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Eating For A Healthy Heart

February 11, 2025 by Dr. Steve Chaney

What Does This Mean For You?

Author: Dr. Stephen Chaney

You may remember the nursery rhyme, “Jack Sprat could eat no fat. His wife could eat no lean…” You may know people who fit these extremes. And in terms of diets these extremes might represent the vegan and keto diets in today’s world.

The nursery rhyme assures us that, “…between them they licked the platter clean.” But were their diets equally healthy? Which of them would have been more likely to live a long and healthy life?

And, since this is Heart Health Month, we might ask, “Which diet would have been better for their hearts?”

If you search Mr. Google – even with AI assist – you might be confused. That’s because AI bases its recommendations on the quantity of posts, not the accuracy of posts. And lots of media influencers recommend both diets, and just about every popular diet in between for heart health.

But what does good science say on the topic of heart healthy diets? Fortunately, a recent comprehensive review and meta-analysis (G. Riccardi et al, Cardiovascular Research, 118: 1118-1204, 2022) has answered that question.

How Was The Study Done?

The investigators reviewed 99 clinical studies with tens of thousands of participants that looked at the associations between foods or food groups and heart disease risk.

Most of the studies were “prospective cohort” studies in which:

Populations are divided into groups (cohorts) based on the foods they consume…

…and followed for a number of years (this is where the term “prospective” comes from)…

…and at the end of the study, the association between food and heart outcomes is measured.

However, the review also included several major randomized controlled clinical trials, including:

The DASH diet study.
The Lyon Diet Heart study.
The PREDIMED study.

Eating For A Healthy Heart

Here are the findings of the study. Most will sound very familiar. But you will note some subtle differences based on recent data.

The overall summary was that for a healthy adult population:

Low consumption of salt and foods of animal origin…

…and increased intake of plant foods…

…are associated with reduced heart disease risk.

Of course, we have known that for years. It’s when they broke the data down further that it became more interesting.

Foods Of Animal Origin:

Processed meats increase heart disease risk. A single serving of processed meat is associated with a 27% to 44% increased risk of heart disease. This is not new.

Unprocessed red meat is also associated with increased risk of heart disease, but this association is not as consistent as for processed meats. The authors noted that some of this may be due to differences in saturated fat content or cooking methods of the red meats included in individual studies.

But this analysis also showed that the effect of red meat on heart disease risk may be dose dependent. For example:

- The studies they reviewed suggested that consuming ≥2 servings per day of red meat is associated with a 27% increased risk of heart disease. However, consuming <3 servings per week may not increase risk.

- The idea that the effect of red meat on heart disease risk may be dose-dependent is novel. However, the authors said we also need to ask what replaces red meat in the diet. They postulated that when red meat consumption is decreased, it is often replaced with healthier protein sources.

White meat such as poultry does not appear to affect heart disease risk. This has been predicted by earlier reports, but this analysis strengthens those predictions.

Fish consumption decreases heart disease risk. This is not new. But this review added precision about recommended fish intake (2-4 servings/week) and a couple of caveats:

- The heart benefits of fish may be due to their omega-3 content and may not apply equally to fish with lower omega-3 content.

- The authors also expressed concerns about the sustainability of high-omega-3 fish populations. I would also add that our oceans are increasingly polluted, so contamination is another concern.

Egg consumption up to one egg/day does not appear to increase heart disease risk. This is consistent with the current American Heart Association recommendations.

However, the authors noted that the effect of eggs on serum cholesterol, and hence heart disease risk depends on several factors.

- Genetics, obesity, and diabetes can make it more difficult to regulate serum cholesterol levels. For these individuals, eggs may need to be eaten only sparingly.

- Diets low in saturated fat and high in fiber from plant foods help the body regulate serum cholesterol. Several studies suggest that eggs may decrease heart disease risk in the context of this type of diet.

Dairy: Neither low-fat nor high-fat dairy foods appear to influence heart disease risk. This is different from the standard recommendation to consume low-fat dairy foods. But it is in line with the trend of recent research studies on dairy and heart disease.

Once again, there were a couple of caveats:

- There is increasing evidence that fermented dairy foods may decrease heart disease risk which may explain why certain high-fat cheeses and other high-fat fermented dairy foods appear to have a neutral or slightly beneficial effect on heart disease risk.

- As with eggs the effect of high-fat dairy foods on heart disease risk may be influenced by genetics and diet context.

Foods Of Plant Origin: The effect of plant foods have been known for some time, and the most recent studies included in this analysis have not changed those conclusions.

