Health Tips From The Professor What Are Intermittent Fasting Benefits?

Posted January 8, 2019 by Dr. Steve Chaney

Will Intermittent Fasting Make You Leaner & Healthier?

Author: Dr. Stephen Chaney

 

intermittent fasting benefits eating habitsIntermittent fasting is all the rage. If you believe the hype, intermittent fasting will make you leaner and healthier. Some of its proponents claim you don’t even need to give up your favorite foods. You don’t need to give up your Big Macs for fruits and vegetables. You don’t need to restrict what you eat. You just need to restrict when you eat.

If you read the blogs about intermittent fasting, you will come across all sorts of metabolic mumbo-jumbo about ketone bodies, adiponectin, leptin, IGF-1, and blood glucose levels. It sounds so convincing. Don’t get sucked in by these pseudo-scientific explanations. At this point they are mostly speculation.

What are intermittent fasting benefits?

Instead, ask “What is the evidence that intermittent fasting works?” More importantly, ask “What is the evidence it works in human?” Most of the studies have been done in animal model systems. Claims based on animal models may not apply to humans.

This week I will discuss a review on caloric restriction and various forms of fasting that recently appeared in Science, one of the most highly respected scientific journals (Di Francesco et al, Science, 362: 770-775, 2018 ).

This article was a comprehensive review of three closely-related dietary approaches:

  • Caloric restriction in which daily caloric intake is restricted by 15-40%.
  • Time-restricted fasting which limits daily intake of food to a 4-12 hour period.
  • Intermittent fasting in which there is a day or more of fasting or decreased food intake between periods of unrestricted eating.

Note:

  • What the review calls time-restricted fasting is referred to in the mass media as intermittent fasting. What the review calls intermittent fasting is referred to in the mass media as alternate day fasting. To avoid confusion, I will use the mass media definitions.
  • I will focus on what the mass media refers to as intermittent fasting and just briefly summarize the other two approaches.

 

Will Caloric Restriction Allow You To Live Longer?

 

intermittent fasting benefits restrict caloric intakeThe concept of caloric restriction has been around for a long time and is the best studied of the dietary approaches covered in this review. In brief:

  • Caloric restriction has been studied in animal model systems ranging from mice to primates. In every animal model studied, caloric restriction reduced the incidence of age-related degenerative diseases and increased either life span or health span or both.
  • In both animal model systems and humans, caloric restriction lowers cholesterol, lowers blood pressure, improves blood sugar control, reduces inflammation, and reduces oxidative damage.
  • Populations that eat a healthy diet and practice voluntary caloric restriction appear to enjoy remarkable longevity.
  • The effects of caloric restriction appear to operate via the sirtuin anti-aging pathway. Most of the other effects are downstream of this pathway.
  • The effects of caloric restriction (including activation of the sirtuin pathway) are mimicked by resveratrol and related polyphenols.

In short:

  • Caloric restriction and some naturally occurring compounds such as resveratrol are clearly effective in animal model systems and are likely to be effective in humans.
  • However, we live too long to allow definitive studies of the effect of caloric restriction on human life span and health span.
  • This dietary approach has never gained popularity because very few people want to starve themselves just so they can live a longer, healthier life.

 

Intermittent Fasting Benefits:  Leaner & Healthier?

 

intermittent fasting benefits leanerThere are many variations to intermittent fasting. As the review stated, intermittent fasting can mean that food consumption is restricted to anywhere from 4 to 12 hours. However, the most popular version of intermittent fasting at present restricts food consumption to 8 hours followed by a 16-hour period of fasting. Here is what you need to know about intermittent fasting:

  • Once again, most of the studies have been done in rodents. Those studies appear to show that intermittent fasting results in weight loss, improved blood sugar control, lower cholesterol and triglyceride levels and reduced inflammation even when caloric intake remains unchanged. These findings have generated the claims you see in the media. However, you need to remember that what works in rodents does not necessarily work in humans.
  • Unlike caloric restriction, the benefits of intermittent fasting are dependent on circadian rhythm. [Note: If you are unfamiliar with the concept of circadian rhythm, it is a master control that is genetically hardwired into almost every organism on the planet, including humans. In general, circadian rhythm is synchronized with the light-dark cycle.] The effect of circadian rhythm that is relevant to this discussion is that metabolic rate and many of the enzymes involved in food metabolism in humans are more active during the day than at night. Not surprising, animal studies suggest that intermittent fasting is most effective when the feed-fast cycle is synchronized with their circadian rhythm.
  • The timing of the feeding portion of the intermittent fasting cycle also appears to be important for humans. According to the review by Di Francesco et al, the few clinical studies that have been performed on humans show:
  • Limiting food intake to the middle of the day decreased glucose levels, cholesterol & triglyceride levels, and inflammation.
  • Eating a larger breakfast and smaller dinner improved metabolic markers better than when participants ate a smaller breakfast and larger dinner.
  • Type 2 diabetics attained better blood sugar control when most of their calories were consumed in the first half of the day. In contrast, restricting their calories to late afternoon or evening resulted in either no blood sugar improvement or a worsening of blood sugar controls.
  • Finally, subjects lost more weight on a reduced calorie diet when most of the food was consumed in the morning rather than in the evening.
  • If you read the very popular “Obesity Code” book by Dr. Fung you will discover he is recommending a diet that consists of fruits & vegetables, fiber-rich foods, healthy protein & healthy fats, and avoids sugar, refined grains, and processed foods. He also recommends avoiding snacking. That is exactly the kind of diet I recommend in my book, “Slaying The Food Myths.”  If the average American adopted that diet and did nothing else, they would be leaner and healthier. So much for the claim that you can eat all your favorite junk foods and become leaner and healthier by intermittent fasting.
  • Finally, most of the human clinical studies have carefully controlled caloric intake. From these studies it is apparent that many of the metabolic benefits of intermittent fasting come from synchronizing your food intake with your circadian rhythm. However, in those studies that focused on time of eating and did not control calories, food intake was reduced by intermittent fasting. This is the unacknowledged benefit of intermittent fasting. When you restrict the time period for eating and restrict snacking you generally end up eating less. Thus, the weight loss associated with intermittent fasting may be caused by reduced caloric intake rather than fasting.

What Does This Mean For You? Here are the take-home lessons from this review:

  • intermittent fasting benefits healthierMost of the studies on intermittent fasting have been done with animals, not with humans.
  • Both animal and human studies suggest that the benefits of intermittent fasting result from synchronizing your food intake with your circadian rhythm. The old adage of “Eat breakfast like a king, lunch like a prince, and dinner like a pauper” may be true for most of us. [Note: Circadian rhythms vary slightly from person to person. Some people will do better by their fast at mid-day rather than at breakfast. However, they will probably still benefit by eating a bigger meal mid-day and a smaller meal in the evening.]
  • Although there is no conscious effort to control calories, intermittent fasting appears to result in an inadvertent reduction in food intake by restricting the time allowed for eating and by eliminating late night snacking. This reduction in caloric intake is likely responsible for much of the weight loss associated with intermittent fasting.
  • In summary, intermittent fasting appears to work, but it is not clear whether you need to follow a rigid schedule of eating and fasting. The available clinical studies suggest that if you eat a healthy, primarily plant-based diet, eat most of your calories early in the day, don’t snack between meals, and don’t eat anything after dinner, you will obtain most, if not all, of the benefits attributed to intermittent fasting.

If you define intermittent fasting that way, the professor has been doing intermittent fasting for years. He just didn’t know that was what he was doing.

 

Does Alternate Day Fasting Make You Healthier?

 

intermittent fasting benefits alternate dayFasting regimens promoted for weight loss typically involve one or several days in which no or few calories are consumed followed by a period of unrestricted eating.

At present, the two most popular regimens are the alternate day fast and the alternate day modified fast. The alternate day fast involves a 24-hour water fast followed by a normal feeding period of 24-hours. The alternate day modified fast reduces caloric intake to 25% of normal on fasting days. Here is a brief summary of what we know about alternate day fasting:

  • Once again, most of the studies have been done in animals.
  • Since neither animals nor humans generally consume double their normal caloric intake during the 24-hour feeding period, alternate day fasting results in an overall reduction in caloric intake. Not surprisingly, the benefits of alternate day fasting in animal studies are similar to the benefits observed with caloric restriction.
  • Short-term human clinical trials suggest that alternate day fasting results in weight loss. The weight loss causes an improvement in blood sugar control, lower blood pressure, and lower cholesterol & triglyceride levels. Based on these studies, alternative day fasting is likely to be an effective strategy for short-term weight loss and has some short-term health benefits.
  • However, there are no long-term studies on the effectiveness of this approach. It is highly unlikely that most people would be able to follow this regimented a diet plan long term. Thus, it is also unlikely that the weight loss and health benefits can be maintained long term.
  • Finally, fasting is not for everyone. It is generally not recommended for people who are hypoglycemic, the elderly, pregnant women, and people with eating disorders.

