Obesity

Diet And Cancer Risk

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What Can You Do To Reduce Your Risk Of Cancer?

Magic WandIt seems like everyone has a magic pill, essential oil, food, or diet that prevents cancer. It doesn’t take a genius to figure out that all the claims can’t be true. No wonder you are confused. You want to know:

  • Which of these claims are true?
  • What can you do to reduce your risk of cancer?

These aren’t trivial questions.

  • Cancer is the second leading cause of death in this country, and some experts predict it will surpass heart disease as the leading cause of death in the near future.
  • While cancer treatments have become much more effective in the past few decades, these treatment successes are often associated with severe side-effects, enormous expense, or both.

That is why I was intrigued by a recent study (FF Zhang et al, JNCI Cancer Spectrum (2019) 3(2): pkz034) on diet and cancer that came from the prestigious Friedman School of Nutrition and Public Policy at Tufts University. This study asked two important questions:

  • How many newly diagnosed cancer cases could have been prevented by changes in the American diet? This is something the authors referred to as the “preventable cancer burden associated with poor diet”.
  • Which foods increased or decreased the risk of cancer? This, of course, is the most useful information for you and me.

Diet And Cancer Risk

Diet And CancerThis study estimated that 80,110 new cancer cases among US adults 20 and older could be primarily attributed to poor diet. While poor diet contributes to many more cancers, the authors of this study felt 80,110 represented the number of cancer cases that were clearly preventable by some simple dietary changes.

While all cancers were affected by diet to some degree, the cancers most affected by poor diet were:

  • Colon cancer (65% of cases)
  • Mouth and throat cancer (18% of cases)
  • Endometrial cancer (4.0% of cases)
  • Breast cancer (3.8% of cases)

When the diet was broken down into individual food groups:

  • Low intake of whole grains was associated with the largest number of preventable cancer cases (35% of cases). This was followed by.
  • Low intake of dairy foods (22% of cases).
  • High intake of processed meats (18% of cases).
  • Low intake of vegetables (16% of cases).
  • Low intake of fruits (10% of cases).
  • High intake of red meat (7.1% of cases).
  • High intake of sugar sweetened beverages (4.0% of cases).

Of the diet-associated cancer cases, the scientists who lead the study estimated that 84% of them represented a direct effect of diet on cancer risk. The dietary factors most likely to directly increase the risk of cancer were:

  • Low intake of whole grains.
  • Low intake of dairy foods.
  • High intake of processed meats.

The scientists estimated that 16% of diet-associated cancer cases were “mediated by obesity”. In layman’s terms, this means that diet increased the risk of obesity and obesity increased the risk of cancer. The dietary factors most likely to increase the risk of obesity-mediated cancers were:

  • High intake of sugar sweetened beverages.
  • Low intake of fruits.

The authors concluded: “More than 80,000 new cancer cases [per year] are estimated to be associated with suboptimal diet among US adults…Our findings underscore the need for reducing cancer burden in the United States by improving the intake of key food groups and nutrients of Americans.”

What Does This Mean For You?

Questioning ManThese findings aren’t novel. Many previous studies have come to the same conclusions. However, many people find these recommendations to be confusing. Should they increase their intake of certain foods? Should they follow some sort of magic diet?

Perhaps we need to get away from the magic food concept. We need to understand that every time we increase one food in our diet, we exclude other foods. We need to step back and look at the overall diet.

Let me break down the recommendations from this study into three categories: foods we should eliminate from our diet, foods we should include in our diet, and foods we should balance in our diet.

Foods we should eliminate from our diet:

  • Sugar Sweetened Beverages. They provide no nutritional benefit, and the sugar in most beverages rushes into our bloodstream and overwhelms our body’s ability to utilize it in a healthy way. This leads to obesity, diabetes, and a host of other health issues.
    • Public enemy number one is sodas. However, this category also includes fruit juices, sweetened teas and energy drinks, and sugary processed foods.
    • This category also includes diet sodas. For reasons we don’t completely understand, diet sodas appear to be just as likely to lead to obesity, diabetes, and heart disease as sugar sweetened sodas. I have discussed the proposed explanations of this phenomenon in a recent issue of “Health Tips From the Professor”.
    • Sugar, however, is not the enemy. Sugar found naturally in fruits and other whole foods enters the bloodstream slowly and is metabolized in healthy ways by the body. I have discussed this in another issue  of “Health Tips From the Professor”. This is what I mean by restoring balance in our diet. Decreasing the sugar intake from sugar sweetened beverages and increasing sugar intake from fruits is associated with a decreased risk of obesity and obesity-related cancers.
  • Processed Meats. The evidence is overwhelming at this point that processed meats directly increase the risk of cancer.
    • If you have trouble completely eliminating processed meats from your diet, my advice is to minimize them and consume them only in the context of an overall healthy diet. Personally, I still consume bacon occasionally as flavoring for a healthy green salad.

