers the question: “How much carbohydrate should we be eating if we desire a long and healthy life?” The answer is “Enough”.

I call this “The Goldilocks Effect”. According to this study, high carbohydrate intake is unhealthy. Low carbohydrate intake is unhealthy. But, moderate carbohydrate intake is “just right”.

Specifically, this study reported:

  1. Moderate carbohydrate intake (50-55%) is healthiest. This is also the carbohydrate intake recommended by current nutritional guidelines.

2) All major studies agree that very high carbohydrate intake (60-70%) is unhealthy. It shortens life expectancy of a 50-year old by about a year.

3) All studies that cover the full range of carbohydrate intake agree that low carbohydrate intake (<40%) is also unhealthy. It shortens life expectancy of a 50-year old by about 4 years.

4) The studies quoted by low carb enthusiasts to support their claim that low-carb diets are healthy don’t include carbohydrate intakes below 40%. That means their claims are misleading. The studies they quote are incapable of detecting the risks of low carbohydrate diets.

5) Meat-based low-carb diets decrease life expectancy while plant-based low carb diets increase life expectancy. This is consistent with the results of previous studies.

The authors concluded: “Our findings suggest a negative long-term association between life-expectancy and both low carbohydrate and high carbohydrate diets…These data also provide further evidence that animal-based low carbohydrate diets should be discouraged. Alternatively, when restricting carbohydrate intake, replacement of carbohydrates with predominantly plant-based fats and proteins could be considered as a long-term approach to healthy aging.”

Simply put, that means if a low carb diet works best for you, it is healthier to replace the carbs with plant-based fats and protein rather than animal-based fats and protein.

For more details, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Which Diets Are Best In 2023?

by

Which Diet Should You Choose?

Author: Dr. Stephen Chaney

Emoticon-BadMany of you started 2023 with goals of losing weight and/or improving your health. In many cases, that involved choosing a new diet. That was only 6 weeks ago, but it probably feels like an eternity.

For many of you the “bloom” has gone off the new diet you started so enthusiastically in January.

  • Perhaps the diet isn’t working as well as advertised…
  • Perhaps the diet is too restrictive. You are finding it hard to stick with…
  • Perhaps you are always hungry or constantly fighting food cravings…
  • Perhaps you are starting to wonder whether there is a better diet than the one you chose in January…
  • Perhaps you are wondering whether the diet you chose is the wrong one for you…

If you are rethinking your diet, you might want to know which diets the experts recommend. Unfortunately, that’s not as easy as it sounds. The diet world has become just as divided as the political world.

Fortunately, you have an impartial resource. Each year US News & World Report invites a panel of experts with different points of view to evaluate popular diets. They then combine the input from all the experts into rankings of the diets in various categories.

If you are still searching for your ideal diet, I will summarize the US News & World Report’s “Best Diets In 2023”. For the full report, click on this link.

How Was This Report Created?

Expert PanelUS News & World Report recruited a panel of 30 nationally recognized experts in diet, nutrition, obesity, food psychology, diabetes, and heart disease to review the 24 most popular diets.

The diets evaluated are not the same each year. Last year they evaluated the top 40 most popular diets. This year they only reviewed the top 24.

That means some good diets were left off the list. For example, the vegan diet is very healthy, but it is also very restrictive. Very few people follow a pure vegan diet, so it didn’t make the top 24 most popular. However, this year’s list did include several primarily plant-based diets that are more popular with the general public.

The panel is also not the same each year. Some experts are rotated off the panel, and others are added. The experts rate each diet in seven categories:

  • How easy it is to follow.
  • Its ability to produce short-term weight loss.
  • Its ability to produce long-term weight loss.
  • its nutritional completeness.
  • Its safety.
  • Its potential for preventing and managing diabetes.
  • Its potential for preventing and managing heart disease.

They converted the experts’ ratings to scores 5 (highest) to 1 (lowest). They then used these scores to construct eleven sets of Best Diets rankings:

