fiber

Are All Carbs Bad?

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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

Can Healthy Eating Help You Lose Weight?

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Who Benefits Most From A Healthy Diet?

Author: Dr. Stephen Chaney 

fad dietsFad diets abound. High protein, low carb, low fat, vegan, keto, paleo – the list is endless. They all claim to be backed by scientific studies showing that you lose weight, lower your cholesterol and triglycerides, lower your blood pressure, and smooth out your blood sugar swings.

They all claim to be the best. But any reasonable person knows they can’t all be the best. Someone must be lying.

My take on this is that fad diet proponents are relying on “smoke and mirrors” to make their diet look like the best. I have written about this before, but here is a brief synopsis:

  • They compare their diet with the typical American diet.
    • Anything looks good compared to the typical American diet.
    • Instead, they should be comparing their diet with other weight loss diets. That is the only way we can learn which diet is best.
  • They are all restrictive diets.
    • Any restrictive diet will cause you to eat fewer calories and to lose weight.
    • As little as 5% weight loss results in lower cholesterol & triglycerides, lower blood pressure, and better control of blood sugar levels.

Simply put, any restrictive diet will give you short-term weight loss and improvement in blood parameters linked to heart disease, stroke, and diabetes. But are these diets healthy long term? For some of them, the answer is a clear no. Others are unlikely to be healthy but have not been studied long term. So, we don’t know whether they are healthy or not.

What if you started from the opposite perspective? Instead of asking, “Is a diet that helps you lose weight healthy long term?”, what if you asked, “Can healthy eating help you lose weight?” The study (S Schutte et al, American Journal of Clinical Nutrition, 115: 1-18, 2022) I will review this week asked that question.

More importantly, it was an excellent study. It compared a healthy diet to an unhealthy diet with exactly the same degree of caloric restriction. And it compared both diets to the habitual diet of people in that area. This study was performed in the Netherlands, so both weight loss diets were compared to the habitual Dutch diet.

How Was The Study Done?

clinical studyThis was a randomized controlled trial, the gold standard of clinical studies. The investigators recruited 100 healthy, abdominally obese men and women aged 40-70. At the time of entry into the study none of the participants:

  • Had diabetes.
  • Smoked
  • Had a diagnosed medical condition.
  • Were on a medication that interfered with blood sugar control.
  • Were on a vegetarian diet.

The participants were randomly assigned to:

  • A high-nutrient quality diet that restricted calories by 25%.
  • A low-nutrient-quality diet that restricted calories by 25%.
  • Continue with their habitual diet.

The study lasted 12 weeks. The participants met with a dietitian on a weekly basis. The dietitian gave them the foods for the next week and monitored their adherence to their assigned diet. They were advised not to change their exercise regimen during the study.

At the beginning and end of the study the participants were weighed, and cholesterol, triglycerides, and blood pressure were measured.

Can Healthy Eating Help You Lose Weight?

Vegetarian DietTo put this study into context, these were not healthy and unhealthy diets in the traditional sense.

  • Both were whole food diets.
  • Both included fruits, vegetables, low-fat dairy, and lean meats.
  • Both restricted calories by 25%.

The diets were designed so that the “high-nutrient quality” diet had significantly more plant protein (in the form of soy protein), fiber, healthy fats (monounsaturated and omega-3 fats), and significantly less fructose and other simple sugars than the “low-nutrient-quality” diet.

At the end of 12 weeks:

  • Participants lost significant weight on both calorie-restricted diets compared to the group that continued to eat their habitual diet.
    • That is not surprising. Any diet that successfully restricts calories will result in weight loss.
  • Participants on the high-nutrient quality diet lost 33% more weight than participants on the low-nutrient-quality diet (18.5 pounds compared to 13.9 pounds).
  • Participants on the high-nutrient quality diet lost 50% more inches in waist circumference than participants on the low-nutrient-quality diet (1.8 inches compared to 1.2 inches).
    • This is a direct measure of abdominal obesity.

When the investigators measured blood pressure, fasting total cholesterol levels, and triglyceride levels:Heart Healthy Diet

  • These cardiovascular risk factors were significantly improved on both diets.
    • Again, this would be expected. Any diet that causes weight loss results in an improvement in these parameters.
  • The reduction in total serum cholesterol was 2.5-fold greater and the reduction in triglycerides was 2-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.
  • The reduction in systolic blood pressure was 2-fold greater and the reduction in diastolic blood pressure was 1.67-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.

The authors concluded, “Our results demonstrate that the nutrient composition of an energy-restricted diet is of great importance for improvements of metabolic health in an overweight, middle-aged population. A high-nutrient quality energy-restricted diet enriched with soy protein, fiber, monounsaturated fats, omega-3 fats, and reduced in fructose provided additional health benefits over a low-nutrient quality energy-restricted diet, resulting in greater weight loss…and promoting an antiatherogenic blood lipid profile.”

In short, participants in this study lost more weight and had a better improvement in risk factors for heart disease on a high-nutrient-quality diet than on a low-nutrient-quality diet. Put another way, healthy eating helped them lose weight and improved their health.

Who Benefits Most From A Healthy Diet?

None of the participants in this study had been diagnosed with diabetes when the study began. However, all of them were middle-aged, overweight, and had abdominal obesity. That means many of them likely had some degree of insulin resistance.

Because of some complex metabolic studies that I did not describe, the investigators suspected that insulin resistance might influence the relative effectiveness of the two energy-restricted diets.

To test this hypothesis, they used an assay called HOMA-IR (homeostatic model assessment of insulin resistance). Simply put, this assay measures how much insulin is required to keep your blood sugar under control.

They used a HOMA-IR score of 2.5 to categorize insulin resistance among the participants.

  • Participants with a HOMA-IR score >2.5 were categorized as insulin-resistant. This was 55% of the participants.
  • Participants with a HOMA-IR score ≤2.5 were categorized as insulin-sensitive. This was 45% of the participants.

When they used this method to categorize participants they found:

  • Insulin-resistant individual lost about the same amount of weight on both diets.
  • Insulin-sensitive individuals lost 66% more weight on the high-nutrient-quality diet than the low-nutrient-quality diet (21.6 pounds compared to 13.0 pounds).

The investigators concluded, “Overweight, insulin-sensitive subjects may benefit more from a high- than a low-nutrient-quality energy-restricted diet with respect to weight loss…”

What Does This Study Mean For You?

Questioning WomanSimply put this study confirms that:

  • Caloric restriction leads to weight loss, and…
  • Weight loss leads to improvement in cardiovascular risk factors like total cholesterol, triglycerides, and blood pressure.
    • This is not new.
    • This is true for any diet that results in caloric restriction.

This study breaks new ground in that a high-nutrient quality diet results in significantly better:

  • Weight loss and…
  • Reduction in cardiovascular risk factors…

…than a low-nutrient quality diet. As I said above, the distinction between a “high-nutrient-quality” diet and a “low-nutrient-quality” diet may not be what you might have expected.

  • Both diets were whole food diets. Neither diet allowed sodas, sweets, and highly processed foods.
  • Both included fruits, vegetables, grains, and lean meats.
  • Both reduced caloric intake by 25%.
    • If you want to get the most out of your weight loss diet, this is a good place to start.

In this study the investigators designed their “high-nutrient-quality” diet so that it contained:

  • More plant protein in the form of soy protein.
    • In this study they did not reduce the amount of animal protein in the “high-nutrient-quality” diet. They simply added soy protein foods to the diet. I would recommend substituting soy protein for some of the animal protein in the diet.
  • More fiber.
    • The additional fiber came from substituting whole grain breads and brown rice for refined grain breads and white rice, adding soy protein foods, and adding an additional serving of fruit.
  • More healthy fats (monounsaturated and omega-3 fats).
    • The additional omega-3s came from adding a fish oil capsule providing 700mg of EPA and DHA.
  • Less simple sugars. While this study focused on fructose, their high-nutrient-quality diet was lower in all simple sugars.

ProfessorAll these changes make great sense if you are trying to lose weight. I would distill them into these 7 recommendations.