Whole GrainsFoods we should include in our diet. I put these in a separate category because Dr. Strangelove and his colleagues have been telling us to eliminate them from our diet, and many Americans are following those recommendations:

  • Whole grains. We can think of whole grains as the underserving victim of the low-carb craze. The low-carb craze is on the mark when it comes to eliminating added sugars and refined grains from the diet. However, eliminating whole grains from the diet may be doing more harm than good. In fact, this and other studies suggest that whole grains are the most effective foods for reducing cancer risk. Why is that?
    • If we assume whole grains are just a good source of fiber and a few vitamins and minerals, it is hard to grasp their importance. We could easily get those nutrients elsewhere.
    • However, we are beginning to realize that whole grains play a unique role in supporting certain species of gut bacteria that are very beneficial to our health. In short, whole grains may be essential for a healthy gut.
  • Dairy Foods. This is another food that has been treated as a villain by Dr. Strangelove and his many colleagues. However, for reasons we don’t completely understand, dairy foods appear to decrease the risk of heart disease and cancer.

Foods we should balance in our diet.

  • Red Meat. Diets high in red meat are consistently associated with a slight increase in cancer risk. The World Health Organization lists red meat as a probable carcinogen, but that has proven to be controversial.
    • Much of the research has centered on why red meat causes cancer. Several mechanisms have been proposed, but none of them have been proven.
    • In contrast, very little consideration has been given to what red meat is displacing from the diet. Diets high in red meat are often low in whole grains, fruits and/or vegetables.
    • Perhaps instead of eliminating red meat from our diets we should be talking about balancing red meat in our diets by consuming less red meat and more whole grains, fruits, and vegetables.

What Can You Do To Reduce Cancer Risk?

American Cancer SocietyYou may have been thinking that 80,110 cases/year represents a small percentage of new cancer cases. That’s because diet is only one component of a holistic cancer prevention strategy. Here is what the American Cancer Society recommends for reducing cancer risk:

  • Avoid tobacco.
  • Limit sun exposure.
  • Achieve and maintain a healthy weight.
  • Eat a healthy diet, with an emphasis on plant foods (Their recommendations are in line with this study).
  • Be physically active.
  • Limit alcohol use.
  • Get vaccinated against HPV.
  • Get regular medical checkups.

Doing any of these things will reduce your cancer risk. But the more of these you can incorporate into your lifestyle, the lower your risk.

The Bottom Line

A recent study looked at diet and cancer risk. The authors reported that 80,110 new cancer cases among US adults 20 and older could be primarily attributed to poor diet.

When the diet was broken down into individual food groups:

  • Low intake of whole grains was associated with the largest number of preventable cancer cases. This was followed in descending order by.
  • Low intake of dairy foods.
  • High intake of processed meats.
  • Low intake of vegetables.
  • Low intake of fruits.
  • High intake of red meat.
  • High intake of sugar sweetened beverages.

The authors concluded: “More than 80,000 new cancer cases [per year] are estimated to be associated with suboptimal diet among US adults…Our findings underscore the need for reducing cancer burden in the United States by improving the intake of key food groups and nutrients of Americans.”

For more details, read the article above. For example, I discuss which foods we should eliminate, which foods we should eat more of, and which foods we should balance in our diet. To add a more holistic perspective, I also discuss the American Cancer Society’s recommendations for reducing cancer risk.

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

Why Do Most Diets Fail?

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How To Lose Weight And Keep It Off

New Year DietTomorrow is the official start of another dieting season. Millions of Americans will be making a New Year’s Resolution to lose weight. The top three reasons for these weight loss resolutions are:

1)    Reduce disease risk (73%). After all, we are being told those excess pounds increase our risk of diabetes, heart disease, cancer, and just about every other disease known to man.

2)    Improve self-esteem (61%). Some of this may be due to the social stigma associated with obesity, but many people simply want to improve the image they see in the mirror every morning when they get out of the shower.

3)    Boost energy (49%).

Those are all good reasons for losing weight. But before you make your New Year’s resolution to embark on another weight loss journey, you should ask yourself “Do weight loss diets work?” If you look at the statistics, they aren’t very encouraging:

1)    45 million Americans go on a weight loss diet every year.

·       50% go on fad diets.