  • Best Diets Overall ranks diets on several different parameters, including whether all food groups are included in the diet, the availability of the foods needed to be on the diet and the use of additional vitamins or supplements. They considered if the diet was evidence-based and adaptable to meet cultural, religious, or other personal preferences. In addition, the criteria also included evaluation of the prep and planning time required for the diet and the effectiveness of the diet for someone who wants to get and stay healthy.
  • Best Plant-Based Diets used the same approach as Best Diets Overall to rank the eight plans emphasizing minimally processed foods from plants that were included in this year’s ratings.
  • Best Commercial Diet ratings used the same approach to rank 15 commercial diet programs that require a participation fee or promote the use of branded food or nutritional products.
  • Best Long-Term Weight-Loss Diet ratings were generated by combining the safety of the rate of weight loss promoted and the likelihood of the plan to result in successful long-term weight loss and maintenance of weight loss.
  • Best Fast Weight-Loss Diets were scored on their effectiveness for someone who wants to lose weight in three months or less.
  • Best Diabetes Diet ratings were calculated equally from the effectiveness of the diet for someone who wants to lower risk factors for diabetes, the nutritional quality of the diet, and research evidence-based support for the diet.
  • Best Heart-Healthy Diet ratings were calculated equally from the effectiveness of the diet for someone who wants to lower risk factors for hypertension and other forms of heart disease, the nutritional quality of the diet, and evidence-based support for the diet.
  • Best Diets for Bone and Joint Health were calculated equally on the effectiveness of the diet for someone who wants to lower their risk factors for inflammation and improve bone and joint health, as well as the nutritional quality and research evidence-based support for the diet.
  • Best Diets for Healthy Eating combines nutritional completeness and safety ratings, giving twice the weight to safety. A healthy diet should provide sufficient calories and not fall seriously short on important nutrients or entire food groups.
  • Easiest Diets to Follow represents panelists’ averaged scores for the relevant lifestyle questions, including whether all food groups are included and if the recommended foods are readily available at the average supermarket.
  • Best Family-Friendly Diets were calculated equally on their adaptability for the whole family, including cultural, religious, and personal preferences, the time required to plan and prep, nutritional value and access to food at any supermarket.

Which Diets Are Best In 2023?

Are you ready? If this were an awards program, I would be saying “Envelop please” and would open the envelop slowly to build suspense.

However, I am not going to do that. Here are the top 3 and bottom 3 diets in each category (If you would like to see where your favorite diet ranked, click on this link.

[Note: I excluded commercial diets from this review. (I have a brief discussion of commercial diets below). If you notice a number missing in my summaries, it is because I eliminated one or more commercial diet from my summary.]

Best Diets Overall 

The Top 3: 

#1: Mediterranean Diet. The Mediterranean diet has been ranked #1 for 6 consecutive years.

#2 (tie): DASH Diet (This diet was designed to keep blood pressure under control, but you can also think of it as an Americanized version of the Mediterranean diet.)

#2 (tie): Flexitarian Diet (A flexible semi-vegetarian diet).

The Bottom 3: 

#20: Keto Diet (A high protein, high fat, very low carb diet designed to achieve ketosis).

#21: Atkins Diet (The granddaddy of the high animal protein, low carb, high fat diets).

#24: Raw Food Diet (A diet based on eating foods that have not been cooked or processed).

Best Plant-Based Diets Overall 

The Top 3: 

#1: Mediterranean Diet.

#2: Flexitarian Diet.

#3: MIND Diet (This diet is a combination of Mediterranean and DASH but is specifically designed to reduce cognitive decline as we age.)

The Bottom 3: 

Since only 8 diets were included in this category, even the bottom 3 are pretty good diets, so I did not include a “list of shame” in this category.

Best Long-Term Weight-Loss DietsWeight Loss

The Top 3: 

#1: DASH Diet

#2 (tie): Volumetrics Diet (A diet based on the caloric density of foods).

#2 (tie): Mayo Clinic Diet (A diet designed to establish lifelong healthy eating habits).

The Bottom 3: 

#22 (tie): Keto Diet.

#22 (tie): Atkins Diet.

#24: Raw Food Diet.

Best Fast Weight-Loss Diets

The Top 3: 

#1: Keto Diet

#2: Atkins Diet

#7 (tie): Mayo Clinic Diet

#7 (tie): South Beach Diet

#7 (tie): Volumetrics Diet

The Bottom 3: 

The diets at the bottom of this list were designed for health and weight maintenance rather than rapid weight loss, so I did not include a “list of shame” in this category.

Best Diabetes Diets

The Top 3: 

#1: DASH Diet

#2: Mediterranean Diet

#3: Flexitarian Diet

The Bottom 3: 

#20: Atkins Diet

#21: Paleo Diet (A diet based on what our paleolithic ancestors presumably ate. It restricts grains and dairy and is heavily meat-based).

#22: Raw Food Diet.

Best Heart-Healthy Diets

Healthy HeartThe Top 3: 

#1: DASH Diet

#2: Mediterranean Diet

#3 (tie): Ornish Diet (A whole food, semi-vegetarian diet designed to promote heart health).

#3 (tie): Flexitarian Diet

The Bottom 3: 

#22 (tie): Raw Foods Diet

#22 (tie): Paleo Diet

#24: Keto Diet

Best Diets for Bone and Joint Health 

The Top 3: 

#1 (tie): DASH Diet

#1 (tie): Mediterranean Diet

#3: Flexitarian Diet

The Bottom 3: 

#21 (tie): Raw Foods Diet

#21 (tie): Paleo Diet

#22: Atkins Diet 

#23: Keto Diet 

Best Diets for Healthy Eating

The Top 3: 

#1: Mediterranean Diet

#2: DASH Diet

#3: Flexitarian Diet

The Bottom 3: 

#22: Keto Diet

#23: Atkins Diet

#24: Raw Foods Diet

Easiest Diets to FollowEasy

The Top 3: 

#1 (tie): Flexitarian Diet

#1 (tie): TLC Diet (This diet was designed by the NIH to reduce cholesterol levels and promote heart health.)

