Diet and Chronic Disease: Type 2 Diabetes and Heart Disease

Written by Dr. Steve Chaney on . Posted in Chronic Disease, Diabetes, Diets, Heart Disease

Can You Cut Your Risk Of Heart Disease And Diabetes In Half?

Author: Dr. Stephen Chaney

 

diet and chronic disease heart attackIt is no secret that heart disease and diabetes are among the top two causes of death in this country. They are killers. Even worse, they can affect your quality of life for years before they kill you. Finally, they are bankrupting our health care system. Anything we can do to reduce the toll of these diseases would be of great benefit.

Is there a connection between diet and chronic disease, specifically type 2 diabetes, stroke, and heart disease?

That is why recent headlines suggesting that deaths due to heart disease, stroke, and diabetes could be cut almost in half simply by changing our diet caught my attention. Of course, those headlines came as no surprise. It almost seems like the American diet is designed to make us fat and unhealthy. It seems designed to make us die prematurely from heart disease, stroke, and diabetes.

 

How Was The Study Done?

diet and chronic disease heart diseaseThis was a major study (R. Micha et al, JAMA, 317: 912-924, 2017 ). They started by using something called the National Health and Nutrition Examination Survey (NHANES). NHANES is a major survey conducted approximately every 10 years by the US government to collect data on demographics, disease, and diet from a cross section of the US population. They used this database to determine how frequently Americans consumed various heart-healthy and heart-unhealthy foods. They collected data from two surveys conducted in 1999-2002 and 2009-2012 to determine how consumption of those foods had changed over that 10-year period.

  • The heart-healthy foods they included in their study were fruits, vegetables, nuts & seeds, whole grains, and seafood omega-3s (long chain omega-3s).
  • The heart-unhealthy foods they included in their study were red meats, processed meats, sugar-sweetened beverages, and sodium.

They then did a meta-analysis of high quality clinical studies measuring the effects of those foods on deaths due to heart disease, stroke, and diabetes. They combined the data from all these studies to calculate the deaths due to all three causes combined, something they called deaths due to cardiometabolic disease.

Diet and Chronic Disease, Preventing Type 2 Diabetes and Heart Disease

diet and chronic disease lifestyleWhen the investigators combined all the data, they estimated that changing one’s diet from heart-unhealthy foods to heart-healthy foods would reduce cardiometabolic deaths (deaths due to heart disease, stroke, and diabetes) by 45.4%. That is an almost 50% reduction just by eating a healthier diet.

  • This probably underestimates the benefit of eating a healthier diet because they did not include the effects of reducing saturated fats, sweets, and refined carbohydrates on cardiometabolic deaths.
  • The reduction in cardiometabolic deaths was consistent across all demographic groups. It ranged from 40% to 60% when they considered gender, age, or ethnicity.
  • The 45.4% reduction in cardiometabolic deaths represents a holistic change to a healthier diet. When you consider the individual components of the standard American diet:
  • Decreasing sodium intake gives a 9.5% reduction in deaths.
  • Increasing intake of nuts and seeds gives an 8.5% reduction in cardiometabolic deaths.
  • Decreasing intake of processed meats gives an 8.2% reduction in cardiometabolic deaths.
  • Increasing intake of vegetables gives a 7.6% reduction in cardiometabolic deaths.
  • Increasing intake of fruits gives a 7.5% reduction in cardiometabolic deaths.
  • Decreasing intake of sugar-sweetened beverages gives a 7.4% reduction in cardiometabolic deaths.
  • Increasing intake of whole grains gives a 5.9% reduction in cardiometabolic deaths.
  • Decreasing red meat consumption gives a 4.2% decease in diabetes deaths. They did not include the effect of red meat consumption on heart disease or stroke deaths in their calculation.

diet and chronic disease heartHolistic changes are best: It would be easy to look at each of those individual changes and conclude that the change is so small that it isn’t worth the effort. That would be totally missing the point. These data clearly show a relationship between diet and chronic disease:

  • A holistic change in diet that includes all these individual changes can make a huge difference in your risk of dying from heart disease, stroke, or diabetes.
  • Even if you are not prepared to make this many changes at once, each individual change gets you one step closer to a longer, healthier life. In fact, if you make just one or two of these changes you have reduced your risk of dying more than if you were taking a statin drug – and with no side effects.