·       They spend $33 billion on weight loss products.

·       90% regain almost all the weight. That’s called the yo-yo effect.

·       On average, Americans gain 11 pounds on every diet yo-yo.

o   They might as well have thrown that $33 billion to the wind.

2)    228,000 Americans get gastric bypass surgery.

·       80% regain almost all the weight.

o   Their digestion and their health will never be the same.

As if those statistics weren’t bad enough, the obesity epidemic gets worse year after year (see the graphic on the Obesity Epidemicright). Americans keep getting fatter. What we are doing clearly isn’t working.

You are probably saying to yourself: “I know that, but this year I’m going to try a new diet.” As the saying goes “Hope springs eternal in the human breast”, but is it realistic to think this time will be different?

Let me share a quote from a book and TV series called “The Weight Of the Nation” by John Hoffman & Dr. Judith Salerno”:

“First we blamed fat – low fat diets didn’t work! Then we blamed carbs, eggs, red meat, dairy, white flour, sugar, juices, sodas, high-fructose corn syrup, & partially hydrogenated fats. One by one, we replaced the evil food du jour…and watched our collective waistlines grow.”

In other words, they are saying it’s not just low-fat diets that don’t work. None of the popular diets work long term. I come across lots of people who tell me the Atkins weight-loss diet works best for them. That would be convincing if they were slender, but they aren’t! They gained it all back and then some. Now that the keto diet has been around for a few years, I am starting to see the same pattern there as well.

Clearly, the problem isn’t losing the weight. Any diet can help you lose weight. The problem is keeping the weight off. Let’s look at why this is.

Why Do Most Diets Fail?

WhyTo understand the answer to this question, let’s start with another quote from “The Weight Of the Nation”: “Our bodies were designed to store fat in times of plenty and retain fat in times of famine”

Essentially, the authors were saying when our ancestors were hunters and gatherers, there were times when food was abundant, and times when food was scarce. In order to survive, our bodies had to store energy in its most efficient form when food was abundant and hold on to those energy stores as long as possible when food was scarce.

Fat provides more than twice as many calories per gram as either carbohydrate or protein. Additionally, our ability to store carbohydrate is limited. And we don’t really have protein stores. All the proteins in our body have essential functions. However, our ability to store fat is unlimited. Now you understand why fat is the preferred energy store in times of plenty and our bodies try to hold on to it as long as possible in times of famine.

With that perspective in mind, there are three reasons why most diets fail:

1)    Most dieters are looking for rapid weight loss (at least 2-5 pounds/week). That is a problem because “Our bodies were designed to…retain fat in times of famine”. When we lose weight quickly, our bodies interpret that as famine. Our bodies respond by decreasing our metabolic rate so we can hold on to those fat stores.

The solution to this problem is to set more reasonable weight loss goals. If we keep the rate of weight loss in the 1-2 pound/week range (0.5-1 pounds/week is even better), we can largely avoid this famine response. You should ask yourself, “What’s the rush?” After all, the average American only gains 1-2 pounds/year. Why do we need to get rid of that excess weight in just a few weeks?

2)    Most dieters are looking for significant weight loss (more than 20 pounds). That is a problem because our bodies are designed to retain fat stores, not protein stores. When our bodies sense a famine they burn our protein stores (lean muscle mass) to spare as much of our fat stores as possible. The longer the diet (famine) lasts, the more muscle mass we lose.

That’s a problem because muscle burns calories much faster than fat. The more muscle we lose, the more our metabolic rate decreases. It gets harder and harder to lose weight, and eventually we reach a plateau. Most people get discouraged at that point and go off their diet.

That’s where the other part of the quote from “The Weight Of The Nation” kicks in: “Our bodies are Yo-Yo with Boydesigned to store fat in times of plenty”. Once again, it is fat we store, not protein. Most people never regain the protein stores they lost, so their metabolic rate remains low. They regain most of the weight they lost, and then some. This is the origin of the yo-yo effect.

There are two solutions to this problem:

·       Increase your resistance exercise and your intake of protein with high levels of the essential amino acid leucine. I have covered this in a previous issue of “Health Tips From The Professor”.

·       Set more reasonable weight loss goals. It is possible to lose more than 20 pounds without losing muscle mass. We just need to think in terms of reaching those weight loss goals in years rather than in months. Once again, remember it took us years to gain the weight. Why not think in terms of years to lose the weight?

3)    Most dieters think in terms of diets rather than lifestyle change. Diets have an expiration date. Then most people just drift back to “the way they really live”. Lifestyle change, on the other hand, is permanent. Once we change to a healthier lifestyle, we no longer need to focus on weight loss. The weight comes off automatically.