#3 (tie): Mediterranean Diet

#3 (tie): DASH Diet

The Bottom 3: 

#19: Atkins Diet

#20: Keto Diet

#22: Raw Foods Diet

Which Diets Are Best For Rapid Weight Loss?

Happy woman on scaleThere are 2 take-home lessons from the rapid weight loss category:

  1. If you are looking for rapid weight loss, any whole food restrictive diet will do.
    • Last year’s diet analysis included the vegan diet, and both vegan and keto diets ranked near the top of the rapid weight loss category. Keto and vegan diets are both very restrictive, but they are polar opposites in terms of the foods they allow and restrict.
      • The keto diet is a meat heavy, very low carb diet. It restricts fruits, some vegetables, grains, and most legumes.
      • The vegan diet is a very low-fat diet that eliminates meat, dairy, eggs, and animal fats.
    • The Atkins and keto diets toppled this year’s rapid weight loss list, but they were joined by the Mayo Clinic, South Beach, and volumetrics diets. Those diets are also restrictive, but, like the vegan diet, they are very different from the Atkins and keto diets.
    • I did not include commercial diets that rated high on this list, but they are all restrictive in one way or another.

2) Whole food, very low carb diets like Atkins and keto are good for rapid weight loss, but they rank near the bottom of the list for every healthy diet category.

    • If you choose to lose weight on the Atkins or keto diets, switch to a healthier diet once you reach your desired weight loss.

Which Diet Should You Choose?

Food ChoicesWith rapid weight loss out of the way, let’s get back to the question, “Which Diet Should You Choose?” My recommendations are:

1) Choose a diet that fits your needs. That is one of the things I like best about the US News & World Report ratings. The diets are categorized. If your main concern is diabetes, choose one of the top diets in that category. If your main concern is heart health… You get the point.

2) Choose diets that are healthy and associated with long term weight loss. If that is your goal, you will notice that primarily plant-based diets top these lists. Meat-based, low carb diets like Atkins and keto are near the bottom of the lists.

  • “Why is that?”, you might ask? The answer is simple. And it’s not that all 30 experts were prejudiced against low carb diets. It’s that the major primarily plant-based diets like Mediterranean, DASH, and flexitarian are backed by long-term clinical studies showing they are healthy and significantly reduce the risk of diabetes, heart disease, and other chronic diseases.
  • On the other hand, there are no long-term studies showing the Atkins and keto diets are healthy long term. And since the Atkins diet has been around for more than 50 years, the lack of clinical evidence that it is healthy long term is damming.

3) Choose diets that are easy to follow. The less-restrictive primarily plant-based diets top this list – diets like Mediterranean, DASH, MIND, and flexitarian. They are also at or near the top of almost every diet category.

4) Choose diets that fit your lifestyle and dietary preferences. For example, if you don’t like fish and olive oil, you will probably do much better with the DASH or flexitarian diet than with the Mediterranean diet.

5) Finally, focus on what you have to gain, rather than on foods you have to give up.

  • On the minus side, none of the diets include sodas, junk foods, and highly processed foods. These foods should go on your “No-No” list. Sweets should be occasional treats and only as part of a healthy meal. Meat, especially red meat, should become a garnish rather than a main course.
  • On the plus side, primarily plant-based diets offer a cornucopia of delicious plant foods you probably didn’t even know existed. Plus, for any of the top-rated plant-based diets, there are websites and books full of mouth-watering recipes. Be adventurous.

What About Commercial Diets?

I chose not to review commercial diets by name, but let me make a few observations.

  • If you look at the gaps in my lists, it should be apparent that several commercial diets rank near the top for fast weight loss, but near the bottom on most healthy diet lists.
  • I do not recommend commercial diets that rely on ready-to-eat, low-calorie, highly processed versions “of your favorite foods”.
    • These pre-packaged meals are expensive. Unless you are a millionaire, you won’t be able to afford these meals for the rest of your life.
    • These pre-packaged meals are not teaching you healthy eating habits that will allow you to keep the weight off.
  • If you wish to spend your hard-earned dollars on a commercial diet, choose a diet that:
    • Relies on whole foods from all 5 food groups.
    • Teaches and provides support for the type of lifestyle change that leads to permanent weight loss.
  • Meal replacement shakes can play a role in healthy weight loss if:
    • They are high quality and use natural ingredients as much as possible.
    • They are part of a holistic lifestyle change program.

The Bottom Line 

For many of you the “bloom” has gone off the new diet you started so enthusiastically in January. If you are rethinking your diet, you might want to know which diets the experts recommend. Unfortunately, that’s not as easy as it sounds. The diet world has become just as divided as the political world.

Fortunately, you have an impartial resource. Each year US News & World Report invites a panel of experts with different points of view to evaluate popular diets. They then combine the input from all the experts into rankings of the diets in various categories. In the article above I summarize the US News & World Report’s “Best Diets In 2023”.

There are probably two questions at the top of your list.

