Is It Too Late To Change Your Diet?

You Can Improve Your Health At Any Age

Author: Dr. Stephen Chaney

Fast Food ExamplesIf you are like most Americans, your dietary preferences as an adult are based on the foods your family ate while you were growing up.

  • Your favorite foods…
  • Your comfort foods…
  • The foods you always avoid…

…are based on your family heritage, not on your genes. And if you are like most Americans, your diet isn’t healthy.

  • It’s high in fat and cholesterol…
  • It’s high in sugar and refined carbohydrates…
  • It’s high in processed foods…
  • It’s low in whole, unprocessed foods…
  • It’s high in calories, so your waistline keeps growing.

You know your diet isn’t healthy, but you keep coasting along through your 30’s and 40’s until…the unthinkable happens. You are diagnosed with a deadly disease, like heart disease, high blood pressure, or diabetes, and your doctor says that unless you change your diet, you are doomed to a short unhealthy life. You have reached a fork in Food Choicesthe road.

Changing the diet you grew up with, the diet you love, is a daunting task. It’s tempting to think, “Why bother…

  • It’s probably too late to change my diet…
  • The damage has already been done…
  • I can’t reverse it now.”

If this scenario describes you or someone you love, you aren’t alone. There are millions of Americans just like you. You want to know whether changing your diet is worth the trouble. You want to know whether it is too late, or whether you can still change your health for the better.

Most clinical studies don’t answer this question. Most clinical studies do a diet assessment at the beginning of the study and look at health outcomes 20 or 30 years later. If they do more than one diet assessment during the study, the purpose of these assessments is to show that most people stick to the same diet throughout the study.

These studies measure the effect of habitual diets on health outcomes. They tell you that good diets lead to good health outcomes, and bad diets lead to bad health outcomes. But they don’t tell you whether changing your diet from bad to good in your 30’s or 40’s can have a significant effect on your health.

Fortunately, a recent study has answered this question. This study (Y Choi et al, Journal of The American Heart Association, 10e020718, 2021) started with people in their mid-20s. It looked at whether changing their diet from bad to good in their 30s and 40s had any effect on their risk of developing heart disease in their 50s and 60s.

How Was This Study Done?

Clinical StudyThe data for this study were obtained from the CARDIA study (Coronary Artery Risk Development in Young Adults). The study enrolled 4946 young adults (average age = 25, 55% female and 45% male, 50% black and 50% white) and followed them for 32 years (average age of participants at the end of the study = 57).

Diet was assessed by a trained interviewer at year 0, year 7 (average age of participants = 32), and year 20 (average age of participants = 45).

Adherence of the participants to a healthy, plant-centered diet was assessed using an analytical tool called APDQS that divided the foods eaten by the participants into 3 groups based on their known influence on heart disease:

1) Beneficial.

    • These foods included fruit, avocado, beans/legumes, green vegetables, yellow vegetables, tomatoes, other vegetables, nuts and seeds, soy products, whole grains, vegetable oil, fatty fish, lean fish, poultry, moderate alcohol, coffee, tea, and low-fat milk/cheese/yogurt.
    • This is what the investigators considered a plant-centered diet. It encompasses diets ranging from vegan to Mediterranean and DASH.

2) Adverse.

    • These foods included fried potatoes, refined grain desserts, salty snacks, pastries, sweets, high-fat red meats, processed meats, organ meats, fried fish/poultry, sauces, soft drinks, whole fat milk/cheese/yogurt, and butter.
    • This could be considered a typical American diet.

3) Neutral.

    • These foods included potatoes, refined grains, margarine, chocolate, meal replacements, pickled foods, lean meats, shellfish, eggs, soups, and fruit juices.
    • These foods are not the healthiest, but the evidence that they have a negative effect on health disease risk is inconclusive.

The participants were divided into 5 quintiles based on adherence to a plant-centered diet, with quintile 1 having the lowest adherence and quintile 5 having the highest adherence to a plant-centered diet.

The effect of diet on heart disease was measured in two ways:

1) The dietary data from years 0, 7 and 20 were averaged and the effect of average adherence to a plant-centered diet on the risk of developing heart disease by the time the participants were 57 was measured. This is similar to the design of most other studies looking at the effect of diet and heart disease.

2) The effect of an improvement in adherence to a plant-centered diet between ages of 32 and 45 on the risk of developing heart disease by age 57 was also measured. This is what makes this study unique. Basically, the investigators were asking if you could eat a bad diet for 30 years or more and still reduce your risk of heart disease by switching to a good diet by the age of 45. That is the question that millions of American are asking themselves right now.

Is It Too Late To Change Your Diet?

Heart Healthy DietAs I described above this study asked two distinct questions:

1) What effect does your habitual diet have on your risk of developing heart disease?

For this portion of the study, the investigators averaged the dietary data collected in years 0, 7, and 20 of the study and ranked the participants diet from 1 to 5 based on their adherence to a plant-centered diet. When they compared the group with best adherence (group 5) with the group with worst adherence (group 1):

    • Adherence to a plant-centered diet reduced their risk of developing heart disease by 48%.
    • This is consistent with previous studies looking at the beneficial effects of plant-centered diets on heart disease.

2) What effect does changing your diet from bad to good when you are in your 30s or 40s have on your risk of developing heart disease? 

For this portion of the study, the investigators compared the dietary data collected at years 7 and 20 (corresponding to average ages 32 and 45 for the participants) and ranked the participants from 1 to 5 based on improved adherence to a plant-centered diet. When they compared the group with best improvement in adherence (group 5) with the group with worst improvement in adherence (group 1):

    • Improved adherence to a plant-centered diet reduced the risk of developing heart disease by 39%.
    • This answers the questions I posed at the beginning of this article. In short, it is never too late to change your diet for the better.

The authors concluded, “In summary, our study shows that long-term consumption of a nutritionally rich plant-centered diet is associated with a lower risk of heart disease. Furthermore, increased [adherence to a] plant-centered diet in young adulthood is associated with a lower subsequent risk of heart disease throughout middle age, independent of the earlier diet quality” [In short, they are saying that changing to a more plant-centered diet in your 30s and 40s reduces your risk of heart disease.]

You Can Improve Your Health At Any Age

I titled this section, “You Can Improve Your Health At Any Age” for a reason. I wanted to make the point that it is never too late to change your diet, and your health, for the better.

Yes, I realize that the study I described above only shows:

  • The effect of changing to a more plant-centered diet in your 30s and 40s.
  • The benefit of changing to a more plant-centered diet on heart disease outcomes.

However, we have ample evidence that changing to a more plant-based diet at any age is likely to reduce the risk of many diseases. For example:

  • There are multiple reports in the literature of people in their 60s and 70s who had a health scare, changed to a more plant-centered diet, and dramatically improved their health.

While neither type of study can be considered definitive by itself, together they suggest it is never too late to change your diet for the better.

But what changes should you make? As I said above, anything from Vegan to Mediterranean or DASH fits the definition of a plant-centered diet (something I have previously referred to as a primarily plant-based diet).

