Is Fructose Good For You Or Bad For You?

Is It The Fructose Or Is It The Food?

Author: Dr. Stephen Chaney

VillainFructose is the villain of the day. It is #1 on everyone’s “No-No” list. Almost every website, blog, and diet book demonize it. Even authors I highly respect say we should absolutely avoid it.

We are told it causes obesity, diabetes, heart disease, and non-alcoholic fatty liver disease – a disease that was unheard of only a few decades ago. We are told to read labels and avoid any foods with fructose or high-fructose corn syrup listed on their label.

But wait. Isn’t fructose a natural sugar? The answer is, “Yes”. It is the main sugar in fruit and many other naturally sweet whole foods. In fact, there is the same amount of fructose in an 8-ounce soda and a medium apple.

Does that mean that fruits are also bad for us? What is the truth?

Is It The Fructose Or Is It The Food?

AppleLet me put this into perspective for you. I have covered this in detail in a previous issue of Health Tips From The Professor. Here is a brief summary.

  • There are no sugar villains. There are no sugar heroes. Most of your favorite “natural” sugars are chemically and biologically indistinguishable from high-fructose corn syrup. Other natural sugars, like agave sugar, contain more fructose than high-fructose corn syrup.
  • All the studies showing the bad effects of fructose have been done with sodas and/or highly processed foods with added sugar. Let’s be clear. Those foods are bad for you.
  • Fruits, on the other hand, are good for you. You’ve heard the old adage, “An apple a day keeps the doctor away”. A recent study showed that isn’t just an “old wives’ tale”. It is true.

Why is that? Why is fructose in sodas and junk foods bad for us and fructose in fruits good for us?

Part of the answer is that fruits are high in fiber, which slows the release of fructose into the intestine as fruits are digested. In addition, the fructose in fruits is trapped in a cellular matrix, which also slows the release of fructose during digestion.

Sodas and highly processed foods, on the other hand, have nothing to slow the release of fructose. It is immediately available as soon as the food reaches the intestine.

A recent study sheds light on why the rate of fructose release in our intestine may be important. The study showed:

  • When fructose is released slowly our bodies know exactly what to do with it.
    • Most of it is metabolized by the cells that line our intestine, and the rest is metabolized by the liver.
    • In both cases fructose is converted to glucose and slowly released into the bloodstream.
    • This stabilizes blood sugar levels.
  • When fructose is released quickly our bodies are overwhelmed and bad things happen.
    • The intestine passes the excess on to the liver, and the liver converts it to fat rather than glucose.
    • The fat is stored in the liver.
    • This leads to insulin resistance, diabetes, heart disease, and fatty liver disease.

But could the fiber in fruits have other beneficial effects such as supporting populations of beneficial gut bacteria? The study ( J Beisner et al, Nutrients, 12: 3444, 2020) I will focus on today suggests the answer is yes.

How Was The Study Done?

Clinical StudyInvestigators from the University of Hohenheim, Germany recruited 12 healthy female volunteers, ages 20 – 40 (average age = 28).

Each of the subjects was given a series of diets to follow for one week each.

  • Week one was a low fructose diet (10 g of fructose/day). For this diet phase subjects had to avoid sweets, highly processed foods, sodas, and fruits and vegetables containing more than 1 g of fructose per serving.
  • Week two was a high fructose fruit diet (100 g of fructose/day). This diet phase emphasized fructose-rich fruits and vegetables. Sweets, highly processed foods, and sodas had to be avoided.
  • Week three was a repeat of the low fructose diet (10 g of fructose/day).
  • Week four was a high-fructose corn syrup diet (100 g of fructose/day). For this diet phase subjects had to sweeten the food they were eating with a measured amount of high-fructose corn syrup. They also had to avoid fructose-rich fruits and vegetables.

The diets were designed to have around 2,000 calories/day and to have the same amounts of fat (30% of calories), protein (15% of calories), and carbohydrate (55% of calories). However, the fiber content of the diets was very different (around 17 g/day on the low fructose and high-fructose corn syrup diets and around 38 g/day on the high fructose fruit diet).

The subjects were given detailed instructions and training before starting on the 4-week program. They also kept a daily dietary record of everything they ate and drank so the investigators would know how closely they stuck to their dietary instructions.

This experimental design was based on previous studies showing that populations of gut bacteria change within 24-48 hours when you go on a new diet. Stool samples were collected at the end of each week and analyzed for gut bacteria.

Is Fructose Good For You Or Bad For You?