Fruits and Vegetables consistently reduce heart disease risk in multiple studies. In each case, the optimal intake appears to be about 2 servings of each per day which provides an 18-21% risk reduction for vegetables and a 21-32% risk reduction for fruits.

Legumes (beans and peas) also consistently reduce heart disease risk in multiple studies. At the optimal intake of around 4 servings per week the risk reduction is around 14%.

Nuts also consistently reduce heart disease risk. At the optimal intake of around one serving (a handful) per day, the risk reduction is around 25%.

Cereals (grains) were divided into 3 categories:

- Refined carbohydrates with a high glycemic index (e.g., white rice, white bread) are associated with increased heart disease risk in multiple studies probably due to their effect on blood sugar levels. And the increased risk is significant (Around 66% higher risk for every 2 servings).

- Refined carbohydrates with a low glycemic index (e.g., pasta, corn tortillas) show an inconsistent effect on heart disease risk.

- Whole grains are consistently associated with a lower heart disease risk. Two servings of whole grains per day are associated with a 25%-34% decreased risk.

Miscellaneous Foods:

Soft Drinks are associated with increased heart disease risk. One serving per day increases the risk by around 15-22% and recent evidence suggests that artificially sweetened soft drinks offer no heart health benefits compared to sugar sweetened soft drinks.

Coffee and Tea are both associated with decreased heart disease risk. For coffee the optimal benefit may occur at around 3 cups/day. Higher levels may have an adverse effect on heart disease risk.

Summary of Heart Health Recommendations

If you are thinking that was a lot of information, the authors provided a numerical summary of their recommendations for a heart-healthy diet. They are:

Two servings per day of vegetables, fresh fruits, and whole grains.

One serving per day of nuts and seeds, low-glycemic index refined cereals, extra-virgin olive oil or non-tropical vegetable oils, and yogurt.

Four servings per week of legumes and fish.

No more than 3 servings per week of white meat, eggs, cheese, and milk.

No more than 2 servings per week of high-glycemic index refined starchy foods, red meat, and butter.

Only occasional consumption of processed meats.

What Does This Study Mean For You?

Of course, nobody wants to follow a “diet by the numbers”. If you are like most of us, you want flexibility and you want to be able to eat some of your favorite foods. So, let me put these recommendations into a more “user friendly” form.

If you want a healthy heart:

Whole, unprocessed or minimally processed, plant foods are your friends.

Your heart-healthy foundation should be fruits, vegetables, whole grains, nuts and seeds, healthy plant oils, and legumes.

Your heart-healthy foundation can also include fermented dairy foods and low-glycemic index refined grains.

Your “go-to” beverages should be water, tea (both caffeinated and herbal teas), and coffee. You should avoid soft drinks and other sugar-sweetened or artificially sweetened beverages.

Once you have achieved a heart-healthy foundation you can add a few servings per week of white meat, eggs, cheese, and dairy, even high-fat dairy.

If you have good adherence to the heart-healthy foundation described above and no genetic or health issues that increase your risk of heart disease, you can probably eat more of these foods.

Conversely, if your adherence to the heart-healthy foundation is poor and/or you are at high risk of heart disease, you may wish to consume less of these foods.

If you have good adherence to the heart-healthy foundation, you can also add up to 1-2 servings of high-glycemic index refined carbohydrates, red meat, or butter per week. With red meat, you may want to consider it as a garnish that adds flavor to a plant-based meal rather than the centerpiece of the meal.

You should eat processed meats seldom or never.

The Bottom Line

A new comprehensive review and meta-analysis of 99 clinical studies with tens of thousands of participants has updated the correlation between foods and heart disease risk.

Many of the recommendations based on this analysis are identical to previous recommendations for a heart-healthy diet.

But there are some subtle changes to those recommendations based on the latest data.

For more details about this study and what a heart-healthy diet might look like 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.

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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

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About The Author

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

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

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

Does Processed Food Give You Gas?

August 23, 2022 by Dr. Steve Chaney

Why Does Processed Food Give You Gas?

Author: Dr. Stephen Chaney

Does it feel like a war is going on in your belly every time you eat? It could be IBD (inflammatory bowel disease). IBD can take several forms, but the two most common are Crohn’s disease and ulcerative colitis.

What do we know about IBD?

The symptoms of IBD can make you miserable. They include:

- Abdominal pain and cramping.

- Diarrhea with occasional bouts of constipation.

- Gas and bloating.

- Loss of appetite and/or unexpected weight loss.

There are about 1.6 million Americans with IBD and 70,000 new cases/year.

- The prevalence of IBD in the United States has increased by 34% between 2006 and 2016.

As you might suspect from its name, IBD is a chronic inflammation of the gastrointestinal tract.