You could choose the plant-centered diet that best fits your preferences and lifestyle and read books or go online to find details and recipes that will help you transition to that diet…or you could simply:

  • Eat more fruit, avocado, beans/legumes, green vegetables, yellow vegetables, tomatoes, other vegetables, nuts and seeds, soy products, whole grains, vegetable oil, fatty fish, lean fish, poultry, moderate alcohol, coffee, tea, and low-fat milk/cheese/yogurt.
  • Eat less fried potatoes, refined grain desserts, salty snacks, pastries, sweets, high-fat red meats, processed meats, organ meats, fried fish/poultry, sauces, soft drinks, whole fat milk/cheese/yogurt, and butter.
  • Eat these foods in moderation: potatoes, refined grains, margarine, chocolate, meal replacements, pickled foods, lean meats, shellfish, eggs, soups, and fruit juices.

The Bottom Line

If you are like most Americans, you know your diet is unhealthy. But it is the diet you grew up with. It’s the diet you love. So, you keep eating it anyway.

Then you have a wake-up call. You find yourself in your doctor’s office, and your doctor is advising you to change your diet. But giving up the diet you love is difficult, and you wonder if it is worth it. Can you really improve your health significantly by changing your diet now, or is it too late? Has the damage already been done?

Fortunately, a recent study has answered these questions. This study started with people in their mid-20s. And it looked at whether changing their diet from bad to good in their 30s and 40s had any effect on their health in their 50s and 60s. This is what the study found.

  • Improved adherence to a plant-centered diet in their 30s and 40s reduced their risk of developing heart disease in their 50s and 60s by 39%.

While this study was very specific in terms of age and disease, I have discussed in the article above why changing to a more plant-based diet at any age is likely to reduce your risk of multiple diseases. In short, it is never too late to change your diet, and your health, for the better.

For more details about this study and how to change your diet for the better, 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 Diet And Gut Bacteria Affect Our Health

Why Is Your Microbiome Important? 

Author: Dr. Stephen Chaney

Vegan FoodsWe have known for years that primarily plant-based diets are healthy. As I have shared in my book, “Slaying The Food Myths”, people who consume primarily plant-based diets have lower risk of heart disease, diabetes, and some cancers and live longer than people who consume the typical American diet.

But why is that?

  • Is it the nutrients, phytonutrients, and fiber plant foods provide?
  • Is it because plant foods are lower in saturated fats and are good sources of healthier monounsaturated and polyunsaturated fats?
  • Or is it because plant foods have a low caloric density, which makes it easier to maintain a healthy weight?

The answer, of course, is that all the above are important. But is there something else? Is there a “missing link” we don’t talk about much? Many experts think our microbiome (our gut bacteria) is that missing link.

You have heard the saying, “We are what we eat”. You might be scratching your head and saying, “I could eat cabbages all day long, but I am never going to become a cabbage.” It seems like a crazy saying.

But for our microbiome that saying is true. What we call fiber, our gut bacteria call food. Consequently, microbiomevegetarians and meat eaters have very different populations of gut bacteria in their microbiome. The question, of course, is whether these differences influence our health. This central question has spurred multiple research studies on our microbiome in recent years.

Two central themes have emerged from these studies:

  • There are certain populations of gut bacteria that are associated with healthy outcomes (lower risk of obesity, diabetes, heart disease, and some cancers). We can think of these as “good bacteria”.
    • There are certain populations of gut bacteria that are associated with unhealthy outcomes (increased risk of obesity, diabetes, heart disease, and some cancers). We can think of these as “bad bacteria”.
  • People consuming primarily plant-based diets tend to have more of the “good bacteria” and less of the “bad bacteria” in their gut microbiome.

However, most of these studies have been small and have looked at individual foods rather than the effect of the overall diet.

The study (KK Koponen et al, American Journal Of Clinical Nutrition, 2021; doi.org/10.1093/ajcn/nqab077 I will describe today was designed to overcome those limitations.

Metabolism 101: What Are Short Chain Fatty Acids And Why Are They Important?

professor owlTo fully understand the findings of this study, you need to understand what short chain fatty acids are and why they are important. Simply put, short chain fatty acids are the end products of fiber digestion by some species of gut bacteria in our intestines. The major short chain fatty acids in our intestines are acetate (2 carbons), propionate (3 carbons), and butyrate (4 carbons).

There are the key facts about short chain fatty acids you should know:

  1. They are formed by anaerobic fermentation of dietary fiber by our gut bacteria. However:
    • Not all gut bacteria can produce short chain fatty acids.
    • The amount and type(s) of dietary fiber determine whether the gut bacteria that can produce short chain fatty acids are present.

2) Acetate is readily absorbed into the bloodstream and is utilized for fat production and other biosynthetic pathways.

3) Short chain fatty acids, especially butyrate, are the primary energy source for cells lining the colon. Because of this, they have several important health benefits.

    • They support the immune cells that line our intestine. This helps strengthen our immune system.
    • They help maintain the integrity of the intestinal wall. This helps protect against leaky gut syndrome.
    • They reduce inflammation. This reduces the risk of inflammatory bowel diseases like ulcerative colitis and Crohn’s disease.
    • They reduce the risk of colon cancer.

4) In addition, small amounts of propionate and butyrate can be absorbed into the bloodstream. Butyrate is of particular interest because it has the potential to regulate gene expression.

    • There is some evidence that short chain fatty acid production in the intestine is correlated with reduced risk of inflammatory diseases, obesity, type 2 diabetes, and heart disease, but these studies remain controversial.

How Was This Study Done?

Clinical StudyThis study made use of data from the FINRISK Study. This study was conducted by the Finnish Institute of Health and Welfare every 5 years between 1972 and 2012 to assess risk factors for noncommunicable diseases, health behavior, and their changes in adult Finns.

This study included 4930 individuals from the 2002 FINRISK assessment. The characteristics of the group were:

  • 53% female, 47% male.
  • Average age = 48.
  • Average BMI = 26.9 (slightly overweight).

Upon entry into the study, the participants were asked to fill out a food frequency questionnaire.

  • The data from this questionnaire were used to calculate a Healthy Food Choices (HFC) score based on the Nordic Nutrition Dietary Guidelines for a healthy diet.
    • The HFC score ranged from 9-745 and was based on the consumption of fiber-rich breads; vegetables (including beans and lentils); fruits; berries; fresh, non- sweetened berry and fruit juices; fish; poultry; low-fat cheeses; salad dressings and oils; nuts; and seeds.
    • In the words of the authors, “A high HFC score effectively acts as an indicator of a healthy omnivorous Nordic diet rich in plants, fiber, and polyunsaturated fatty acids.”
  • The data were also used to calculate a total dietary fiber score.

The participants were also asked to provide a stool sample. DNA was extracted from the stool sample and sequenced to determine the number and types of bacteria in their gut microbiome. These data were analyzed for:

  • Bacterial diversity (greater bacterial diversity is associated with better health outcomes).
  • Species of gut bacteria known to be associated with better health outcomes.
  • Species of bacteria known to produce short chain fatty acids.

How Diet And Gut Bacteria Affect Our Health

MicrobiomeMicrobiome research is complex. But here is a description of the results in simple terms.