MicrobiomeThe study showed:

  • Consumption of a high-fructose, fruit-rich diet resulted in:
    • An increase in beneficial butyrate-producing bacteria (more about that below).
    • A decrease in bacteria associated with elevated total and LDL cholesterol.
    • Decreased blood levels of total and LDL cholesterol.
  • Consumption of a high-fructose corn syrup diet had the opposite effect. It resulted in:
    • A decrease in beneficial butyrate-producing bacteria.
    • An increase in bacteria associated with elevated total and LDL cholesterol.
    • Increased blood levels of total and LDL cholesterol.

The authors concluded: “We provide evidence that the high-fructose corn syrup diet induces an imbalanced microbiota [gut bacteria] profile characterized by a significantly reduced abundance of beneficial butyrate-producing bacteria and of bacteria known for anti-obesity effects…Despite the high fructose content, the fruit-rich diet shifts the intestinal microbiota composition in a protective manner…”

The authors said that there were probably two mechanisms for the different effects of fructose in high-fructose corn syrup and in fruits.

  • The fiber found in fruit supports the growth of beneficial bacteria in our intestine.
  • When high-fructose corn syrup is present in foods with low fiber content, it is released rapidly in the intestine. As I noted above, the cells that line our intestine become overwhelmed and pass some of that excess fructose on to our liver. However, the authors cited previous studies showing that some of that excess fructose remains in our intestine and supports the growth of unhealthy bacteria.

What Does Butyrate Do?

Question MarkYou are probably wondering what is special about butyrate-producing bacteria. Here is a brief synopsis.

  • Butyrate is a short chain fatty acid. As you might expect from its name, it was originally identified as a constituent of butter.
  • Some species of gut bacteria convert the fats in our diet to butyrate.
    • It is used as a preferred energy source for the cells that line our intestine. Consequently, butyrate production in our intestines has been linked to:
      • Reduced inflammation of the cells lining our intestine, which reduces the risk for diseases like inflammatory bowel disease (IBS) and Crohn’s Disease.
      • Reduced risk of “leaky gut syndrome”.
      • Reduced risk of colon cancer.
    • It is also absorbed into the bloodstream and appears to affect several metabolic pathways. For example, butyrate production in the intestine is associated with:
      • Decreased cholesterol levels.
      • Improved blood sugar control.
      • A healthy body weight.

What Does This Mean For You?

Questioning ManThis was a small study. As the authors noted, larger studies of longer duration are needed to confirm that the effects of fructose on our gut bacteria depend on the food the fructose is in. However, several other studies have come to similar conclusions.

More importantly, this study merely shows that the effect of fructose-containing foods on our gut bacteria is a potential mechanism for explaining why the effect of fructose depends on the food it is in.

There is already overwhelming evidence that fructose in fruits is good for us, while high-fructose corn syrup in sodas and highly processed foods is bad for us.

Does that mean high-fructose corn syrup is villainous? Should we read labels and avoid any food containing high-fructose corn syrup?

I would remind you that the amount of fructose and the relative abundance of fructose and glucose are virtually identical in fruits and high-fructose corn syrup. It is not high-fructose corn syrup that is the problem, it is the foods it is found in.

We don’t need to become compulsive label readers. We just need to eat more foods without labels.

The Bottom Line 

High-fructose corn syrup has been vilified in recent years. However, there is increasing evidence that it is not fructose that is the problem. It is the foods it is found in.

A recent study was designed to test that hypothesis. The investigators fed subjects high fructose diets in which the fructose came either from fruits or high-fructose corn syrup. The amount of fructose was identical in the two diets. The investigators then asked what effect the two diets had on gut bacteria. In short:

  • Consumption of the high-fruit diet increased healthy levels of beneficial gut bacteria and suppressed levels of unhealthy gut bacteria.
  • Consumption of the high-fructose corn syrup diet had the opposite effect. It increased unhealthy bacteria and suppressed beneficial bacteria.

The authors concluded: “We provide evidence that the high-fructose corn syrup diet induces an imbalanced microbiota [gut bacteria] profile characterized by a significantly reduced abundance of beneficial…bacteria and of bacteria known for anti-obesity effects…Despite the high fructose content, the fruit-rich diet shifts the intestinal microbiota composition in a protective manner…”

My take is as follows: This study shows that the effect of fructose-containing foods on our gut bacteria is a potential mechanism for explaining why the effect of fructose depends on the food it is in.

There is already overwhelming evidence that fructose in fruits is good for us, and high-fructose corn syrup in sodas and highly processed foods is bad for us.

Does that mean that high-fructose corn syrup is villainous? Should we read labels and avoid any food containing high-fructose corn syrup?

I would remind you that the amount of fructose and the relative abundance of fructose and glucose is virtually identical in fruits and high-fructose corn syrup. It is not high-fructose corn syrup that is the problem, it is the foods it is found in.

We don’t need to become compulsive label readers. We just need to eat more foods without labels.