#1: Which diets are best for rapid weight loss? Here are 2 general principles:

  1. If you are looking for rapid weight loss, any whole food restrictive diet will do.

2) If you choose to lose weight on the Atkins or keto diets, switch to a healthier diet once you reach your desired weight loss. Atkins and keto diets are good for rapid weight loss, but they rank near the bottom of the list for every healthy diet category.

#2: Which diet should you choose? Here the principles are:

  1. Choose a diet that fits your needs.

2) Choose diets that are healthy and associated with long term weight loss.

3) Choose diets that are easy to follow.

4) Choose diets that fit your lifestyle and dietary preferences.

5) Finally, focus on what you have to gain, rather than on foods you have to give up.

For more details on the diet that is best for you and my thoughts on commercial diets, read the article above.

Which Diet Is Best For Diabetics?

by

What Did This Study Show? 

Author: Dr. Stephen Chaney 

High Blood SugarWhen you were first diagnosed with diabetes, your doctor probably told you that your life will forever be changed. Among other things he or she probably told you that you would need to make some radical changes to your diet.

But what changes? Both the American Diabetes Association (ADA) and Diabetes UK (the British version of ADA) recommend:

  • An individualized approach. This recognizes that we are all different. What works for some diabetics may not work for others.
  • A diet that incorporates more non-starchy vegetables and minimizes added sugars and refined grains.

But these recommendations are vague. Most people want a specific diet to follow. It’s here that Diabetes UK and the ADA part ways.

  • Diabetes UK gives its highest recommendation to the Mediterranean diet.
  • The ADA gives equal recommendations to the Mediterranean diet and both low-carbohydrate and very-low carbohydrate diets.

But which diet is best? It’s hard to know because most studies compare one of these diets to the standard American diet (SAD), and anything is better than the standard American diet.

Fortunately, one recent study (CD Gardner et al, American Journal of Clinical Nutrition, 116: 640-652, 2022) directly compares the two extremes of ADA-recommended diets, the Mediterranean diet and the Keto diet.

How Was This Study Done?

clinical studyThis study recruited 33 participants with diabetes or prediabetes from the San Francisco Bay area. The participants in the study:

  • Were between 41 and 77 years old (average age = 60.5).
  • Were 61% male, 45% non-Hispanic white, and mostly (85%) college educated.
  • Had either prediabetes (61%) or diabetes (39%).
  • Had BMIs ranging from 22.7 (normal) to 39.7 (obese) (average BMI = 30 (borderline obese).
  • Had elevated levels of HbA1c (hemoglobin A1c, a measure of long-term blood sugar control).

People were excluded from the study if they were:

  • Underweight (<110 pounds) or morbidly obese (BMI ≥40).
  • Had extremely high cholesterol (LDL cholesterol >190 mg/dL) or blood pressure (>169 mmHg).
  • On insulin or certain medications to lower blood sugar levels.

This was a randomized, crossover, interventional study. Simply put, that means:

  • The study started with participants eating a typical American diet. The intervention was either a Keto diet or a Mediterranean diet.
  • Each patient was randomly assigned to one of the diets for 12 weeks. Then they “crossed over” to the other diet for 12 weeks. In this type of study each patient serves as their own control.
  • Finally, there was a 12-week follow-up period in which they could choose which of the two diets to follow.

It was a very well-controlled study:

  • Participants were given detailed guidelines to follow and received weekly individual education sessions by a registered dietitian and certified diabetes educator.
  • During the first 4 weeks of each diet, participants were provided at no cost all meals and snacks from a local food delivery service.
  • During the next 8 weeks of each diet, the participants purchased their own foods using the same guidelines they had been given during the first 4 weeks.
    • They were also provided with a recipe booklet and suggestions for diet-compliant menu items at local restaurants for each diet.
  • This was not designed as a weight loss diet. The participants were provided with 2,800 calories of food per day and instructed to eat until they were full.
  • Compliance with the diet was assessed in three ways:
    • During week 4 and week 12 of each diet phase, 3 unannounced 24-hour dietary recalls (2 on weekdays and 1 on a weekend day) were administered over the phone by a trained nutritionist.
    • Participants were also given an app to log in their food intake daily.
    • Participants on the Keto diet were given blood ketone monitors and strips.
  • Finally, at the beginning and end of the study and during weeks 4 and 12 of each diet phase participants went to a medical facility for blood work and weight measurements.

The primary focus of this study was measuring the effect of each diet on HbA1c. HbA1c measures blood sugar control over the previous 12 weeks (which is why each diet phase was 12 weeks long). But the study also measured the effect of each diet on LDL cholesterol, HDL cholesterol, and triglycerides.

What Were The Diets Like?

Vegetarian DietThese were not ordinary versions of the Mediterranean and Keto diets:

  • Sugar and refined flour are often part of the diet in Mediterranean regions. So, this study used the “Mediterranean Plus (Med-Plus)” diet which restricts both sugar and refined grains.
  • Keto convenience foods are often a witch’s brew of artificial ingredients. So, this study used the “Well-Formulated Keto Diet (WFKD)” which is composed of whole, unprocessed foods. In fact, both diets were whole food diets.