Both the Healthy Food Choice (HFC) and fiber scores correlated positively with:

  • Bacterial diversity (greater bacterial diversity is associated with better health outcomes).
  • Species of gut bacteria known to be associated with better health outcomes.
  • Species of bacteria known to produce short chain fatty acids that are associated with better health outcomes.

Simply put, a healthy, primarily plant-based Nordic diet produces the kind of gut microbiome that is associated with better health outcomes.

When the authors analyzed the contribution of individual components of the diet to a healthy microbiome:

  • Vegetables; berries; fruits; fiber-rich breads; salad dressings and oils; low-fat cheeses; poultry; fresh, unsweetened juices; and fish were all positively associated with a healthy microbiome.
    • Each of these foods supported the growth of different gut bacteria that contributed to the healthy microbiome.
    • Simply put, none of these foods was sufficient by itself. It was a healthy diet with all these foods that resulted in a healthy microbiome.
  • Nuts and seeds did not affect the microbiome. This may have been because there was too little of them in the diet to have a significant effect.
  • Red and processed meats were negatively associated with a healthy microbiome.

The authors concluded, “Our results from a large, population-based survey confirm and extend the findings of other, smaller-scale studies that plant- and fiber-rich dietary choices are associated with a more diverse and compositionally distinct microbiome with a greater potential to produce short chain fatty acids.”

The authors also said, “The associated between red and processed meat products and the gut microbiome cannot be ignored either…[Our data] indicate that increased usage of red and processed meat is associated with the microbiome composition in an opposite manner to that of a healthy diet.”

Why Is Your Microbiome Important?

happy gut bacteriaThe most important message from this and previous studies is that your gut microbiome is the “missing link” between a healthy diet and a healthy body.

Simply put,    healthy diet →→→healthy microbiome→→→healthy body

However, I also need to acknowledge microbiome research is in its infancy. That is because our microbiome is very complex:

  • We have around 38 trillion microorganisms (give or take a few trillion) in our intestine. That means we have slightly more microorganisms than we do cells in our body.
  • Each of us have more than 1,000 different species of bacteria in our intestine.
  • Collectively, these bacteria have around 750,000 genes. That is 30 times more than the number of genes in our DNA.
  • Finally, we all have different species of bacteria in our intestines. We are all unique.

The only simplifying principle is that these bacteria exist in communities that generally group together. Unraveling the complexities and identifying the communities of bacteria in our intestines requires high throughput DNA sequencing and supercomputers to analyze the data.

Studies like this one can identify the associations between diet and distinct communities of bacteria. They can even identify which foods in the diet support the growth of these bacterial communities. Other studies can identify the association between distinct communities of bacteria and healthy outcomes.

The strength of this study is that it identifies the kind of diet and the kinds of food that support the communities of bacteria associated with healthy outcomes. However, these are just associations. They don’t tell us why these associations occur. Specifically:

  • We don’t know why certain diets are associated with different communities of gut bacteria. However, we do know several things.
    • High fiber diets are a major driving force in creating a healthy gut microbiome. This is because what we call fiber, our gut bacteria call food.High Fiber Foods
    • The diet should contain a variety of high fiber foods. This is because different kinds of fiber support the growth of different kinds of gut bacteria, and the diversity of our gut microbiome is associated with healthy outcomes. As I have said before, “We have 5 food groups for a reason”.
    • However, the type of fat and the type of protein in the diet also influence the type of bacteria that thrive in our intestines. We know less about why that is.
  • We also don’t know why certain communities of gut bacteria are associated with healthy outcomes.
    • The exception is communities of bacteria that produce short chain fatty acids. We do have a good idea why short chain fatty acids are associated with gut health.

However, the fact we don’t know why these associations occur, doesn’t detract from the strength of these associations.

  • The associations between a healthy, primarily plant-based diet and a healthy microbiome are not based on this study alone. The same associations have been seen in multiple studies.
  • The associations between a healthy microbiome and better health outcomes have also been seen in multiple studies.

The evidence for these associations is too strong to ignore.

What Does This Study Mean For You?

Questioning WomanThis study shows that a healthy Nordic diet is associated with a healthy microbiome. “But what is a healthy Nordic diet?”, you might ask. Simply put, it is a whole food, omnivorous, primarily plant-based diet with Scandinavian food preferences.

And, if pickled herring, potato pancakes, and meatballs aren’t your favorite foods, never fear. You have lots of other options:

  • The Mediterranean diet is essentially the same diet with Mediterranean food preferences.
  • The DASH diet is essentially the same diet with American food preferences.
  • You can start with a semi-vegetarian diet and tailor it to your food preferences. Of course, some common sense is required here. You will need to primarily include whole, unprocessed food preferences in your diet.

Let me close with some simple advice I have shared before:

  • We are what we eat. Our microbiome (gut bacteria) reflects what we eat.
  • What we call fiber, our gut bacteria call food. A primarily plant-based diet is best because our friendly gut bacteria thrive on the fiber it provides.
  • We have 5 food groups for a reason. Each plant food group provides different kinds of fiber and feeds different families of friendly gut bacteria. We eliminate plant food groups at our peril.
  • We should think of red meat as a condiment, not a main course. Plants contain antidotes to many of the harmful ingredients in red meat. Two to three ounces of steak as part of a green salad or stir fry is much healthier than an 8-ounce steak and fries.

The Bottom Line

Most previous studies on the effect of diet on our microbiome have been small and have looked at individual foods rather than the effect of the overall diet. In this week’s “Health Tips From the Professor” I report on a large, well-designed study that examined the effect of a healthy Nordic diet on our microbiome.

In case you were wondering, the investigators defined a healthy Nordic diet as a whole food diet that:

  • Includes lots of fruits, vegetables, and whole grains and is, therefore, high in fiber.
  • Uses fish, poultry, and low-fat cheeses as its primary protein source.
  • Minimizes red and processed meats.
  • Has more polyunsaturated oils than saturated fats.
  • Reflects Scandinavian food preferences.

This study found that a healthy Nordic diet correlated positively with:

  • Bacterial diversity (greater bacterial diversity is associated with better health outcomes).
  • Species of gut bacteria known to be associated with better health outcomes.
  • Species of bacteria known to produce short chain fatty acids that are associated with better gut health outcomes.

Simply put, a healthy, primarily plant-based Nordic diet produces the kind of gut microbiome that is associated with better health outcomes. To put this into perspective, a healthy Nordic diet is similar to a healthy Mediterranean diet or a healthy DASH diet except that the Mediterranean diet reflects Mediterranean food preferences, and the Dash diet reflects American food preferences.

The most important message from this and previous studies is that your gut microbiome is the “missing link” between a healthy diet and a healthy body.

Simply put,    healthy diet →→→healthy microbiome→→→healthy body

I summed up the article with some simple advice I have shared before:

  • We are what we eat. Our microbiome (gut bacteria) reflects what we eat.
  • What we call fiber, our gut bacteria call food. A primarily plant-based diet is best because our friendly gut bacteria thrive on the fiber it provides.
  • We have 5 food groups for a reason. Each plant food group provides different kinds of fiber and feeds different families of friendly gut bacteria. We eliminate plant food groups at our peril.
  • We should think of red meat as a condiment, not a main course. Plants contain antidotes to many of the harmful ingredients in red meat. Two to three ounces of steak as part of a green salad or stir fry is much healthier than an 8-ounce steak and fries.