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.

Could Mom’s Stress Affect Her Baby’s Health?

How Can You Minimize Stress During Pregnancy?

StressIf you are pregnant, the advice you see on the internet can be overwhelming. There are so many things you “must do” and so many things you “must avoid” if you want a healthy baby. It’s enough to stress you out.

As if that weren’t bad enough, we are probably living through the most stressful period in recent memory. So, the last thing you want to hear is that your stress during pregnancy can affect the health of your baby.

Before I go any further, let me make it clear that the studies I will discuss in this issue of “Health Tips From the Professor” are intriguing, but they are preliminary. I don’t want to add to your stress.

Let me start by reviewing the literature:

  • Several studies suggest that stress during pregnancy is associated with preterm birth, low birthweight, and infant mortality.
  • Other studies suggest that stress during pregnancy is associated with suboptimal cognitive development, hyperactivity, and asthma in the offspring.

The big question, of course, is how a mom’s stress during pregnancy can affect the health of her child months or years later. One hypothesis is that stress affects the mom’s gut bacteria, and those gut bacteria are passed along to the child as he or she passes through the birth canal.

We know that stress can affect your gut bacteria, but can it affect your child’s gut bacteria? Studies in mice suggest it can. Today I will discuss the first large clinical study (AK Aatsinki et al, Pyschoneuroendocrinology, 119 (2020) 104754) designed to evaluate that hypothesis in humans.

How Was This Study Done?

Clinical StudyThis study was an offshoot of an ongoing FinnBrain Cohort Project, which aims to study the influence of stress exposures during pregnancy on later childhood development and health outcomes. This particular study was designed to investigate the role of chronic stress during pregnancy on the population of gut bacteria in infants. There were 399 mothers and their babies who completed this study.

All Participants in the FinnBrain Project:

  • Filled out self-reported prenatal questionnaires at gestational weeks 14, 24, and 34. These questionnaires provided background information about the health, weight, age, and education level of the moms, as well as whether they were taking antidepression medications during their pregnancy.
  • Were also asked about breast feeding 2.5 months after giving birth.
  • Duration of gestation, birth weight, and method of delivery information were obtained from Finland’s National Institute for Health and Welfare.

Participants in this study:

  • Were evaluated for depression and anxiety symptoms three times during pregnancy and at 3 months after giving birth. It should be noted that the questionnaires used to evaluate depression and anxiety symptoms did not measure the stressors (events causing the stress). Instead they were measuring the mom’s response to those stressors.
  • Cortisol levels were measured at gestational week 24 as another measure of the mother’s stress level.
  • Fecal samples were obtained from the offspring at the age of 2.5 months and analyzed for the population of gut bacteria.

Could Mom’s Stress Affect Her Baby’s Health?

Bad BacteriaThe results of this study were intriguing:

Infants born to mothers who experienced high levels of stress (such as depression and/or anxiety) during pregnancy had an increased abundance of potentially pathogenic gut bacteria such as:

  • Serratia, Haemophilus, Citrobacter, and Campylobacter from the Proteobacteria group of bacteria.
  • Veillonella and Finegoldia from the Firmicutes group of bacteria.

In addition, infants born to mothers with elevated cortisol levels (another measure of stress) had decreased abundance of potentially health promoting gut bacteria such as Lactobacillus.

In contrast:

  • Infants born to mothers who experienced low levels of stress had increased levels of potentially health promoting gut bacteria, such as Akkermansia.
  • Infants born to mothers with low cortisol levels had an increased abundance of Lactobacillus in their gut.

In short:

  • High levels of stress in the mother during pregnancy are associated with an increased abundance of unhealthy bacteria in their baby’s intestine.
  • Low levels of stress in the mother during pregnancy are associated with an increased abundance of healthy bacteria in their baby’s intestine.

The authors concluded:

“The observed fecal bacteria signature in the infants with exposure to chronic maternal stress, such as increased abundance of potentially inflammatory bacteria from the Proteobacteria group of bacteria, warrant future follow-up of these children, since similar alterations of fecal bacteria have previously been associated with adverse health outcomes such as asthma in children.

The results of this study describe only associations, yet corroborate certain interesting findings reported in earlier literature and offer hypotheses for future mechanistic studies.”

How Can You Minimize Stress During Pregnancy?

Simply put, this study shows that chronic stress during pregnancy increases populations of gut bacteria in the newborn that are associated with adverse health outcomes in children. More studies are needed to confirm and understand this observation, but it raises an issue that is often ignored.

Pregnancy can be a stressful time, especially if you are a first-time mom. Plus, we are living in the most stressful time any of us can remember. So, this study is particularly relevant today.