In summary, the two diets were:

  • Alike in that both emphasized non-starchy vegetables and minimized sugar and refined grains.
  • Alike in that they were both whole food diets.
  • Different in that the Keto diet eliminated legumes, fruits, and whole grains while the Mediterranean diet included them.

The macronutrient composition of the two diets was about what you would expect.

USDA

Guidelines

 Baseline Keto

(Weeks

1-4)

 Keto

(Weeks

5-12)

 Med

(Weeks

1-4)

 Med

(Weeks

5-12)
Protein 10-35% 18% 25% 22% 19% 21%
Carbs 45-65% 41% 12% 18% 37% 37%
Fat <30% 41% 63% 60% 44% 42%
  • The baseline diet was typical of the American diet. It was higher than recommended for fat. While carbohydrate intake appeared to be moderate, it was high in sugar and refined grains.
  • The Keto and Mediterranean diet interventions were separated into 2 phases. In phase 1 (weeks 1-4) every meal and snack were provided to the participants. In phase 2 (weeks 5-12) they purchased their own food.
  • As expected, carbohydrate intake was much lower, fat intake much higher, and protein intake slightly higher than baseline for the Keto diet. And this pattern was maintained during the 8 weeks the participants purchased their own food.
  • Macronutrient composition on the Mediterranean diet was not much different than baseline and did not change much during weeks 5-12.

The fat composition of the two diets was also different.

Baseline Keto

(Weeks

1-4)

 Keto

(Weeks

5-12)

 Med

(Weeks

1-4)

 Med

(Weeks

5-12)
Monounsaturated 42% 48% 43% 52% 45%
Polyunsaturated 23% 15% 19% 23% 25%
Saturated 35% 37% 38% 25% 30%
  • The Keto diet was significantly lower in percent polyunsaturated fat and slightly higher in percent monounsaturated and saturated fat than baseline (the typical American diet) in weeks 1-4. However, remember that the Keto diet was 50% higher in total fat than the other diets. This makes it significantly higher in saturated fat than either the baseline or Mediterranean diets.
  • As expected, the Mediterranean diet was significantly higher in percent monounsaturated fat and lower in percent saturated fat than baseline in weeks 1-4.
  • Not surprisingly, both diets trended towards the baseline diet in the 8 weeks participants were buying their own food.

Other interesting differences between the two diets:

  • The Keto diet contained around 12% plant protein and 88% animal protein, while the Mediterranean diet contained about 50% of each.
  • Fiber intake decreased by 33% compared to baseline on the Keto diet, while fiber intake increased by 50% on the Mediterranean diet.
  • In terms of nutritional adequacy, the Keto diet was significantly lower in fiber, vitamin C, folate, and magnesium than the Mediterranean diet.

What Did The Study Show?

Question Mark1. Participants consumed around 300 fewer calories/day and lost about 15 pounds on both diets.

    • The authors speculated this was because both diets were more filling than the baseline diet, presumably because both diets were whole food diets while the baseline diet contained lots of processed foods high in sugar and refined grains.

2) Both diets reduced HbA1c (a cumulative measure of how much the diets improved blood sugar control compared to the baseline diet) by about the same extent.

3) LDL cholesterol (bad cholesterol) increased by about 10% on the Keto diet, while it decreased by about 9% on the Mediterranean diet. This difference was highly significant.

4) HDL cholesterol increased by about the same extent on both diets.

5) Triglycerides decreased by around 20% on the Keto diet and by 10% on the Mediterranean diet. This difference was also highly significant.

6) Finally, adherence to the Keto diet was less than for the Mediterranean diet. Plus, more people chose the Mediterranean diet during the follow-up phase when they were allowed to choose their own diet.

The authors concluded, “HbA1c values…improved from baseline on both diets, likely due to several shared dietary aspects. The WFKT [Keto diet] led to a greater decrease in triglycerides, but also had untoward risks from elevated LDL cholesterol and lower nutrient intakes from avoiding legumes, fruits, and whole, intact grains, as well as being less sustainable [easy to follow long-term].

Which Diet Is Best For Diabetics?

Mediterranean Diet Foods

Animal Protein Foods

Vs

 

 

 

 

Once again, I have covered lots of information in this blog. But if you are diabetic, you are probably wondering, “What does this mean for me?” Let me start by reviewing the purpose of this study.

  • This study was designed to compare the two extremes of recommended diets (Mediterranean and Keto) with respect to their effectiveness at keeping blood sugar under control.
  • These were both more restrictive versions of the two diets than most people follow. In this study, both diets:
    • Were whole food diets. No sodas, processed, or convenience foods were allowed.
    • Minimized the consumption of sugars and refined grains.