  • Follow a whole food diet. Avoid sodas, sweets, and highly processed foods.
  • Include all 5 food groups in your weight loss diet. Fruits, vegetables, whole grains, dairy, and lean proteins all play an important role in your long-term health.
  • Eat a primarily plant-based diet. My recommendation is to substitute plant proteins for at least half of your high-fat animal proteins. And this study reminds us that soy protein foods are a convenient and effective way to achieve this goal.
  • Eat a diet high in natural fibers. Including fruits, vegetables, whole grains, beans, nuts, seeds, and soy foods in your diet is the best way to achieve this goal.
  • Substitute healthy fats (monounsaturated and omega-3 fats) for unhealthy fats (saturated and trans fats) in your diet. And this study reminds us that it is hard to get enough omega-3s in your diet without an omega-3 supplement.
  • Reduce the amount of added sugar, especially fructose, from your diet. That is best achieved by eliminating sodas, sweets, and highly processed foods from the diet. I should add that fructose in fruits and some healthy foods is not a problem. For more information on that topic, I refer you to a previous “Health Tips” article .
  • Finally, I would like to remind you of the obvious. No diet, no matter how healthy, will help you lose weight unless you cut back on calories. Fad diets achieve that by restricting the foods you can eat. In the case of a healthy diet, the best way to do it is to cut back on portion sizes and choose foods with low caloric density.

I should touch briefly on the third major conclusion of this study, namely that the “high-nutrient quality diet” was not more effective than the “low-nutrient-quality” diet for people who were insulin resistant. In one sense, this was not news. Previous studies have suggested that insulin-resistant individuals have more difficulty losing weight. That’s the bad news.

However, there was a silver lining to this finding as well:

  • Only around half of the overweight, abdominally obese adults in this study were highly insulin resistant.
    • That means there is a ~50% chance that you will lose more weight on a healthy diet.
  • Because both diets restricted calories by 25%, insulin-resistant individuals lost weight on both diets.
    • That means you can lose weight on any diet that successfully reduces your caloric intake. That’s the good news.
    • However, my recommendation would still be to choose a high-nutrient quality diet that is designed to reduce caloric intake, because that diet is more likely to be healthy long term.

The Bottom Line 

A recent study asked, “Can healthy eating help you lose weight?” This study was a randomized controlled study, the gold standard of clinical studies. The participants were randomly assigned to:

  • A high-nutrient quality diet that restricted calories by 25%.
  • A low-nutrient-quality diet that restricted calories by 25%.
  • Continue with their habitual diet.

These were not healthy and unhealthy diets in the traditional sense.

  • Both were whole food diets.
  • Both included fruits, vegetables, low-fat dairy, and lean meats.
  • Both restricted calories by 25%.

The diets were designed so that the “high-nutrient quality” diet had significantly more plant protein (in the form of soy protein), fiber, healthy fats (monounsaturated and omega-3 fats), and significantly less fructose and other simple sugars than the “low-nutrient-quality” diet.

At the end of 12 weeks:

  • Participants on the high-nutrient quality diet lost 33% more weight than participants on the low-nutrient-quality diet (18.5 pounds compared to 13.9 pounds).

When the investigators measured cardiovascular risk factors at the end of 12 weeks:

  • The reduction in total serum cholesterol was 2.5-fold greater and the reduction in triglycerides was 2-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.
  • The reduction in systolic blood pressure was 2-fold greater and the reduction in diastolic blood pressure was 1.67-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.

The authors concluded, “Our results demonstrate that the nutrient composition of an energy-restricted diet is of great importance for improvements of metabolic health in an overweight, middle-aged population. A high-nutrient quality energy-restricted diet enriched with soy protein, fiber, monounsaturated fats, omega-3 fats, and reduced in fructose provided additional health benefits over a low-nutrient quality energy-restricted diet, resulting in greater weight loss…and promoting an antiatherogenic blood lipid profile.”

In short, participants in this study lost more weight and had a better improvement in risk factors for heart disease on a high-nutrient-quality diet than on a low-nutrient-quality diet. Put another way, healthy eating helped them lose weight and improved their health.

For more details on this study, what this study means for you, and my 7 recommendations for a healthy weight loss diet, 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.

Do Whole Grains Reduce Inflammation?

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Are Low Carb Diets Healthy Long Term?

Author: Dr. Stephen Chaney 

InflammationInflammation is a bit like Dr. Jekyll and Mr. Hyde. Acute inflammation plays a valuable role in our immune response. But chronic inflammation is a scourge. Chronic inflammation:

  • Is a key component of all the “itis” diseases.
  • Can lead to autoimmune diseases.
  • Is thought to play an important role in heart disease.
  • Is associated with many other diseases, such as diabetes, cancer, Alzheimer’s disease, and inflammatory bowel diseases (IBS).

While there are many causes of chronic inflammation, diet plays an important role. In a previous issue of “Health Tips From the Professor” I have described how an anti-inflammatory diet can quell the fires of chronic inflammation.

Fiber from unprocessed plant foods is a key component of an anti-inflammatory diet. But are all plant fibers equally effective at reducing inflammation? Here is what we know:

  • Fiber from whole grains, vegetables, and fruits have different chemical and physical characteristics and support the growth of different species of friendly bacteria in our intestines.
  • Previous studies have shown that higher intakes of dietary fiber are associated with lower risk of heart disease.
    • Studies have suggested that fiber from whole grains may be more effective than fiber from fruits and vegetables at reducing heart disease risk.
  • Chronic inflammation is highly associated with the development of heart disease. This has led to the hypothesis that fiber from whole grains may be more effective than other plant fibers at reducing chronic inflammation.
    • Some studies have supported this hypothesis, but they have all been done with middle-aged participants, not with elderly participants who characteristically have higher levels of inflammation.

The study (R Shivakoti et al, JAMA Network Open, 5(3): e225012, 2022) I will describe today was designed to:

  • Test the hypothesis that whole grain fiber is more effective than vegetable or fruit fiber at reducing inflammation.
  • Determine how important reducing inflammation is at reducing the risk of heart disease.
  • Extending these findings to an older population group.

How Was The Study Done?

Clinical StudyThe data for this study was obtained from the Cardiovascular Health Study (CHS), a study designed to characterize factors influencing cardiovascular health in American adults aged 65 years or older. This study analyzed data from 4,125 participants (40% men, 95% white) who enrolled in the CHS study from 1989 to 1990.

These participants did not have heart disease at the time they were enrolled in the study. They had an average age of 72.6 at the beginning of the study and were followed for an average of 11.9 years. During that time 1,941 (47%) of them developed heart disease.

When the participants were enrolled in the study:

  • A food frequency questionnaire was administered to them by a trained dietitian to assess their long-term usual dietary intake. This information was used to assess:
    • Their total fiber intake and…
    • Their fiber intake from various dietary sources (whole grains, vegetables, and fruits).
  • Fasting blood samples were collected and used to analyze various markers of inflammation.

A follow-up via phone was conducted every 6 months to track an initial diagnosis of cardiovascular disease.

At the end of the study, the investigators analyzed:

  • The effect of total fiber and fiber from different food sources on the risk of developing heart disease.
  • The effect of total fiber and fiber from different food sources on inflammatory markers in the blood.
  • The extent to which decreased inflammation could explain the effect of whole grain fiber on reducing heart disease.

Do Whole Grains Reduce Inflammation?

With respect to inflammation:

  • Increased intake of total fiber was associated with healthier levels of the inflammatory markers CRP, IL-1RA, and sCD163.
    • Increased intake of fiber from whole grains was associated with healthier levels of the inflammatory markers CRP, IL-6, and IL-1RA.
    • Increased intake of vegetable fiber was not significantly associated with healthier levels of any inflammatory marker.
    • Increased intake of fiber from fruits was associated with healthier levels of the inflammatory marker sCD163.

With respect to cardiovascular disease:

  • Every 5g/day increase in total fiber decreased the risk of heart disease by 5%.
    • Every 5g/day increase in fiber from whole grains decreased the risk of heart disease by 14%.
    • Increased intake of fiber from vegetables and fruits did not have a statistically significant effect on the risk of heart disease.

Finally, when the investigators did a statistical analysis to determine to extent to which the effect of whole grain fiber on inflammation, could explain its effect on heart disease, they concluded:

  • The effect of whole grain fiber on inflammation could explain only about 16% of its effect on heart disease.

In the words of the authors, “In this prospective study of older adults, higher intakes of total fiber were associated with lower levels of various inflammatory markers, and this inverse association was primarily due to cereal fiber intake. Vegetable and fruit fiber intakes were not consistently associated with lower levels of inflammatory markers. These results suggest that specifically cereal fibers might be more effective in reducing systemic infection, which will need to be tested in interventional studies of specific populations.