To better understand the power of lifestyle change let’s look at something called “The National Weight Control Registry”.

How To Lose Weight And Keep It Off

Happy woman on scaleRather than focus on the abysmal statistics for long-term weight loss, doctors Rena Hill and James O Wing decided to focus on the characteristic of people who manage to keep their weight off. They founded something called “The National Weight Control Registry” and invited people who were successful at keeping the weight off to participate in their program.

Currently, the National Weight Control Registry is tracking over 10,000 individuals who have lost 30 pounds or more and have kept it off for long periods of time. They use detailed questionnaires and annual follow-up surveys to study the behavioral and psychological characteristics and the strategies of weight loss maintainers.

When you look at how they lost weight, they are a very diverse group:

·       They lost weight on every possible diet – from vegan to keto to just plain crazy.

·       50% lost weight on commercial diet programs. 50% lost weight on their own.

·       Some lost weight quickly. Some lost weight slowly.

When you look at weight maintenance, you realize that the dismal weight maintenance statistics don’t have to apply to you. The good news is:

·       On average, people in The National Weight Control Registry have lost 66 pounds and have kept it off for 5 years or more.

·       12-14% of them have maintained a weight loss of 100 pounds or more for 5 or more years.

·       Even better, once they maintained their weight loss for 2-5 years, it became easy.

They no longer had to battle hunger and a sluggish metabolism. They no longer had to think about the lifestyle changes they were trying to maintain. Their new lifestyle became what they did automatically, without even thinking about it. Their weight loss had become permanent.

By now, you are probably wondering how they do it. Here are the top 7 characteristics of those who are successfulhealthy living at keeping the weight off:

1)    They consumed reduced calorie, low-fat, healthy diets.

2)    They had internalized their eating patterns. It had become how they ate every day without even thinking about it.

3)    They monitored their weight regularly. This allowed them to make adjustments whenever they saw their weight start to creep up.

4)    They ate breakfast on a regular basis.

5)    They got lots of exercise (on average, about 1 hour/day).

6)    They watched less than 10 hours of TV/week. If you were wondering where you would find the time to exercise an hour/day, this is probably your answer.

7)    They were consistent. They had no planned “cheat days”. This doesn’t mean they were purists. They still allowed themselves to eat some of their favorite unhealthy foods on an occasional basis. They just didn’t set aside regular times when they planned to “pig out”.

There was one other interesting observation from this study:

·       Those who used meal replacement shakes as part of their weight loss, focused more on diet and included meal replacement shakes as part of their maintenance program.

·       Those who lost weight on their own, also followed healthy eating habits, but put a bit more emphasis on exercise to keep themselves on track.

·       Both approaches were effective.

The take-home message of the National Weight Control Registry is clear. There is no magic diet that guarantees you will keep the weight off. The “secret” to keeping the weight off is a healthy eating pattern and a healthy lifestyle.

In short, if your resolution is to lose weight next year, don’t focus on the diet you will follow to lose the weight. Instead, focus on the healthy lifestyle you will follow to keep the weight off.

Of course, you will be most successful if the diet you are following to lose weight incorporates the healthy lifestyle you plan to follow to maintain your weight loss.

What Role Do Habits Play In Weight Loss?

Habits-Old-vs-NewFinally, I would like to share a recent study (G Cleo et al, International Journal of Obesity, 43: 374-383, 2019) that puts the whole issue of weight loss and weight maintenance in a different perspective. This study looked at the role that habits play in weight loss.

In short, the study enrolled 130 participants who wanted to lose weight. All the participants were told this was a weight loss study, but none of the participants were given detailed diet and exercise recommendations to follow. The study had a 12-week intervention phase followed by a 12-month follow-up phase. The participants were divided into three groups.

1)    Group 1 received no advice during the intervention phase. This was the control group.

2)    Group 2 focused on breaking old habits. During the intervention phase they were sent daily tests suggesting new habit patterns. These were suggestions like “Drive a different route to work today”. None of the texts had anything to do with diet or lifestyle.

3)    Group 3 focused on creating new healthy habits. They were given a list of 10 healthy habits. During the intervention phase they were asked to log how many of these habits they implemented each day. The 10 healthy habits were:

#1: Keep to a daily meal routine.

#2: Choose reduced fat versions of foods.

#3: Walk off the weight (aim for 10,000 steps/day).

#4: Pack a healthy snack (Choose healthy options such as fruits, nuts, or low-fat yogurt).

#5: Read labels.

