Do Whole Grains Keep Diabetes Away?

Are Whole Grains Healthy? 

Author: Dr. Stephen Chaney

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

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

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

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

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

How Was This Study Done?

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

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

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

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

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

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

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

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

Do Whole Grains Keep Diabetes Away?

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

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

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

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

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

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

Once again, the risk reduction was nonlinear.

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

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

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

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

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

Are Whole Grains Healthy?

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

Are Whole Grains Healthy?

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

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

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

Which Whole Grains Are Healthy?

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

However, there are some caveats:

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

Why Are Whole Grains Healthy?

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

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

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

In addition:

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

How Many Whole Grain Foods Should I Be Eating?

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

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

Are Low Carb Diets Healthy?

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

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

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

The Bottom Line

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

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

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

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

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

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

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

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

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

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

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.

 

Is The Paleo Diet Based On A Myth?

Are Starchy Foods Bad For Us? 

Author: Dr. Stephen Chaney

the paleo dietThe Paleo Diet is still very popular. And it does have its good points. It is a whole food diet. It eliminates sodas, junk foods, and highly processed foods. Any diet that does that can’t be all bad.

But is it unnecessarily restrictive? It eliminates starchy foods like grains, beans, peas, and corn. It is true that widespread consumption of these foods did not occur until after the agricultural revolution some 12,000 years ago. Our paleolithic ancestors probably did not consume significant quantities of these foods.

But did they consume other starchy foods? Our ideas about this have come primarily from comparing the diets of modern man with the diets of the few primitive hunter-gatherer populations that currently exist in our world. Based on that comparison, some Paleo advocates have concluded that the paleolithic diet contained few, if any, starchy foods.

More importantly, some Paleo advocates have gone a step further to assert that our bodies are not designed to eat starchy foods. They claim that foods like grains, legumes, corn, and potatoes are bad for us. They should be avoided.

How can we test whether these claims are true? After all, we don’t have any way of directly determining whether our paleolithic ancestors ate starchy foods or not. Or do we? That question is the topic of a new study (JA Fellows et al, PNAS, 118 No. 20 e2021655118 I will share with you today.

But first I need to acquaint you with what starch is and how we digest it. Once again, it is time for Biochemistry 101.

Biochemistry 101

professor owlStarch is simply a long polymer of glucose molecules. Digestion of starch starts in our mouth. Our saliva contains an enzyme called alpha-amylase that breaks the bond between adjacent glucose molecules. Alpha-amylase breaks starch down sequentially, first to maltodextrin (a shorter polymer of glucose molecules), then to maltose (two glucose molecules), and finally to glucose.

[Note: The nutrition gurus that tell you to read labels and avoid foods with maltodextrin are ignoring the fact that we produce maltodextrin naturally whenever we digest starch in the foods we eat.]

All humans contain the alpha-amylase gene. Simply put, that means that all humans have the potential to digest starchy foods.

However, not all humans have the same number of copies of the alpha-amylase gene. When we habitually consume a diet containing starchy foods, our bodies duplicate the alpha-amylase gene until our saliva contains enough alpha-amylase to easily digest the amount of starchy foods we are consuming. Simply put, that means our bodies are designed to easily adapt to the amount of starchy foods in our diet.

Most modern human populations have between six and 30 copies of the alpha-amylase gene. Our saliva contains a lot of alpha-amylase. However, the few primitive hunter-gatherer societies that still exist in our world have only two or three copies of the alpha-amylase gene. Their saliva contains very little alpha-amylase.

It is this difference that has led to the hypothesis that our paleolithic ancestors did not possess salivary alpha-amylase, which implies they didn’t eat starchy foods. This hypothesis also assumes that humans only began producing significant quantities of salivary alpha-amylase after the agricultural revolution when starchy foods like grains, rice, and beans became widely available.

This hypothesis is one of the central tenets of the Paleo diet. But we need to remember that it is just a hypothesis. It has not been directly tested because we thought there was no way to determine the starch content of the paleolithic diet – until now. However, before we get to the study that explodes this hypothesis, I want to revisit the Paleo Diet myths I described in an earlier issue of “Health Tips From The Professor”. I call this next section “Unicorns And The Paleo Diet”.

Unicorns And the Paleo Diet

the paleo diet and unicornsI titled this section “Unicorns and the Paleo Diet” because both are myths. In fact, the Paleo Diet is based on several myths.

Myth #1: Our ancestors all had the same diet. What we currently know as the Paleo diet is based on the diets of a few primitive hunter-gatherer societies that still exist in some regions of the world. However, when you look at the data more carefully, you discover that the diet of primitive societies varies with their local ecosystems.

The “Paleo diet” is typical of ecosystems in which game is plentiful and fruits and vegetables are less abundant or are seasonal. In ecosystems where fruits and vegetables are abundant, primitive societies tend to be more gatherers than hunters. They eat more fruits and vegetables and less meat.

The assumption that starchy foods were absent in the paleolithic diet is also a myth. For some primitive societies, starchy fruits or starchy roots are a big part of their diet. In short, our paleolithic ancestors ate whatever nature provided.

Myth #2: Our genetic makeup is hardwired around the “paleolithic diet”. In fact, humans are very adaptable. We are omnivores, which means we can eat whatever nature provides. We are designed to thrive in a wide variety of ecosystems. It is this adaptability that has allowed us to expand to every nook and cranny of the world.

For example, the enzymes needed to digest grains are all inducible, which means the body can turn them on when needed. Our paleolithic ancestors may not have eaten much grain, but we can very quickly adapt to the introduction of grains into our diet. As I described above, for alpha-amylase this adaptation occurs through gene duplication.

Myth #3: Our paleolithic ancestors were healthier than modern man: It some respects, the paleolithic diet is healthy, as I mentioned above. However, we need to remember that our paleolithic ancestors rarely lived past 30 or 40. They simply did not live long enough to experience degenerative diseases like heart disease and cancer. We have no idea whether a diet that served our paleolithic ancestors well will keep us healthy into our 70s, 80s and beyond.

How Was This Study Done?

Clinical StudyThis is a fascinating study, and one that would have been impossible just a few years ago. As I have described in previous issues of “Health Tips From the Professor”, studies on our microbiome, the bacteria that inhabit our bodies, is a rapidly evolving area of research.

When we talk about our microbiome, we generally think about our gut bacteria. However, the term “microbiome” includes all the bacteria that reside in our body, including those that reside in our oral mouth.

