Fructose Archives - Health Tips From The Professor

Is Erythritol Bad For Your Heart?

March 28, 2023 by Dr. Steve Chaney

Who Should Be Concerned About Erythritol Intake?

Author: Dr. Stephen Chaney

Everyone is searching for the perfect sweetener. And if you were in the marketing department of Big Food Inc, the perfect sweetener would be defined as:

Natural, meaning that it is found in fruits, vegetables, or other plant foods.

Low in calories. Of course, a perfect sweetener would have zero calories because it is not metabolized in our bodies.

Low glycemic, meaning that it would have a minimal effect on blood sugar levels. Once again, a perfect sweetener would have zero effect on blood sugar levels.

Safe, meaning that it has no adverse effects on our health.

Sugar alcohols appear to meet all these criteria, so they have become the sweetener of choice for lots of highly processed foods. This is especially true for the sugar alcohol, erythritol, since it is currently the least expensive of the sugar alcohols.

So, a recent study (M Witowski et al, Nature Medicine, 2023) suggesting that erythritol might increase the risk of heart disease was quite surprising.

This is the first study to suggest a link between erythritol and heart disease, and it was a flawed study (I will discuss the flaws below).

Reputable scientists don’t put much credence in a weak first study like this one. We generally consider the conclusions of a first study like this one to be an unproven hypothesis at this point.

But we are cautious. There will be many follow-up, better designed studies, to test this hypothesis. Once these studies have been published, the scientific community will look at all the evidence and either issue a warning or conclude that there is no reason for concern.

But that doesn’t stop the Dr. Strangeloves of the world from warning you of the “dangers” of erythritol and telling you to avoid it at all costs.

For that reason, I felt it was appropriate to address this issue. I will:

Describe the study and its flaws.

Put the study into the broader perspective of what we know about sweeteners.

Identify the two population groups who should be most concerned about erythritol.

How Was The Study Done And What Did It Show?

This study can be divided into three parts.

#1: An Association Between Erythritol Blood Levels And Heart Disease.

There were three separate experiments included in this section of the study. In each experiment patients were recruited after visiting cardiac clinics for diagnostic procedures. The average age of these patients was 67 and 45% of them already had experienced a non-fatal heart attack prior to the study. In other words, these were all older patients with pre-existing heart disease who were at high risk of heart attack or stroke in the near future.

The first study was a metabolomic study. In simple terms this means that high-tech equipment and computing were used to measure hundreds of metabolites in the blood of the patients and, in this case, correlate each of them with the occurrence of heart attacks and strokes over the next three years.

This study identified 16 sugar alcohols and related metabolites in the blood of these patients that were associated with an increased risk of heart attack and stroke. (I will discuss the significance of this observation in more detail later.)

Because erythritol was among the top 6 compounds in terms of association with increased heart attack and stroke risk, and erythritol is the most commonly used sugar alcohol in processed foods, the next two studies focused on the association between blood levels of erythritol and heart attack/stroke risk. Their results were predictable.

High blood levels of erythritol were associated with an increased risk of heart attack and stroke over the next three years.

Flaws In This Portion Of The Study:

As the authors of the study pointed out, these studies were done with older patients with pre-existing heart disease who were at high risk of heart attack or stroke. They acknowledged that it is not known whether these associations exist with younger, healthier patients.

As the authors also pointed out, these are associations. They do not prove cause and effect. In particular, the studies did not measure the diet, exercise habits, and other lifestyle factors of these patients that may have contributed to their increased risk of heart attack and stroke.

When you look closely at the data, it is clear that the association is only seen at the highest blood levels of erythritol. Specifically, the blood levels of erythritol in these patients were divided into quartiles. The risk of heart attack and stroke in the first three quartiles (low to moderate blood levels of erythritol) were identical to the control. However, the fourth quartile (highest blood levels of erythritol) was associated with a dramatically increased risk of heart attack and stroke. That raises three important questions:

- “How much erythritol were patients in the fourth quartile consuming?”