#6: Be cautious with your portions.

#7: Break up your sitting time (Stand for 10 minutes every hour).

#8: Think about your drinks (Choose water instead of sodas and fruit juices).

#9: Focus on your food (Slow down. Don’t eat while watching TV).

#10: Don’t forget your 5 servings of fruits and vegetables a day.

The results were:

·       People in both habit change groups lost significantly more weight than people in the control group.

·       People in the habit change groups continued to lose weight for 12 months after the intervention ended.

·       Weight loss was essentially identical in the two habit change groups.

The last observation is particularly interesting. Remember that one of the habit change groups was simply focused on breaking old habits, yet people in this group did just as well as people who were taught healthy lifestyle habits. This implies that people already know about healthy lifestyle habits. They just don’t know how to break their old habits. Once they become comfortable breaking old habits, they find it easy to adopt healthier lifestyle habits.

In short, change your habits, change your lifestyle. Change your lifestyle, control your weight.

What Does This Mean For You?

why-do-most-dirts-failI covered a lot of information in this article. Let me sum it up by giving you my top 10 tips for losing weight and keeping it off.

1)    You don’t need to achieve your “ideal weight”. Losing 5-10% of your body weight may be enough.

2)    Ditch diets. Focus on lifestyle change.

3)    Slow and steady wins the day.

4)    Change your habits, change your weight.

5)    Long-term weight loss is possible.

6)    Low-fat, healthy eating patterns are best.

7)    Once you have internalized healthy habits, they become automatic.

8)    If you stick with a healthy lifestyle long enough, keeping the weight off becomes easy.

9)    Focus on all the healthy food choices you have, not what you have to give up. There is a cornucopia of great tasting, healthy foods to choose from.

10)  Never say never. Allow yourself to enjoy your old favorite foods on occasion. Just don’t make it a habit.

The Bottom Line

I cover a lot of information in this article. Let me sum it up by giving you my top 10 tips for losing weight and keeping it off.

1)    You don’t need to achieve your “ideal weight”. Losing 5-10% of your body weight may be enough.

2)    Ditch diets. Focus on lifestyle change.

3)    Slow and steady wins the day.

4)    Change your habits, change your weight.

5)    Long-term weight loss is possible.

6)    Low-fat, healthy eating patterns are best.

7)    Once you have internalized healthy habits, they become automatic.

8)    If you stick with a healthy lifestyle long enough, keeping the weight off becomes easy.

9)    Focus on all the healthy food choices you have, not what you have to give up. There is a cornucopia of great tasting, healthy foods to choose from.

10)  Never say never. Allow yourself to enjoy your old favorite foods on occasion. Just don’t make it a habit.

For more details on how to lose weight and keep it off, read the article above. In fact, if you plan to lose weight in the coming year, you should really read this article first.

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

 

 

Does Obesity Cause Cancer?

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Is The Obesity Epidemic Killing Us?

Author: Dr. Stephen Chaney

Does obesity cause cancer?

does obesity cause cancerYou probably already know that we are in the midst of a world-wide obesity epidemic. If not, here are some of the alarming statistics that characterize that epidemic:

  • The global prevalence of obesity has increased by 27.5% between 1980 and 2013.
  • 35% of the adult population worldwide is now overweight (BMI ≥ 25), including 12% who are classified as obese (BMI ≥30).
  • According to the NIH the situation is even worse in developed countries like the US where 75.1% of adults are now overweight, including 35.7% who are obese, and 6.3% who are very obese (BMI ≥40).

Unfortunately, overweight and obesity are not benign. You probably already knew that those excess pounds increase your risk of diabetes, heart disease, kidney failure and much more. You probably also knew that those excess pounds increase your risks of certain types of cancer such as colon, rectal, kidney, pancreatic, postmenopausal breast, ovarian and uterine cancer.

It’s been a little more difficult to determine just how much obesity increases cancer risk. However, a recent study suggests that the increased risk could be quite significant. In fact, if this study is correct, obesity may only be second to smoking as a preventable cause of cancer. The truth might just scare you skinny!

Does Obesity Cause Cancer?

cancer epidemicThe International Agency For Research On Cancer did a worldwide study, (Arnold et al, The Lancet Oncology 16: 36-45, 2015),  in which they looked at the effect of BMI on cancer incidence in adults aged 20 years or older. The BMI data was collected in 2002 and was segregated by sex and age groups. Recognizing that cancer takes decades to develop, they then collected data on newly diagnosed cancers in adults 30 and older in the same countries in 2012.  They were determined to get closer to answering the question, does obesity cause cancer?