And, like our gut bacteria, the species of bacteria that reside in our mouth are heavily dependent on the foods we eat. Specifically, there are three species of oral bacteria that thrive on starch. They possess an “amylase binding protein” that allows them to capture salivary alpha-amylase and use it to break down dietary starch so they can use it as an energy source.

Consequently, the abundance of these three bacterial species in the oral microbiome is a precise marker for the amount of starch in a person’s diet. More importantly, high throughput DNA sequencing and supercomputers have made it simple to sequence all the bacteria in the oral microbiome and quantify the relative abundance of these three bacterial species.

You are probably thinking, “That’s fine, but how could you possibly determine the abundance of those bacteria in the mouth of a paleolithic human?” Here is where it gets really interesting!

The bacteria in our mouth form biofilms on our teeth, something we refer to as plaque. If the plaque remains on our teeth long enough, it calcifies, forming what is referred to as dental calculus (tooth tartar).

In the modern world we remove dental biofilms by brushing after every meal. We remove dental plaque and tartar by semi-annual visits to the dentist. But these are recent developments. They are not something our ancestors did.

Our ancestors simply accumulated dental calculus during their lifetime. More importantly, the dental calculus excluded air and water, so it preserved the DNA of the bacteria in their oral microbiome. That was the basis of the current study.

The study was a collaboration of 50 scientists over a 7-year period. The scientists sequenced 124 oral microbiomes from humanoid species in Africa, including Neanderthals (430,000 to 40,000 years ago), Late Pleistocene (129,000 to 11,700 years ago) humans, and modern-day humans.

Bacterial DNA from modern-day humans was obtained from dental calculus obtained during routine dental cleaning procedures by practicing dentists. The older DNA samples were obtained from dental calculus in the teeth of skeletal remains. The oldest DNA sample was obtained from a Neanderthal that lived around 100,000 years ago.

For comparison they also obtained bacterial DNA from the dental calculus of chimpanzees and gorillas, man’s closest primate relatives.

The species of bacteria in the oral microbiome from all these samples were determined by high throughput sequences and computerized analysis using high speed supercomputers.

Is The Paleo Diet Based On A Myth?

Question MarkThere were three important findings from this analysis:

  1. The species of bacteria in the oral microbiome of Neanderthals and Late Pleistocene humans was much more diverse than for modern humans. This suggests that their diets were more diverse (perhaps depending on what foods were available in their environment), while modern diets have become more standardized.

2) The species of bacteria that thrive on starchy foods were remarkably constant in the oral microbiome of all human species from Neanderthals to Late Pleistocene humans to modern-day humans.

3) The species of bacteria that thrive on starchy foods were virtually absent from the oral microbiomes of our most closely related primates – chimpanzees and gorillas.

The authors concluded, “This … supports an early importance of starch-rich foods in Homo evolution.”

In other words, our paleolithic ancestors likely did eat starchy foods. Their diet may not have contained grains, rice, or beans in significant quantities. However, they consumed whatever starchy roots, fruits, and vegetables they could find.

So, is the Paleo diet based on a myth? It depends on how you phrase the question.

  • If we ask whether our paleolithic ancestors consumed grains, rice, or beans, the answer is probably, “No”. The introduction of these foods in significant quantities probably depended on the agricultural revolution that occurred thousands of years later.
  • If we ask whether our paleolithic ancestors consumed starchy foods, the answer is probably, “Yes”. The foundation of the Paleo diet was based on a myth. Their oral microbiome contained bacterial species that thrived on starchy foods. In fact, starchy foods may have been an important staple in their diet because they are more calorie dense than other fruits and vegetables.
  • If we ask whether our paleolithic ancestors were capable of thriving on a diet that included grains, rice, and beans, the answer is also probably, “Yes”. The oral bacterial species that thrive on starchy foods do so by utilizing the alpha-amylase in human saliva. This means our paleolithic ancestors likely had enough alpha-amylase in their saliva to digest and to thrive on starchy foods like grains, rice, and beans.

Are Starchy Foods Bad For Us?

Starchy FoodsIt is not just the Paleo diet. Many popular diets have villainized starchy foods. Are starchy foods as bad for us as some “experts” would have you believe?

Let’s start by identifying starchy foods. If we think in terms of whole foods, they are:

  • Root vegetables (for example, potatoes, sweet potatoes, beets, carrots, and parsnips).
  • Legumes (for example, beans, peas, and lentils).
  • Grains (for example, wheat, rye, barley, oats, and rice).
  • Winter squash (for example, acorn squash, butternut squash, hubbard squash, and pumpkin).
  • Corn

These foods are good sources of nutrients and phytonutrients. Many of them are also excellent sources of fiber, including a special type of fiber called resistant starch. (I have described the benefits of resistant starch in a previous issue of “Health Tips From the Professor”.) These are foods that definitely deserve to be part of a healthy diet.

The only drawback of starchy vegetables is that they tend to be more calorie dense than other vegetables. While this was a “plus” for our paleolithic ancestors, it is not quite as advantageous in our modern world. If you are trying to watch your calories, my advice is to incorporate these foods into your diet sparingly.

However, there is another class of starchy foods you want to avoid. Of course, I am talking about highly processed foods made from grains, legumes, and corn. They retain all the calories but lose most of the nutrients, phytonutrients, and fiber of the foods they came from.

In short, starchy whole foods are a valuable part of a healthy diet. It is the starchy processed foods made from these whole foods you want to avoid. Of course, I am talking about bread, pasta, and pastries made from refined grains and sugar.

So, how do you know which starchy foods to avoid? My advice is not to become an expert label reader. Just eat foods without labels.

The Bottom Line

One of the founding principles on which the Paleo diet is based is that our paleolithic ancestors ate very few starchy foods, and the human body really isn’t designed to handle these foods. Accordingly, the Paleo diet recommends we should avoid starchy foods like grains and legumes. This has the unfortunate effect of creating an unbalanced diet that overemphasizes meat and animal fats.

But is this founding principle correct, or is it just a myth? When you look beneath the surface, you discover that it is a hypothesis based on the diets of the few primitive hunter-gatherer populations that still exist in our world.

It has been assumed that was as good an estimate of the paleolithic diet as we could get. After all there was no way to directly determine the starch content of the paleolithic diet – until now.

In this issue of “Health Tips From the Professor” I describe a novel approach that allowed scientists to determine the species of bacteria residing in the mouth of our humanoid ancestors based on the DNA extracted from the plaque coating their teeth. (For details on how this was done, read the article above.)