In addition, cereal fiber was associated with a lower risk of CVD, although inflammation mediated less than 20% of the observed inverse association between cereal fiber and CVD. This suggests that the association of cereal fiber is primarily due to factors … other than systemic inflammation.”

Note: This conclusion underplays the role of fruit fiber in reducing inflammation. The statement is correct in saying only whole grain fiber reduces the inflammatory markers CRP, IL-6, and IL-1RA. However, both total fiber and fruit fiber increase the anti-inflammatory marker sCD163. That is why I chose to use the term “healthier levels” rather than lower or higher levels when describing the effects of whole grain and fruit fibers on markers of inflammation.

What Does This Study Mean For You?

confusion#1: The biggest takeaway from this study is that whole grains are good for you.

  • This study shows that whole grain fiber decreases our risk of developing heart disease.
    • This is fully consistent with multiple previous studies showing that whole grains decrease the risk of heart disease.
    • Previous studies have also shown that whole grains reduce the risk of cancer and diabetes.
  • This study also suggests that whole grain fiber reduces chronic inflammation.

There are also some takeaways from this and previous studies that may not be so obvious.

#2: Fiber has many important benefits beyond its effect on inflammation. For example:

  • This study concluded that the reduction in inflammation only explained a small part of the beneficial effect of whole grain fiber on reducing heart disease risk.
  • That is because whole grain fiber also:
    • Feeds friendly bacteria that improve gut function.
    • Provides satiety that can result in reduced fat and calorie intake.
    • Binds cholesterol, which improves blood cholesterol level.
    • Slows the rate at which dietary sugar enters the bloodstream, which improves blood sugar control.

#3: Whole plant foods have many benefits beyond their fiber content.

  • This study concluded that whole grain fiber was more beneficial than fiber from fruits and vegetables at reducing inflammation and reducing the risk of heart disease.
  • Previous studies have also shown that fruit and vegetables significantly decrease the risk of heart disease, stroke, and cancer.
  • That is because whole grains and unprocessed fruits and vegetables:
    • Displace sugar, refined flour, and highly processed foods from the diet.
    • Have a lower caloric density than processed foods, making it easier to achieve a healthy weight.
    • Provide nutrients and phytonutrients not found in processed foods.
    • Support a wide variety of healthy gut bacteria.

Are Low Carb Diets Healthy Long Term?

low carb dietconfusionWhen you consider all the benefits of whole grains, fresh fruits, and vegetables, it brings us to the final take home message.

#4: Despite what Dr. Strangelove has told you, low-carb diets may not be healthy long term.

  • There are no long-term (10 or 20-year) studies of low-carb diets. We simply have no evidence to support the claim that they are healthy long term.
  • Most low-carb diets eliminate or severely limit fruits and whole grains. Considering the many health benefits they provide, it is unlikely that any diet that restricts them is healthy long term.

The Bottom Line 

A recent study looked at the effect of plant fiber on inflammation and on heart disease.

With respect to inflammation the study found:

  • Increased intake of total fiber was associated with healthier levels of the inflammatory markers CRP, IL-1RA, and sCD163.
    • Increased intake of fiber from whole grains was associated with healthier levels of the inflammatory markers CRP, IL-6, and IL-1RA.
    • Increased intake of vegetable fiber was not significantly associated with healthier levels of any inflammatory marker.
    • Increased intake of fiber from fruits was associated with healthier levels of the inflammatory marker sCD163.

With respect to cardiovascular disease:

  • Every 5g/day increase in total fiber decreased the risk of heart disease by 5%.
  • Every 5g/day increase in fiber from whole grains decreased the risk of heart disease by 14%.
    1. The biggest takeaway from this study is that whole grains are good for you.

 Other takeaways from this and previous studies are:

2) Fiber has many important benefits beyond its effect on inflammation.

3) Whole plant foods have many benefits beyond their fiber content.

4) Despite what Dr. Strangelove has told you, low-carb diets may not be healthy long term.

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.

How Does Red Meat Cause Colon Cancer?

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How Can You Decrease Your Risk Of Colon Cancer? 

Author: Dr. Stephen Chaney

Grilled HamburgersBoth red meat and processed meat consumption are associated with increased risk of colon cancer. But the strength of that association differs between the two.

Processed meat has been classified as a carcinogen by the IARC*, indicating the evidence that processed meat causes colon cancer is definitive. Red meat, on the other hand, has been classified as a probable carcinogen by the IARC*. That means the evidence that red meat causes colon cancer is strong, but not definitive.

*[In case you were wondering, the IARC (International Agency for Research on Cancer) is an international agency charged by the WHO to, among other things, determine the risk of cancer from various foods, industrial chemicals, and environmental pollutants.]

As I said above, red meat consumption is associated with increased risk of colon cancer. But…

  • Not all studies agree (more about that later), and…
  • Association doesn’t prove cause and effect. It could be some other characteristic of red meat eaters that increases their risk of colon cancer.
  • Until recently we had no clear idea of how red meat might cause colon cancer.

Several mechanisms have been proposed. I will discuss each mechanism and ways to reduce the risk of colon cancer by that mechanism:

#1: When fat and juices from the meat drip onto an open flame, carcinogenic polyaromatic hydrocarbons (PAHs) Barbecue Gatheringare formed that stick to the surface of the meat. PAHs can be metabolized to cancer causing chemicals in our body.

  • PAH formation can be reduced by marinating the meat prior to cooking or by using cooking techniques that don’t involve an open flame.
  • PAH formation can be reduced, but not eliminated, by lower fat meat choices, such as grass-fed beef.
  • High fiber diets reduce exposure to PAHs by binding to them and flushing them through the intestine.
  • Cruciferous vegetables block the conversion of PAHs to cancer causing chemicals in our body.

#2: When red meats are cooked at high temperatures, amino acids in the meat combine with creatine, which is found in all red meats, to form heterocyclic amines (HCAs). HCAs can also be metabolized to cancer causing chemicals in our body.

  • HCA formation can be reduced by cooking the meat at lower temperatures.
  • Grass-fed beef does not reduce HCA formation because this mechanism is not dependent on the fat content of the meat.
  • High fiber diets and cruciferous vegetables reduce the danger of HCAs by the same mechanisms as for PAHs.

#3: The nitrates and nitrites used as preservatives in many processed meats react with amino acids from the meat to form carcinogenic N-nitrosamines in our intestines.

  • Antioxidant-rich fruits and vegetables can divert nitrates and nitrites into an alternative pathway that coverts them into nitric oxide, which is beneficial to our bodies. I have discussed this in a previous issue of “Health Tips From the Professor”.

#4: Heme, which is found in all red meats, combines with amino acids in the meat to form carcinogenic N-nitrosamines and similar N-nitroso compounds in our intestines.

  • This mechanism is inherent in all red meats and cannot be eliminated by choosing grass-fed beef or cooking at lower temperatures.
  • The formation of N-nitroso compounds from red meat appears to be carried out by gut bacteria. We know that meat eaters and vegetarians have very different populations of gut bacteria, but we don’t know whether this influences N-nitroso formation.

Mechanism #4 (formation of N-nitroso compounds from heme-containing red meat in our intestines) is the one I will be discussing in this article. But first, it’s time for Metabolism 101.

Metabolism 101: Why Should We Fear N-Nitroso Compounds?

ProfessorSimply put, N-nitroso compounds react with our DNA. They transfer methyl and ethyl groups to the nucleotides that make up our DNA sequence. The general term for these reactions is alkylation of the DNA.

  • In some cases, this causes the alkylated nucleotides to miscode during DNA replication. This can lead to cancer causing mutations.
  • In other cases, this causes genes to be permanently turned on or off.

To understand why this is a problem, you need to know a bit about cancer cell biology.

  • We have certain genes called “oncogenes”. These are genes that turn on processes like cell division. Normally these genes are tightly regulated so that cell division only occurs when it is needed. When these genes are permanently turned on, unregulated, continuous cell division occurs. In short, the cell becomes a cancer cell.
  • We have other genes called “tumor suppressor genes”. These are genes that do things like shutting down cell division when it is not needed. When these genes are permanently turned off, unregulated cell division can occur.