Now let me divide the discussion into two sections:

  1. Which diet is best for diabetics in the short term (in this case, 12 weeks)?
    • Participants consumed 300 fewer calories and lost about 15 pounds on both diets in spite of being given more than they could eat and not being encouraged to lose weight.
      • The authors attributed this to whole food diets being more filling.
      • However, it is also consistent with my contention that any restrictive diet will lead to short-term weight loss and improvement in blood sugar control. I summarize the 5 reasons for this phenomenon in last week’s “Health Tips From the Professor” article
    • Blood sugar control over 12 weeks, as measured by HbA1c, improved by the same amount on both diets.
      • That is consistent with the American Diabetes Association’s position that a variety of diets, ranging from Mediterranean to Keto, are suitable for diabetics.
      • This also means that you can forget the advice that diabetics need to follow a low carb diet and give up fruits, whole grains, and legumes to keep their blood sugar under control.
      • However, this is not a “get out of jail free card”. Diabetics do need to avoid sodas, processed, and convenience foods and minimize sugar and refined grains.
    • There was considerable individual variability. Some people did better on the Mediterranean diet. Others did better on the Keto diet.
    • This is consistent with the American Diabetes Association’s recommendation that diabetic diets should be individualized.

In short, this study suggests that in the short term (12 weeks) the Med-Plus and WFKD Keto diets are equally effective at promoting weight loss and improved blood sugar control for both diabetics and prediabetics.

However, there is considerable individual variability, meaning that diabetics can chose the diet that works best for them.

2) Which diet is best for diabetics in the long term?

If both diets are equally effective short term, the important question becomes whether they are equally successful and equally healthy long term.

As noted in the author’s conclusion, this study raised several “red flags” which suggest the Keto diet might be less successful and less healthy long term. But this is a short-term study.

You may be wondering, “What do long-term studies show?” Unfortunately, there are very few long-term studies to guide us. But here is what we do know.

    • There are multiple studies showing that the Mediterranean diet reduces the risk of diabetes, heart disease, and some cancers long term. There is no evidence that meat-based low carb diets are healthy long term. This includes the Atkins diet, which has been around more than 50 years.
    • A 6-year study reported that the group with the lowest carbohydrate intake had an increased risk of premature death – 32% for overall mortality, 50% for cardiovascular mortality, 51% for cerebrovascular mortality, and 36% for cancer mortality.
    • A 20-year study reported that women consuming a meat-based low carb diet for 20 years gained just as much weight and had just as high risk of diabetes and heart disease as women consuming a high carbohydrate, low fat diet.

In short, the few long-term studies we do have suggest that the Mediterranean diet is a better choice for long-term health and reduced risk of diabetes than low-carb diets.

The Bottom Line 

If you are diabetic or prediabetic, the American Diabetes association recommends a diet that is individualized and ranges from Mediterranean to low carb and very low carb (Keto).

However, low carb and Keto enthusiasts insist that diabetics need to follow a low carb or very low carb diet. And that seems to make sense. After all, aren’t carbs the problem for diabetics?

To resolve this question, a recent study was designed to compare the two extremes of the ADA-recommended diets (Mediterranean and Keto) with respect to their effectiveness at keeping blood sugar under control.

These were not ordinary versions of the Mediterranean and Keto diets:

  • Sugar and refined flour are often part of the diet in Mediterranean regions. So, this study used the “Mediterranean Plus (Med-Plus)” diet which restricts both sugar and refined grains.
  • Keto convenience foods are often a witch’s brew of artificial ingredients. So, this study used the “Well-Formulated Keto Diet (WFKD)” which is composed of whole, unprocessed foods. In fact, both diets were whole food diets.

In short, this study found that in the short term (12 weeks) the Med-Plus and WFKD Keto diets are equally effective at promoting weight loss and improved blood sugar control for both diabetics and prediabetics.

The authors concluded, “HbA1c values…improved from baseline on both diets, likely due to several shared dietary aspects. The WFKT [Keto diet] led to a greater decrease in triglycerides, but also had untoward risks from elevated LDL cholesterol and lower nutrient intakes from avoiding legumes, fruits, and whole, intact grains, as well as being less sustainable [easy to follow long-term].

If both diets are equally effective short term, the important question becomes whether they are equally successful and equally healthy long term.

As noted in the author’s conclusion, this study raised several “red flags” suggesting that the WFKD Keto diet may be less successful and less healthy long term than the Med-Plus diet. However, this was a short-term study.

So, the question becomes, “What do long-term studies show?” There are few long-term studies of low-carb diets, but the few long-term studies we do have suggest that the Mediterranean diet is a better choice for both long-term health and reduced risk of diabetes than most low-carb diets.

For more details on this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

Walking Your Way To Health

by

How Much Should You Walk? 

Author: Dr. Stephen Chaney 

Overweight People ExercisingThe new year is almost here. If you are like millions of Americans, you may already be making plans to join a gym, get a personal trainer, or join a spin class.

The problem is these are all expensive options. And a good portion of that money is wasted. To put it into perspective, let’s look at some statistics

  • Around 6 million Americans buy gym memberships every January.
  • 67% of those memberships are never used.
  • For those memberships used in January, another 50% are not in use 6 months later.
  • Americans spend about 1.6 billion dollars on unused gym memberships every year.
  • And that doesn’t include those gym memberships that are only occasionally used.