- - The authors did not look at dietary intake of erythritol but did note a previous study estimated that Americans consume up to 30 grams of erythritol a day.

- 30 grams of erythritol a day is a huge amount of erythritol. Where does that erythritol come from?

- - Much of it comes from erythritol-containing highly processed foods like zero calorie sugar substitutes (either erythritol alone or erythritol mixed with artificial sweeteners to improve the taste); reduced- and low calorie carbonated and non-carbonated beverages; hard candy and cough drops, cookies, cakes, pastries, and bars; puddings and pie fillings; soft candies; syrups and toppings; ready to eat cereals; fruit novelty snacks; and frozen desserts.

- - But it is also found in foods you might not suspect, such as plant-based “milk” substitutes; chocolate and flavored milks; barbecue and tomato sauce, fruit-based smoothies, the syrup used in canned fruits, yoghurt; low calorie salad dressings; and salty snacks.

- - In other words, the only way anyone can consume 30 grams of erythritol in a day is to consume large quantities of erythritol-containing highly processed foods (I will discuss the significance of this observation later).

- “What else was different about patients in the fourth quartile?”

- - When you look carefully at the data, the patients in the fourth quartile were significantly older, with a higher incidence of diabetes, pre-existing coronary artery disease, previous non-fatal heart attacks, congestive heart failure, and greater triglycerides – all of which significantly increase their risk of heart attack and stroke.

#2: Mechanistic Studies:

Next the authors did in vitro and animal studies looking at the effect of high levels of erythritol on blood clotting.

These studies showed that high levels of erythritol promoted blood clotting both in vitro and in mice. The authors concluded that these studies provided a plausible mechanism for a link between high erythritol blood levels and increased risk of heart attack and stroke.

Flaws In This Portion Of The Study:

Other critics have pointed out that the assays used were not accurate models of blood clotting in humans. This particular critique is beyond my expertise, so I won’t comment further. However:

- As someone who was involved in cancer drug development for over 30 years, I know that in vitro and animal models are poor indicators of how things work in humans.

- And as a biochemist, I have two concerns:

- - The authors provided no mechanistic rationale for why erythritol would enhance blood clotting.

- - The authors made no effort to show that the effect of erythritol was unique. Would high levels of other sugar alcohols or other naturally occurring sugars have the same effect on blood clotting in their assays? We don’t know.

#3: Blood Levels Of Erythritol After Oral Intake.

Finally, the authors gave subjects 30 grams of erythritol and measured blood levels over the next several days.

This experiment showed that very high blood levels of erythritol were attained and maintained for at least two days before gradually decreasing to baseline. The authors concluded this experiment showed that it was feasible to attain and maintain high blood levels of erythritol for several days following a single ingestion of 30 grams of erythritol.

Flaws In This Portion Of The Study:

I have already pointed out that 30 grams per day is a huge amount of erythritol. However, erythritol in the diet will come from a variety of foods, some of which will contain components (fiber etc.) that slow the absorption of erythritol.

In contrast, the subjects in this experiment were given 300 ml of liquid containing 30 grams of erythritol and told to drink it in two minutes!

In other words, these subjects were consuming 30 grams of erythritol in 2 minutes rather than 24 hours, and they were consuming it in the most easily absorbable form. For a study like this, that makes the effective dose orders of magnitude greater than the amount of erythritol that anyone consumes from their diet over a 24-hour period. The study design was completely unrealistic.

Is Erythritol Bad For Your Heart?

As described above, this is the first study to suggest an association between erythritol and heart disease, and it was a highly flawed study.

It is also important to know that erythritol is not an artificial sweetener. It is found naturally in foods like grapes, peaches, pears, watermelons, and mushrooms. It is also found in some fermented foods like cheese, soy sauce, beer, sake, and wine.

It is also a byproduct of normal human metabolism, so we always have some of it circulating in our bloodstream. Our body knows how to handle low to moderate intakes of erythritol.