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.

 

Which Diet Is Best For Your Heart?

Why Are Dietary Studies So Confusing? 

Author: Dr. Stephen Chaney

heart diseaseYou are concerned about your heart.

  • Perhaps it is because of genetics. Everyone on one side of your family tree had their first heart attack in their mid-forties.
  • Perhaps it is because your doctor has warned you that your heart is a ticking time bomb. Unless you make some drastic changes, you will die of a heart attack in the near future.
  • Perhaps you already have some symptoms of heart disease, and you are scared.

You want to make some changes. You want to protect your heart. What should you do?

The short answer is that a holistic approach is best, and I will share the American Heart Association recommendations below. But let’s start by asking what you should eat. There are two important questions:

#1: Which diet is best for your heart?

  • A whole food vegan diet, the Mediterranean diet, and the DASH diet are all strong contenders for the best heart healthy diet.
  • But there are many other diets that claim to be heart healthy. Some enthusiasts even claim the Paleo and keto diets are heart healthy.
  • The problem is that few studies have compared these diets against each other. That makes it difficult to settle the question of which diet is best for your heart.

#2: Which protein source is best for your heart – plant protein, fish, poultry, or red meat?

  • Plant and fish protein are both strong contenders for the most heart healthy protein.
  • Poultry has the reputation of being more heart healthy than red meat. But this has become controversial. Some recent studies suggest poultry is no better than red meat in terms of heart health.

Fortunately, a recent study (F Petermann-Rocha et al, European Heart Journal, 42: 1136-1143, 2021) has made this comparison. It compared vegetarians, fish eaters, poultry eaters, and red meat eaters for the risk of developing heart disease.

How Was This Study Done?

Clinical StudyThis study made use of data from the UK Biobank program. The UK Biobank program recruited over 500,000 participants (ages 37-73) from England, Wales, and Scotland between 2006 and 2010 and followed them for an average of 8.5 years.

At entry into the program, each participant filled out a touchscreen questionnaire, had physical measurements taken, and provided biological samples.

Dietary intake was assessed based on the touchscreen questionnaire and the average of 5 24-hour dietary recalls. The participants were divided into four groups based on this dietary analysis:

  • Vegetarians (All participants in the study consumed cheese and eggs, so this group would more accurately be described as lacto-ovo-vegetarians).
  • Fish eaters.
  • Poultry eaters.
  • Red meat eaters.

Over the next ~8.5 years, each group was compared with respect to the following heart health parameters:

  • Risk of developing cardiovascular disease (all diseases of the circulatory system).
  • Risk of developing ischemic heart disease (lack of sufficient blood flow to the heart. The most common symptom of ischemic heart disease is angina).
  • Risk of having a myocardial infarction (commonly referred to as a heart attack).
  • Risk of having a stroke.
  • Risk of developing heart failure.

Which Diet Is Best For Your Heart?

The study compared vegetarians, fish eaters, and poultry eaters with red meat eaters with respect to each of the heart disease parameters listed above. The results were:

  • When fish eaters were compared with meat eaters, they had:
    • 7% lower risk of cardiovascular diseases of all types.
    • 21% lower risk of ischemic heart disease (angina).
    • 30% lower risk of myocardial infarction (heart attack).
    • 21% lower risk of stroke.
    • 22% lower risk of heart failure.
  • When vegetarians were compared with meat eaters, they had:
    • 9% lower risk of cardiovascular diseases of all types.
    • Lower, but statistically non-significant, risk of other heart disease parameters.
  • When poultry eaters were compared with meat eaters there were no significant differences in heart disease outcomes.

The authors concluded, “Eating fish rather than meat or poultry was associated with a lower risk of adverse cardiovascular outcomes…supporting its role as a healthy diet that should be encouraged. Vegetarianism was only associated with a lower risk of cardiovascular disease incidence.”

Why Are Dietary Studies So Confusing?

confusionSo, you are probably thinking, “Are diets with fish protein really more heart healthy than diets with plant protein?”

Fish have a lot going for them. They are an excellent source of heart healthy omega-3 fats. And, when substituted for red meat protein, they decrease intake of saturated fats.”

But plant protein has a lot going for it as well. Numerous studies have shown that vegetarian diets are more heart healthy than the typical American diet. And only plant-based diets have been shown to reverse atherosclerosis.

So, why are dietary studies so confusing? The problem is that diets are complex. They have many moving parts. When we focus on one aspect of a diet, we are ignoring the rest of the diet. The food we have focused on may be healthy. But if it is paired with unhealthy foods, the overall diet can still be unhealthy.

The current study is a perfect example of that principle:

  • The participants represented a cross section of the British population. All the “diets” were high in sugar, sugary drinks, saturated fat, and processed meals bought from the supermarket. None of them were optimal.
  • In addition to consuming cheese and eggs, “vegetarians” consumed more crisps, slices of pizza, and smoothie drinks than meat-eaters. [In case you were wondering, the English refer to small thin salty snacks like potato chips as crisps. They reserve the term chips for what we call French Fries.]
  • “Vegetarians” also consumed a lot of highly processed vegetarian alternatives designed to taste like other meat products.
  • On the other hand, fish eaters consumed more fruits and vegetables than meat-eaters. It wasn’t just the fish that made this diet more heart healthy.

In other words, the “vegetarian diet” in this study was not nearly as healthy as the whole food vegetarian diets that have previously been shown to be heart healthy. And the “fish-eaters diet” was healthier than the “meat-eaters diet” because of both the fish and the extra fruits and vegetables these people were consuming.

In the words of the authors, “…As a group, vegetarians consumed more unhealthy foods, such as crisps, than meat eaters. Therefore, vegetarians should not be considered a homogeneous group, and avoidance of meat will not be sufficient to reduce health risk if the overall diet is not healthy.”

My summary:

  • Whole food plant-based diets (the true definition of vegetarianism) are very heart healthy. [Note: The diet in this study was lacto-ovo-vegetarian rather than a true vegetarian diet. However, recent studies have suggested that addition of small amounts of dairy and eggs to a vegetarian diet may make them more heart healthy rather than less heart healthy.]
  • Primarily plant-based diets with fish as the main protein source (otherwise known as pescatarian diets) are also very heart healthy.
  • If you want a healthy heart, choose the one that best fits your preferences and your lifestyle.

A Holistic Approach: The American Heart Association Recommendations

Doctor With Patient

  • If you smoke, stop.
  • Choose good nutrition.
    • Choose a diet that emphasizes vegetables, fruits, whole grains, low-fat dairy products, poultry, fish, legumes, non-tropical vegetable oils, and nuts.
    • Choose a diet that limits sweets, sugar-sweetened beverages, and red meats.
    • Reduce high blood cholesterol and triglycerides.
    • Reduce your intake of saturated fat, trans fat and cholesterol.
  • Lower High Blood Pressure.
  • Be physically active every day.
    • Aim for at least 150 minutes per week of moderate-intensity physical activity per week.
  • Aim for a healthy weight.
  • Manage diabetes.
  • Reduce stress.
  • Limit alcohol.
  • Have a regular physical checkup.