What the scientists found was that all human species, including a Neanderthal who died 100,000 years ago, harbored bacteria in their mouths that thrive on starchy foods.

The scientists concluded, “This … supports an early importance of starch-rich foods in Homo evolution.” In other words, our paleolithic ancestors likely did eat starchy foods. Restricting whole grains and legumes from the Paleo diet is based on a myth. They are an important part of a healthy diet.

For more details about the study and which starchy foods are bad for you, read the article above.

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

Should I Avoid Whole Grains?

Will Whole Grains Kill Me?

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

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

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

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

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

How Was The Study Done?

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

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

Will Whole Grains Kill Me?

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

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

That is not what this study showed.

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

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

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

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

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

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

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

Should I Avoid Whole Grains?

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

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

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

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

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

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

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

The Bottom Line

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

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

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

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

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

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

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

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

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

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

For more details read the article above.

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

Which Foods Should I Avoid?

What Is Nutritionism?

In Defense Of FoodRecently, I have been reading Michael Pollan’s book “In Defense of Food”. Yes, I know the book has been around for a long time. Normally I read the scientific literature rather than popular health books. However, in the past few weeks I have had a lot more time to read books, so I decided to read this one.

Some of the things he says are “off the wall”. As he readily admits, he isn’t a scientist or a medical doctor. However, a lot of what he says is “right on”. He echoes many of the things I have been talking about for years. But he does a masterful job of pulling everything together into a framework he calls “nutritionism”.

If you have a chance, I highly recommend that you read his book.

I will briefly summarize his discussion of nutritionism below. I will also share some scientific support for what he is saying. Finally, I will close by sharing what the Bible says on the subject.

What Is Nutritionism?

Low Fat LabelSimply put, nutritionism is the belief that we can understand food solely in terms of its nutritional and chemical constituents and our requirements for them. I use the term “belief” purposely. As Michael Pollan puts it: “As the ‘-ism’ suggests, nutritionism is not a scientific subject, but an ideology.”

What Michael Pollan is referring to is taking food constituents like saturated fats, cholesterol, sugar, carbohydrates, polyunsaturated fats, monounsaturated fats, fiber, antioxidants, and probiotics and labeling them as either “good” or “bad”.

As he points out, that leads to debacles like the creation of margarine as a substitute for butter. Of course, everyone reading this article knows that we subsequently found out that the trans fat in margarine was worse for us than the saturated fat in butter. He offers many other examples like this.

He also points out that the nutritionism concept has given free rein to the food industry to replace whole foods with processed foods that are cholesterol-free, sugar-free, low-fat, low-carb, or high in fiber, omega-3s, etc. He says that these foods are seldom healthier than the foods they replace. I agree.

Finally, he points out that the scientific support for the classification of individual ingredients or foods as “good” or “bad” is weak. That’s because when scientists design a study that removes a chemical constituent or a food from the diet, they have to replace it with something. And what they replace it with determines the outcome of the study. I give some examples of this in the next section.

The essence of Michael Pollan’s message is:

  • The effect of an individual nutrient or chemical constituent on your health depends on the food it is found in. Forget the fancy nutrition labels. Whole foods are almost always healthier than processed foods.
  • The effect of a food or food constituent on your health also depends on your overall diet. We should be thinking about healthy diets rather than the latest “magical” or “forbidden” food.

I will discuss these points below.

Which Foods Should I Avoid?

Question MarkNow, let’s get to the question, “Which Foods Should I Avoid?” If we are talking about whole foods, the short answer is “None”. As I said in my book, “Slaying The Food Myths”, “We have 5 food groups for a reason”.

For example, if we are talking about plant foods, each plant food group:

  • Has a unique blend of vitamins and minerals.
  • Has a unique blend of phytonutrients.
  • Has a unique blend of fiber.
  • Supports the growth of a unique combination of beneficial gut bacteria.
  • Dr Strangelove and his friends are telling you to eliminate whole grains, fruits, and legumes (beans) from your diet. Recent studies suggest that might not be a good idea. Here is one example.

If we are talking about animal foods, each animal food group:

  • Has a unique blend of vitamins and minerals.
  • May have unique components that are important for our health. [Note: This is an active area of research. Theories have been proposed for which components in animal foods may be important for our health, but they have not been confirmed.]
  • Vegan purists will tell you that you have no need for meat and dairy foods. Recent studies suggest otherwise. Here is one example.

With that as background, let’s turn our attention to nutritionism and look at some of science behind claims that certain food components are either good for us or bad for us.

Saturated Fat. Saturated fat is the poster child for nutritionism.lowfat

First, we were told by the American Heart Association and other health organizations that saturated fat was bad for us. Recently Dr. Strangelove and his friends are telling us that saturated fat is good for us. Instead of limiting saturated fat, we should be limiting carbs by cutting out fruits, whole grains, and legumes. Both cite clinical studies to support their claims. How can this be?

Perhaps a little history is in order. When the American Heart Association recommended that we decrease intake of saturated fat, they were envisioning that we would replace it with monounsaturated and polyunsaturated fat in the context of a healthy diet of fruits, vegetables, whole grains, and legumes. That never happened.

Big Food quickly realized that if the American public were to follow the AHA guidelines, it would be disastrous for their bottom line. So, they sprang into action. They mixed sugar, white flour, and a witch’s brew of chemicals to create highly processed, low fat “foods”. Then they told the American public, “Don’t worry. You don’t have to give up your favorite foods. We have created low fat alternatives.”

This is the essence of what Michael Pollan refers to as nutritionism. By marketing their fake foods as low fat Big Food created the halo of health. In fact, Big Food’s fake foods were less healthy than the foods they replaced. Americans got fatter and sicker.

Now let’s look at the conflicting claims that saturated fat is bad for us or good for us. How can clinical studies disagree on such an important question? The answer is simple. It depends on what you replace it with. You need to consider saturated fat intake in the context of the overall diet.

I discussed this in a previous issue of “Health Tips From the Professor”, but let me summarize it briefly here. The American Heart Association tells us that replacing half of the saturated fat in a typical American diet with:

  • Trans fats, increases heart disease risk by 5%.
  • Refined carbohydrates and sugars (the kind of carbohydrates in the typical American Diet), slightly increases heart disease risk.
  • Complex carbohydrates (whole grains, fruits & vegetables), decreases heart disease risk by 9%.
  • Monounsaturated fats (olive oil & peanut oil), decreases heart disease risk by 15%.
  • Polyunsaturated fats (vegetable oils and fish oil), decreases heart disease risk by 25%.
  • Unsaturated fats in the context of a Mediterranean diet, decreases heart disease risk by 45%.