However, to help you really understand what this study means, I need to put it into the context of other studies. I will do this in story form (You will find more details about these studies in my book “Slaying The Food Myths”).

First, let’s look at highly processed food consumption:

Multiple recent studies have shown that high consumption of highly processed food is associated with increased risk of obesity, diabetes, heart disease, and premature death. We don’t know what it is about highly processed food consumption that is responsible for the increased risk, but it is unlikely to be just one thing.

As I pointed out above, the only way to achieve the high blood levels of erythritol associated with increased heart disease risk is to consume large quantities of erythritol-containing highly processed foods.

Next, let’s follow the history of sweeteners in highly processed foods.

When I was a young man, sucrose (table sugar) was added to most highly processed foods. Sucrose is found naturally in many fruits and vegetables. Small to moderate intake of sucrose in unprocessed and minimally processed foods posed no problem. However, large intakes of sugar in highly processed foods were found to increase the risk of obesity, diabetes, heart disease, and premature death.

At that point, sucrose became a “sugar villain”, and Big Food, Inc substituted fructose and high fructose corn syrup (a mixture of fructose and glucose) for sugar in their highly processed foods. As with sucrose, fructose is found naturally in many foods, and small to moderate intakes of fructose and high fructose corn syrup posed no health risks. However, large intakes of fructose and high fructose corn syrup in highly processed foods were found to increase the risk of obesity, diabetes, heart disease, and premature death.

Fructose and high fructose corn syrup then became the sugar villains. And because high fructose corn syrup is chemically and biologically indistinguishable from natural sugars like honey, date sugar, coconut sugar, it is likely that high intakes of these sugars in highly processed foods would cause the same problem.
So Big Food, Inc started relying on artificial sweeteners in their highly processed foods. But guess what? Recent studies have suggested that artificial sweeteners in highly processed foods are associated with obesity, diabetes, and heart disease.

That has caused Big Food, Inc to rely more on sugar alcohols in their highly processed foods, particularly erythritol because it is the least expensive of the sugar alcohols. Now the current study comes along and suggests that high intake of erythritol in highly processed foods may increase the risk of heart disease.

If this hypothesis is confirmed by better designed studies, it is not clear what Big Food, Inc will do next. The metabolomic study described above showed that high blood levels of several other sugar alcohols are associated with an increased risk of heart disease.

Hopefully, you are starting to see a pattern here. It’s time to ask the question, “Is it the sweetener, or is it the food?”

Clearly, it doesn’t matter what sweetener we are talking about. Large intake of any natural sweetener in the context of a diet rich in highly processed foods appears to have an adverse effect on our health. And we don’t know whether these adverse health effects are caused by the sweetener or some other component of the highly processed foods.

If you want to improve your health, the best solution is to decrease your intake of highly processed foods. That will automatically reduce your intake of sweeteners and other unhealthy components of highly processed foods and increase your intake of healthy components from the whole foods you will be eating instead.

Who Should Be Concerned About Erythritol Intake?

The authors of this study identified two groups who should be most concerned about erythritol consumption – diabetics and adherents of the keto diet.

Diabetics are at high risk because they are told to consume non-caloric sweeteners instead of sugars, and they are not told to avoid highly processed foods. Consequently, they consume much higher amounts of non-caloric sweeteners than the average American.

I must admit that I didn’t foresee keto adherents as a high-risk group. However, it appears that keto enthusiasts love their sweets as much as the rest of us, and the sweetener of choice for keto-friendly sweets is erythritol. The authors said that a single serving of keto ice cream contains 30 grams of erythritol. I can hardly imagine how much erythritol they must be getting in their diet.

And, once again, the best advice for both groups is to simply decrease the amount of highly processed food in their diet.

The Bottom Line

Erythritol is not an artificial sweetener. It is found naturally in foods like grapes, peaches, pears, watermelons, and mushrooms. It is also found in some fermented foods like cheese, soy sauce, beer, sake, and wine.