However, let’s put this into perspective. It’s not the stress in our lives that harms us. It is how we respond to the stress. This study did not measure stress, per se. It measured depression, anxiety, and cortisol levels associated with the stress.

Some of the women in this study had very low levels of all three. It wasn’t that they led stress-free lives. They simply coped better with stress. So, the real question isn’t how to minimize stress. It’s how to better cope with stress. Here are some suggestions.

1) Take time to relax. What you do with this time will be different for each of you. Think about what kind of activity relaxes you the most. Here are some suggestions.

    • Meditation or prayer.
    • Yoga or Tai chi.
    • Watching a comedy.
    • Listening to your favorite music.

2) Make time for hobbies. Again, these would be different for each of you. They should be something that you enjoy and engages your mind. Examples include:

    • Reading.
    • Creating your favorite art. It could be painting, pottery, or knitting, for example.
    • Playing your favorite sport such as golf or tennis.
    • Doing puzzles.
    • Playing cards or board games.
    • Watching a movie.

3) Exercise on a regular basis. Exercise produces endorphins that elevate your mood. It’s even better if you are exercising outdoors so you can enjoy nature or listening to your favorite music while you exercise.

4) Relax your muscles. This is particularly important after you have exercised. Examples include:

    • Do some stretching exercises.
    • Take a luxurious hot bath.
    • Set a regular time to go to bed and get a good night’s sleep.
    • Get a massage.

5) Eat a healthy diet. Studies have shown that people who eat lots of junk and processed foods tend to be depressed and anxious. Aim for a whole food diet with lots of fruits and vegetables. That kind of diet is best for your baby as well.

6) Try deep breathing exercises.

7) Ask for support from your family members, especially if they are stressors in your life.

8) Talk with someone. Find a friend or family member who is willing to listen and support you.

In short, take care of yourself. Don’t let stress affect your health and the health of your baby.

The Bottom Line

Pregnancy can be a stressful time, especially if you are a first-time mom. Plus, we are living in the most stressful time any of us can remember. That is why a recent study is particularly relevant.

Simply put, the study showed that chronic stress during pregnancy increases populations of gut bacteria in the newborn that are associated with adverse health outcomes in children. More studies are needed to confirm and understand this observation, but it raises an issue that is often ignored.

However, let’s put it into perspective. It’s not the stress in our lives that harms us. It is how we respond to the stress. This study did not measure stress, per se. It measured depression, anxiety, and cortisol levels associated with the stress.

Some of the women in this study had very low levels of all three. It wasn’t that they led stress-free lives. They simply coped better with stress. So, the real question isn’t how to minimize stress. It’s how to better cope with stress.

For more details and a discussion on how to cope with stress, 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.

Could A Probiotic Supplement Make You Healthier?

What Is The Truth About Our Microbiome?

Myth BusterOur gut bacteria, often referred to as our microbiome, are a “hot” topic in today’s world. They have been in the news a lot in recent years. If you believe the headlines, the right gut bacteria can make you smarter, healthier, and cure what ails you. They appear to have almost mystical powers. Could a probiotic supplement make you healthier?

How much of this is true and how much is pure speculation? It’s hard to say. Our microbiome is incredibly complex. To make matters more confusing, the terminology used to classify our gut bacteria into groups is not consistent. It varies from study to study.

Perhaps it is time to take an unbiased look at the data and separate fact from speculation.

Could A Probiotic Supplement Make You Healthier?

Probiotic SupplementTo answer the question of whether a probiotic supplement could make you healthier, we need to differentiate between what we know is true and what we think might be true. Let’s start with what we know for certain:

  • Our gut bacteria are affected by diet. People consuming a primarily plant-based diet have different populations of gut bacteria than people consuming a primarily meat-based diet.
    • The populations of gut bacteria found in people consuming a plant-based diet are associated with better health outcomes, but associations have their limitations as discussed below.
  • Our gut bacteria are affected by exercise.
    • It’s not clear whether it is the exercise or the fitness (increased muscle mass, decreased fat mass, improved metabolism) associated with exercise that is responsible for this effect.

Most of the other claims for the effects of gut bacteria on our health are based on associations. However, associations do not prove cause and effect. For example:

  • Certain populations of gut bacteria are associated with obesity.
    • Do our gut bacteria make us obese, or does obesity affect our gut bacteria? There is evidence to support both viewpoints.
  • Certain populations of gut bacteria are associated with better mental health.
    • Do gut bacteria influence mental health, or does the stress associated with poor mental health influence our gut bacteria? Again, there is evidence to support both viewpoints.
  • Certain populations of gut bacteria are associated with better health outcomes (reduction in diseases like heart disease, diabetes, and high blood pressure).
    • Here the question is a little different. In general, the populations of gut bacteria associated with disease reduction are produced by a healthy diet, exercise, and weight control. In this case, the question becomes: Is it the gut bacteria that caused disease reduction, or is it diet, exercise, and weight control that caused disease reduction?