 

The Bottom Line

 

In this article I discussed a recent review of intermittent fasting and other approaches that involved fasting or long-term caloric restriction. Here are the take-home lessons on intermittent fasting:

  • Most of the studies on intermittent fasting have been done with animals, not with humans. Many of the claims you hear about on the benefits of intermittent fasting are based on the animal studies. They may not apply to humans.
  • Both animal and human studies suggest that the benefits of intermittent fasting result from synchronizing your food intake with your circadian rhythm. The old adage of “Eat breakfast like a king, lunch like a prince, and dinner like a pauper” may be true for most of us. [Note: Circadian rhythms vary slightly from person to person. Some people will do better by breaking their fast at mid-day rather than at breakfast. However, they will probably still benefit by eating a bigger meal mid-day and a smaller meal in the evening.]
  • Although there is no conscious effort to reduce calories, intermittent fasting appears to result in an inadvertent reduction in food intake by restricting the time allowed for eating and by eliminating late night snacking. This reduction in caloric intake is likely responsible for much of the weight loss associated with intermittent fasting.
  • In summary, intermittent fasting appears to be beneficial, but it is not clear whether you need to follow a rigid schedule of eating and fasting. The available clinical studies suggest that if you eat a healthy, primarily plant-based diet, eat most of your calories early in the day, don’t snack between meals, and don’t eat anything after dinner, you will obtain most, if not all, of the benefits attributed to intermittent fasting. If you define intermittent fasting that way, the professor has been doing intermittent fasting for years. He just didn’t know that was what he was doing.

For more details on intermittent fasting and for a discussion of long-term caloric restriction and alternate day fasting read the article above.

 

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

Health Tips From The Professor How Long Do the Benefits of Supplements Last?

Posted October 23, 2018 by Dr. Steve Chaney

Can Supplements Set You On A Path Towards A Healthier Life?

Author: Dr. Stephen Chaney

 

benefits of supplements heartA recent study (U Alehagen et al, PLOS One, April 11, 2018, 1-15 ) reported that the heart benefits of supplementation with coenzyme Q10 and selenium persisted for 12 years after supplementation ended. You would have thought a story like that would have made the headlines. Nope. Hardly a mention. Perhaps it did not match the narrative of the media and health professionals that supplements are worthless.

This study broke new ground. Most studies last a year or two and report whether there were any benefits of supplementation. A few studies have been extended a few years beyond the original supplementation period and have reported continued benefits of supplementation. However, in those studies the intervention group was still taking supplements. The intervention period was simply extended.

However, this study was unique in that supplementation was discontinued after 4 years. However, the positive effects of supplementation during that four-year period persisted for another 12 years without additional supplementation.

 

How Was The Study Done?

benefits of supplements monitoring heartIn this study 443 elderly individuals (average age =78) were recruited from a rural village in Sweden. They were given either supplements providing 200 mg/day of coenzyme Q10 and 200 mcg/day of selenium yeast or placebo pills. They were followed for four years. At this point the intervention phase of the trial ended, and the participants were followed for another 12 years without supplementation.

Cardiovascular deaths and all-cause mortality were recorded at 4 years (the end of the original intervention period), 10 years, and 12 years. The Swedish health care system is incredibly efficient. None of the participants were lost to follow-up.

Note on study design: Both coenzyme Q10 and selenium have heart health benefits and they compliment each other. Coenzyme Q10 was included in this study because our bodies lose the ability to make coenzyme Q10 as we age. By the time we reach age 80, we only make around half the coenzyme Q10 we made when we were younger. Selenium was included in the study because most Swedes are selenium deficient.

This study measured selenium levels and confirmed that all participants were selenium deficient at the beginning of the study. Selenium levels increased to near optimal in the supplemented group during the 4-year intervention period. In contrast, the placebo group remained selenium deficient.

 

How Long Do the Benefits of Supplements Last?

benefits of supplementationThe results of the study were truly amazing.

When you compared the group that had received coenzyme Q10 and selenium during the first 4 years of the study with the placebo group:

  • Cardiovascular mortality was 38% less and all-cause mortality was 24% less 12 years later in the supplement group.
  • The decrease in cardiovascular mortality lessened slightly with time (53% lower at 4 years, 46% lower at 10 years, and 38% lower at 12 years.
  • In contrast, the decrease in all-cause mortality remained relatively constant.
  • The effect was greater for women (who have lower coenzyme Q10 levels than men) than it was for men.
  • The decrease in cardiovascular mortality was 57% for women and 22% for men.
  • Cardiovascular mortality was decreased by 40-50% for people at high risk of cardiovascular death because of atherosclerosis, diabetes, high blood pressure, or impaired heart function.