It is also a byproduct of normal human metabolism, so we always have some of it circulating in our bloodstream. Our body knows how to handle erythritol.

That is why it was a surprise when a recent study claimed that high intake of erythritol is associated with an increased risk of heart attack and stroke. The Dr. Strangeloves of the world are already starting to tell you that erythritol is deadly and you should avoid it at all costs. But reputable scientists are saying, “Not so fast”.

This is the first study to suggest an association between erythritol and heart disease, and it was a highly flawed study.

In fact, the study showed that low to moderate intakes of erythritol had no effect on heart disease risk. It was only the highest intake of erythritol that was associated with increased risk of heart disease. And given the distribution of erythritol in the American diet, the only way someone could take in that much erythritol is to consume large amounts of erythritol-sweetened highly processed foods.

A brief review of the literature on sweeteners reveals that this is a common pattern for every natural sweetener tested. Low to moderate intake of these sweeteners has no adverse health effects. However, high intake of every sweetener tested in the context of a highly processed food diet is associated with an increased risk of obesity, diabetes, heart disease, and premature death.

That raises the question, “Is it the sweetener, or is it the food?”

Clearly, it doesn’t matter what sweetener we are talking about. Large intake of any natural sweetener in the context of a diet rich in highly processed foods is likely to have an adverse effect on our health. And we don’t know whether these adverse health effects are caused by the sweetener or some other component of a highly processed food diet.

For more details on the study and information about which foods are likely to contain erythritol and the population groups who should be most concerned about erythritol consumption, 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

Can Healthy Eating Help You Lose Weight?

September 27, 2022 by Dr. Steve Chaney

Who Benefits Most From A Healthy Diet?

Author: Dr. Stephen Chaney

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

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

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

They compare their diet with the typical American diet.

- Anything looks good compared to the typical American diet.

- Instead, they should be comparing their diet with other weight loss diets. That is the only way we can learn which diet is best.

They are all restrictive diets.

- Any restrictive diet will cause you to eat fewer calories and to lose weight.

- As little as 5% weight loss results in lower cholesterol & triglycerides, lower blood pressure, and better control of blood sugar levels.

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

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

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

How Was The Study Done?

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

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

The participants were randomly assigned to:

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

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

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

Can Healthy Eating Help You Lose Weight?

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

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

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

At the end of 12 weeks:

Participants lost significant weight on both calorie-restricted diets compared to the group that continued to eat their habitual diet.

- That is not surprising. Any diet that successfully restricts calories will result in weight loss.

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

Participants on the high-nutrient quality diet lost 50% more inches in waist circumference than participants on the low-nutrient-quality diet (1.8 inches compared to 1.2 inches).

- This is a direct measure of abdominal obesity.

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

These cardiovascular risk factors were significantly improved on both diets.

- Again, this would be expected. Any diet that causes weight loss results in an improvement in these parameters.

The reduction in total serum cholesterol was 2.5-fold greater and the reduction in triglycerides was 2-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.

The reduction in systolic blood pressure was 2-fold greater and the reduction in diastolic blood pressure was 1.67-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.

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

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

Who Benefits Most From A Healthy Diet?

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

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

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

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

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

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

When they used this method to categorize participants they found:

Insulin-resistant individual lost about the same amount of weight on both diets.

Insulin-sensitive individuals lost 66% more weight on the high-nutrient-quality diet than the low-nutrient-quality diet (21.6 pounds compared to 13.0 pounds).

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

What Does This Study Mean For You?

Simply put this study confirms that:

Caloric restriction leads to weight loss, and…

Weight loss leads to improvement in cardiovascular risk factors like total cholesterol, triglycerides, and blood pressure.

- This is not new.

- This is true for any diet that results in caloric restriction.

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

Weight loss and…

Reduction in cardiovascular risk factors…

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

Both diets were whole food diets. Neither diet allowed sodas, sweets, and highly processed foods.

Both included fruits, vegetables, grains, and lean meats.
Both reduced caloric intake by 25%.

- If you want to get the most out of your weight loss diet, this is a good place to start.