To better understand these points, let’s look at four recently published studies. After reviewing those studies, I will come back to the question of whether a probiotic supplement might decrease our disease risk.

Is Our Microbiome Better Than Our Genes For Predicting Disease?

Predict DiseaseThis study (T. Tierney et al, bioRxiv, 2020) reviewed 47 studies that analyzed people’s microbiome (their gut bacteria) and their genes and asked which was better at predicting their risk of various diseases. The study focused on 13 diseases that are considered “complex” because they are caused by both genetic and environmental factors such as diet and exercise. Examples include diabetes, high blood pressure, digestive disorders, asthma, Parkinson’s disease, and schizophrenia.

The study found that our microbiome was a better predictor of these diseases than our genes. This finding is not surprising. Our microbiome is heavily influenced by diet and other environmental factors. Our DNA sequence is not.

This study supports previous studies in suggesting that our microbiome is a better predictor of most diseases than our DNA sequence. The exception would be diseases that are clearly caused by gene mutations, such as sickle cell disease.

Does this mean our microbiome is directly influencing these diseases, or is it merely serving as a marker for diet and other environmental factors that are influencing these diseases? Nobody knows.

Does The Mediterranean Diet Support Gut Bacteria Linked To Healthy Aging?

Mediterranean dietThis study ( TS Ghosh et al, Gut, 17 February 2020) divided people aged 65-79 into two groups. One group consumed a Mediterranean diet rich in fruits, vegetables, nuts, legumes, olive oil, and fish and low in red meat and saturated fat. The other group consumed a typical western diet. After a year on the diets the gut bacteria in the microbiomes of the two groups was analyzed.

The study found that the group consuming the Mediterranean diet had an increase in gut bacteria associated with healthy aging, reduced inflammation, and reduced frailty.

The title of the paper describing this study was “Mediterranean diet intervention alters the gut microbiome in older people, reducing frailty and improving health status”. But is that true?

There is already good evidence that the Mediterranean diet improves health status. Is it the gut bacteria supported by the Mediterranean diet that were responsible for healthy aging, or were other aspects of the Mediterranean diet responsible for healthy aging? Nobody knows.

Are Low Fat Diets Healthy Because Of Their Effect On Our Microbiome?

Heart Healthy DietThis study (Y Wang et al, Gut Microbes, 21 January 2020) put participants on a low fat diet (20% fat and 66% carbohydrates), a moderate fat diet (30% fat and 56% carbohydrate) or a high fat diet (40% fat, 46% carbohydrates). To assure the accuracy of the diets, participants were provided with all foods and beverages they consumed. After 6 months on the three diets, the gut bacteria of each group were analyzed.

Note: Because all food and beverages were provided, none of the diets included sodas, added sugar, refined flour, saturated fats, or highly processed food. In short, the diets were very different than the typical low fat or low carb diets consumed by the average American.

This study found that participants consuming the high fat, low carb diet had gut bacteria associated with increased risk of heart disease and diabetes. In contrast, the low fat, high carbohydrate diet group had gut bacteria associated with decreased risk of heart disease and diabetes.

To understand this study, you need to reevaluate what you may have learned from Dr. Strangelove’s health blog. It is true that low fat diets in which fat has been replaced with sugar, refined flour, and highly processed low-fat foods are unhealthy. But that’s not what happened in this study.

Remember that all the food and drink the participants consumed was selected by dietitians.

When you replace the fat with whole foods – fresh fruits and vegetables, whole grains, nuts, and legumes, as was done in this study, you end up with a very healthy diet.

The authors talked about the importance of the “diet-gut axis” for reducing the risk of heart disease and diabetes. However, is it the gut bacteria that influenced the risk of heart disease and diabetes, or is it the diets themselves that influenced disease risk? Nobody knows.

Can Gut Bacteria Reduce Heart Disease Risk?

MicrobiomeThis study (Y Heianza et al, Journal of The American College Of Cardiology, 75: 763-772, 2019) focused on the interactions between diet, gut bacteria, and a metabolite called TMAO (trimethylamine N-oxide).

Here is what we know for certain:

  • L-carnitine (found in high levels in red meat) can be converted to TMA (trimethylamine) by gut bacteria and then to TMAO in the liver.
  • The gut bacteria of meat eaters are very efficient at converting L-carnitine to TMA. Thus, meat eaters tend to have high levels of TMAO in their blood.
  • The gut bacteria of vegans and vegetarians are very inefficient at converting L-carnitine to TMA. Thus, people consuming a primarily plant-based diet tend to have low TMAO levels in their blood.