Putting This Study Into Perspective

benefits of supplements wellnessI don’t want to read too much into this study. It has multiple limitations:

  • It is a very small study.
  • It is the first study I am aware of that has followed study participants years after supplementation has ended. More studies like this are clearly needed before any firm conclusions can be drawn.
  • It may be unique to Sweden where selenium deficiency is widespread. Selenium deficiency is much less prevalent in some other countries such as the United States.
  • It is possible that once the study population heard about the results of the initial 4-year study they started self-supplementing with coenzyme Q10 and selenium. However, since the participants did not know whether they were in the supplement or placebo group, that would likely affect both groups equally.

However, it is the implications of the study that fascinate me.

  • The authors of the study speculated that the improvement in endothelial cell function (Endothelial cells line the arteries and play an important role in arterial health) and/or decreased inflammation may have persisted long after supplementation stopped.
  • A more interesting idea is that supplementation (or the effects of supplementation) caused modifications to the DNA that were persistent (something we refer to as epigenetics). Moreover, those DNA modifications may have altered gene expression in a manner that reduced heart disease risk.

Much more work needs to be done before we know whether epigenetic modifications were responsible for the persistent benefit of supplementation in this, or any other, study. However, the ramifications of this idea are substantial. We think of supplementation as something that provides benefit only while we are taking the supplement. What if, under the right conditions, supplementation could send us down an entirely different path to better health? That would be worth major headlines.

 

The Bottom Line

 

A recent study in Sweden looked at the effects of supplementation with coenzyme Q10 and selenium on heart health 12 years after supplementation had ended.

  • The study reported that cardiovascular mortality was 38% less and all-cause mortality was 24% less 12 years later in the group that supplemented during the first 4 years.

The study has multiple limitations and needs to be repeated before drawing any definite conclusions. However, if true, it has interesting implications. What if the benefits of supplementation didn’t stop when you stopped supplementing? What if supplementation sent you down an entirely different path, a path towards better health?

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.

 

Health Tips From The Professor The Economic Benefits of Plant-Based Diets

Could Plant-Based Diets Cut Healthcare Costs?

Author: Dr. Stephen Chaney

 

Could saving the healthcare system be one of the economic benefits of plant-based diets?

economic benefits of plant-based diets healthcare system costsI don’t need to tell you that our healthcare system is in crisis. Costs are out of control. The Centers for Medicare and Medicaid Services (CMS) estimates that healthcare costs will account for 25% of the gross domestic product by 2025. They also predict that 47% of that spending will be financed by federal. State, and local governments. That is unsustainable.

Our politicians have no answer. Neither political party has a viable plan to cut costs. Perhaps it is time to take matters into our own hands. What if there were a way to improve our own health and the viability of our healthcare system? A recent study suggests there may be a way to accomplish both goals.

How Was The Study Done?

In a recent study (L. Annemans and J. Schepers, Nutrition, 48: 24-32, 2018 ) scientist at Ghent university in Belgium set out to investigate the effect on public health and healthcare costs if just 10% of the population of Belgium and England switched to a primarily plant-based diet. They started with two diets for which the health benefits have been well established by multiple studies. These diets are:

economic benefits of plant-based diets soy#1: A Soy-Containing Diet: This is defined as a diet in which soy protein foods were consumed in place of animal protein foods more than 5 times per week. The soy foods included in their study were soybeans, tofu, miso, soy protein drinks, and soy yoghurt.

The soy-containing diet was chosen because previous studies have shown it protects against obesity, heart disease, stroke, diabetes, and breast, colon, stomach, lung, and prostate cancer.  (Yes. In spite of the erroneous information you find on the internet, soy foods decrease cancer risk.)

#2: The Mediterranean Diet: This is defined as a diet rich in fruits, vegetables, whole grains, nuts, seeds and large amounts of olive oil. It includes a moderate to high consumption of fish and other seafood and a low intake of meat and dairy products.

economic benefits of plant-based diets mediterranean dietsThe Mediterranean diet was chosen because previous studies have shown it protects against heart disease, stroke, diabetes, and breast cancer. I have documented these health benefits in more detail in my book “Slaying The Food Myths.”

This study did not look at the benefits of other plant-based diets. For example, as discussed in “Slaying The Food Myths,” the Seventh-Day Adventist studies have shown comparable health benefit for a variety of vegetarian diets.