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

More plant protein in the form of soy protein.

- In this study they did not reduce the amount of animal protein in the “high-nutrient-quality” diet. They simply added soy protein foods to the diet. I would recommend substituting soy protein for some of the animal protein in the diet.

More fiber.

- The additional fiber came from substituting whole grain breads and brown rice for refined grain breads and white rice, adding soy protein foods, and adding an additional serving of fruit.

More healthy fats (monounsaturated and omega-3 fats).

- The additional omega-3s came from adding a fish oil capsule providing 700mg of EPA and DHA.

Less simple sugars. While this study focused on fructose, their high-nutrient-quality diet was lower in all simple sugars.

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

Follow a whole food diet. Avoid sodas, sweets, and highly processed foods.

Include all 5 food groups in your weight loss diet. Fruits, vegetables, whole grains, dairy, and lean proteins all play an important role in your long-term health.

Eat a primarily plant-based diet. My recommendation is to substitute plant proteins for at least half of your high-fat animal proteins. And this study reminds us that soy protein foods are a convenient and effective way to achieve this goal.

Eat a diet high in natural fibers. Including fruits, vegetables, whole grains, beans, nuts, seeds, and soy foods in your diet is the best way to achieve this goal.

Substitute healthy fats (monounsaturated and omega-3 fats) for unhealthy fats (saturated and trans fats) in your diet. And this study reminds us that it is hard to get enough omega-3s in your diet without an omega-3 supplement.

Reduce the amount of added sugar, especially fructose, from your diet. That is best achieved by eliminating sodas, sweets, and highly processed foods from the diet. I should add that fructose in fruits and some healthy foods is not a problem. For more information on that topic, I refer you to a previous “Health Tips” article .

Finally, I would like to remind you of the obvious. No diet, no matter how healthy, will help you lose weight unless you cut back on calories. Fad diets achieve that by restricting the foods you can eat. In the case of a healthy diet, the best way to do it is to cut back on portion sizes and choose foods with low caloric density.

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

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

Only around half of the overweight, abdominally obese adults in this study were highly insulin resistant.

- That means there is a ~50% chance that you will lose more weight on a healthy diet.

Because both diets restricted calories by 25%, insulin-resistant individuals lost weight on both diets.

- That means you can lose weight on any diet that successfully reduces your caloric intake. That’s the good news.

- However, my recommendation would still be to choose a high-nutrient quality diet that is designed to reduce caloric intake, because that diet is more likely to be healthy long term.

The Bottom Line

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

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

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

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

At the end of 12 weeks:

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

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

The reduction in total serum cholesterol was 2.5-fold greater and the reduction in triglycerides was 2-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.

The reduction in systolic blood pressure was 2-fold greater and the reduction in diastolic blood pressure was 1.67-fold greater in the high-nutrient quality diet group than in the low-nutrient-quality diet group.

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

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

Is It The Sugar Or Is It The Food?

July 26, 2022 by Dr. Steve Chaney

Is Fructose Bad For You?

Author: Dr. Stephen Chaney

I don’t usually report on studies done in mice, but this study sheds light on a particularly puzzling question: Why is fructose bad for us?

The studies are clear-cut. High fructose consumption is associated with inflammation, obesity, non-alcoholic liver disease, insulin resistance, type 2 diabetes, kidney disease, increased LDL cholesterol and triglycerides, and heart disease. Based on these associations, fructose appears to be deadly. Why would anyone want to consume it?

Yet fructose is found in virtually every fruit. In fact, fructose, also known as fruit sugar, was first isolated from fruits. Hence the name fructose. Humans have been eating fruits safely for thousands of years. Fruits are very good for us. That raises the question: “If fruits are good for us, how can fructose be bad for us?”.

An important clue can be found by looking at what the food industry has done to the American diet. Because fructose imparts a pleasurable, sweet taste to foods the food industry keeps adding it to more and more foods. As a result, dietary intake of fructose has increased 100-fold over the past two centuries. It has reached the point where fructose now accounts for almost 10% of the caloric intake in the United States.