The Bottom Line

A recent study in the United Kingdom compared vegetarians, fish eaters, poultry eaters, and red meat eaters for the risk of developing heart disease and the risk of dying from heart disease. The results were:

  • When fish eaters were compared with meat eaters, they had:
    • 7% lower risk of cardiovascular diseases of all types.
    • 21% lower risk of ischemic heart disease (angina).
    • 30% lower risk of myocardial infarction (heart attack).
    • 21% lower risk of stroke.
    • 22% lower risk of heart failure.
  • When vegetarians were compared with meat eaters, they had:
    • 9% lower risk of cardiovascular diseases of all types.
    • Lower, but statistically non-significant, risk of other heart disease parameters.
  • When poultry eaters were compared with meat eaters there were no significant differences in heart disease outcomes.

The authors concluded, “Eating fish rather than meat or poultry was associated with a lower risk of adverse cardiovascular outcomes…supporting its role as a healthy diet that should be encouraged. Vegetarianism was only associated with a lower risk of cardiovascular disease incidence.”

However, the “vegetarian diet” in this study was not nearly as healthy as the whole food vegetarian diets that have previously been shown to be heart healthy. And the “fish-eaters diet” was healthier than the “meat-eaters diet” because of both the fish and the extra fruits and vegetables this group of people were consuming.

In the words of the authors, “…As a group, vegetarians consumed more unhealthy foods, such as crisps [potato chips], than meat eaters. Therefore, vegetarians should not be considered a homogeneous group, and avoidance of meat will not be sufficient to reduce health risk if the overall diet is not healthy.”

My summary:

  • Whole food plant-based diets (the true definition of vegetarianism) are very heart healthy.
  • Primarily plant-based diets with fish as the main protein source (otherwise known as pescatarian diets) are also very heart healthy.
  • If you want a healthy heart, choose the one that best fits your preferences and your lifestyle.

For more details about this study, 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.

Are Vegan Diets Bad For Your Bones?

The Secrets To A Healthy Vegan Diet

Author: Dr. Stephen Chaney

Frail ElderlyOsteoporosis is a debilitating and potentially deadly disease associated with aging. It affects 54 million Americans. It can cause debilitating back pain and bone fractures. 50% of women and 25% of men over 50 will break a bone due to osteoporosis. Hip fractures in the elderly due to osteoporosis are often a death sentence.

As I discussed in a previous issue of “Health Tips From The Professor”, a “bone-healthy lifestyle requires 3 essentials – calcium, vitamin D, and weight bearing exercise. If any of these three essentials is presence in inadequate amounts, you can’t build healthy bones. In addition, other nutrients such as protein, magnesium, zinc, vitamin B12, and omega-3 fatty acids may play supporting roles.

Vegan and other plant-based diets are thought to be very healthy. They decrease the risk of heart disease, diabetes, and some cancers. However, vegan diets tend to be low in calcium, vitamin D, zinc, vitamin B12, protein, and omega-3 fatty acids. Could vegan diets be bad for your bones?

A meta-analysis of 9 studies published in 2009 (LT Ho-Pham et al, American Journal of Clinical Nutrition 90: 943-950, 2009) reported that vegans had 4% lower bone density than omnivores, but concluded this difference was “not likely to be clinically relevant”.

However, that study did not actually compare bone fracture rates in vegans and omnivores. So, investigators have followed up with a much larger meta-analysis (I Iguacel et al, Nutrition Reviews 77, 1-18, 2019) comparing both bone density and bone fracture rates in vegans and omnivores.

How Was This Study Done?

Clinical StudyThe investigators searched the literature for all human clinical studies through November 2017 that compared bone densities and frequency of bone fractures of people consuming vegan and/or vegetarian diets with people consuming an omnivore diet.

  • Vegan diets were defined as excluding all animal foods.
  • Vegetarian diets were defined as excluding meat, poultry, fish, seafood, and flesh from any animal but including dairy foods and/or eggs. [Note: The more common name for this kind of diet is lacto-ovo vegetarian, but I will use the author’s nomenclature in this review.]
  • Omnivore diets were defined as including both plant and animal foods from every food group.

The investigators ended up with 20 studies that had a total of 37,134 participants. Of the 20 studies, 9 were conducted in Asia (Taiwan, Vietnam, India, Korea, and Hong-Kong), 6 in North America (the United States and Canada), and 4 were conducted in Europe (Italy, Finland, Slovakia, and the United Kingdom).

Are Vegan Diets Bad For Your Bones?

Here is what the investigators found:

Unhealthy BoneBone density: The clinical studies included 3 different sites for bone density measurements – the lumbar spine, the femoral neck, and the total body. When they compared bone density of vegans and vegetarians with the bone density of omnivores, here is what they found:

Lumbar spine:

    • Vegans and vegetarians combined had a 3.2% lower bone density than omnivores.
    • The effect of diet was stronger for vegans (7% decrease in bone density) than it was for vegetarians (2.3% decrease in bone density).

Femoral neck:

    • Vegans and vegetarians combined had a 3.7% lower bone density than omnivores.
    • The effect of diet was stronger for vegans (5.5% decrease in bone density) than it was for vegetarians (2.5% decrease in bone density).

Whole body:

    • Vegans and vegetarians combined had a 3.2% lower bone density than omnivores.
    • The effect of diet was statistically significant for vegans (5.9% decrease in bone density) but not for vegetarians (3.5% decrease in bone density). [Note: Statistical significance is not determined by how much bone density is decreased. It is determined by the size of the sample and the variations in bone density among individuals in the sample.]

Bone FractureBone Fractures: The decrease in bone density of vegans in this study was similar to that reported in the 2009 study I discussed above. However, rather than simply speculating about the clinical significance of this decrease in bone density, the authors of this study also measured the frequency of fractures in vegans, vegetarians, and omnivores. Here is what they found.

  • Vegans and vegetarians combined had a 32% higher risk of bone fractures than omnivores.
  • The effect of diet on risk of bone fractures was statistically significant for vegans (44% higher risk of bone fracture) but not for vegetarians (25% higher risk of bone fractures).
  • These data suggest the decreased bone density in vegans is clinically significant.

The authors concluded, “The findings of this study suggest that both vegetarian and vegan diets are associated with lower bone density compared with omnivorous diets. The effect of vegan diets on bone density is more pronounced than the effect of vegetarian diets, and vegans have a higher fracture risk than omnivores. Both vegetarian and vegan diets should be appropriate planned to avoid dietary deficiencies associated with bone health.”

The Secrets To A Healthy Vegan Diet

Emoticon-BadThe answer to this question lies in the last statement in the author’s conclusion, “Both vegetarian and vegan diets should be appropriate planned to avoid dietary deficiencies associated with bone health.” 

The problem also lies in the difference between what a nutrition expert considers a vegan diet and what the average consumer considers a vegan diet. To the average consumer a vegan diet is simply a diet without any animal foods. What could go wrong with that definition? Let me count the ways.