If you want to get fit and healthy in the new year, perhaps you should consider a less expensive option – like walking. Your only investments are a good pair of walking shoes and a device that keeps track of the number of steps you take (eg, Fitbit, smart watch, or smart phone).

You still may give up on your New Year’s goal of getting fitter at some point. But you won’t have wasted so much money.

Of course, you probably have some questions about the benefits of walking, such as:

  1. Is walking enough to significantly improve my fitness and health?

2) How far (how many steps) should I walk?

3) How fast should I walk?

Fortunately, two recent studies (B del Pozo-Cruz et al, JAMA Internal Medicine, 182: 1139-1148, 2022; J del Pozo-Cruz et al, Diabetes Care, 45: 2156-2158, 2022) have answered all three questions.

How Were These Studies Done?

clinical studyThe first study (B del Pozo-Cruz et al, JAMA Internal Medicine, 182: 1139-1148, 2022) followed 78,500 participants (average age 61, 55% female, 97% white) enrolled in the UK Biobank study for an average of 7 years.

At the time of enrollment, each participant was given an accelerometer (a device that measures the number and frequency of steps) to wear on their dominant wrist for 24 hours/day for 7 days. The investigators used the accelerometer data to categorize several types of physical activity.

  • Daily step counts (the average number of steps per day for 7 days). These step counts were further subdivided into two categories:
  • Incidental steps (It was assumed that ˂40 steps/min represented steps taken that were incidental to normal daily activities).
  • Purposeful steps (It was assumed that ≥40 steps/min represented steps taken as part of planned exercise).
  • Stepping intensity (the highest frequency of steps/min averaged over 30 min intervals for all 7 days).

At the end of the study, each of these variables was correlated with the risk of premature deaths due to all causes, cancer, and heart disease.

The second study (J del Pozo-Cruz et al, Diabetes Care, 45: 2156-2158, 2022) was similar except that it:

  • Used data from 1687 adults (average age = 55, 56% male, with diabetes or prediabetes when the study began) in the 2005-2006 National Health and Nutrition Examination Survey in the US.
  • Followed participants for 9 years instead of 7.
  • Only measured total steps/day
  • Correlated total steps/day with premature death for participants who already had prediabetes or diabetes when they entered the study.

Walking Your Way To Health

Study 1 looked at the effect of walking on health outcomes in multiple ways.

woman walking dog#1: Increase in number of steps/day:

  • On average study participants took an average of 7200 steps per day, but this ranged from a low of 3,200 steps/day to a high of 12,200 steps/day.
  • Each increase of 2,000 steps/day was associated with a:
    • 8% decrease in all-cause mortality.
    • 11% decrease in cancer mortality.
    • 10% decrease in heart disease mortality.
  • Overall, increasing from 3,200 steps/day to 10,000 steps/day decreased all-cause, cancer, and heart disease mortality by around 36%.
  • There was no minimum threshold to this beneficial effect of walking on the risk of premature death.
  • The benefits of walking appeared to plateau at 10,000 steps/day.

#2: Increase in number of incidental steps/day (steps taken that are incidental to normal daily activities):

  • On average study participants took 3240 incidental steps/day, but this ranged from a low of 2,100 steps/day to a high of 4,400 steps/day.
  • Each 10% increase in incremental steps/day was associated with a:
    • 6% decrease in all-cause mortality.
    • 6% decrease in cancer mortality.
    • 10% decrease in heart disease mortality.

#3: Increase in number of purposeful steps/day (steps taken as part of planned exercise):

  • On average study participants took 4,600 purposeful steps/day, but this ranged from a low of 1,600 steps/day to a high of 8,600 steps/day.
  • Each 10% increase in purposeful steps/day was associated with a:
    • 7% decrease in all-cause mortality.
    • 8% decrease in cancer mortality.
    • 10% decrease in heart disease mortality.

#4: Increase in speed of walking or cadence. The measurement they used was “peak-30 cadence” – the Walking Fasthighest average steps/min during a 30-minute interval within a day:

  • On average study participants had a “peak-30 cadence” of 76 steps/min, but this ranged from a low of 47 steps/min to a high of 109 steps/min.
  • Each 10% increase in “peak-30 cadence” was associated with a:
    • 8% decrease in all-cause mortality.
    • 9% decrease in cancer mortality.
    • 14% decrease in heart disease mortality.
  • The benefits of walking rapidly (increase in “peak-30 cadence”) were in addition to the benefits seen by increasing the number of steps per day.
  • Overall, increasing from a “peak-30 cadence” of 47 steps/min to 109 steps/min decreased all-cause, cancer, and heart disease mortality by an additional 34%.
  • There was no minimum threshold to this beneficial effect of increasing “peak-30 cadence” (the speed of walking) on the risk of premature death.
  • The benefits of increasing “peak-30 cadence” appeared to plateau at 100 steps/min.