My advice: Saturated fat is neither good for you nor bad for you. A little bit of saturated fat in the context of a healthy diet is fine. A lot of saturated fat in the context of an unhealthy diet is problematic.

fatty steakRed Meat. Is red meat bad for you? Like saturated fat, it depends on the amount of red meat and the overall diet. I covered this in detail in “Slaying The Food Myths”, but let me summarize briefly here:

According to the World Health Organization, red meat is a probable carcinogen. If we look at the postulated mechanisms by which it causes cancer, they can be mostly neutralized by components of various plant foods.

My advice: An 8-ounce steak with fries and a soda is probably bad for you. Three ounces of that same steak in a green salad or stir fry may be good for you.

I should make one other point while I am on the topic. Dr. Strangelove and his friends have been telling you that grass-fed beef is better for you than conventionally raised beef. Once again, that is nutritionism.  Grass-fed beef is lower in saturated fat and high in omega-3s than conventionally raised beef. That may be better for your heart, but it has no effect on the cancer-causing potential of red meat. It doesn’t give the license to eat 8-ounce steaks on a regular basis. You still want to aim for 3-ounces of that grass-fed beef in a green salad or stir fry. 

High-Fructose Corn Syrup. This one seems to be on everyone’s “naughty list”. You are being told to read labels, and if the food has high-fructose corn syrup on the label, put it back on the shelf. But is that good advice?

It turns out that all the studies on the bad effects of high-fructose corn syrup have been done with sodas and highly processed foods. This should be your first clue.

Of course, as soon as high-fructose corn syrup gained its “bad” reputation, Big Food started replacing it with Sugar Comparisons“heathier” sugars. Does that make those foods healthier?

The answer is a clear “No”. Both chemically and biologically, high-fructose corn syrup is identical to sucrose (table sugar), honey, molasses, maple syrup, coconut sugar, date sugar, or grape juice concentrate. Agave sugar is even higher in fructose than high-fructose corn syrup. This is your second clue.

Substituting these sugars for high-fructose corn syrup doesn’t turn sodas and processed foods into health foods. This is nutritionism at its worst.

My advice: Forget reading the label. Forget trying to avoid foods with high-fructose corn syrup. Avoid sodas and processed foods instead.

Sugar. Once the public started to realize that natural sugars in processed foods were just as bad for us as high-fructose corn syrup, sugars became “bad”. We were told to avoid all foods containing sugar in any form. In fact, we were told we needed to become “label detectives” and recognize all the deceptive ways that sugar could be hidden on the label.

Apple With Nutrition LabelI have discussed this in detail in a previous issue of “Health Tips From The Professor”.

Let me just summarize that article with one quote, “It’s not the sugar. It’s the food. There is the same amount and same types of sugar in an 8-ounce soda and a medium apple. Sodas are bad for you, and apples are good for you.” If you are wondering why that is, I have covered it in another issue of “Health Tips From the Professor”.

Before leaving this subject, I should mention that nutritionism has risen its ugly head here as well. Big Food has struck again. They have replaced sugar with a variety of artificial sweeteners.

Once again, nutritionism has failed. Those artificially sweetened sodas and processed foods are no healthier and no more likely to help you keep the weight off than the sugar-sweetened foods they replace. I have covered the science behind that statement in several previous issues of “Health Tips From the Professor”. Here is one example.

My advice: Forget about sugar phobia. You don’t need to become a label detective. Just avoid sodas, sugar-sweetened beverages, and sweet processed foods. Get your sugar in its natural form in fruits and other whole foods.

low carb dietCarbs. Dr. Strangelove and his friends are now telling you that you need to avoid all carbs. That is pure nutritionism. Carbs are neither good nor bad. It depends on the type of carb and what you replace it with.

Once again, clinical studies have given conflicting outcomes. Each side of the carbohydrate debate can provide clinical studies to support their position. How can that be? The answer is simple. It depends on what assumptions went into the design of the clinical studies. I have written several articles on this topic in “Health Tips From the Professor”, but let me give you one example here.

In this example, I looked at two major studies. The PURE (Prospective Urban Rural Epidemiology) study included data from 135,000 participants in 18 countries. In this study, the death rate decreased as the % carbohydrate in the diet decreased. The low-carb enthusiasts were doing a victory dance.

However, it was followed by a second, even larger study. The ARIC (Atherosclerosis Risk In Communities) study included 432,000 participants from even more countries. In this study, the death rate decreased as the % carbohydrate decreased to about 40%. Then a curious thing happened. As the % carbohydrate in the diet decreased further, the death rate increased.

How can you explain this discrepancy? When you examine the PURE study:

  • The % carbohydrate only ranged from 70% to 40%.
  • The data for the PURE study was obtained primarily with third world countries. That is an important distinction because:
    • In those countries, it is primarily the well to do that can afford sodas, processed foods, and meat.
    • The poor subsist on what they can grow and inexpensive staples like beans and rice.
  • Simply put, in the PURE study, the type of carbohydrate changed as well as the amount of carbohydrate.
    • At the highest carbohydrate intakes, a significant percentage of the carbohydrate came from sugar and refined grains.
    • At the lowest carbohydrate intakes, most of the carbohydrate intake came from beans, whole grains, and whatever fruits and vegetables they could grow.

When you examine the ARIC study:how much carbohydrates should we eat aric

  • The % carbohydrate ranged from 70% to 20%.
  • The ARIC study added in data from the US and European countries. That is an important distinction because:
    • Low carb diets like Atkins and Keto are popular in these countries. And those are the diets that fall into the 20-40% carbohydrate range.
    • Most people can afford diets that contain a lot of meat in those countries.
  • Simply put, at the lower end of the scale in the ARIC study, people were eating diets rich in meats and saturated fats and eliminating healthy carbohydrate-containing foods like fruits, whole grains and legumes.

My advice: The lesson here is to avoid simplistic nutritionism thinking and focus on diets rather than on foods. When you do that it is clear that carbs aren’t bad for you, it’s unhealthy carbs that are bad for you.

Which Foods Should I Avoid? By now the answer to the question, “Which Foods Should I Avoid?” is clear. Avoid sodas, sugar-sweetened beverages and processed foods (The term processed foods includes convenience foods, junk foods, and most sweets).