With this in mind, let us review what we know about red meat and colon cancer:

  • Red meat consumption is associated with increased risk of colon cancer.
  • Red meat consumption is also associated with increased concentrations of N-nitroso compounds in the colon. Studies also show:
  • The formation of N-nitroso compounds correlates with the heme content of the meat.
  • The formation of N-nitroso compounds in the colon is dependent on certain strains of gut bacteria.
  • The formation of N-nitroso compounds is reduced by diets high in fiber. It is likely this is because high fiber diets influence the types of bacteria in the colon, but that has not been proven yet.

What is missing is evidence that colon cancer cells contain the kind of DNA modifications (DNA alkylation) caused by N-nitroso compounds. That is what the current study (C Gurjao et al, Cancer Discovery, published online June 17, 2021) was designed to test.

How Was This Study Done?

Clinical StudyOne reason previous studies had not been able to demonstrate a clear correlation between red meat consumption and DNA modifications was that the studies were too small to obtain statistically significant results.

So, the authors of this study combined data from women in the Nurses’ Health Study, the Nurses’ Health Study II, and men in the Health Professionals Follow-Up Study. There were over 238,130 women and 51,529 men in these three studies.

None of the participants had cancer at the time they entered the studies. The participants were followed for at least 27 years. During that time 4855 participants developed colon cancer.

At the beginning of each study and every 4 years later the participants were asked to fill out a food frequency questionnaire to collect information about their usual diet over the past year. Validation studies showed that the diets of the participants changed little over the interval of the studies.

The participants in these studies were sent follow-up questionnaires every two years to collect information on lifestyle and newly diagnosed diseases like colon cancer.

For those who developed colon cancer, their medical records were reviewed to collect data on tumor size, tumor location, and disease stage.

The diagnoses of colon cancer often involves removing tissue from the cancer and from surrounding normal tissue and putting it in formalin-fixed paraffin-embedded tissue blocks. These were collected, and the DNA was extracted and sequenced to determine the extent and genetic location of alkylated DNA sequences.

How Does Red Meat Cause Colon Cancer?

colon cancerThis study measured the effect of red meat consumption on the extent and location of what the authors called “alkylation signatures”, which refers to the kinds of DNA modifications caused by N-nitroso compounds. Here is what they found:

  • Red meat consumption was positively associated with an increase in alkylation signatures caused by N-nitroso compounds in tumor tissue from patients with colon cancer.
    • This was true for both processed and unprocessed red meat.
    • There was no difference between men and women after adjusting for differences in red meat intake.
    • White meat (chicken and fish) did not cause an increase in alkylation damage in colon cells.
  • More importantly, there was an inverse association between alkylation damage in the tumor tissue and patient survival. Simply put, high levels of alkylation damage were associated with short survival times.

Previous studies have shown that processed red meat consumption was associated with increased levels of N-nitroso compounds and an increased risk of colon cancer in the distal colon.

  • This study showed colon cancer patients who had been consuming processed red meats had higher alkylation damage in tumors in the distal colon.

Previous studies have shown that certain oncogenes (genes that drive the conversion of normal cells to cancer cells) are activated in colon cancer cells and this activation is associated with alkylation damage to their DNA.

  • This study showed that tumors with activated oncogenes were enriched with the alkylation signature characteristic of N-nitroso compounds.

I realize this study is highly technical. It is not easy to understand, so let me simplify it.

  • Previous studies have shown that red meat consumption is associated with an increased risk of colon cancer.
  • Previous studies have also shown that red meat consumption is associated with an increased concentration of carcinogenic N-nitroso compounds in the colon.
  • This study shows that red meat consumption is associated with the kind of DNA damage caused by N-nitroso compounds in colon tumor cells. More importantly, this is the kind of damage that can lead to cancer-causing mutations. In addition:
    • The DNA damage occurs in the exact location of the colon predicted from earlier studies.
    • The DNA damage occurs in genes known to drive the conversion of normal colon cells to cancer cells.

In short, this study provides a plausible mechanism for the effect of red meat consumption on increased risk of colon cancer. It shows how red meat can cause colon cancer.

“In the words of the authors, “Our study has leveraged a comprehensive dataset with repeated dietary measures over years…and [DNA sequencing] on a large collection of colorectal tumors. It provides unique evidence supporting the direct impact of dietary behaviors on colorectal carcinogenesis…”

How Can You Decrease Your Risk Of Colon Cancer?

Steak SaladWhen this study is combined with previous studies, it provides a clear explanation of how red and processed meats can cause colon cancer. And, unfortunately, grass-fed beef is not a “Get Out Of Jail Free” card. This mechanism is equally applicable to grass-fed beef and conventionally raised beef.

Does this mean you need to become a vegan? While I have nothing against veganism, the answer appears to be no. As I discussed above whole, unprocessed plant foods are the antidote to the carcinogenic compounds formed from red meat. This is due to:

  • Their fiber, which sweeps some carcinogens out of the intestine before they can be absorbed.
  • Their antioxidants, which prevent some carcinogens from being formed.
  • Their phytonutrients, which block the activation of some carcinogens.
  • The friendly gut bacteria they support, which displace the bad bacteria that form some carcinogen precursors in the intestine.

The good news is that some red meat may be OK in the context of a primarily plant-based diet. For example, 3 ounces of red meat in a green salad or stir fry is less likely to increase your risk of colon cancer than an 8-ounce steak and fries.

The bad news is this is why not all studies have shown an association of red meat consumption and increased risk of colon cancer. Unfortunately, far too many of these studies have ignored other components of the diet.

The Bottom Line

A recent study looked at the effect of red meat consumption on DNA modifications in colon cells that are associated with the conversion of normal cells to cancer cells. It is a highly technical study, but the simplified version is:

  • Previous studies have shown that red meat consumption is associated with an increased risk of colon cancer.
  • Studies have also shown that red meat consumption is associated with an increased concentration of carcinogenic N-nitroso compounds in the colon.
  • This study shows that red meat consumption is associated with the kind of DNA damage caused by N-nitroso compounds in colon tumor cells – the kind of damage that can lead to cancer-causing mutations. In addition:
    • The DNA damage occurs in the exact location of the colon predicted from earlier studies.
    • The DNA damage occurs in genes known to drive the conversion of normal colon cells to cancer cells.

In short, this study provides a plausible mechanism for the effect of red meat consumption on increased risk of colon cancer. It shows how red meat can cause colon cancer.

“In the words of the authors, “Our study has leveraged a comprehensive dataset with repeated dietary measures over years…and [DNA sequencing] on a large collection of colorectal tumors. It provides unique evidence supporting the direct impact of dietary behaviors on colorectal carcinogenesis…”

For more details about this study and how you can eat red meat and still reduce your risk of colon cancer, 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.

Do Whole Grains Keep Diabetes Away?

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Are Whole Grains Healthy? 

Author: Dr. Stephen Chaney

deceptionLow carb enthusiasts will tell you that carbohydrates are the villain. They tell you that cutting carbohydrates out of your diet will reduce your risk of obesity, diabetes, heart disease, and cancer.

If they limited their list of villainous foods to highly processed foods with white flour and/or added sugars, many nutrition experts would agree with them. There is widespread agreement in the nutrition community that we eat far too much of these foods.

However, I don’t have to tell you that many low carb diets also eliminate whole grains, fruits, and beans from their diets based solely on the carbohydrate content of these foods. Is this good advice? Is there any data to back up this claim?

The short answer is no. Last week I shared a study showing that fruits reduced your risk of developing type 2 diabetes.

This week I will review a study looking at the effect of whole grain consumption on the risk of developing type 2 diabetes.

How Was This Study Done?

Clinical StudyThis study combined data from women in the Nurses’ Health Study (1984-2014) and the Nurses’ Health Study II (1991-2017), and men in the Health Professionals Follow-Up Study (1986-2016). There were 158,259 women and 36,525 men in these three studies.

None of the participants had type 2 diabetes, cardiovascular disease, or cancer at the time they entered the studies.

At the beginning of each study and every 4 years later the participants were asked to fill out a food frequency questionnaire to collect information about their usual diet over the past year. Validation studies showed that the diets of the participants changed little over the interval of the studies. [Note: This is a strength of these studies. Many clinical studies only collect dietary data at the beginning of the study, so there is no way of knowing whether the participant’s diets changed over time.]

The participants in these studies were followed for an average of 24 years. They were sent follow-up questionnaires every two years to collect information on diseases they had been diagnosed with over the past two years. Participants who reported type 2 diabetes were sent a supplementary questionnaire to confirm the diagnosis.