The good news is that Americans have made some positive changes in their diet between the first and second NHANES survey, and, as a result, cardiometabolic deaths declined by 26.5%. The biggest contributors to this improvement were:

  • Increased polyunsaturated fat consumption (-20.8%).
  • Increased nut and seed consumption (-18%).
  • Decreased sugar sweetened beverage consumption (-14.5%).
  • This was partially offset by increased processed meat consumption (+14.4%)

The authors concluded: “Dietary factors were estimated to be associated with a substantial proportion of deaths from heart disease, stroke, and type 2 diabetes. These results should help identify priorities, guide public health planning, and inform strategies to alter dietary habits and improve health.”  Below is a summary of the relationship between diet and chronic disease (specifically type 2 diabetes, stroke, and heart disease).

 

The Bottom Line

It almost seems like the American diet is designed to make us fat and unhealthy. It seems designed to make us die prematurely from heart disease, stroke, and diabetes. A recent study looked at the effect of a healthier diet on what they called cardiometabolic deaths (deaths due to heart disease, stroke, and diabetes). They concluded:

  • changing one’s diet from heart-unhealthy foods to heart-healthy foods would reduce cardiometabolic deaths by 45.4%. That is an almost 50% reduction just by eating a healthier diet.
  • This probably underestimates the benefit of eating a healthier diet because they did not include the effects of reducing saturated fats, sugary foods, and refined carbohydrates on cardiometabolic deaths.
  • The reduction in cardiometabolic deaths was consistent across all demographic groups. It ranged from 40% to 60% when they considered gender, age, or ethnicity.
  • The 45.4% reduction in cardiometabolic deaths represents a holistic change to a healthier diet. When you consider the individual components of the standard American diet:
    • Decreasing sodium intake gives a 9.5% reduction in deaths.
    • Increasing intake of nuts and seeds gives an 8.5% reduction in cardiometabolic deaths.
    • Decreasing intake of processed meats gives an 8.2% reduction in cardiometabolic deaths.
    • Increasing intake of vegetables gives a 7.6% reduction in cardiometabolic deaths.
    • Increasing intake of fruits gives a 7.5% reduction in cardiometabolic deaths.
    • Decreasing intake of sugar-sweetened beverages gives a 7.4% reduction in cardiometabolic deaths.
    • Increasing intake of whole grains gives a 5.9% reduction in cardiometabolic deaths.
    • Decreasing red meat consumption gives a 4.2% reduction in diabetes deaths. They did not include the effect of red meat consumption on heart disease or stroke deaths in their calculation.

It would be easy to look at each of those individual changes and conclude that the change is so small that it isn’t worth the effort. That would be totally missing the point. These data clearly show:

  • A holistic change in diet that includes all these individual changes can make a huge difference in your risk of dying from heart disease, stroke, or diabetes.
  • Even if you are not prepared to make this many changes at once, each individual change gets you one step closer to a longer, healthier life. In fact, if you make just one or two of these changes you have reduced your risk of dying more than if you were taking a statin drug – and with no side effects.

The authors concluded: “Dietary factors were estimated to be associated with a substantial proportion of deaths from heart disease, stroke, and type 2 diabetes. These results should help identify priorities, guide public health planning, and inform strategies to alter dietary habits and improve 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.

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Is Our Microbiome Affected By Exercise?

Posted November 6, 2018 by Dr. Steve Chaney

Microbiome Mysteries

Author: Dr. Stephen Chaney

is our microbiome affected by exerciseIn a recent post,  What is Your Microbiome and Why is it Important,  of “Health Tips From The Professor” I outlined how our microbiome, especially the bacteria that reside in our intestine, influences our health. That influence can be either good or bad depending on which species of bacteria populate our gut. I also discussed how the species of bacteria that populate our gut are influenced by what we eat and, in turn, influence how the foods we eat are metabolized.

I shared that there is an association between obesity and the species of bacteria that inhabit our gut. At present, this is a “chicken and egg” conundrum. We don’t know whether obesity influences the species of bacteria that inhabit our gut, or whether certain species of gut bacteria cause us to become obese.

Previous studies have shown that there is also an association between exercise and the species of bacteria that inhabit our gut. In particular, exercise is associated with an increase in bacteria that metabolize fiber in our diets to short chain fatty acids such as butyrate. That is potentially important because butyrate is a primary food source for intestinal mucosal cells (the cells that line the intestine). Butyrate helps those cells maintain the integrity of the gut barrier (which helps prevent things like leaky gut syndrome). It also has an anti-inflammatory effect on the immune cells that reside in the gut.