  1. Sugar and white flour are vegan. A vegan expert thinks of a vegan diet as a whole food diet – primarily fruits, vegetables, whole grains, beans, nuts, and seeds. A vegan novice includes all their favorites – sodas, sweets, and highly processed foods. And that may not leave much room for healthier vegan foods.

2) Big Food, Inc is not your friend. Big Food tells you that you don’t need to give up the taste of animal foods just because you are going vegan. They will just combine sugar, white flour, and a witch’s brew of chemicals to give you foods that taste just like your favorite meats and dairy foods. The problem is these are all highly processed foods. They are not healthy. Some people call them “fake meats” or “fake cheeses”. I call them “fake vegan”.

If you are going vegan, embrace your new diet. Bean burgers may not taste like Big Macs, but they are delicious. If need other delicious vegan recipe ideas, I recommend the website https://forksoverknives.com.

3) A bone healthy vegan diet is possible, but it’s not easy. Let’s go back to the author’s phrase “…vegan diets should be appropriate planned to avoid dietary deficiencies associated with bone health.” A vegan expert will do the necessary planning. A vegan novice will assume all they need to do is give up animal foods. 

As I said earlier, vegan diets tend to be low in calcium, vitamin D, zinc, vitamin B12, protein, and omega-3 fatty acids. Let’s look at how a vegan expert might plan their diet to get enough of those bone-healthy nutrients.

    • Calcium. The top plant sources of calcium are leafy greens and soy foods at about 100-250 mg (10-25% of the DV) of calcium per serving. Some beans and seeds are moderately good sources of calcium. Soy foods are a particularly good choice because they are a good source of calcium and contain phytoestrogens that stimulate bone formation.

A vegan expert makes sure they get these foods every day and often adds a calcium supplement.

    • Protein. Soy foods, beans, and some whole grains are the best plant sources of protein.soy

It drives me crazy when a vegan novice tells me they were told they can get all the protein they need from broccoli and leafy greens. That is incredibly bad advice.

A vegan expert makes sure they get soy foods, beans, and protein-rich grains every day and often adds a protein supplement.

    • Zinc. There are several plant foods that supply around 20% the DV for zinc including lentils, oatmeal, wild rice, squash and pumpkin seeds, quinoa, and black beans.

A vegan expert makes sure they get these foods every day and often adds a multivitamin supplement containing zinc.

    • Vitamin D and vitamin B12. These are very difficult to get from a vegan diet. Even vegan experts usually rely on supplements to get enough of these important nutrients.

4) Certain vegan foods can even be bad for your bones. I divide these into healthy vegan foods and unhealthy “vegan” foods. 

    • Healthy vegan foods that can be bad for your bones include.
      • Pinto beans, navy beans, and peas because they contain phytates.
      • Raw spinach & swiss chard because they contain oxalates.
      • Both phytates and oxalates bind calcium and interfere with its absorption.
      • These foods can be part of a healthy vegan diet, but a vegan expert consumes them in moderation.
    • Unhealthy “vegan” foods that are bad for your bones include sodas, salt, sugar, and alcohol.
      • The mechanisms are complex, but these foods all tend to dissolve bone.
      • A vegan expert minimizes them in their diet.

5) You need more than diet for healthy bones. At the beginning of this article, I talked about the 3 Weight Trainingessentials for bone formation – calcium, vitamin D, and exercise. You can have the healthiest vegan diet in the world, but if you aren’t getting enough weight bearing exercise, you will have low bone density. Let me close with 3 quick thoughts:

    • None of the studies included in this meta-analysis measured how much exercise the study participants were getting.
    • The individual studies were generally carried out in industrialized countries where many people get insufficient exercise.
    • The DV for calcium in the United States is 1,000-1,200 mg/day for adults. In more agrarian societies dietary calcium intake is around 500 mg/day, and osteoporosis is almost nonexistent. What is the difference? These are people who are outside (vitamin D) doing heavy manual labor (exercise) in their farms and pastures every day.

In summary, a bone healthy vegan lifestyle isn’t easy, but it is possible if you work at it.

The Bottom Line 

A recent meta-analysis asked two important questions about vegan diets.

  1.     Do vegans have lower bone density than omnivores?

2) Is the difference in bone density clinically significant? Are vegans more likely to suffer from bone fractures?

The study found that:

  • Vegans had 5.5%–7% lower bone density than omnivores depending on where the bone density was measured.
  • Vegans were 44% more likely to suffer from bone fractures than omnivores.

The authors of the study concluded, ““The findings of this study suggest that…vegan diets are associated with lower bone density compared with omnivorous diets, and vegans have a higher fracture risk than omnivores…Vegan diets should be appropriate planned to avoid dietary deficiencies associated with bone health.”

In evaluating the results of this study, I took a detailed look at the pros and cons of vegan diets and concluded, “A bone healthy vegan lifestyle isn’t easy, but it is possible if you work at it.”

For more details about study and my recommendations for a bone healthy vegan lifestyle 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.

What Is An Anti-Inflammatory Diet?

Can Diet Douse The Flames?

Author: Dr. Stephen Chaney

InflammationIf you have arthritis, colitis, bursitis, or any of the other “itis” diseases, you already know that inflammation is the enemy. Chronic, low level inflammation is also a contributing factor to heart disease, cancer, and many other diseases. Clearly, inflammation is a bad actor. It is something we want to avoid.

Obesity and diabetes are two of the biggest contributors to inflammation, but does diet also play a role? With all the anti-inflammation diets circulating on the internet, you would certainly think so. How good is the evidence that certain foods influence inflammation, and what does an anti-inflammatory diet look like?

The Science Behind Anti-Inflammatory Diets

ScientistLet me start by saying that the science behind anti-inflammatory diets is nowhere near as strong as it is for the effect of primarily plant-based diets on heart disease and diabetes. The studies on anti-inflammatory diets are mostly small, short duration studies. However, the biggest problem is that there is no standard way of measuring inflammation.

There are multiple markers of inflammation, and they do not change together. That means that in every study some markers of inflammation are altered, while others are not. There is no consistent pattern from one study to another.

In spite of these methodological difficulties, the studies generally point in the same direction. Let’s start with the strongest evidence and work our way down to the weakest evidence. 

Omega-3 fats are anti-inflammatory (I. Reinders et al, European Journal of Clinical Nutrition, 66: 736-741, 2011). The evidence is strongest for the long chain omega-3s found in fish and fish oil, but the shorter chain omega-3s found in foods like walnuts, flaxseeds, chia seeds and flaxseed oil, soybean oil, and canola oil also appear to be anti-inflammatory. 

Inflammation is directly correlated with glycemic index (L. Qi and F.B. Lu, Current Opinion in Lipidology, 18: 3-8, 2007). This has a couple of important implications.

The most straightforward is that refined carbohydrates and sugars (sodas, pastries, and desserts), which have a high glycemic index, increase inflammation. In contrast, complex carbohydrates (whole grains, most fruits and vegetables) decrease inflammation. No surprise there. The second implication is that it is the glycemic index, not the sugar, that is driving the inflammatory response.