- It is thought to be caused by “dysbiosis of the gastrointestinal track” (In layman’s terms that means damage to your intestine caused by too many bad bacteria and not enough good bacteria).

- There is also a genetic component to the disease. Some people are much more susceptible to IBD than others.

If you watch TV, you know that there are drugs for treating IBD. The ads make them sound like miracle drugs. But if you listen carefully, you also know that these drugs have a long list of side effects. And some of the side effects are pretty scary.

Are There Natural Approaches For Controlling IBD?

So, if your belly is a bit rumbly, you might be wondering if there is a more natural approach you could take. We know that diet affects the balance between bad and good bacteria in our intestine. Could something as simple as changing your diet, quell the fire in your belly?

While the answer seems obvious, it has been hard to prove. The results of previous studies have been inconclusive. That is because previous studies:

Included too few people. 1.6 million people in the US with IBD may sound like a lot, but that represents only 0.4% of the population. Unless you have a really big study, there won’t be enough people who develop IBD to give you statistically significant results.

Were too short. IBD doesn’t develop overnight.

Did not include a diverse enough population. Previous studies were confined to individual countries or specific regions within a country.

This study (N Narula et al, British Medical Journal, 2021;374:n1554) was designed to overcome the limitations of previous studies. It also looked at the effect of diet on IBD from a different perspective than most previous studies.

It did not focus on the effect of individual foods on IBD. Since consumption of processed foods is known to affect the population of intestinal bacteria, the authors of this study asked whether processed food consumption might influence the likelihood of developing IBD.

How Was The Study Done?

The authors of this study used data collected from the PURE (Prospective Urban Rural Epidemiology) study between January 1, 2003, and December 31, 2016. The PURE study collected data from a very diverse population. Specifically, it collected data from 21 low-, middle-, and high-income countries across 7 geographical regions (Europe, North America, South America, Africa, Middle East, South Asia, Southeast Asia, and China).

This study followed 116,087 adults aged 35-70 years (average age 50, percent women = 60%) in the PURE study for an average of 9.7 years. During that time, 467 participants (0.4%) developed IBD.

All participants filled out a baseline food-frequency questionnaire that had been designed and validated for foods specific to their country.

Participants were asked if they had a diagnosis of Crohn’s disease or ulcerative colitis as part of an annual follow-up questionnaire. To assure the accuracy of these answers they were validated with medical records whenever possible.

Does Processed Food Give You Gas?

Does processed food give you gas? Does it give you abdominal pain, diarrhea, and bloating? In short, does it give you IBD? That is the question this study was designed to answer. Here are the results of the study:

When comparing those eating the most processed food (≥5 servings/day) to those consuming the least (≤1 serving/day), processed food consumption increased the risk of developing IBD by 1.82-fold. This finding was equally true for:

- Both Crohn’s disease and ulcerative colitis.

- Adults <50 and adults >50.

- Every region of the world included in the PURE study.

When the investigators looked at different categories of processed foods:

- Processed meat intake increased the risk of IBD by 2.07-fold.

- Soft drink intake increased the risk of IBD by 1.94-fold.

- Refined sweetened food intake increased the risk of IBD by 2.58-fold.

- Salty food and snack intake increased the risk of IBD by 2.06-fold.

When the investigators looked at different categories of unprocessed foods:

- White meat, red meat, dairy, starchy foods, fruits, vegetables, and legumes had no effect on the risk of developing IBD.

- Sodium intake (as measured by urinary excretion of sodium) also had no effect on the risk of developing IBD.

Why Does Processed Food Give You Gas?

You may be wondering why does processed food give you gas – and other symptoms of IBD.

The simplest explanation is that whole grains, unprocessed fruits & vegetables, and legumes provide the fiber that supports the growth of friendly gut bacteria. Processed foods displace these foods from our diet.

But these investigators think something else about processed foods may be contributing to the increased risk of IBD. That is because in their study:

Processed meat increased the risk of IBD, but unprocessed white and red meat had no effect on IBD.

Processed sweetened foods increased the risk of IBD, but unprocessed starchy foods and naturally sweet fruits had no effect on IBD.

Processed salty foods and snacks increased the risk of IBD, but sodium intake had no effect on IBD.

The investigators also noted that in mouse studies:

Some food additives found in processed foods cause bacteria to stick to the epithelial lining of the intestine and/or cause leaky gut syndrome, both of which can lead to chronic inflammation of the intestine.

The investigators concluded, “In this study, higher ultra-processed food intake was associated with a higher risk of IBD.”