This study looked at the prevalence of each of these diseases in Belgium and England and estimated what the effect would be if the prevalence of these diseases were reduced by the amounts reported in previous studies of soy-based and Mediterranean diets.

The study reported two outcomes: the increase in Quality of Life Years (QALYs) and the decrease in healthcare costs. Increased Quality of Life Years simply means the increase in disease-free years. That is the outcome most important to each of us personally. However, we should be equally interested in the decreased healthcare costs. The dollars our government spends on healthcare don’t grow on trees. They come out of our pockets.

 

Economic Benefits of Plant-Based Diets: Decreasing Healthcare Costs?

 

economic benefits of plant-based dietsWith that buildup, you are probably wondering what the outcome of the study was. The news was good:

If 10% of the population switched to a soy-based diet there would be:

  • An increase of 154 Quality of Life Years/1,000 people and a decrease in healthcare costs of $1.9 billion/20 years in Belgium.
  • An increase of 130 Quality of Life Years/1,000 people and a decrease in healthcare costs of $10.7 billion/20 years in England.

If 10% of the population switched to a Mediterranean diet there would be:

  • An increase of 166 Quality of Life Years/1,000 people and a decrease in healthcare costs of $1.6 billion/20 years in Belgium.
  • An increase of 116 Quality of Life Years/1,000 people and a decrease in healthcare costs of $7.4 billion/20 years in England.

[Note: In case you were wondering, the authors said the reason why plant-based diets had less of an effect on Quality of Life Years in England than in Belgium is because public health interventions have already significantly decreased the incidence of heart attack and stroke in England. Conversely, the reason healthcare savings are higher in England is because healthcare costs are higher there.]

Finally, if one were to extrapolate the British healthcare savings to the costs of the US healthcare system, one would predict:

  • If 10% of the US population were to switch to a soy-based diet, healthcare savings might amount to $17 billion/20 years.
  • If 10% of the US population were to switch to a Mediterranean diet, healthcare savings might amount to $12 billion/20 years.

The authors concluded: “The result of the present analysis suggests that both a soy-containing diet and the Mediterranean diet could contribute to health promotion because they are predicted to lead to substantial health benefits and societal savings.”

How Accurate Are These Estimates?

The benefits of soy-based and Mediterranean diets on which these estimates are based are very solid. The benefits are based on association studies, but the studies are very well done and are remarkably consistent.

The major weakness of these estimates is the benefits of these diets have been demonstrated in other parts of the world and are being extrapolated to a region of the world where neither of those diets are commonly followed. The authors tried very hard to control for all confounding variables, but the possibility remains that lifestyle differences unique to those geographic regions also contributed to the health benefits of soy-based and Mediterranean diets.

The authors acknowledged that some of the foods that are normally part of soy-based and Mediterranean diets were not as readily available in Belgium and England. They raised the possibility that something like the “New Nordic Diet”, which is also primarily plant-based but incorporates more familiar foods, might be equally effective. The equivalent diet in the US might be the DASH diet.

The economic benefits of plant-based diets may not depend so much on the diet, as long as it is plant-based and those foods are readily available.

 

The Bottom Line:

 

A recent study looked at the effect of a plant-based diet on Quality Of Life Years (disease free years) and healthcare costs in Belgium and England. The study estimated:

If 10% of the population switched to a soy-based diet there would be:

  • An increase of 154 Quality of Life Years/1,000 people and a decrease in healthcare costs of $1.9 billion/20 years in Belgium.
  • An increase of 130 Quality of Life Years/1,000 people and a decrease in healthcare costs of $10.7 billion/20 years in England.

If 10% of the population switched to a Mediterranean diet there would be:

  • An increase of 166 Quality of Life Years/1,000 people and a decrease in healthcare costs of $1.6 billion/20 years in Belgium.
  • An increase of 116 Quality of Life Years/1,000 people and a decrease in healthcare costs of $7.4 billion/20 years in England.

If one were to extrapolate the British healthcare savings to the costs of the US healthcare system, one would predict:

  • If 10% of the US population were to switch to a soy-based diet, healthcare savings might amount to $17 billion/20 years.
  • If 10% of the US population were to switch to a Mediterranean diet, healthcare savings might amount to $12 billion/20 years.

The authors concluded: “The result of the present analysis suggests that both a soy-containing diet and the Mediterranean diet could contribute to health promotion because they are predicted to lead to substantial health benefits and societal savings.”

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.