What Does This Mean To You?

Questioning ManNow that we are clear on which foods you should avoid, let’s look at the flip side of the coin. Let’s ask, “Which foods should you include in your diet?

As I said at the beginning of this article, “We have 5 food groups for a reason”. We should consider whole foods from all 5 food groups as healthy.

Of course, each of us is different. We all have foods in some food groups that don’t treat us well. Some of us do better with saturated fats or carbs than others. We need to explore and find the foods and diets that work best for us.

However, whenever we assume one diet is best for everyone, we have crossed the line into nutritionism.

What Does The Bible Say?

Let me start this section by saying that I rely on the Bible for spiritual guidance rather than nutritional guidance. However, as part of our church’s Bible reading plan, I was reading 1 Timothy. A passage from 1 Timothy 4:1-5 leapt out at me. It reinforces the theme of Michael Pollan’s book and seems uniquely applicable to the times we live in.

“The Spirit clearly says that in later times some will abandon the faith and follow deceiving spirits and things taught by demons. Such teachings come through hypocritical liars, whose consciences have been seared as with a hot iron. They…order people to abstain from certain foods, which God created to be received with thanksgiving by those who believe and who know the truth. For everything God created is good, and nothing is to be rejected if it is received with thanksgiving, because it is consecrated by the word of God and prayer.”

Interesting.

The Bottom Line

In this article, I have discussed the concept of “nutritionism” introduced in Michael Pollan’s book “In Defense Of Food”. He defines nutritionism as the belief that we can understand food solely in terms of its nutritional and chemical constituents and our requirements for them.

What Michael Pollan is referring to is taking food constituents like saturated fats, cholesterol, sugar, carbohydrates, polyunsaturated fats, monounsaturated fats, fiber, antioxidants, and probiotics and labeling them as either “good” or “bad”. He points out that when we accept these simplistic labels, we often end up creating foods and diets that are less healthy than the ones we were trying to replace.

At the beginning of the article, I asked the question, “Which Foods Should I Avoid?” I then looked at several foods or food groups we have told to avoid, including saturated fats, red meat, high-fructose corn syrup, sugar, and carbs. When you look at the science behind these recommendations from the lens of nutritionism, you come to two conclusions:

  • We should avoid sodas, sugar-sweetened beverages and processed foods (The term processed foods includes convenience foods, junk foods, and most sweets).
  • Whole foods from all 5 food groups should be considered as healthy.

Of course, each of us is different. We all have foods in some food groups that don’t treat us well. Some of us do better with saturated fats or carbs than others. We need to explore and find the foods and diets that work best for us.

However, whenever we assume one diet is best for everyone, we have crossed the line into nutritionism.

For more details and a bible verse that supports the theme of Michael Pollan’s book and seems uniquely applicable to the times we live in, read the article above.

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

Does Fiber Reduce Breast Cancer Risk?

Start Young And Finish Strong

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

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

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

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

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

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

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

How Was The Study Done?

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

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

Does Fiber Reduce Breast Cancer Risk?

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

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

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

Start Young And Finish Strong

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

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

When comparing the highest versus the lowest fiber intake:

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

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

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

Other important observations from this study were:

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

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

What Does This Mean For You?

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

Here are some thoughts to consider:

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

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

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

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

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

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

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

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

The Bottom Line

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

The first study showed that:

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

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

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

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

For more details read the article above.

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

Which Foods Affect Stroke Risk?

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.

 

Is The Impossible Burger Healthy For You?

Is The Impossible Burger Healthy For the Planet?

Vegan BurgerAmericans love their meat. In 2018 we averaged over 200 pounds of meat per person. If we just focus on beef, we eat about 54 pounds per year. That’s equivalent to four quarter pounders a week!

But we are also getting the message that too much meat, especially red meat, may be bad for us. Nearly 40% of us are trying to eat a more plant-based diet.

The problem is that we love the convenience of fast food restaurants, and we love our burgers. Plus, in the past the meatless burgers on the market were, in a word, disappointing. Their taste and texture left something to be desired. You really needed to be committed to a plant-based diet to eat them in place of a regular burger.

That all changed a few years ago with the introduction of the and new generation of meatless burgers – the Impossible Burger and the Beyond Burger. They had the taste and texture of a real burger, but they were completely plant-based. What wasn’t to like?

  • Both companies claimed that their meatless burgers were healthier for the planet than regular burgers. For example, Impossible Food’s mission statement is: “Animal agriculture occupies almost half the land on earth, consumes a quarter of our freshwater, and destroys our ecosystems. So, we’re doing something about it: We’re making meat using plants, so that we never have to use animals again”.
  • Neither company claims their burgers are healthier for you. However, because their burgers are plant-based, the almost universal assumption has been that they are healthier than regular burgers.

Since their introduction they have taken the world by storm. You can find them in almost every supermarket and in many of your favorite fast food restaurants. Now that they are omnipresent, it is perhaps time to step back and take a closer look at this new generation of meatless burgers. In this article, I will ask two questions:

  • Are they healthier for you than regular burgers?
  • Are they healthier for the planet than regular burgers?

For the sake of simplicity, I will focus on the Impossible Burger with occasional comparisons with the Beyond Burger. It is beyond the scope of this article to compare these burgers with the many other meatless burgers that are now starting to flood the marketplace.

What’s In The Impossible Burger?

  • When we think of a burger, the first thing we think of is protein. The Impossible Burger gets its protein from soy, while the Beyond Burger gets its protein from peas.

Coconut OilHowever, soy and pea protein don’t give you the mouth feel, flavor, red color, and texture of a beef burger.

  • The mouth feel of a burger comes from its saturated fat. Both the Impossible Burger and Beyond Burger use coconut oil as their source of saturated fat.
    • Coconut oil has gained a reputation as a “healthier” saturated fat. However, as I have discussed in my book, “Slaying The Food Myths”, we have no long term studies on the health effects of diets high in coconut oil. We don’t really know whether it is healthier than other saturated fats.
  • The taste and color of a beef burger come from its heme content. Heme does not occur in the parts of plants we eat. However, heme is involved in nitrogen fixation, so it is found in the roots of some legumes.
    • The Impossible Burger has genetically engineered yeast to produce a type of heme called leghemoglobin that is found in soy roots. The Beyond Burger uses beet juice extract and annatto for the color and unspecified “natural flavor” for the flavor.
  • To get the texture of a beef burger, both the Impossible Burger and the Beyond Burger use maltodextrin, modified food starch, and a variety of other ingredients. They are both highly processed foods.
  • Iron is another important nutrient you expect to get from a beef burger. The Impossible Burger contains 4.5 mg of iron and the Beyond Burger contains 5.4 mg of iron.
    • However, that is only part of the story. When iron is attached to a heme molecule, it is more efficiently absorbed by our bodies. Beef burgers and the Impossible Burger contain heme iron. The Beyond Burger does not.
  • In addition, the Impossible Burger adds in the vitamins, including B12, that we would expect to get from a beef burger. The Beyond Burger does not.