#5 Effect of walking on the prevention of heart disease and cancer: The investigators measured this by strong heartlooking at the effect of walking on the “incidence” of heart disease and cancer (defined as new diagnoses of heart disease and cancer) during the study. They found.

  • Each 2,000-step increase in the total number of steps/day decreased the risk of developing heart disease and cancer by 4% during this 7-year study.
  • Each 10% increase in the number of purposeful steps/day decreased the risk of developing heart disease and cancer by 4% during this study.
  • Each 10% increase in “peak-30 cadence” decreased the risk of developing heart disease and cancer by 7% during this study.

The authors concluded, “The findings of this population-based…study of 78,500 individuals suggest that up to 10,000 steps/day may be associated with a lower risk of mortality and cancer and CVD incidence. Steps performed at a higher cadence may be associated with additional risk reduction, particularly for incident disease.”

Study 2 extended these findings to diabetes. They started with participants that had either prediabetes or diabetesdiabetes and followed them for 9 years. They found that:

  • Study participants with prediabetes ranged from a low of 3,800 steps/day to a high of 10,700 steps/day.
    • Prediabetic participants walking 10,700 steps/day were 25% less likely to die during the study than participants walking only 3,800 steps/day.
  • Study participants with diabetes ranged from a low of 2,500 steps/day to a high of 10,200 steps/day.
    • Diabetic participants walking 10,200 steps/day were also 25% less likely to die during the study than participants walking only 2,500 steps/day.
  • Even small increases in the number of steps per day decreased the risk of premature death for both prediabetic and diabetic participants.
  • Once again, 10,000 steps/day appeared to be the optimal dose to lower the risk of premature death for both diabetic and prediabetic patients.

The authors of this study concluded, “Accumulating more steps/day up to ~10,000 steps/day may lower the risk of all-cause mortality of adults with prediabetes and diabetes.”

How Much Should You Walk?

Walking CoupleThat was a lot of information. You are probably wondering what it means for you. Let’s start with the big picture:

  • Going from couch potato to 10,000 steps per day may reduce your risk of premature death due to all causes, cancer, and heart disease by 36% (24% if you are already prediabetic or diabetic).
  • Increasing the speed with which you walk from 47 steps/min to 109 steps/min sustained for 30 minutes may reduce your risk of premature death by an additional 34%.

In other words, simply walking more and walking faster can have a significant on your health. I am not recommending walking as your only form of exercise. I’m just saying not to consider it inferior to other forms of exercise.

  • There is no lower limit to the benefits of walking. Even small increases in the number of steps/day you take and the speed with which you walk may have a beneficial effect on your health.

In other words, you don’t need to speed walk 10,000 steps/day to reap a benefit from walking. Even small increases are beneficial. That’s good news for those of you who may not be able to speed walk long distances. It also means that if you are a couch potato, you don’t need to attempt 10,000 steps at high speed from day 1. You can work up to it gradually.

  • Incidental walking (walking that is incidental to your daily activities) is almost as beneficial as purposeful walking (walking as part of a planned exercise).

That’s good news for those of you who may not have time for long walks. It also means that advice like “park your car at the far end of the parking lot and walk” or “take the stairs rather than the elevator” can have a meaningful impact on your health.

  • The benefits of walking appear to max out at around 10,000 steps per day and a cadence of 100 steps/min sustained for 30 minutes.

That means once you get to those levels, it’s time to consider adding other kinds of exercise to your regimen. More and faster walking may offer little additional benefit.

Finally, in the words of the authors, “This information could be used to motivate the least active individuals to increase their steps and the more-active individuals to reach the 10,000-step target.”

The Bottom Line 

The new year is almost here. If you are like millions of Americans, you may already be making plans to join a gym, get a personal trainer, or join a spin class.

If you want to get fit and healthy in the new year, perhaps you should also consider a less expensive option – like walking.

Of course, you probably have some questions about the benefits of walking, such as:

1) Is walking enough to significantly improve my fitness and health?

2) How far (how many steps) should I walk?

3) How fast should I walk?

Fortunately, two recent studies have answered all three questions. They found:

  • Going from couch potato to 10,000 steps per day may reduce your risk of premature death due to all causes, cancer, and heart disease by 36% (24% if you are already prediabetic or diabetic).
  • Increasing the speed with which you walk from 47 steps/min to 109 steps/min sustained for 30 minutes may reduce your risk of premature death by an additional 34%.
  • There is no lower limit to the benefits of walking. Even small increases in the number of steps/day you take and the speed with which you walk may have a beneficial effect on your health.
  • Incidental walking (walking that is incidental to your daily activities) is almost as beneficial as purposeful walking (walking as part of a planned exercise).
  • The benefits of walking appear to max out at around 10,000 steps per day and a cadence of 100 steps/min sustained for 30 minutes.

In the words of the authors of these studies, “This information could be used to motivate the least active individuals to increase their steps and the more-active individuals to reach the 10,000-step target.”

For more details on this study and what it means for you, read the article above.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease.

 

Health Tips From The Professor