Is It The Sugar, Or Is It The Food?

Let me expand the discussion by using a couple of graphics I developed for my book, “Slaying The Food Myths”

There Are No Sugar Villains. There Are No Sugar Heroes:

Honey and coconut sugar are about 45% fructose. Sucrose and grape juice concentrate are around 50% fructose. Apple juice concentrate is around 60% fructose, and agave sugar comes in at a whopping 80% fructose.

In other words, if fructose is the culprit that everyone makes it out to be, “healthy” sugars are no better than high fructose corn syrup. Simply substituting a “healthy” sugar for high fructose corn syrup is unlikely to provide any meaningful benefit.

Is It The Sugar, Or Is The Food?

This graphic shows us what a nutrition label would look like on a medium apple. I am sure that label is a wake-up call for many of you. The amount of sugar and the percentage of fructose and glucose are about the same as in an 8-ounce soda sweetened with high fructose corn syrup. The same is true for virtually every other fruit you can think of.

Now let me share one more thing you won’t hear from what I refer to as “Dr. Strangelove’s Health Blog” (You probably know the ones I am referring to). Virtually all the studies showing the bad effects of fructose consumption have been done with sodas and sugary junk foods. They haven’t been done with apples.

In fact, virtually every study looking at fruit and vegetable consumption has shown they are incredibly good for us. They lower inflammation and reduce the risk of obesity, diabetes, heart disease, and cancer. And the more the better. One study found that the health benefits of fruit and vegetable consumption topped out at around 10 servings a day.

With this background, you should now fully understand why the question “If fruits are good for us, how can fructose be bad for us?” is so perplexing.

My simplistic explanation has always been that whole foods like fruits have fiber, which slows the absorption of fructose from the intestine. Our bodies were designed to handle fructose in a safe manner when it enters the bloodstream slowly. It is taken up by the liver, converted to glucose, and then slowly metered back into the bloodstream. This provides our brain and other tissues with the glucose they need for energy without blood sugar spikes. This is how fructose is supposed to be metabolized by our bodies.

Sodas and junk foods, on the other hand, have little to slow the absorption of fructose. When lots of fructose enters the bloodstream rapidly, our “safe” metabolic pathways for handling it are overwhelmed, and it is forced into the pathways that are harmful. For example, the “excess” fructose is converted to fat by the liver, which causes inflammation, obesity, fatty liver disease, and triglyceride production.

This is, of course, simply my hypothesis for explaining the different effect of fructose in fruits and sodas. It is based on sound metabolic principles, but it is far from proven. That is why I found a recent study (C. Jang et al, Cell Metabolism, 27: 351-361, 2018) so interesting. It provides a metabolic rationale for my hypothesis.

How Was The Study Done?

Mice were fed a 1:1 mixture of fructose and glucose at doses that approximated the ranges of typical human fructose consumption. The fructose was isotopically labeled so that fructose and its metabolites could be identified by LC-MS (liquid chromatography – mass spectrometry). After feeding the mice the labeled fructose, the investigator measured the amount of fructose and its metabolites in various organs and in the portal vein, which transports sugars from the intestine to the liver for additional metabolism before they enter the bloodstream.

Is Fructose Bad For You?

The first surprise was that most of the fructose was metabolized by the intestinal mucosal cells that line the small intestine rather than the liver. Previous reports had assumed that fructose was primarily metabolized by the liver because that was where most of the bad effects of fructose metabolism had been observed.

These investigators observed that fructose was primarily converted to glucose and small molecular weight metabolites by the intestinal mucosal cells before being released into the portal vein, where they were transported to the liver. However, there was a strong dose response effect.

At low fructose doses, 90% of fructose was metabolized by intestinal mucosal cells before being released to the liver.

At high fructose doses, only 70% of fructose was metabolized by intestinal mucosal cells.