That means we need to look more closely at foods than at sugars. Sodas, pastries and desserts are likely to cause inflammation, but sugar-containing foods with a low glycemic index are unlikely to be inflammatory. 

Fruits and vegetables are anti-inflammatory. This has been shown in multiple studies. At this point most of the research is centered on identifying the nutrients and phytonutrients from fruits and vegetables that are responsible for the reduction in inflammation. I suspect the investigators are hoping to design an anti-inflammatory supplement and make lots of money. I will stick with the fresh fruits and vegetables. 

Saturated fats are inflammatory. At face value, the data on saturated fats appear to be contradictory. Some Fatty Foodsstudies say that saturated fats increase inflammation, while others say they do not. However, similar to my earlier discussion on saturated fats and heart disease), the outcome of the study depends on what the saturated fats are replaced with.

When saturated fats are replaced with refined carbohydrates, sugar and highly processed foods (the standard American low-fat diet), inflammation doesn’t change. This doesn’t mean that a diet high in saturated fat is healthy. It just means that both diets are bad for you. Both are inflammatory.

However, when saturated fat is replaced with omega-3 polyunsaturated fats (J.A. Paniagua et al, Atherosclerosis, 218: 443-450, 2011) or monounsaturated fats (B. Vessby et al, Diabetologia, 44: 312-319, 2001), markers of inflammation decrease. Clearly, saturated fats are not the best fat choice if you wish to keep inflammation in check.

I would be remiss if I did not address the claims by the low-carb diet proponents that saturated fats do not increase inflammation in the context of a low-carb diet. I want to remind you of two things we have discussed previously:

  • The comparisons in those studies are generally with people consuming a diet high in simple carbohydrates and sugars.
  • These studies have mostly been done in the short-term when the participants are losing weight on the low-carb diets. Weight loss decreases inflammation, so the reduction in inflammation on the low-carb diet could be coming from the weight loss.

The one study (M. Miller et al, Journal of the American Dietetic Association, 109: 713-717, 2009) I have found that compares a low-carb diet (the Atkins diet) with a good diet (the Ornish diet, which is a low-fat, lacto-ovo vegetarian diet) during weight maintenance found that the meat based, low-carb Atkins diet caused greater inflammation than the healthy low-fat Ornish diet.

Red meat is probably pro-inflammatory. Most, but not all, studies suggest that red meat consumption is associated with increased inflammation. If it is pro-inflammatory, the inflammation is most likely associated with its saturated fat, its heme iron content, or the advanced glycation end products formed during cooking.

What Is An Anti-Inflammatory Diet?

Colorful fruits and vegetablesAnti-inflammatory diets have become so mainstream that they now appear on many reputable health organization websites such as Harvard Health, WebMD, the Mayo Clinic, and the Cleveland Clinic. Each have slightly different features, but there is a tremendous amount of agreement. 

Foods an anti-inflammatory diet includes: In a nutshell, an anti-inflammatory diet includes fruits and vegetables, whole grains, plant-based proteins (like beans and nuts), fatty fish, and fresh herbs and spices. Specifically, your diet should emphasize:

  • Colorful fruits and vegetables. Not only do they help fight inflammation, but they are a great source of antioxidants and other nutrients important for your health.
  • Whole grains. They have a low glycemic index. They are also a good source of fiber, and fiber helps flush inflammatory toxins out of the body.
  • Beans and other legumes. They should be your primary source of protein. They are high in fiber and contain antioxidants and other anti-inflammatory nutrients.
  • Nuts, olive oil, and avocados. They are good sources of healthy monounsaturated fats, which fight inflammation.
  • Fatty fish. Salmon, tuna, and sardines are all great sources of long chain omega-3 fatty acids, which are fish and fish oilincorporated into our cell membranes. Those long chain omega-3s in cell membranes are, in turn, used to create compounds that are powerful inflammation fighters.

Walnuts, flaxseeds, and chia seeds are good sources of short chain omega-3s. The efficiency of their conversion to long chain omega-3s that can be incorporated into cell membranes is only around 2-5%. If they fight inflammation, it is probably because they replace some of the saturated fats and omega-6 fats you might otherwise be eating.

  • Herbs and spices. They add antioxidants and other phytonutrients that fight inflammation.

Foods an anti-inflammatory diet excludes: In a nutshell, an anti-inflammatory diet should exclude highly processed, overly greasy, or super sweet foods, especially sodas and other sweet drinks. Specifically, your diet should exclude:

  • Refined carbohydrates, sodas and sugary foods. They have a high glycemic index, which is associated with inflammation. They can also lead to weight gain and high blood sugar, both of which cause inflammation.
  • Foods high in saturated fats. This includes fatty and processed meats, butter, and high fat dairy products.
  • Foods high in trans fats. This includes margarine, coffee creamers, and any processed food containing partly hydrogenated vegetable oils. Trans fats are very pro-inflammatory.
  • French fries, fried chicken, and other fried foods. They used to be fried in saturated fat and/or trans fat. Nowadays, they are generally fried in omega-6 vegetable oils. A little omega-6 in the diet is OK, but Americans get too much omega-6 fatty acids in their diet. Most studies show that a high ratio of omega-6 to omega-3 fatty acids is pro-inflammatory.
  • Foods you are allergic or sensitive to. Eating any food that you are sensitive to can cause inflammation. This comes up most often with respect to gluten and dairy because so many people are sensitive to one or both. However, if you are not sensitive to them, there is no reason to exclude whole grain gluten-containing foods or low-fat dairy foods from your diet.

Can Diet Douse The Flames?

FlamesIn case you didn’t notice, the recommendations for an anti-inflammatory diet closely match the other healthy diets I have discussed previously. It should come as no surprise then that both the Mediterranean (L. Gallard, Nutrition in Clinical Practice, 25: 634-640, 2010; L. Schwingshackl and G. Hoffmann, Nutrition Metabolism and Cardiovascular Diseases, 24: 929-939, 2014) and DASH (D.E. King et al, Archives of Internal Medicine, 167: 502-506, 2007) diets are anti-inflammatory.

Vegan and vegetarian diets also appear to be anti-inflammatory as well. The anti-inflammatory nature of these diets undoubtedly contributes to their association with a lower risk of heart disease, diabetes, and cancer.

As for the low-carb diets, the jury is out. There are no long-term studies to support the claims of low-carb proponents that their diets reduce inflammation. The few long-term studies that are available suggest that low-carb diets are only likely to be anti-inflammatory if vegetable proteins and oils replace the animal proteins and fats that are currently recommended.

What does this mean for you if you have severe arthritis or other inflammatory diseases? An anti-inflammatory diet is unlikely to “cure” your symptoms by itself. However, it should definitely be a companion to everything else you are doing to reduce inflammation.

The Bottom Line 

If you have arthritis, colitis, bursitis, or any of the other “itis” diseases, you already know that inflammation is the enemy. Chronic, low level inflammation is also a contributing factor to heart disease, cancer, and many other diseases. Clearly, inflammation is a bad actor. It’s something we want to avoid.