Here is what we are uncertain about:

  • High TMAO levels are associated with increased heart disease risk. However, there is no direct evidence that TMAO causes heart disease.

What made this study unique is that it measured TMAO levels in the study participants at their entrance into the study and again 10 years later. The study found:

  • Participants with the greatest increase in TMAO levels over the 10 years had a 67% increased risk of heart disease compared to participants whose TMAO levels remained constant.
  • Participants consuming a healthy, primarily plant-based diet had little or no increase in TMAO levels over 10 years. It was the participants consuming an unhealthy diet who had significant increases in their TMAO levels.

This study strengthens the association between TMAO levels and heart disease risk. Because gut bacteria are required to produce TMAO, it also strengthens the association between gut bacteria and heart disease risk. However, is it the high TMAO levels that increased heart disease risk or is it the unhealthy diet that increased heart disease risk? Nobody knows.

What Is The Truth About Our Microbiome?

MicrobiomeBy now you have probably noticed a common theme that runs through all four studies. This is also true of most published studies on our microbiome.

  • We have good evidence that whole food, primarily plant-based diets lead to improved long-term health outcomes.
  • We also have good evidence that whole food, primarily plant-based diets influence the populations of gut bacteria found in our microbiome.
  • We know the populations of gut bacteria supported by primarily plant-based diets are associated with improved health outcomes.
  • We don’t really know whether it is the gut bacteria or the diets that are responsible for the improved health outcomes.

Don’t misunderstand me. I am not a microbiome skeptic. I think we have enough evidence to say that our gut bacteria are likely to have an important effect on our health. However, to claim that gut bacteria play a primary role in influencing our health would be pure speculation at this point.

A Cautionary Tale

HDL CHolesterolWhy do I make this point? It’s because I suspect that some in the supplement industry will be tempted to make probiotic supplements and claim they contain bacteria “known” to reduce the risk of heart disease, diabetes, or cancer. You wouldn’t need to change your diet. All you would need to do to improve your health would be to take their probiotic supplement.

Lest you be taken in by such future claims, let me share a cautionary tale.

High HDL cholesterol levels are associated with a reduced risk of heart disease. Exercise and weight loss increase HDL levels. However, those require work. They aren’t easy. So, pharmaceutical companies were constantly looking for ways to raise HDL levels without the hard work.

A few years ago, a pharmaceutical company discovered a drug that increased HDL levels. They thought they had discovered a wonder drug that would bring in billions of dollars. People wouldn’t need to exercise. They wouldn’t need to lose weight. All they would need to do would be to take their drug. HDL levels would go up and heart disease risk would go down.

However, when they tested their drug in a major clinical trial, it didn’t move the needle. HDL levels went up, but heart disease risk stayed the same. It turns out it was the exercise and weight loss that decreased heart disease risk, not the increase in HDL levels.

My message is simple. Even if our gut bacteria are found to play a major role in mediating the effect of diet on health outcomes, don’t assume we can take a probiotic and forget about the role of diet and exercise. Good health starts with a whole food, primarily plant-based diet and a healthy lifestyle.

The Bottom Line

Our gut bacteria, often referred to as our microbiome, are “hot”. If you believe the headlines, the right gut bacteria can make you smarter, healthier, and cure what ails you. How much of this is true and how much is pure speculation? In this article I reviewed four recent studies on diet, gut bacteria, and health outcomes. I took an unbiased look at the data and separated fact from speculation.

There was a common theme that ran through all four studies. This is also true of most published studies on our microbiome.

  • We have good evidence that whole food, primarily plant-based diets lead to improved long-term health outcomes.
  • We also have good evidence that whole food, primarily plant-based diets influence the populations of bacteria found in our gut, also known as our microbiome.
  • We know the populations of gut bacteria supported by primarily plant-based diets are associated with improved health outcomes.
  • We don’t really know whether it is the gut bacteria or the diets that are responsible for the improved health outcomes.

Don’t misunderstand me. I am not a microbiome skeptic. I think we have enough evidence to say that our gut bacteria are likely to have an important effect on our health. However, to claim that gut bacteria play a primary role in influencing our health would be pure speculation at this point.

Why do I make this point? It’s because I suspect that some in the supplement industry will be tempted to make probiotic supplements and claim they contain bacteria “known” to reduce the risk of heart disease, diabetes, or cancer. You wouldn’t need to change your diet. All you would need to do to improve your health would be to take their probiotic supplement.

My message is simple. Even if our gut bacteria are found to play a major role in mediating the effect of diet on our health outcomes, don’t assume we can take a probiotic and forget about the role of diet and exercise. Good health starts with a whole food, primarily plant-based diet and a healthy lifestyle.