What Are The Pluses Of The Impossible Burger?

thumbs upThere are some definite pluses for the Impossible Burger and Beyond Burger:

  • Both the Impossible Burger and Beyond Burger are made from plant-based ingredients rather than from meat.
  • Both are cholesterol free.
  • Both contain modest amounts of fiber (3 grams for the Impossible Burger and 2 grams for the Beyond Burger), while a meat burger contains none.
  • Both are good sources of iron, and the iron in the Impossible Burger is heme-iron, which is efficiently absorbed by our bodies.

What Are The Minuses of the Impossible Burger?

thumbs downThere are, however, some definite minuses as well.

  • Both the Impossible Burger and Beyond Burger are high in saturated fat. The Impossible Burger is higher in saturated fat and the Beyond Burger contains the same amount of saturated fat as a real burger. That’s important because the latest advisory of the American Heart Association warns that saturated fat increases our risk of heart disease (I have discussed this finding in detail in a previous issue of “Health Tips From the Professor”).
    • The saturated fat in both burgers comes from coconut oil. However, as I discussed above, we don’t know whether coconut oil is better or worse for us than other saturated fats. The relevant studies have not been done.
  • Both the Impossible and Beyond burgers are high in sodium. They have almost 5-times more sodium than a beef burger.
  • The heme in red meat catalyzes the formation of N-nitroso compounds in our gut which increase the risk of colon cancer. We do not know whether the form of heme added to Impossible Burgers catalyzes the same reaction, but it is likely.
  • Both plant-based burgers are low in protein compared to a beef burger (~20 grams versus 27 grams). On the other hand, 20 grams of protein is reasonable for a single meal.
  • The plant proteins used for these burgers (soy for the Impossible Burger and pea for the Beyond Burger) are highly processed. They lack the phytonutrients found in the unprocessed proteins.
    • The isoflavones found in soy are thought to decrease the risk of cancer and osteoporosis.
    • The phytonutrients found in peas have antioxidant and anti-inflammatory benefits. They are also thought to decrease the risk of certain cancers.
  • The Impossible Burger is GMO. The leghemoglobin is produced by genetically engineered yeast, and the soy is also GMO.
  • Neither the Impossible Burger nor Beyond Burger are certified organic. Organic certification refers to how the plant was grown. Both burgers are highly processed. Many of the ingredients in both burgers came from factories, not farms.

Is The Impossible Burger Healthy For You?

Eating Impossible BurgerNow, it is time to return to the original question: “Is the Impossible Burger healthy for you?” Since it is plant-based, it would be easy to assume that it is healthier than a burger made from beef. However, when you look more closely, it is not clear that it is healthier.

The manufacturers of the Impossible Burger and similar burgers have gone to the laboratory and have been successful at creating meatless burgers with the taste, mouth feel, and texture of real burgers. However, these improvements have come with a price.

  • The Impossible Burger and similar burgers are higher in saturated fat than a beef burger. This means they may be just as likely to increase the risk of heart disease as a beef burger.
  • The Impossible Burger contains as much heme as a beef burger, which means it may be just as likely to increase the risk of cancer as a beef burger.
  • The Impossible Burger and similar burgers are highly processed. That means:
    • The plant proteins no longer contain the phytonutrients thought to be responsible for some of their health benefits.
    • They also don’t contain the vitamins you would expect to find associated with the plant proteins.
  • The Impossible Burger and similar burgers are not organic. Even worse, the Impossible Burger is GMO.

On balance, we can’t really assume the Impossible Burger is any healthier than the beef burgers it replaces. Plus, if you include the usual condiments and add fries and a soft drink, any slight health benefits of the Impossible Burger will be lost.

It would be much healthier to choose a bean burger. They don’t taste like beef, but many of them are quite tasty. Plus, if you do some label reading, you can find ones that use only whole, unprocessed ingredients.

For example, I looked up the Organic Sunshine brand South West Black Bean burgers. It only provides half as much protein as an Impossible Burger, but all the ingredients are organic, non-GMO, and minimally processed. Note: I am not recommending a particular brand. However, with a little research I am confident you can find a healthy meatless burger with a taste you will enjoy.

Is The Impossible Burger Healthy For the Planet?

impossible burger good for planetNow, let’s look at the second question: “Is the Impossible Burger healthy for the planet?” The answer to this question seems obvious. As the Impossible Burger company states in their mission statement: “Animal agriculture occupies almost half the land on earth, consumes a quarter of our freshwater, and destroys our ecosystems”. It seems logical that any meatless burger would be an improvement.

If we are talking about a minimally processed black bean burger, like the one I described above, the answer is a clear yes. It is healthier for the planet. However, when you look more closely at the Impossible Burger, the answer isn’t as clear.

  • As coconut oil has increased in popularity massive areas of untouched, forested land have been cleared for coconut plantations.
    • These forested areas provide an essential ecosystem for animals and provide natural storm protection by absorbing rainwater. Therefore, coconut oil, like beef, also destroys our ecosystems.
    • In addition, many of the coconut plantations use large amounts of chemical fertilizers which contribute to phosphate pollution and algae overgrowth in lakes, rivers, and coastal ocean areas. This also degrades our environment.
  • The Impossible Burgers and similar meatless burgers contain many highly processed ingredients. Each of these ingredients imposes its own environmental burden. For example:
    • Coconut oil is often processed with hexane, which is categorized as a hazardous air pollutant by the Environmental Protection Agency.
    • In addition, coconut oil is primarily grown in the Philippines, Indonesia, and India. Transporting it to this country generates significant greenhouse gas emissions.
    • And, of course, coconut oil represents only one of the many highly processed ingredients in the Impossible Burger and similar meatless burgers.