This study measured the effect of whole grain consumption, and frequently consumed whole grain foods, on the long term (24 year) risk of developing type 2 diabetes.

The data were adjusted for multiple possible confounding variables (other factors that might affect the risk of developing type 2 diabetes) including age, ethnicity, smoking status, alcohol intake, multivitamin use, healthy eating index (a measure of how healthy the overall diet was), caloric intake, obesity, family history of diabetes, and use of oral contraceptives or postmenopausal hormones.

In addition, a stratified analysis was performed to assess the extent to which obesity, physical activity, smoking status, and family history of diabetes influenced the outcome.

In short, this was a very rigorous and well-controlled study.

Do Whole Grains Keep Diabetes Away?

Whole GrainsTotal whole grain consumption was divided into five groups ranging from 2 servings per day to < 0.1 serving per day. When participants with the highest whole grain intake were compared to those with the lowest whole grain intake:

  • Whole grain consumption was associated with a 29% lower risk of developing type 2 diabetes.
    • The association between whole grain consumption and reduced risk of developing type 2 diabetes was stronger for lean individuals (45% reduction in risk) than for overweight (34% reduction in risk) or obese individuals (23% reduction in risk).
    • The association between whole grain consumption and reduced risk of developing type 2 diabetes was not affected by physical activity, smoking status, or family history of diabetes.

When they looked at the entire range of whole grain intake among participants in the study:

  • The risk reduction for developing type 2 diabetes was nonlinear.
    • The greatest portion of risk reduction (30% decreased risk) occurred between 0 and 2 servings/day.
    • However, the reduction in risk continued to decrease at a slower rate up to 4.5 servings/day (38% decreased risk), the highest intake recorded for participants in this study.

When they looked at the most frequently consumed whole grain foods and compared the risk of developing type 2 diabetes for participants consuming one or more servings per day compared with less than 1 serving per month:

  • People consuming whole grain cold breakfast cereals were 19% less likely to develop type 2 diabetes.
  • People consuming whole grain breads were 21% less likely to develop type 2 diabetes.
  • People consuming popcorn were 8% more likely to develop type 2 diabetes.

Once again, the risk reduction was nonlinear.

  • For whole grain cold breakfast cereals risk reduction plateaued at around 0.5 servings per day.
  • For whole grain breads the greatest portion of risk reduction occurred at around 0.5 servings per day (17% decreased risk), but the reduction in risk continued to decrease at a slower rate up to 4 servings/day (28% decreased risk).
  • For popcorn, the risk reduction curve was non-linear. There was a slight, non-significant, decrease in risk at about 0.2 servings per day, followed by a steady increase in risk up to 1.75 servings per day (24% increased risk).

When they looked at less frequently consumed whole grain foods and compared the risk of developing type 2 diabetes for participants consuming two or more servings per week compared with less than 1 serving per month:

  • People consuming oatmeal were 21% less likely to develop type 2 diabetes.
  • People consuming brown rice were 12% less likely to develop type 2 diabetes.
  • People consuming added bran were 15% less likely to develop type 2 diabetes.

There were not enough people consuming these whole grains for the investigators to determine how many servings were optimal.

The authors concluded, “Higher consumption of total whole grains and several commonly eaten whole grain foods, including whole grain breakfast cereal, oatmeal, whole grain bread, brown rice, and added bran, was significantly associated with a lower risk of type 2 diabetes. These findings provide further support for the current recommendations of increasing whole grain consumption as part of a healthy diet for the prevention of type 2 diabetes.”

Are Whole Grains Healthy?

Question MarkThis is a very impressive study. As described above, it is a large (194,784 participants), long lasting (24 years), and well-designed study. With this data in mind, we can answer several important questions.

Are Whole Grains Healthy?

This study explodes the myth that you should avoid whole grains if you want to prevent diabetes. Instead, the study shows that whole grain consumption decreases your risk of developing type-2 diabetes.

I recently reviewed another large, well-designed study showing that whole grain consumption reduces your risk of dying from heart disease, cancer, and all causes combined.

So, clearly whole grains are good for you. They should be an important part of your diet.

Which Whole Grains Are Healthy?

According to this study, whole grain breakfast cereals, whole grain breads, oatmeal, brown rice, and bran are all healthy. All of them significantly reduce your risk of developing type 2 diabetes. Other whole grains are likely to be healthy too, but Americans consume so little of them, they could not be analyzed in this study.

However, there are some caveats:

  • You have to read labels carefully. Unless it says “100% whole grain”, it probably contains more refined grains than whole grains.
    • Yes, food manufacturers are intentionally deceptive. Who knew?
  • You have to look at the food, not just “whole grain” on the label.
    • It is hard to imagine, but Dr. Kellogg originally created breakfast cereals as health food. However, today many “whole grain” cereals are loaded with sugar and artificial ingredients. They are highly processed foods that are anything but healthy.
    • The case of popcorn is a perfect example. Popcorn is loaded with fiber. It should reduce your risk of diabetes. However, in this study it increased the risk of diabetes. That’s because 70% of the popcorn that Americans consume is purchased either pre-popped or ready to pop. It contains unhealthy ingredients like salt, butter, sugar, trans fats, and artificial flavors. It is a highly processed food. Air popped popcorn without the added ingredients is probably very healthy.

Why Are Whole Grains Healthy?

Dr. Strangelove and his buddies have told you to avoid all grains because they contain carbohydrates that are converted to sugar. That is good advice for refined grains. Not only are they rapidly converted to sugar. But they are also found in highly processed foods along with sugar, fat, and a witch’s brew of chemicals.

However, whole grains are different. Yes, whole grains are carbohydrate-rich foods, and the carbohydrate is converted to sugar during digestion. But:

  • They also contain fiber, which slows the digestion of the carbohydrate and delays the absorption of the sugar released during digestion.
  • The carbohydrate is trapped in a cellular matrix, which must be digested before the carbohydrate can be released.

In addition:

  • Whole grains contain nutrients and phytonutrients not found in refined grains.
  • The fiber in whole grains supports the growth of friendly bacteria in the gut.

How Many Whole Grain Foods Should I Be Eating?

This study found that you get the biggest “bang for your buck” when you go from 0 to around 2 servings per day of whole foods.

  • If you aren’t fond of whole grain foods, that is good news. It is also in line with USDA recommendation that half the grains we eat should be whole grains. You don’t need to eat whole grains with every meal.
  • If you are a purist, you can reduce your diabetes risk even more by increasing your whole grain intake up to at least 4.5 servings per day, the highest intake measured in this study.

Are Low Carb Diets Healthy?

Low carb diets may be effective for short term weight loss, but there is no evidence that they are healthy long term. And, because they cut out one or more food groups many experts feel they are likely to be unhealthy long term.

My advice is to forget “low carb” and focus on “healthy carb” instead.

  • Eliminate refined carbs and the highly processed foods they are found in.
  • Include fruits, whole grains, and beans as part of your diet. They are high carbohydrate foods, but, as this and other studies have shown, the carbohydrates in those foods are healthy carbs.

The Bottom Line

Low carb enthusiasts tell you to eliminate whole grains from your diet if you want to reduce your risk of developing diabetes. Is this true? Is it good advice?

A recent study put this advice to the test. It was a large (194,784 participants), long lasting (24 years), and well-designed study. Here is what the study found.

When participants with the highest whole grain intake were compared to those with the lowest whole grain intake:

  • Whole grain consumption was associated with a 29% lower risk of developing type 2 diabetes.

When they looked at the entire range of whole grain intake among participants in the study:

  • The risk reduction for developing type 2 diabetes was nonlinear.
  • The greatest portion of risk reduction (30% decreased risk) occurred between 0 and 2 servings/day.
  • But the reduction in risk continued to decrease at a slower rate up to 4.5 servings/day (38% decreased risk), the highest intake recorded for participants in this study.

When they looked at individual foods, whole grain breakfast cereals, whole grain bread, oatmeal, brown rice, and added bran all reduced diabetes risk.

The authors concluded, “Higher consumption of total whole grains and several commonly eaten whole grain foods, including whole grain breakfast cereal, oatmeal, whole grain bread, brown rice, and added bran, was significantly associated with a lower risk of type 2 diabetes. These findings provide further support for the current recommendations of increasing whole grain consumption as part of a healthy diet for the prevention of type 2 diabetes.”

For more details about 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.

Should I Avoid Whole Grains?