That means at high fructose doses the amount of fructose reaching the liver unchanged increases from 10% to 30%. That is a 3-fold increase!

The authors concluded:

“Based on these findings, we propose that the small intestine shields the liver from fructose and that excessive doses of fructose overwhelm the small intestine, spilling over to the liver where they cause toxicity.”

“A key difference between the health effects of fiber-rich fruits (and perhaps even fiber-rich prepared foods) and juices/sodas is their rate of intestinal fructose release.”

“It is likely that the appearance rate of free fructose in the small intestine plays a critical role in dictating its metabolic fate. Like the lower doses in our experiments, a slower rate of fructose appearance will result in more complete intestinal clearance, whereas higher doses and faster rates result in fructose overflow to the liver.”

This study needs to be confirmed, and the mechanism may be entirely different in humans. However, whether mechanism is the same in mice and humans is immaterial. We already know that fructose in sodas and junk foods exerts a very different effect on our health than fructose in fruits and other fiber-containing foods.

Despite what Dr. Strangelove tells you, fructose is not bad for you. It isn’t the problem. It is sodas and junk foods containing high-fructose corn syrup that are the problem. And substituting other sugars for high-fructose corn syrup doesn’t make them any better. As I showed you above, the so called “healthy” sugars are chemically and biologically indistinguishable from high-fructose corn syrup.

The Bottom Line

Previous studies have clearly shown that fructose in sodas and junk foods is bad for us, while fructose in fruits is good for us. A recent study in mice provides a metabolic explanation for this difference. The study found:

At low fructose doses, 90% of fructose was metabolized by intestinal mucosal cells before being released to the liver.

At high fructose doses, only 70% of fructose was metabolized by intestinal mucosal cells.

That means at high fructose doses the amount of fructose reaching the liver unchanged increases from 10% to 30%. That is a 3-fold increase!

The authors concluded:

“Based on these findings, we propose that the small intestine shields the liver from fructose and that excessive doses of fructose overwhelm the small intestine, spilling over to the liver where they cause toxicity.”

“A key difference between the health effects of fiber-rich fruits (and perhaps even fiber-rich prepared foods) and juices/sodas is their rate of intestinal fructose release.”

“It is likely that the appearance rate of free fructose in the small intestine plays a critical role in dictating its metabolic fate. Like the lower doses in our experiments, a slower rate of fructose appearance will result in more complete intestinal clearance, whereas higher doses and faster rates result in fructose overflow to the liver.”

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 Fructose Good For You Or Bad For You?

January 26, 2021 by Dr. Steve Chaney

Is It The Fructose Or Is It The Food?

Author: Dr. Stephen Chaney

Fructose 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?

Let 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?

Investigators 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?

The 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?

You 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.

Butyrate has a number of beneficial effects (RB Canani et al, World Journal of Gastroenterology, 17: 1519-1528, 2012) in our bodies.

- 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?

This 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.

Which Foods Should I Avoid?

May 26, 2020 by Dr. Steve Chaney

What Is Nutritionism?

Recently, 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?

Simply 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.”

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?

Now, 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.

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.

Red 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 “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.

I 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.

Carbs. 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:

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?

Now 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.

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.

Why Is Fructose Bad For You?

July 31, 2018 by Dr. Steve Chaney

Is It The Sugar, Or Is It The Food?

Author: Dr. Stephen Chaney

I don’t usually report on studies done in mice, but this study sheds light on a particularly puzzling question: Why is fructose bad for you?

An important clue can be found by looking at what the food industry has done to the American diet. Because fructose imparts a pleasurable, sweet taste to foods, the food industry keeps adding it to more and more foods. As a result, dietary intake of fructose has increased 100-fold over the past two centuries. It has reached the point where fructose now accounts for almost 10% of the caloric intake in the United States.

Is It The Sugar, Or Is It The Food?

Let me expand the discussion by using a couple of graphics I developed for my book, “Slaying The Food Myths.”