They went on to say, “As white meat, unprocessed red meat, dairy, starchy foods, fruits, vegetables, and legumes were not found to be associated with development of IBD, this study suggests that it may not be the food itself that confers this risk but rather the way the food is processed or ultra-processed…Further studies are needed to identify specific potential contributing factors among processed foods that might be responsible for the observed associations in our study.”

[Note: This is a fancy way of saying that the detrimental effects of processed foods may be due to more than the fact that they displace healthier foods from the diet. It may also be due to the effect of food additives on the risk of developing IBD.]

What Does This Study Mean For You?

IBD is a rare disease (0.4% of the population). If you don’t have digestive issues, it would be easy to ignore this study and continue with a diet of highly processed foods.

However, I would remind you that in recent issues of “Health Tips From the Professor”, I have shared recent studies showing that highly processed foods increase your risk of:

Obesity.

Diabetes.

Cancer.

And these studies are just the tip of the iceberg. We know that diets rich in whole grains and unprocessed fruits and vegetables decrease the risk of heart attack, stroke, and Alzheimer’s disease. And a diet rich in whole grains, fruits, and vegetables is the antithesis of a processed food diet.

The evidence is overwhelming. Highly processed foods may be convenient and tasty. But if you value your health, they are not your friends.

The Bottom Line

A recent study looked at the effect of consuming processed foods on the risk of developing inflammatory bowel disease (IBD). The study found:

When comparing those eating the most processed food (≥5 servings/day) to those consuming the least (≤1 serving/day), processed food consumption increased the risk of developing IBD by 1.82-fold. This finding was equally true for:

- Both Crohn’s disease and ulcerative colitis.

- Adults <50 and adults >50.

- Every region of the world included in the study.

The investigators concluded, “In this study, higher ultra-processed food intake was associated with a higher risk of IBD.”

They went on to say, “…This study suggests that it may not be the food itself that confers this risk but rather the way the food is processed or ultra-processed…Further studies are needed to identify specific potential contributing factors among processed foods that might be responsible for the observed associations in our study.”

[Note: This is a fancy way of saying that the detrimental effect of processed foods may be due to more than the fact that they displace healthier foods from the diet. It may also be due to the effect of food additives commonly found in processed foods on the risk of developing IBD.]

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

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

Does Red Meat Cause Frailty In Older Women?

May 31, 2022 by Dr. Steve Chaney

Which Proteins Are Best?

Author: Dr. Stephen Chaney

The ads from the meat lobby say, “Red meat does a body good”. Are the ads true?

If we consider the health consequences of regularly eating red meat, the answer appears to be a clear, “No”. Multiple studies have shown a link between red meat consumption and:

Coronary heart disease.
Stroke
Type 2 diabetes.
Colon cancer, prostate cancer, and breast cancer.

And, if we consider the environmental consequences of red meat production, the answer also appears to be, “No”. I have discussed this in a recent issue of “Health Tips From the Professor”.

But what about muscle mass and strength? Red meat is a rich source of protein, and we associate meat consumption with an increase in muscle mass. Surely, red meat consumption must help us build muscle mass and strength when we are young and preserve muscle mass and strength as we age.

This is why the recent headlines claiming that red meat consumption increases the risk of frailty in older women were so confusing. I, like you, found those headlines to be counterintuitive. So, I have investigated the study (EA Struijk et al, Journal of Cachexia, Sarcopenia and Muscle, 13: 210-219, 2022) behind the headlines. Here is what I found.

How Was The Study Done?

This study utilized data acquired from the Nurses’ Health Study (NHS). The NHS began in 1976 with 121,700 female nurses aged 30 to 55. This study followed 85,871 nurses in the NHS once they reached age 60 for an average of 14 years.

Dietary intake was assessed using a food frequency questionnaire that was administered to all participants in the study every four years between 1980 and 2010. The long-term intake of red meat and other protein sources was based on a cumulative average of all available diet questionnaires for each participant.

The participants also filled out a Medical Outcomes Short Report every four years between 1992 and 2014. Data from this survey was used to calculate something called the FRAIL scale, which includes the following frailty criteria:

Fatigue

Low muscle strength.

Reduced aerobic capacity.

Having ≥5 of the following chronic diseases:

- Cancer
- High blood pressure
- Type 2 diabetes
- Angina
- Myocardial infarction (heart attack)
- Congestive heart failure
- Asthma
- COPD (chronic obstructive pulmonary disease)
- Arthritis
- Parkinson’s disease
- Kidney disease
- Depression

Greater than ≥5% weight loss in two consecutive assessments.

Frailty was defined as having met 3 or more criteria in the FRAIL scale. The study looked at the effect of habitual consumption of red meat or other protein sources on the development of frailty during the 14-year follow-up period.