In short, the Impossible Burger may be slightly healthier for the planet than a beef burger, but it is much less environmentally friendly than your typical, minimally processed, bean burger.

The Bottom Line

Two weeks ago, I wrote about recent headlines claiming that the best advice for the American public was to eat as much red meat as they like. I looked at the study behind the headlines and pointed out the many flaws in that study.

Last week I wrote about headlines claiming that red meat was just as heart healthy as white meat. I looked at the study behind the headlines and showed it was an excellent example of how the beef industry influences the design of clinical trials to minimize the health risks of red meat. It is also an example of how the media misleads and confuses the public about the effect of nutrition on their health.

What the studies I reviewed the last two weeks really showed was that very small amounts (2-3 ounces) of very lean red meat is probably OK as part of a healthy diet like the Mediterranean diet. Larger servings of fattier cuts of red meat as part of the typical American diet is problematic.

However, if you love your burgers, what are you to do? Are the meatless burgers like the Impossible Burger and Beyond Burger that are showing up in your favorite fast food restaurants the answer? Specifically, you are probably asking:

  • Is the Impossible Burger, and similar burgers, healthy for you?
  • Is the Impossible Burger, and similar burgers, healthy for the planet?

I looked at the composition, pluses, and minuses of this new generation of meatless burgers in this article. The bottom line is:

  • On balance, the Impossible Burger is only slightly healthier than the beef burgers it replaces. And, if you include the usual condiments and add fries and a soft drink, any slight health benefits of the Impossible Burger will be lost.

It would be much healthier to choose a bean burger. They don’t taste like beef, but many of them are quite tasty. Plus, if you do some label reading, you can find ones that are organic, non-GMO, and use only whole, unprocessed ingredients.

  • Similarly, the Impossible Burger may be slightly healthier for the planet than a beef burger, but it is much less environmentally friendly than your typical, minimally processed, bean burger.

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.

Is The Paleo Diet Bad For Your Heart?

Is The Paleo Diet Bad For Your Gut?

the paleo dietThere is a lot to like about the Paleo diet:

·       It is a whole food diet. Any diet that eliminates sodas, junk foods, and highly processed foods is an improvement over the American diet.

·       It includes lots of vegetables and some fruits.

·       It helps you lose weight, and any diet that results in weight loss improves your blood work – things like cholesterol, triglycerides, blood sugar control and more.

However, there are concerns the Paleo diet may not be healthy long term.

·       In part, that is because the diet is high in meat, red meat, and saturated fat.

·       Equally important, however, is what the diet eliminates – namely whole grains, legumes (beans), and dairy.

Those of you who have read my book, “Slaying The Food Myths”, know that I say: “We have 5 food groups for a reason”. This is particularly true for the plant food groups. That’s because each plant food group provides a unique blend of:

·       Vitamins and minerals. Those can be replaced with good multivitamin/multimineral supplement.

·       Phytonutrients. You can only get the full complement of health-promoting phytonutrients from a variety of foods from all 5 food groups.

·       Fiber. There are many kinds of fiber and they each play different roles in our intestine. You can only get all the health-promoting varieties of fiber by consuming fruits, vegetables, whole grains and legumes.

·       Gut bacteria. What we call fiber, our gut bacteria call food. Each of the plant food groups supports different populations of friendly gut bacteria.

Based on this reasoning, one might suspect that the Paleo diet might alter our gut bacteria in ways that could be bad for our health. Until recently, this sort of reasoning was just a theoretical concern. That’s because:

1)    We knew far too little about the health effects of different populations of bacteria. This is rapidly changing. Several recent studies have systematically investigated the connection between gut bacteria and health outcomes.

2)    We knew our diet influenced the bacteria populations found in our gut, but we had no understanding of how these changes might influence our health. This too is changing. The study (A Genoni et al, European Journal of Nutrition, https://doi.org/10.1007/s00394-019-02036-y) I discuss this week is an excellent example of recent studies linking diet, gut bacteria, and risk factors for disease.

How Was The Study Done?

can you believe clinical studies doctorThis study recruited 91 participants from Australia and New Zealand. It was a very well designed study in that:

·       The Paleo diet group (44 participants) was recruited based on self-proclaimed adherence to the Paleo diet (< 1 serving/day of grains and dairy products) for one year or more. This is important because short term effects of switching to a new diet are confounded by weight loss and other factors.

o   After analyzing the diets of the Paleo group, the investigators found it necessary to subdivide the group into Strict Paleo (< 1 serving/day of grains and dairy products) and Pseudo-Paleo (> 1 serving/day of grains and dairy).

·       The control group (47 participants) was recruited based on self-proclaimed adherence to a “healthy diet” for 1 year or more with no change in body weight (A healthy diet was defined as a whole food diet containing a variety of foods from all 5 food groups). This is important because far too many studies compare the diet they are promoting to an unhealthy diet with a lot of sugar and highly processed junk foods. These studies provide little useful information because almost anything is better than an unhealthy diet.

·       The participants completed a diet survey based on the frequency of consumption of various foods during the previous year. However, because diet surveys based on the recollection of participants can be inaccurate, the investigators used two rigorous tests to validate the accuracy of those diet surveys.

o   The first was a 3-day weighed dietary record (WDR). Simply put, this means that participants weighed and recorded all foods and beverages before they were eaten for 3 days. Two of those days were weekdays, and one was a weekend day.

o   Secondly, the investigators used blood, urine, and metabolic measures to independently determine protein and energy intake of each participant. Participants who were identified by these means as under reporting both protein and energy were considered unreliable dietary reporters and were excluded from the analysis.

o   It is very rare to find a study that goes to this length to validate the accuracy of the dietary data used in their analysis.

The participants also provided blood, urine and stool samples and completed a physical activity assessment.

What Were The Differences Between The Paleo Diet And The Healthy Control Diet?

Paleo FoodsOnly the Strict Paleo Diet group was faithfully following the Paleo diet. In addition, most of the results with the Pseudo Paleo Diet Group were intermediate between the other two diets. Therefore, to simplify my discussion of this study I will only compare the Strict Paleo Diet group, which I refer to as the Paleo Diet group, with the Healthy Diet control group.

The Paleo diet emphasizes fresh vegetables, especially green leafy vegetables, and discourages grains. Thus, it is no surprise that:

·       The Paleo Diet group ate 74% more vegetables and 3 times more leafy green vegetables than the Healthy Diet group.

·       The Paleo Diet group ate only 3% of the grains and 3% of the whole grains compared to the Healthy Diet group.