For more details, read the article above. You may be particularly interested in the cautionary tale I shared about HDL and heart disease risk.

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

Maximizing Polyphenols Benefits

The Symbiotic Relationship Between Gut Bacteria And Polyphenols

Author: Dr. Stephen Chaney

 

How to maximize polyphenols benefits?

grape polyphenolsPolyphenols are ubiquitous in the plant world. There are many kinds of polyphenols, and they are found in a wide variety of fruits, vegetables, whole grains, and legumes. You probably already know that polyphenols are also found in tea, coffee, chocolate, and many herbs and spices.

Polyphenols are thought to have a wide array of health benefits. For example, the polyphenols in grapes are thought to:

  • Reduce inflammation.
  • Reduce the risk of heart disease, cancer, and diabetes.
  • Prevent or delay the onset of neurodegenerative diseases like Alzheimer’s.

The amazing thing is that polyphenols are effective at all. They are poorly absorbed and rapidly eliminated from the circulation. For example, resveratrol, a polyphenol found in red grapes, only stays in the circulation for a few hours.

In the case of resveratrol, we know that, during its brief time in our bodies, it turns on “anti-aging” genes that control things like inflammation, protection against free radical damage, cholesterol metabolism, blood sugar control, and blood pressure. We are less certain how other polyphenols exert their beneficial effects during the short time they are in our bodies.

When we scientists are facing a problem like this, it stimulates our creative thinking. We start asking questions like:

  • Can we improve the absorption of beneficial polyphenols into the bloodstream?
  • Would that improve their effectiveness and health benefits?

A recent review (D Zhao et al, Critical Reviews In Food Science and Nutrition: Jan 7, 1-29, 2019) looked at the first question. It summarized the most promising strategies for improving the absorption of grape polyphenols. We don’t yet know the answer to the second question.

Before I discuss the most promising strategies, the professor in me wants to cover Polyphenols 101, something I call “The Symbiotic Relationship Between Gut Bacteria and Polyphenols”.

 

The Symbiotic Relationship Between Gut Bacteria and Polyphenols

 

polyphenols gut bacteriaThe world of polyphenols is complex. For example:

  • Resveratrol is the best-known and best-studied polyphenol in grapes, but there are dozens of other beneficial polyphenols in grapes.
  • Each of these polyphenols have unique metabolic pathways and unique health benefits.
  • Each variety of grapes has a unique blend of polyphenols.
  • Each polyphenol is metabolized differently by our gut bacteria and by enzymes in our body.
  • You start with dozens of polyphenols in the grape and end up with hundreds of metabolites in the body.
  • Some of these metabolites are better absorbed. Some are not absorbed at all. Some of these metabolites are highly active. Others are inactive. The possibilities are endless.

As if that weren’t enough, there are two more complexities to factor into the equation.

  • There is a symbiotic relationship between gut bacteria and polyphenols.
  • Our gut bacteria influence the metabolism and absorption of the polyphenols in our diet.
  • The polyphenols we consume influence the population of bacteria in our gut.
  • The kinds of fiber we consume influence which bacteria populate our gut, and that, in turn, influences how we metabolize the polyphenols we consume.

Faced with this level of complexity, there have been two types of approaches to improving the absorption of polyphenols.

  • The pharmaceutical approach, which tries to bypass the complexities of polyphenol absorption.
  • The natural approach, which tries to optimize the complexities of polyphenol absorption.

The review (D Zhao et al, Critical Reviews In Food Science and Nutrition: Jan 7, 1-29, 2019) gives examples of each type of approach, which I will discuss below.

 

Maximizing Polyphenols Benefits

 

polyphenols effectivenessPharmaceutical Approaches: These are approaches designed to bypass the complexities of polyphenol absorption. The authors considered the following two strategies to have the most probability of success:

  • Chemical alteration of polyphenol structure. This is a classical pharmaceutical strategy. You start with naturally occurring compound that has medicinal benefit. Then you chemically modify it in multiple ways until you find a chemical modification that is efficiently absorbed and is stable in the circulation. There are two drawbacks to this approach:
  • You have created a new compound with its own properties. You have created a drug that needs to be tested for safety and efficacy. Resveratrol, for example, offers a cautionary tale. A drug company modified it. The modified form was efficiently absorbed and was stable in the bloodstream. They thought they had created the perfect drug. Unfortunately, when they tested it, they found out it was toxic.
  • Even if you did optimize safety and efficacy of the polyphenol, you have only optimized one polyphenol out of the dozens found in the real food.
  • Incorporate the polyphenol into nanoparticles that are absorbed so efficiently by the intestine that they effectively bypass metabolism by gut bacteria. This is a strategy currently being explored by drug companies to improve the efficacy of poorly absorbed drugs. Even if successful, this approach has the same type of drawbacks.
  • This is a relatively new technology. There are some concerns it may not be safe.
  • Foods have dozens of polyphenols. A nanoparticle strategy may improve the absorption of one or two polyphenols, but it is unlikely to replace the real food.

maximize polyphenols benefitsNatural Approaches: These approaches are designed to optimize the complexities of polyphenol absorption.