Obesity and diabetes are two of the biggest contributors to inflammation, but does diet also play a role? With all the anti-inflammation diets circulating on the internet, you would certainly think so. In this article I review the evidence that certain foods influence inflammation and describe what an anti-inflammatory diet looks like.

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?

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.

 

Does Diet Affect Sperm Quality?

Do Real Men Eat Meat?

Enjoying Red MeatMeat has a certain mystique among some men. They believe real men eat meat, especially red meat. The belief is that eating red meat makes them bigger, stronger, and more virile. In that world view, vegetarianism is effeminate.

How much of that is true? Let’s start by looking at the bigger and stronger part:

  • Animal proteins are higher in the branched chain amino acids, especially leucine, which help drive the increase in muscle mass associated with exercise. However, meat protein is digested slowly.
  • Milk protein is also high in branched chain amino acids and is digested more quickly. That’s why many body building supplements are whey protein based.
  • In addition, leucine is now being added to some of the plant protein supplements. Those supplements are often as effective as whey protein supplements at driving the increase in muscle mass associated with exercise

But what about virility? Does meat make men more virile? Fortunately, we now have an answer to these questions. A recent study (L Nassan et al., JAMA Network Open, 2020; 3(2) :e1921610) has looked at the effect of diet on sperm count and sperm quality.

How Was The Study Done?

Clinical StudyIn Denmark, all men are required to undergo a physical examination around age 18 to determine their fitness for military service. Research staff at the University Department of Growth and Reproduction at Rigshospitalet in Copenhagen approached young men undergoing their physical exams and invited them to participate in this study.

The men filled in a food frequency questionnaire, answered questions about their lifestyle and medical history and provided semen and blood samples for the study prior to undergoing their physical exam. 2935 men who were unaware of their fertility status and not using anabolic steroids were included in the data analysis.

The average age of participants in the study was 19 and 78% of them were of normal body weight.

The participants were divided into four groups based on their diet:

1.     Western Diet characterized by a higher intake of pizza, French fries, processed and red meats, snacks, refined grains, sugary beverages and sweets.

2.     Danish Diet characterized by a higher intake of cold processed meats, whole grains, fruits, mayonnaise, cold fish, condiments, and dairy.

3.     Vegetarian Diet characterized by a higher intake of vegetables, soymilk, and eggs, without red meat or chicken.

4.     Prudent (Healthy) Diet characterized by a higher intake of fish, chicken, vegetables, fruit, nuts, and water.

The effect of these diets on sperm count and sperm quality were compared.

Does Diet Affect Sperm Quality?

SpermWhen the authors measured sperm counts in the study participants, the results were as follows:

  • Greatest adherence to a prudent diet resulted in a sperm count of 167 million.
  • Greatest adherence to a vegetarian diet resulted in a sperm count of 151 million.
  • Greatest adherence to a Danish diet resulted in a sperm count of 146 million.
  • Greatest adherence to a Western diet resulted in a sperm count of only 122 million -27% lower than for men eating a prudent diet.
  • Similar results were reported for measure of sperm quality, such as sperm motility (how fast the sperm can swim) and normal sperm morphology (sperm without visible defects).
  • These results are similar to several earlier studies showing that men eating a healthy diet have greater sperm count and sperm quality.

The authors concluded: “Our findings support the evidence that adhering to generally healthy diet patterns is associated with better semen quality and more favorable markers of testicular function. Because diet is modifiable, these results suggest the possibility of using dietary intervention as a potential approach to improving testicular function in men of reproductive age.”

Do Real Men Eat Meat?

SteakNow it is time to come back to the original question, “Do real men eat meat”. Or more specifically, does red meat consumption increase virility? Of course, the whole question of whether a single food affects virility, or any other aspect of manliness, is bogus.

Individual foods don’t affect our health. Diets do. So, let’s review how diets affect men’s sperm count and sperm quality.

  • The highest sperm count and sperm quality was associated with the prudent diet. This diet relied primarily on fish and chicken as protein sources but did not exclude red meat. It was also a diet high in vegetables, fruits, nuts, and water (in place of sugary beverages).
  • The second highest sperm count and sperm quality was associated with the vegetarian diet. This diet relied on beans and eggs as the primary protein sources. It specifically excluded red meat and chicken but did not exclude fish. It was also high in fruits and nuts. Soy milk, tea, and coffee were the main beverages.
  • The third highest sperm count and sperm quality was associated with the Danish diet. This diet relied on cold processed meats (some of which were red meats), cold fish, and dairy for protein. However, it also was rich in whole grains and fruits. Water and sugary beverages were consumed in equal proportions.
  • The lowest sperm count and sperm quality was associated with the Western diet. This diet relied on red and processed meats as the primary protein source. However, it was also high in refined grains, snacks, sugary beverages, sweets, and junk foods.

So, if we are using sperm count and sperm quality as a measure of virility, it is clear that real men don’t eat red meat. Or put another way, a diet rich in red meat is more likely to reduce sperm count and sperm quality than it is to increase it.

However, a small amount of red meat as part of an overall healthy diet can be consistent with good sperm count and quality.

In short, diet does affect sperm quality. For example, based on this study:

  • An 8-ounce steak with French fries, cherry pie, and a soft drink (or, in our part of the country, sweet tea) may not be good for your sex life.
  • If you don’t want to give up red meat, a better choice might be 3-ounces of steak in a vegetable stir fry, fruit for dessert, and water or tea as your beverage.
  • If you want to maximize sperm count and sperm quality, an even better choice would be chicken, fish, or beans with vegetables, fruit for dessert, and water or tea as your beverage.

The Bottom Line

Meat has a certain mystique among some men. They believe real men eat meat, especially red meat. The belief is that eating red meat makes them bigger, stronger, and more virile.

How much of that is true. We already know that meat has no magical power to make men bigger and stronger. But what about virility? Does meat make men more virile? Fortunately, we now have an answer to that question. A recent study has looked at the effect of diet on sperm count and sperm quality.

  • The highest sperm count and quality was associated with a prudent diet. This diet relied primarily on fish and chicken as protein sources but did not exclude red meat. It was also a diet rich in vegetables, fruits, nuts, and water (in place of sugary beverages). In other words, it was a healthy diet.
  • The lowest sperm count and quality was associated with the Western diet. This is a diet that relies on red and processed meats as the primary protein source. However, it is also high in refined grains, snacks, sugary beverages, sweets, and junk foods.

So, if we are using sperm count and sperm quality as a measure of virility, it is clear that real men don’t eat red meat. Or put another way, a diet rich in red meat is more likely to reduce sperm count and quality than it is to increase it.

However, a small amount of red meat as part of an overall healthy diet can be consistent with good sperm count and sperm quality.

In short, it appears that diet does affect sperm quality:

  • An 8-ounce steak with French fries, cherry pie, and a soft drink (or, in our part of the country, sweet tea) may not be good for your sex life.
  • If you don’t want to give up red meat, a better choice might be 3-ounces of steak in a vegetable stir fry, fruit for dessert, and water or tea as your beverage.
  • If you want to maximize sperm count and sperm quality, an even better choice would be chicken, fish, or beans with vegetables, fruit for dessert, and water or tea as your beverage.

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