Does Red Meat Cause Frailty In Older Women?

The investigators separated the participants into 5 quintiles based on total red meat consumption, unprocessed red meat construction, or processed red meat consumption. The range of intakes was as follows.

Total red meat: 0.4 servings per day to 1.8 servings per day.

Unprocessed red meat: 0.3 servings per day to 1.3 servings per day.

Processed red meat: 0.04 servings per day to 0.6 servings per day.

Clearly none of the women in this study were consuming either vegan or keto diets. As might be expected from a cross-section of the American public, there was a fairly narrow range of daily meat consumption.

Here are the results of the study:

Each serving per day of total red meat increased frailty by 13%.

Each serving per day of unprocessed red meat increased frailty by 8%.

Each serving per day of processed red meat increased frailty by 26%.

When each component of the frailty index was examined individually, all of them were positively associated with red meat consumption except for weight loss.

This was perhaps the most unexpected finding of the study. Not only did red meat consumption increased the risk of chronic diseases in these women, which would be expected from many previous studies. But red meat consumption also made these women more tired, weaker, and shorter of breath.

The authors concluded, “Habitual consumption of any type of red meat was associated with a higher risk of frailty.”

Which Proteins Are Best?

The investigators then asked if replacing one serving/day of red meat with other protein sources was associated with a significantly lower risk of frailty. Here is what they found:

Replacing one serving per day of unprocessed red meat with a serving of:

- Fish reduced frailty risk by 22%.

- Nuts reduced frailty risk by 14%.

Replacing one serving per day of processed red meat with a serving of:

- Fish reduced frailty risk by 33%

- Nuts reduced frailty risk by 26%

- Low-fat dairy reduced frailty risk by 16%

- Legumes reduced frailty risk by 13%.

The authors concluded, “Replacing red meat with another source of protein including fish, nuts, legumes, and low-fat dairy may be encouraged to reduce the risk of developing frailty syndrome. These findings are in line with dietary guidelines promoting diets that emphasize plant-based sources of protein.” [I would note that fish and low-fat dairy are hardly plant-based protein sources.]

What Does This Study Mean For You?

I am not yet ready to jump on the “eating red meat causes frailty” bandwagon. This is a very large, well-designed study, but it is a single study. It needs to be replicated by future studies.

And, as a biochemist, I am skeptical about any study that does not offer a clear metabolic rationale for the results. As I said earlier, increased protein intake is usually associated with an increase in muscle mass when we are young and a preservation of muscle mass as we age. There is no obvious metabolic explanation for why an increase in red meat consumption in older women would cause a decrease in muscle mass and other symptoms of frailty.

On the other hand, there are plenty of well documented reasons for decreasing red meat intake. Consumption of red meat is bad for our health and bad for the health of the planet as I have discussed in an earlier issue of “Health Tips From the Professor”. And substituting other protein sources, especially plant proteins, is better for our health and the health of our planet.

Finally, we also need to consider the possibility that this study is correct and that future studies will confirm these findings. Stranger things have happened.

As we age, we begin to lose muscle mass, a process called sarcopenia. Increased protein intake and resistance exercise can help slow this process. While I am not ready to say that red meat causes decreased muscle mass, I do think this study should make us think about which protein sources we use to prevent sarcopenia. At the very least we should not use age-related muscle loss as an excuse to increase our red meat intake. That might just be counterproductive.

The Bottom Line

A recent study looked at the effect of red meat consumption on frailty in older women. It came to the unexpected conclusion that:

Each serving per day of total red meat increased frailty by 13%.

Each serving per day of unprocessed red meat increased frailty by 8%.

Each serving per day of processed red meat increased frailty by 26%.

The increase in frailty could be reduced by replacing one serving/day of red meat with a serving of fish, nuts, low-fat dairy, or legumes.

I am not yet ready to jump on the “eating red meat causes frailty” bandwagon. This is a very large, well-designed study, but it is a single study. It needs to be replicated by future studies. And, as a biochemist, I am skeptical about any study that does not offer a clear metabolic rationale for the results.

On the other hand, there are plenty of well documented reasons for decreasing red meat intake. Consumption of red meat is bad for our health and for the health of the planet.

Finally, we also need to consider the possibility that this study is correct and that future studies will confirm these findings. Stranger things have happened.

As we age, we begin to lose muscle mass, a process called sarcopenia. Increased protein intake and resistance exercise can help slow this process. This study should make us think about which protein sources we use to prevent sarcopenia. At the very least we should not use age-related muscle loss as an excuse to increase our red meat intake. That might just be counterproductive.

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.