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Will Whole Grains Kill Me?

Whole GrainsIt seems like just yesterday that health experts all agreed that whole grains were good for us. After all:

  • They are a good source of fiber, B vitamins, vitamin E, and the minerals magnesium, iron, zinc, manganese, and selenium.
  • Their fiber fills you up, so you are less likely to overeat. This helps with weight control.
  • Their fiber also supports the growth of friendly bacteria in your gut.

In fact, the USDA still recommends that half of the grains we eat should be whole grains. And, outside experts, not influenced by the food industry, feel this recommendation is too low. They feel most of the grains we eat should be whole grains. Foods made from refined grains should be considered as only occasional treats.

Then the low-carb craze came along. Diets like Paleo and Keto were telling you to avoid all grains, even whole grains. Even worse, Dr. Strangelove and his colleagues were telling you whole grains contained something called lectins that were bad for you. Suddenly, whole grains went from being heroes to being villains.

You are probably asking, “Should I avoid whole grains?” What is the truth? Perhaps the best way to resolve this debate is to ask, how healthy are people who consume whole grains for many years? This week I share a recent study (G Zong et al, Circulation, 133: 2370-2380, 2016) that answers that very question.

How Was The Study Done?

This study was a meta-analysis of 14 clinical trials that:

  • Enrolled a total of 786,076 participants.
  • Obtained a detailed diet history at baseline.
  • Followed the participants for an average of 15 years (range = 6-28 years).
  • Determined the effect of whole grain consumption on the risk of death from heart disease, cancer, and all causes.

Will Whole Grains Kill Me?

deadDr. Strangelove and his colleagues are claiming that whole grains cause inflammation, which increases your risk of heart disease and cancer. Heart disease and cancer are the leading causes of death in this country. In fact, according to the CDC, heart disease and cancer accounted for 44% of all deaths in the US in 2017.

Therefore, if Dr. Strangelove and his colleagues were correct, consumption of whole grains should increase the risk of deaths due to heart disease and cancer – and increase the risk of death due to all causes.

That is not what this study showed.

When the highest whole grain intake (5 servings/day) was compared with the lowest whole grain intake (0 servings/day), whole grain consumption reduced the risk of death from:

  • Heart disease by 18%.
  • Cancer by 12%.
  • All causes by 16%.

Furthermore, the effect of whole grains on mortality showed an inverse dose response. Simply put, the more thumbs upwhole grains people consumed, the lower the risk of deaths from heart disease, cancer, and all causes.

However, the dose response was not linear. Simply going from 0 servings of whole grains to one serving of whole grains reduced the risk of death from.

  • Heart disease by 9%.
  • Cancer by 5%.
  • All causes by 7%.

The authors concluded: “Whole grain consumption was inversely associated with mortality in a dose-response manner, and the association with cardiovascular mortality was particularly strong and robust. These observations endorse current dietary guidelines that recommend increasing whole grain intake to replace refined grains to facilitate long-term health and to help prevent premature death.”

The authors went on to say: “Low-carbohydrate diets that ignore the health benefits of whole grain foods should be adopted with caution because they have been linked to higher cardiovascular risk and mortality.”

Should I Avoid Whole Grains?

Question MarkAs for the original question, “Should I avoid whole grains?”, the answer appears to be a clear, “No”.

The strengths of this study include the large number of participants (786,076) and the demonstration of a clear dose-response relationship between whole grain intake and reduced mortality.

This study is also consistent with several other studies that show whole grain consumption is associated with a lower risk of heart disease, diabetes, cancer – and appears to lead to a longer, healthier life.

In short, it appears that Dr. Strangelove and the low-carb enthusiasts are wrong. Whole grains aren’t something to avoid. They reduce the risk of heart disease, diabetes, and cancer. And they reduce the risk of premature death. We should be eating more whole grains, not less.

However, the authors did point out that this study has some weaknesses:

  • It is an association study, which does not prove cause and effect.
  • Study participants who consumed more whole grains also tended to consume more fruits and vegetables – and less red meat, sodas, and highly processed foods.

However, I would argue the second point is a strength, not a weakness. We need to give up the idea that certain foods or food groups are “heroes” or “villains”. We know that primarily plant-based diets like the Mediterranean and DASH diets are incredibly healthy. Does it really matter how much of those health benefits come from whole grains and how much comes from fruits and vegetables?

The Bottom Line

Dr. Strangelove and low-carb enthusiasts have been telling us we should avoid all grains, including whole grains. Is that good advice?

If Dr. Strangelove and his colleagues were correct, consumption of whole grains should increase the risk of deaths due to the top two killer diseases, heart disease and cancer. Furthermore, because heart disease and cancer account for 44% of all deaths in this country, whole grain consumption should also increase the risk of death due to all causes.

A recent study showed the exact opposite. The study showed:

When the highest whole grain intake (5 servings/day) was compared with the lowest whole grain intake (0 servings/day), whole grain consumption reduced the risk of death from:

  • Heart disease by 18%.
  • Cancer by 12%.
  • All causes by 16%.

Furthermore, the effect of whole grains on mortality showed an inverse dose response. Simply put, the more whole grains people consumed, the lower the risk of deaths from heart disease, cancer, and all causes.

However, the dose response was not linear. Simply going from 0 servings of whole grains to one serving of whole grains reduced the risk of death from.

  • Heart disease by 9%.
  • Cancer by 5%.
  • All causes by 7%.

The authors concluded: “Whole grain consumption was inversely associated with mortality in a dose-response manner, and the association with cardiovascular mortality was particularly strong and robust. These observations endorse current dietary guidelines that recommend increasing whole grain intake to replace refined grains to facilitate long-term health and to help prevent premature death.”

The authors went on to say: “Low-carbohydrate diets that ignore the health benefits of whole grain foods should be adopted with caution because they have been linked to higher cardiovascular risk and mortality.”

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.

Does Fiber Reduce Breast Cancer Risk?

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Start Young And Finish Strong

Vegan FoodsThe idea that dietary fiber reduces the risk of breast cancer has been around for a long time. But it is controversial. It has been difficult to prove.

Part of the difficulty arises from what scientists call confounding variables. What do I mean by confounding variables? Let me explain.

A high fiber diet is usually a primarily plant-based diet. Plant foods contain much more than just fiber. They are full of antioxidants and phytonutrients. A primarily plant-based diet is, by definition, low in refined grains. It is usually low in sugar and saturated fat as well.

People who eat primarily plant-based diets are often health conscious. They tend to exercise more, weigh less, and smoke less than the general public.

Each of these things are confounding variables. They could reduce the risk of breast cancer on their own. That confounds (makes it more difficult to interpret) the data. Was the reduction in breast cancer risk due to the high fiber diet or to these factors that go along with a high fiber diet?

It is possible to correct for these confounding variables statistically, but that requires a very large study (a large population group) for the correction to be accurate. Large studies are expensive. Thus, you tend to end up with lots of small studies. And once they have been corrected for confounding variables, small studies give conflicting results. Some show a benefit of fiber. Some do not.

That is why this study (MS Farvid et al, Cancer, DOI: 10.1002/cncr.32816) is important. It is a meta-analysis of 20 clinical studies with almost 2 million women.

How Was The Study Done?

Clinical StudyThe meta-analysis combined data from 20 clinical studies with 1,994,910 women. Fiber intake was calculated from a food frequency questionnaire administered at the beginning of the study for all except one study that used 24-hour dietary records administered at the beginning of the study.

  • Study duration ranged from 2 to 20 years. Nine of the studies (1.37 million women) lasted for 10 years or more.
  • Four studies reported results for premenopausal breast cancer, fifteen studies reported results for postmenopausal breast cancer, and one study reported results for both.

Does Fiber Reduce Breast Cancer Risk?

breast cancerAfter correcting for confounding variables, the results of the study were as follows:

  • When comparing the highest intake with the lowest intake, total fiber consumption was associated with an 8% lower risk of breast cancer.
  • The effect was stronger for premenopausal breast cancer (18%) than for postmenopausal breast cancer (9%).
  • The effect was greater with soluble fiber (10% decreased risk) than for insoluble fiber (7% decreased risk).
    • Note: All plant foods contain a mixture of soluble fiber and insoluble fiber. However, the common foods richest in soluble fiber are fruits, oatmeal, nuts, beans, peas, and lentils.