  • Develop a probiotic supplement containing bacteria that improve polyphenol uptake. There is some promising research in this area.
  • However, when we talk about gut bacteria, the phrase “It takes a village” takes on a whole new meaning. There may be dozens of bacteria involved in improving polyphenol uptake, not just one or two. The probiotic supplement may need to be a horse pill
  • Add fiber to the diet to support the growth of the gut bacteria that enhance the absorption of polyphenols. This may be the most promising strategy.
  • Studies have already shown that pectin and similar non-digestible polysaccharides improve the absorption of polyphenols found in grapes and many other foods.
  • While grapes are low in pectin, other fruits (most notably apples, peaches, citrus fruit, apricots, and plums) are high in pectin. Legumes and some vegetables are also high in pectin. The only reason you don’t find them on most lists of high pectin foods is these lists are for foods that have enough pectin to make good jams without any added pectin. Legumes and vegetables are also high in insoluble fibers, which interfere with the gelling required for a good jam. Besides, kale or pea jam are probably not high on anyone’s list of favorite jams.
  • The best thing about this approach is that it is completely natural. It involves eating a plant-based diet with fruits, vegetables whole grains, and legumes, something humans have been doing for thousands of years. This a diet chock full of beneficial polyphenols and the fiber needed to support the gut bacteria that help us utilize those polyphenols. There are no side effects. There is no danger associated with this approach. 

Once again, Mother Nature knows best.

Addendum

While writing this article I happened to read “The People’s Pharmacy” column by Joe & Terry Graedon in our local paper (Yes, I still read a physical newspaper). They were talking about combining pectin with grape juice to relieve arthritis pain. Some of the polyphenols in grape juice have anti-inflammatory effects. But, grape juice alone is not very effective at relieving arthritis pain. However, it turns out that pectin plus grape juice, something called “purple pectin remedy,” is a home remedy for arthritis pain relief that has been around since the 1940s. They did not discuss a mechanism, but now we know how it works.

Note: I suppose if you are getting your grape polyphenols from grape juice, wine, or some other liquid source, you could stir in some pectin to improve their absorption. However, my recommendation would be to consume a primarily plant-based diet with a variety of fruits, vegetables, whole grains, and legumes along with your liquid polyphenol source.

 

The Bottom Line

 

Resveratrol and other polyphenols found in grapes have many health benefits. However, these polyphenols are poorly absorbed. A recent review described ongoing research into approaches for improving the absorption of grape polyphenols

I discuss the various approaches that are being studied in my article above. Some are pharmaceutical approaches that involve structural alterations to the polyphenol or nanoparticle delivery systems to improve absorption. Others involve probiotics that contain bacterial strains that enhance polyphenol absorption. Each of these approaches have limitations, or dangers, or both.

The most promising approach was to simply add fiber to the diet to support the growth of the gut bacteria that enhance the absorption of polyphenols.

  • Studies have already shown that pectin and similar non-digestible polysaccharides improve the absorption of polyphenols found in grapes and many other foods.
  • While grapes are low in pectin, other fruits (most notably Apples, peaches, citrus fruit (especially the skin), apricots, and plums) are high in pectin. Legumes and some vegetables are also high in pectin. The only reason you don’t find them on most lists of high pectin foods is these lists are for foods that have enough pectin to make good jams without any added pectin. Legumes and vegetables are also high in insoluble fibers, which interfere with the gelling required for a good jam. Besides, kale or pea jam are probably not high on anyone’s list of favorite jams.
  • The best thing about this approach is that it is completely natural. It involves eating a plant-based diet with fruits, vegetables whole grains, and legumes, something humans have been doing for thousands of years. This a diet chock full of beneficial polyphenols and the fiber needed to support the gut bacteria that help us utilize those polyphenols. There are no side effects. There is no danger associated with this approach.

Once again, Mother Nature knows best.

Note: If you are getting your grape polyphenols from grape juice, wine, or some other liquid source, you could stir in some pectin to improve their absorption. However, my recommendation would be to consume a primarily plant-based diet with a variety of fruits, vegetables, whole grains, and legumes along with your liquid polyphenol source.

For more details read the article above. You will also find an interesting story about the “purple pectin remedy”.

 

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