However, associations don’t prove cause and effect. We don’t know whether the differences in gut bacteria were caused by differences in diet or leanness in populations who exercised regularly and those who did not. This is what the present study (JM Allen et al, Medicine & Science In Sports & Exercise, 50: 747-757, 2018 ) was designed to clarify.  Is our microbiome affected by exercise?

 

How Was The Study Designed?

is our microbiome affected by exercise studyThis study was performed at the University of Illinois. Thirty-two previously sedentary subjects (average age = 28) were recruited for the study. Twenty of them were women and 12 were men. Prior to starting the study, the participants filled out a 7-day dietary record. They were asked to follow the same diet throughout the 12-week study. In addition, a dietitian designed a 3-day food menu based on their 7-day recall for the participants to follow prior to each fecal collection to determine species of gut bacteria.

The study included a two-week baseline when their baseline gut bacteria population was measured, and participants were tested for fitness. This was followed by a 6-week exercise intervention consisting of three supervised 30 to 60-minute moderate to vigorous exercise sessions per week. The exercise was adapted to the participant’s initial fitness level, and both the intensity and duration of exercise increased over the 6-week exercise intervention. Following the exercise intervention, all participants were instructed to maintain their diet and refrain from exercise for another 6 weeks. This was referred to as the “washout period.”

VO2max (a measure of fitness) was determined at baseline and at the end of the exercise intervention. Stool samples for determination of gut bacteria and concentrations of short-chain fatty acids were taken at baseline, at the end of the exercise intervention, and again after the washout period.

In short, this study divided participants into lean and obese categories and held diet constant. The only variable was the exercise component.

 

Is Our Microbiome Affected By Exercise?

is our microbiome affected by exercise fitnessThe results of the study were as follows:

  • Fitness, as assessed by VO2max, increased for all the participants, and the increase in fitness was comparable for both lean and obese subjects.
  • Exercise induced a change in the population of gut bacteria, and the change was comparable in lean and obese subjects.
  • Exercise increased fecal concentrations of butyrate and other short-chain fatty acids in the lean subjects, but not in obese subjects.
  • The exercise-induced changes in gut bacteria and short-chain fatty acid production were largely reversed once exercise training ceased.

The authors concluded: “These findings suggest that exercise training induces compositional and functional changes in the human gut microbiota that are dependent on obesity status, independent of diet, and contingent on the sustainment of exercise.” [Note: To be clear, the exercise-induced changes in both gut bacteria and short-chain fatty acid production were independent of diet and contingent on the sustainment of exercise. However, only the production of short-chain fatty acids was dependent on obesity status.]

 

What Does This Study Mean For You?

is our microbiome affected by exercise gut bacteriaThere are two important take home lessons from this study.

  • With respect to our gut bacteria, I have consistently told you that microbiome research is an emerging science. This is a small study, so you should regard it as the beginning of our understanding of the effect of exercise on our microbiome rather than conclusive by itself. It is consistent with previous studies showing an association between exercise and a potentially beneficial shift in the population of gut bacteria.

The strength of the study is that it shows that exercise-induced changes in beneficial gut bacteria are probably independent of diet. However, it is the first study to look at the interaction between obesity, exercise and gut bacteria, so I would interpret those results with caution until they have been replicated in subsequent studies.

  • With respect to exercise, this may be yet another reason to add regular physical activity to your healthy lifestyle program. We already know that exercise is important for cardiovascular health. We also know that exercise increases lean muscle mass which increases metabolic rate and helps prevent obesity. There is also excellent evidence that exercise improves mood and helps prevent cognitive decline as we age.

Exercise is also associated with decreased risk of colon cancer and irritable bowel disease. This effect of exercise has not received much attention because the mechanism of this effect is unclear. This study shows that exercise increases the fecal concentrations of butyrate and other short-chain fatty acids. Perhaps, this provides the mechanism for the interaction between exercise and intestinal health.

 

The Bottom Line

A recent study has reported that:

  • Exercise induces a change in the population of gut bacteria, and the change was comparable in lean and obese subjects.
  • Exercise causes an increase in the number of gut bacteria that produce butyrate and other short-chain fatty acids that are beneficial for gut health.
  • These effects are independent of diet, but do not appear to be independent of obesity because they were seen in lean subjects but not in obese subjects.
  • The exercise-induced changes in gut bacteria and short-chain fatty acid production are largely reversed once exercise training ceases.

The authors concluded: “These findings suggest that exercise training induces compositional and functional changes in the human gut microbiota that are dependent on obesity status, independent on diet, and contingent on the sustainment of exercise.”

For more details and my interpretation of the data, 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.

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