The authors concluded, “A random-effects meta-analysis of prospective observational studies demonstrated that high total fiber consumption was associated with a reduced risk of breast cancer. This finding was consistent for soluble fiber as well as for women with premenopausal and postmenopausal cancer.”

Start Young And Finish Strong

Mother & Daughter Eating ApplesAn 8% risk reduction doesn’t seem like very much, but the 18% risk reduction in premenopausal breast cancer caught my eye. With a little digging I found a study (MS Farvid et al, Pediatrics 137, March 2016: e20151226) that focused on the effect of fiber intake in young women on their subsequent risk developing both premenopausal and postmenopausal breast cancer. This was, in fact, one of the studies included in the meta-analysis I described above.

This study followed 90,534 women (mean age 36 years) for 20 years. The women competed a food frequency questionnaire at enrollment and every four years thereafter. They also completed a questionnaire about their diet during their teenage years.

When comparing the highest versus the lowest fiber intake:

  • High fiber intake reduced total breast cancer risk by 19%.
    • Postmenopausal breast cancer risk was reduced by 13%.
    • Premenopausal breast cancer risk was reduced by 23%.

Interestingly, only 34% of women who consumed high fiber diets during their teenage years continued to consume high fiber diets as young adults. However, high fiber diets in the teenage years were important. When they looked at teenage diets:

  • High fiber intake reduced total breast cancer risk by 16%.
    • Postmenopausal breast cancer risk was reduced by 15%.
    • Premenopausal breast cancer risk was reduced by 25%.

Other important observations from this study were:

  • There was a 13% decrease in breast cancer risk for every 10 gram increase in fiber intake.
    • 10 grams of fiber is equivalent to one apple plus two slices of 100% whole wheat toast or half a cup of cooked kidney beans plus half a cup of cooked cauliflower or squash.
  • Both soluble fiber (14% decreased risk) and insoluble fiber (20% decreased risk) were effective.
    • In terms of foods, the most significant effects were seen with fruits and vegetables.

The authors concluded, “Our findings support the hypothesis that higher fiber intakes reduce breast cancer risk and suggest that intake during adolescence and early adulthood may be particularly important.”

What Does This Mean For You?

Questioning WomanAs I said before, an 8% decrease in breast cancer risk may not sound like much. You might be tempted to say, “Why bother? Why should I give up my favorite processed and convenience foods and switch to a more whole food, plant-based diet?”

Here are some thoughts to consider:

1) As I mentioned above, there are side benefits to a plant-based diet.

    • Plant based diets have a lower caloric density, so you are less likely to be overweight.
    • Your intake of antioxidants and phytonutrients is increased.
    • Plant foods feed beneficial gut bacteria.
    • Your diet is likely to be lower in sugar, highly processed foods, and saturated fat.

All these factors decrease your risk of developing breast cancer, but they were statistically factored out in calculating the 8% reduction in risk. In other words, the 8% reduction in risk was based on fiber intake only. When you consider all the beneficial effects that accompany a high fiber diet, your actual reduction in risk is likely to be substantially more than 8%.

2) When you consume a high fiber diet, your risk of developing premenopausal breast cancer is decreased by 18%. That is twice the risk reduction seen for postmenopausal breast cancer. This is consistent with several other studies showing the premenopausal breast cancer is more influenced by diet than postmenopausal breast cancer. There are a couple of likely explanations for this.

    • By the time they reach menopause women are more likely to be overweight and some of those fat calls accumulate in breast tissue. Those fat cells continue to produce estrogen after menopause. Even worse, that estrogen is produced right next to the breast cells, where it can do the maximum damage.
    • Mutations accumulate in breast tissue as we age, and some of those mutations increase the risk of breast cancer.

3) When you start consuming a healthy, high fiber diet early in life your risk reduction is much greater (a 13-15% decreased risk of developing postmenopausal breast cancer and a 23-25% decreased risk of developing premenopausal breast cancer). Now, we are talking about numbers that should get your attention!

Plus, these numbers are based on fiber intake only. Once again, when you consider all the other benefits of a high fiber diet, your real risk reduction is likely to be much greater.

In closing I should mention that none of the studies were done with fiber supplements. A fiber supplement may help you be more regular, but there is no evidence that a fiber supplement will reduce your risk of breast cancer.

The Bottom Line

Two recent studies have looked at the effect of fiber intake on the risk of developing breast cancer.

The first study showed that:

  • High fiber diets decreased the overall risk of breast cancer by 8% and the risk of premenopausal breast cancer by 18%.
  • As I describe in the article above, these reductions in risk were based on fiber intake only. If you consider all the side benefits of a high fiber diet, the actual risk reduction is likely to be much greater.

The second study looked at fiber intake during adolescence and early adulthood. It found that when high fiber diets were started early in life:

  • High fiber diets decreased the overall risk of breast cancer by 13-15% and the risk of premenopausal breast cancer by 23-25%.
  • Once again, if you consider all the side benefits of a high fiber diet, the actual risk reduction is likely to be much greater.

The authors of both studies concluded that high fiber diets reduce the risk of developing breast cancer. The risk reduction is greater for premenopausal breast cancer than for postmenopausal breast cancer. Finally, the risk reduction is greatest when high fiber diets are started early in life.

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 Foods Affect Stroke Risk?

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Why Is Diet And Stroke Risk So Confusing?

strokeOne day we are told vegetarian diets reduce our stroke risk. The next day we are told they increase stroke risk. It’s the same with red meat, dairy, and eggs. We keep getting mixed messages. It’s enough to make your head spin. Why is diet and stroke risk so confusing?

Part of the problem is that there are two distinct types of stroke. The technical names for them are ischemic stroke and hemorrhagic stroke.

An ischemic stroke occurs when an artery in the brain becomes blocked, shutting off blood flow and damaging part of the brain. This is usually caused by the gradual buildup of fatty deposits and cholesterol plaques in the arteries. When a blood clot forms and lodges in one of the narrowed arteries leading to the brain, an ischemic stroke occurs.

  • Ischemic strokes account for 87% of all strokes.
  • Ischemic strokes are associated with obesity, elevated cholesterol, diabetes, high blood pressure, and smoking.

A hemorrhagic stroke occurs when a weakened blood vessel bursts and bleeds into the surrounding region of the brain. Because our brains are surrounded by a protective skull, that blood has nowhere to go. Pressure from the buildup of blood damages brain cells in the vicinity of the bleed.

  • Hemorrhagic strokes account for only for only 15% of strokes but are responsible for 40% of stroke deaths.
  • The most common cause of a hemorrhagic stroke is the localized enlargement of a blood vessel due to chronic high blood pressure. This weakens the wall of the blood vessel, making it prone to rupturing.

Part of the confusion about diet and stroke risk is because many earlier studies did not distinguish between the two types of stroke.

  • If the studies just measured the incidence of stroke, the data were dominated by ischemic strokes (87% of strokes are ischemic).
  • However, if the studies focused on stroke deaths, hemorrhagic stroke made a larger contribution to the data set (40% of stroke deaths are hemorrhagic).

Fortunately, recent studies have started to focus on the effect of diet on ischemic and hemorrhagic strokes separately. However, many of those studies have been too small to accurately assess the effects of diet on hemorrhagic stroke.

The latest study (TYN Tong et al, European Heart Journal, ehaa007, published February 24, 2020) is one of the largest studies to look at the effect of diet on both kinds of stroke. It has enough patients in the hemorrhagic group to get an accurate estimate of the effect of diet on hemorrhagic stroke.

How Was The Study Done?

Clinical StudyThis study analyzed data on diet and stroke from 418,329 participants in the EPIC (European Prospective Investigation into Cancer and Nutrition). Although the study has cancer in the title, it actually investigated the effect of nutrition on multiple diseases (Presumably, the study title was chosen because EPIC is a more appealing acronym than EPID (European Prospective Investigation into Diseases and Nutrition)).

The participants were recruited from 9 European countries (Denmark, Germany, Greece, Italy, the Netherlands, Norway, Spain, Sweden, and the UK). The average age of participants was 50, and they were followed for an average of 12.7 years.

At the beginning of the study participants completed country-specific dietary and lifestyle questionnaires.

The dietary assessment was a food frequency questionnaire that asked participants about their dietary intake for the year prior to enrollment in the study. The food frequency data were used to estimate daily intake of red meat, processed meat, poultry, fish, dairy products, eggs, grains, fruits, vegetables, legumes, nuts, seeds, and dietary fiber (It measured total fiber and fiber from grains, fruits and vegetables individually).