By comparing BMIs in 2002 with the incidence of newly diagnosed cancers 10 years later they were able to calculate the effect of excess body weight (BMI ≥25) on cancer incidence. The results were startling:

  • They estimated that 481,000 new cases of cancer in 2012 in adults over 30 were attributable to excess weight.
  • That represents 3.6% of all new cancer cases, which makes overweight second only to smoking as a preventable cause of cancer.
  • Uterine cancer, postmenopausal breast cancer, and colon cancer accounted for 63.6% of all cancers caused by overweight. Other cancers affected by excess weight were rectal cancer, pancreatic cancer, kidney cancer, gallbladder cancer, and ovarian cancer.
  • The effect of excess weight on cancer risk was almost 3-fold greater for women (5.4% of new cancer cases) than for men (1.9% of new cancer cases).
  • In North America 111,000 new cases of cancer in 2012 for adults over 30 were attributable to excess weight. That represents 3.5% of all new cancers in men and 9.4% of all new cancers in women.
  • A quarter (about 118,000) of the worldwide cancer cases related to high BMI in 2012 could be attributed to the increase in BMI that has occurred since 1982.

The authors concluded “These findings emphasize the need for a global effort to abate the increasing numbers of people with high BMI. Assuming that the association between the high BMI and cancer is causal, the continuation of current patterns of population weight gain will lead to continuing increases in the future burden of cancer.”

What Does This Study Mean For You?

We have to stop kidding ourselves. That excess flab isn’t harmless. It is killing us, and cancer is a particularly gruesome way to go. It’s time to get serious about weight loss. Here are my top 5 tips for lasting weight loss.

  • fad dietsEat healthy low calorie meals and snacks with plenty of protein so that you maintain muscle mass while you are losing fat.
  • Avoid the fad diets. You don’t need to restrict carbohydrates or fats. You just need to focus on fresh fruits and vegetables, healthy proteins and modest amounts of healthy fats and healthy carbohydrates.
  • Find an exercise program you like and stick with it every day.
  • Focus on true lifestyle change rather than short term diets. A good strategy is to make one healthy change at a time rather than trying to do everything at once.
  • Change how you think about food, think about exercise, and think about your ability to make the kinds of changes that will lead to permanent weight loss. Don’t think of yourself as a fat person who is trying to lose weight. Think of yourself as a skinny person who happens to have a few extra pounds that are on their way out.

Of course, getting to a healthier weight isn’t the only change you want to make if you are trying to reduce your risk of cancer. Here are my top 7 lifestyle change suggestions (besides weight loss) for reducing cancer risk.

  • healthy eatingIf you smoke, stop. No ifs, ands, or buts. Smoking is still the #1 cause of cancer.
  • Eat a healthy diet (including supplements to fill the gaps).
  • Eat plenty of fresh fruits and vegetables, especially those that are good sources of cancer-fighting antioxidants, carotenoids, flavonoids, and polyphenols.
  • Eat fish and fish oil supplements to make sure that you get plenty of omega-3 fatty acids.
  • Minimize saturated fats and avoid trans fats. Substitute olive oil for vegetable oils whenever possible.
  • If you drink alcohol, drink it in moderation.
  • Avoid sun exposure as much as possible, and use sunscreen when outdoors.
  • Eat healthy proteins.
  • Minimize consumption of red meats and processed meats.
  • Use chicken, fish and vegetable proteins whenever possible.
  • Soy protein is particularly helpful for reducing the risk of breast cancer. (Yes, those scary blogs about soy and breast cancer are wrong. For accurate information, just go to https://www.chaneyhealth.com/healthtips and type soy in the search box).
  • Get plenty of exercise.
  • Get regular check-ups.

So, does obesity cause cancer?  I think you now know the answer.

 

The Bottom Line

 

  • A recent study has shown:
  • 481,000 new cases of cancer worldwide each year are attributable to excess weight.
  • That represents 3.6% of all new cancer cases, which makes overweight second only to smoking as a preventable cause of cancer.
  • Uterine cancer, postmenopausal breast cancer, and colon cancer accounted for 63.6% of all cancers caused by overweight.
  • The effect of excess weight on cancer risk was almost 3-fold greater for women (5.4% of new cancer cases) than for men (1.9% of new cancer cases).
  • In North America 111,000 new cases of cancer for adults over 30 are attributable to excess weight. That represents 3.5% of all new cancers in men and 9.4% of all new cancers in women.
  • That excess flab isn’t harmless. It is killing us, and cancer is a particularly gruesome way to go. For my top 5 tips for lasting weight loss and my top 7 tips for reducing your risk of cancer, 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.