There Are No Sugar Villains. There Are No Sugar Heroes:

Virtually all sweeteners are primarily a mixture of fructose and glucose. The graphic on the left compares high fructose corn syrup (the current villain) with other “natural” sweeteners used in foods (our current heroes). High fructose corn syrup ranges from about 40% fructose to 55% fructose. The exact percentage depends on what kind of food product is being made with it. Honey and coconut sugar are about 45% fructose. Sucrose and grape juice concentrate are around 50% fructose. Apple juice concentrate is around 60% fructose, and agave sugar comes in at a whopping 80% fructose.

Is It The Sugar, Or Is The Food?

In fact, virtually every study looking at fruit and vegetable consumption has shown they are incredibly good for us. They lower inflammation and reduce the risk of obesity, diabetes, heart disease, and cancer. And, the more the better. One study found that the health benefits of fruit and vegetable consumption topped out at around 10 servings a day.

With this background, you should now fully understand why the question “If fruits are good for us, how can fructose be bad for us?” is so perplexing.

My simplistic explanation has always been that whole foods like fruits have fiber, which slows the absorption of fructose from the intestine. Our bodies were designed to handle fructose in a safe manner when it enters the bloodstream slowly. Sodas and junk foods, on the other hand, have little to slow the absorption of fructose. When fructose enters the bloodstream rapidly, our “safe” metabolic pathways for handling it are overwhelmed, and it is forced into the pathways that are harmful. For example, the “excess” fructose is converted to fat by the liver, which causes inflammation, obesity, fatty liver disease, and triglyceride production.

This is, of course, simply my hypothesis for explaining the different effect of fructose in fruits and sodas. It is based on sound metabolic principles, but it is far from proven. That is why I found the current study (C. Jang et al, Cell Metabolism, 27: 351-361, 2018 ) so interesting. It provides a metabolic rationale for my hypothesis.

How Was The Study Done?

Why Is Fructose Bad For You?

At low fructose doses, 90% of fructose was metabolized by intestinal mucosal cells before being released to the liver.
At high fructose doses, only 70% of fructose was metabolized by intestinal mucosal cells.
That means at high fructose doses the amount of fructose reaching the liver unchanged increases from 10% to 30%. That is a 3-fold increase!

The authors concluded:

“Based on these findings, we propose that the small intestine shields the liver from fructose and that excessive doses of fructose overwhelm the small intestine, spilling over to the liver where they cause toxicity.”
“A key difference between the health effects of fiber-rich fruits (and perhaps even fiber-rich prepared foods) and juices/sodas is their rate of intestinal fructose release.”
“It is likely that the appearance rate of free fructose in the small intestine plays a critical role in dictating its metabolic fate. Like the lower doses in our experiments, a slower rate of fructose appearance will result in more complete intestinal clearance, whereas higher doses and faster rates result in fructose overflow to the liver.”

This study needs to be confirmed, and the mechanism may be entirely different in humans. However, whether the mechanism is the same in mice and humans is immaterial. We already know that fructose in sodas and junk foods exerts a very different effect on our health than fructose in fruits and other fiber-containing foods.

The Bottom Line

At low fructose doses, 90% of fructose was metabolized by intestinal mucosal cells before being released to the liver.
At high fructose doses, only 70% of fructose was metabolized by intestinal mucosal cells.
That means at high fructose doses the amount of fructose reaching the liver unchanged increases from 10% to 30%. That is a 3-fold increase!

The authors concluded:

“Based on these findings, we propose that the small intestine shields the liver from fructose and that excessive doses of fructose overwhelm the small intestine, spilling over to the liver where they cause toxicity.”
“A key difference between the health effects of fiber-rich fruits (and perhaps even fiber-rich prepared foods) and juices/sodas is their rate of intestinal fructose release.”
“It is likely that the appearance rate of free fructose in the small intestine plays a critical role in dictating its metabolic fate. Like the lower doses in our experiments, a slower rate of fructose appearance will result in more complete intestinal clearance, whereas higher doses and faster rates result in fructose overflow to the liver.”

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.