The outcome measured was the incidence of ischemic and hemorrhagic strokes during the 12.7-year follow-up.

Which Foods Affect Stroke Risk?

Heart Healthy DietFor ischemic stroke:

  • Each 200 gram/day increase in consumption of fruits and vegetables decreased ischemic stroke risk by 13% (200 grams roughly corresponds to one large apple or one large orange without the skin).
  • Each 10 gram/day increase in consumption of fiber decreased ischemic stroke risk by 23%. Most of this decreased stroke risk was due to fiber from whole grains, fruits, and vegetables.
    • Each 4 gram/day increase in fiber from whole grains decreased ischemic stroke risk by 10%.
    • Each 4 gram/day increase in fiber from fruits and vegetables decreased ischemic stroke risk by 12%.
  • Dairy foods decreased ischemic stroke risk with the following breakdown:
    • Each cup of milk decreased ischemic stroke risk by 5%.
    • Each half cup of yogurt decreased ischemic stroke risk by 9%.
    • Each ounce of cheese decreased ischemic stroke risk by 12%.
  • Each 50 grams/day (2 ounces) of red meat increased ischemic stroke risk by 14%.
    • However, red meat was only half as likely to increase risk of ischemic stroke when the diet was also rich in fruits, vegetables, whole grains, and legumes.

For hemorrhagic stroke:

  • Each 20 gram/day increase in consumption of eggs increased hemorrhagic stroke risk by 25% (20 grams roughly corresponds to about 1/2 of a small egg or 1/3 of a jumbo egg).
  • This study did not measure the effect of salt intake on hemorrhagic stroke risk.

No other foods measured in this study had a significant effect on hemorrhagic stroke risk.

high blood pressureHowever, hemorrhagic stroke is highly associated with high blood pressure. When we look at the influence of foods on high blood pressure, here are the Harvard School of Medicine recommendations for keeping blood pressure low:

  • Eat more fish, nuts and beans in place of high-fat meats.
  • Choose fruits and vegetables instead of sugary, salty snacks and desserts.
  • Select whole grains rather than refined grains.Eat fruit instead of drinking fruit juice.
  • Use unsaturated fats like olive, canola, soybean, peanut, corn or safflower oils instead of butter, coconut oil, or palm-kernel oil.
  • Use herbs, spices, vinegar, and other low-sodium flavorings instead of salt; Choose low-sodium foods whenever possible.

Why Is Diet And Stroke Risk So Confusing?

egg confusionAs I mentioned at the start of this article, part of the reason that the headlines about diet and stroke risk are so confusing is:

  • Many studies did not distinguish between the two types of stroke.
  • Other studies were too small to reliably estimate the effect of food on hemorrhagic stroke risk.

However, there are still some unexplained inconsistencies among recently published studies. It is these inconsistencies I would like to address. For example:

1) In a recent issue of Health Tips From the Professor I reported on a major study (500,000 people followed for 8.9 years) in China. That study came to the opposite conclusion about eggs and risk of hemorrhagic than the EPIC study I discussed above. It found:

  • People consuming one egg per day had a 26% decrease in hemorrhagic stroke risk and a 28% decrease in hemorrhagic stroke deaths compared to people who never or rarely consumed eggs.

In other words, the two studies came to opposite conclusions. In the China study eggs decreased risk of hemorrhagic stroke. In the European study (EPIC) eggs increased risk of hemorrhagic stroke. The reason for this discrepancy is not clear, but one can speculate it might be explained by differences in the underlying diets of the two countries:

  • In China the diet is primarily plant-based. The addition of an egg/day may provide needed protein, fat, and cholesterol (Some cholesterol is essential. We just overdo it in this country).
  • In Europe the diet is already high in protein, saturated fat, and cholesterol. Getting more of them from eggs may not be such a good thing.

In short, if your diet is primarily plant-based, the addition of an egg/day may be a good thing. However, if your diet is already high in meat, saturated fat, and cholesterol, the addition of an egg/day may not be a good thing.

Vegan Foods2) In another recent issue of Health Tips From the Professor I reported on the EPIC-Oxford study that claimed vegetarians had 20% increased risk of hemorrhagic stroke compared to meat eaters.

Interestingly, the EPIC-Oxford study represented a very small portion (~10%) of the overall EPIC study and differed from the rest of the EPIC study in two important ways.

  • It looked at the effect of diets rather than foods on stroke risk.
  • Oxford was the only one of the 22 research centers involved in the EPIC study to invite people following a vegetarian diet to enroll in the study, so it had a much higher proportion of vegetarians than other centers that participated in the study.

The current study did not find any evidence that fruits, vegetables, nuts, seeds, beans, or whole grains influenced the risk of hemorrhagic stroke. In other words, in this much larger data set there was no evidence that the foods associated with a vegetarian diet increased hemorrhagic stroke risk.

However, most of the participants in larger EPIC study were also eating meats. They were not following a pure vegetarian diet.

As I said previously, “If the data on hemorrhagic stroke risk in the EPIC-Oxford study are true, it suggests it may not be a good idea to completely eliminate meat from our diet. However, you don’t need to add much meat to a vegetarian diet. The fish eaters in this study were consuming 1.4 ounces of fish per day. That was enough to eliminate the increased risk of hemorrhagic stroke.”

What Does This Mean For You?

Questioning WomanFor ischemic stroke (blockage of blood flow to the brain), which is the most common form of stroke, the data are clear cut:

  • Fruits, vegetables, whole grains and dairy foods are good for you. (Your mother was right.)
  • Red meat is not so good for you. However, the bad effect of red meat on ischemic stroke risk can be reduced by including plenty of fruits, vegetables, and whole grains in your diet.
  • These conclusions are consistent with multiple previous studies, and the mechanisms of these effects are well established.

For hemorrhagic stroke (bleeding from a weakened blood vessel in the brain) the data are not as clear cut.

  • If you are consuming a primarily plant-based diet, eggs appear to reduce your risk of hemorrhagic stroke.
  • If you are consuming a diet with lots of meat, saturated fat, and cholesterol, adding eggs may increase your risk of hemorrhagic stroke.
  • A vegetarian diet may increase your risk of hemorrhagic stroke. But you don’t need to add much meat to a vegetarian diet. Consuming 1.4 ounces of fish per day appears to be enough to eliminate the increased risk of hemorrhagic stroke.
  • The mechanisms of these effects of food on hemorrhagic stroke are unclear, so these conclusions may be modified by subsequent studies.

In terms of an overall take-home lesson on diet and stroke risk, my advice is: “A primarily plant-based diet is a good idea, but you don’t need to become a vegan purist. Nor do you want to follow fad diets that eliminate whole food groups. We have 5 food groups for a reason. Eliminating any of them may not be a good idea.”

The Bottom Line

A recent study examined the effect of various foods on the risk of the two major forms of stroke.

For ischemic stroke (blockage of blood flow to the brain), which is the most common form of stroke, the data are clear cut:

  • Fruits, vegetables, whole grains and dairy foods are good for you. (Your mother was right.)
  • Red meat is not so good for you. However, the bad effect of red meat on ischemic stroke risk can be reduced by including plenty of fruits, vegetables, and whole grains in your diet.
  • These conclusions are consistent with multiple previous studies, and the mechanisms of these effects are well established.

For hemorrhagic stroke (bleeding from a weakened blood vessel in the brain) the data are not as clear cut.

  • If you are consuming a primarily plant-based diet, eggs appear to reduce your risk of hemorrhagic stroke.
  • If you are consuming a diet with lots of meat, saturated fat, and cholesterol, adding eggs may increase your risk of hemorrhagic stroke.
  • A vegetarian diet may increase your risk of hemorrhagic stroke. But you don’t need to add much meat to a vegetarian diet. Consuming 1.4 ounces of fish per day appears to be enough to eliminate the increased risk of hemorrhagic stroke.
  • The mechanisms of these effects of food on hemorrhagic stroke are unclear, so these conclusions may be modified by subsequent studies.

In terms of an overall take-home lesson on diet and stroke risk, my advice is: “A primarily plant-based diet is a good idea, but you don’t need to become a vegan purist. Nor do you want to follow fad diets that eliminate whole food groups. We have 5 food groups for a reason. Eliminating any of them may not be a good idea.”

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.

 

Health Tips From The Professor