The Paleo diet encourages consumption of meat and eggs and discourages consumption of dairy and plant proteins. Thus, it is not surprising that:

·       The Paleo Diet group ate 3 times more red meat and 5 times more eggs than the Healthy Diet group.

·       The Paleo Diet group ate 10% of dairy foods compared to the Healthy Diet group.

·       The Paleo Diet group consumed two times more saturated fat and cholesterol than the Healthy Diet group.

The most interesting comparison between the two diets was the following:

·       Intake of total fiber, insoluble fiber, and soluble fiber was comparable on the two diets.

·       However, intake of resistant starch was 50% lower in the Paleo Diet group. This is significant because:

o   Resistant starch is a type of fiber found primarily in whole grains, legumes, potatoes, and yams (Potatoes and yams are also dietary “no nos” on most low-carb diets).

o   Resistant starch is an especially good food for certain species of healthy gut bacteria.

Is The Paleo Diet Bad For Your Gut?

Bas BacteriaBecause resistant starch affects gut bacteria, the study next looked at the effect of the two diets on the populations of gut bacteria. This is where the story starts to get interesting. When they looked at different groups of gut bacteria, they discovered that:

·       Bifidobacteria were much more abundant in the Healthy Diet group than in the Paleo Diet group, and the amount of Bifidobacteria in the gut was directly proportional to the amount of whole grains in the diet.

o   This is important because previous studies have suggested Bifidobacteria help maintain intestinal barrier integrity and protect against irritable bowel syndrome and obesity.

·       Roseburia were also much more abundant in the Healthy Diet group and proportional to the amount of whole grains in the diet.

o   This is important because previous studies have suggested Roseburia protect against inflammatory bowel diseases like Crohn’s disease and ulcerative colitis.

·       Hungatella were much more abundant in the Paleo Diet group and were inversely proportional to the amount of whole grains in the diet.

o   This is important because Hungatella metabolize carnitine and choline, which are found in meats (especially red meats), egg yolks, and high fat dairy, into a compound called trimethylamine or TMA. TMA is then further metabolized in the liver to trimethylamine-N-oxide, or TMAO.

o   TMAO is a bad player. It is positively associated with heart disease, stroke, kidney disease, diabetes, and Alzheimer’s disease. However, the evidence is strongest for heart disease. TMAO has been called an independent risk factor for cardiovascular death.

Because of this, the study looked at TMAO levels in the blood of the two diet groups. These results were concerning:

·       TMAO levels were 2.5-fold higher in the Paleo Diet group than in the Healthy Diet group.

·       As might be expected, TMAO levels were positively correlated with red meat intake and inversely proportional to whole grain intake.

Is The Paleo Diet Bad For Your Heart?

heart diseaseWhen you put all the evidence together you have a compelling argument that the Paleo diet is likely to increase the risk of heart disease. Let me summarize the data briefly:

1)    The Paleo diet discourages the consumption of whole grains.

2)    Whole grains are a major source of a dietary fiber called resistant starch.

3)    Because the Paleo diet is low in resistant starch, it causes a decrease in two healthy types of gut bacteria and an increase in a type of gut bacteria called Hungatella.

4)    Hungatella metabolize compounds found in meat, eggs, and dairy to a precursor of a chemical called TMAO. This study showed that TMAO levels were 2.4-fold higher in people consuming a Paleo diet.

5)    TMAO is associated with coronary artery disease and is considered an independent risk factor for cardiovascular death.

The authors of the study concluded: “Although the Paleo diet is promoted for improved gut health, results indicate long-term adherence is associated with different gut microbiota and increased TMAO. A variety of fiber components, including whole grain sources, may be required to maintain gut and cardiovascular health.”

Of course, studies like this are looking at associations. They are not definitive. What we need are long term studies looking at the effect of the Paleo diet on heart disease outcomes like heart attack and stroke. Until we have these studies my advice is:

·       Don’t accept claims that the Paleo diet is heart healthy. There are no long-term clinical studies to back up that claim.

·       Be aware that the Paleo diet affects your gut bacteria in ways that may be bad for your heart.

The more we learn about our gut bacteria, the more we appreciate the importance of including all 5 food groups in our diet, especially all the plant food groups.

Are Low Carb Diets Healthy?

low carb dietThe Paleo diet is not the only diet that is high in red meat and low in whole grains. The same is true for virtually all the popular low-carb diets. There are studies showing other low-carb diets also alter gut bacteria and raise TMAO levels, so there is a similar concern that they may also increase the risk of heart disease.

This is in addition to concerns about the high saturated fat consumption which increases the risk of heart disease and red meat consumption, which may increase the risk of certain cancers.

Finally, there are no studies showing that any low-carb diet is healthy long term, even the Atkins diet, which has been around for more than 50 years. Until we have long-term studies about the health consequences of low-carb diets, my advice is similar to that for the Paleo diet.

·       Don’t accept claims that low-carb diets are healthy. There are no long-term clinical studies to back up that claim.

·       Be aware that low-carb diets affect your gut bacteria in ways that may be bad for your health.

The Bottom Line

A recent study looked at the effect of the Paleo diet on an important risk factor for heart disease. Here is a brief summary of the data:

1)    The Paleo diet discourages the consumption of whole grains.

2)    Whole grains are a major source of a dietary fiber called resistant starch.

3)    Because the Paleo diet is low in resistant starch, it causes a decrease in two healthy types of gut bacteria and an increase in a type of gut bacteria called Hungatella.

4)    Hungatella metabolize compounds found in meat, eggs, and dairy to a precursor of a chemical called TMAO. This study showed that TMAO levels were 2.4-fold higher in people consuming a Paleo diet.

5)    TMAO is associated with coronary artery disease and is considered an independent risk factor for cardiovascular death.

Of course, studies like this are looking at associations. They are not definitive. What we need are long term studies looking at the effect of the Paleo diet on heart disease outcomes – like heart attack and stroke. Until we have these studies my advice is:

·       Don’t accept claims that the Paleo diet is heart healthy. There are no long-term clinical studies to back up that claim.

·       Be aware that the Paleo diet affects your gut bacteria in ways that may be bad for your heart.

·       Virtually all the popular low-carb diets discourage consumption of whole grains, so my advice for them is the same as for the Paleo diet.

The more we learn about our gut bacteria, the more we appreciate the importance of including all 5 food groups in our diet, especially all the plant food groups.

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

Health Tips From The Professor