Skinny Fat

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Overweight Vs. Obesity

Author: Dr. Stephen Chaney

skinny fatAre you skinny fat?  Weight loss season is upon us. Many of you are jumping on your bathroom scales so that you can decide how much weight you need to lose this year. For some the motivation for these New Year’s resolutions to lose weight is purely cosmetic. You just want to look better. For others the motivation for losing weight is better health. Obesity is a killer. It is associated with increased risk of diabetes, heart attack and stroke – and that’s just the tip of the iceberg.

But what if your bathroom scale says that you are normal weight? Are you off the hook? Maybe not. A recent study suggests that if you are normal weight but have central obesity (a fancy scientific term for belly fat), you are more likely to die prematurely than someone with normal fat distribution regardless of how overweight they are. That’s a pretty scary thought. It has even generated a new risk category called “skinny fat”.

How Can You Be Obese Without Being Overweight?

In recent years there has been some controversy about the health risks of obesity. Part of that controversy has arisen because obesity can be defined in multiple ways. Most of us simply hop on the scale and rely on actuarial tables to tell us what a healthy weight is for our height. Scientists, on the other hand use two very different measures of obesity.

#1 is Body Mass Index or BMI.BMI is a person’s weight in kilograms (kg) divided by his or her height in meters squared. By this measure:

  • Normal body weight is defined as a BMI of 18.5-24.9 kg/m2.
  • Overweight is defined as a BMI of 25-29.9 kg/m2.
  • Obesity is defined as a BMI of ≥30 kg/m2.

#2 is waist to hip ratio or WHR. WHR is a measure of central adiposity (belly fat). By this measure:

  • Obesity is defined as excess central adiposity (excess belly fat), which is a waist to hip ratio ≥0.85 in women and ≥0.90 in men.

In general BMI and WHR correlate. However:

  • 11% of men and 3.3% of women are normal weight according to BMI measurements, but have excess belly fat according to WHR measurements.These are the individualswho are obese according to their WHR measurements without being overweight according to their BMI measurements. These are the individuals often referred to as “skinny fat”.
  • There are similar percentages of men and women who are overweight or obese according to BMI measurements, but have low WHR measurements. These are often referred to as “pear shaped” obese individuals to distinguish them from the “apple shaped” obese individuals with a lot of belly fat.

Being Skinny Fat Can Kill You

obesity vs. overweightNumerous studies have shown that “apple shaped” obesity is much more likely to be associated with disease and premature death than “pear shaped” obesity, but there have been very few studies comparing health outcomes for normal weight individuals who have excess belly fat (people who are “skinny fat”) with health outcomes of overweight and obese individuals. This study (Sahakyanet al, Annals of Internal Medicine, 2015 Nov 10 doi: 10.7326/M14-2525) was designed to fill that void.

These scientists analyzed data from the National Health and Nutrition Survey III (NHANES III). NHANES III collected BMI, WHR and health data from 15,184 Americans (52.8% women) aged 18 to 90 years (average age 45) and followed the study participants for 14.3 years. By that time 3222 of them had died, with 1413 of those deaths being due to heart disease. The results were enlightening:

  • Normal weight individuals with excess belly fat (“skinny fat” individuals) were 1.5 – 2.0 fold more likely to die during the 14.3 year follow up period than individuals who were normal weight and had little belly fat (“skinny lean” individuals). This was expected because this had been shown in several previous studies.
  • However, the surprising finding was that normal weight individuals with excess belly fat were also more likely to die than individuals who were overweight or obese. Specifically:
  • Men who were “skinny fat” were 2.2 – 2.4 fold more likely to die prematurely than men who were either overweight or obese, but did not have excess belly fat (men with a “pear shaped” fat distribution). “Skinny fat” women were 1.3 – 1.4 fold more likely to die prematurely than overweight or obese women with “pear shaped” fat distribution.
  • Men who were “skinny fat” were even slightly more likely to die prematurely than overweight or obese men with excess belly fat (men with “apple shaped” fat distribution). “Skinny fat” women were just as likely to die as overweight or obese women with “apple shaped” fat distribution.
  • When they looked at deaths due to cardiovascular disease the results were essentially the same.
  • These results were novel and should, perhaps serve as a wake-up call for normal weight individuals with excess belly fat.

The authors concluded:

  • “Our analysis of data…show that normal-weight U.S. adults with central obesity [excess belly fat] have the worst long-term survival compared with participants with normal fat distribution, regardless of BMI category.”
  • “To our knowledge, our study is the first to show that normal-weight central obesity, measured by WHR, is associated with an increased risk of cardiovascular mortality.”
  • “Our findings suggest that persons with normal-weight central obesity may represent an important target population for lifestyle modification and other preventative strategies.”

Why Is Being Skinny Fat So Dangerous?

health riskAs the authors of this study pointed out, it is well established that excess belly fat is associated with:

  • Insulin resistance, which can lead to diabetes and predispose to heart disease.
  • High triglycerides and high levels of “bad” cholesterol, which can lead to heart disease.
  • Inflammation, which can lead to a number of deadly diseases.

The metabolic effects of excess belly fat are sufficient to explain why someone who is “skinny fat” is more likely to die prematurely than someone who is “skinny lean”. However, the effect of excess belly fat is not sufficient by itself to explain why a “skinny fat” individual is more likely to die prematurely than someone who is overweight or obese.

To understand this we need to recognize that both fat and muscle contribute to body weight (and to BMI). The “skinny fat” individual has more fat mass AND less muscle mass than a “skinny lean” individual of the same weight. That is a huge factor because metabolically speaking muscle is protective. It opposes all of the bad metabolic effects of belly fat.

Simply put, being “skinny fat” is extremely dangerous because you have increased all the bad metabolic effects of excess belly fat, ANDyou have decreased the protective metabolic effect of muscle mass.

How Do You Go From Being “Skinny Lean” To “Skinny Fat”?

Most of us were lean in our younger years. For those of us who end up as “skinny fat” as we age, it is pretty obvious that there are two processes going on simultaneously.

#1: Loss of Muscle Mass:It would be easy to say that becoming “skinny fat” is a natural part of aging. The natural tendency is to loose muscle mass and replace it with fat mass as we age. If we “just go with the flow” all of us will end up being “skinny fat” at some point. However, the loss of muscle mass as we age is accelerated by our sedentary lifestyle and our diet (more on that below).

#2: Gain of Belly Fat:To some extent whether we store excess fat as “pears” or “apples” is genetically determined. However, what we eat can also exert a major influence. For example:

  • Alcohol: The term “beer belly” says it all. Excess alcohol consumption is associated with an increase in belly fat. Once you understand the metabolism of alcohol the explanation is pretty simple. Alcohol causes blood sugar to drop, which increases appetite. Alcohol also interferes with our judgement, which can cause us to make poor food choices.
  • Excess saturated fat tends to be stored preferentially as belly fat.
  • Excess sugars and simple carbohydrates are rapidly converted to fat stores and stored as belly fat.

What Can You Do If You Are Already Skinny Fat?

gain muscle massLet’s start with what you shouldn’t do. You should not go on a reduced calorie weight loss diet to get rid of your excess belly fat. The last thing you want to do is to end up being underweight with excess belly fat! Here is what you should do:

#1: Increase Your Muscle Mass:I said that loss of muscle mass was a natural part of aging. I didn’t say that it was an inevitable part of aging. If you want to prevent or reverse loss of muscle mass you need to:

  • Get really serious about exercise. I’m talking about 30 minute workouts at least 3-5 times per week. These workouts need to include strength training as well as aerobics and flexibility exercises. I would suggest you ask your health professional what kind of exercise program is best for you and start your exercise program under the guidance of a personal trainer or physical therapist.
  • Make sure that your diet contains enough protein and enough of the essential amino acid leucine to maximize the gain of lean muscle mass following your workouts. I have covered the latest age-appropriate recommendations in, leucine and muscle gain, a previous “Health Tips From The Professor.”

#2: Lose Your Belly Fat:To some extent you will start to lose your belly fat naturally if you follow the recommendations above. In addition, you will want to:

  • Drink alcohol in moderation.
  • Make food choices that allow you to replace saturated fat with monounsaturated fat and polyunsaturated fats, especially the omega-3 polyunsaturated fats.
  • Replace excess sugars and simple carbohydrates with complex carbohydrates from fresh fruits and vegetables along with modest amounts of whole grain foods.

The Bottom Line

  • A recent study has shown that being “skinny fat” (having normal body weight, but excess belly fat) is more likely to result in premature death than if you were overweight, or even obese.
  • The most likely explanation for this alarming statistic is that someone who is “skinny fat” has excess belly fat, which predisposes to a number of diseases, and a loss of muscle mass, which protects against those same diseases.
  • If you are overweight or obese, you need to reduce your caloric intake to lose weight. However, if you are “skinny fat”, you don’t want to reduce your caloric intake. You need to change your exercise and diet habits.
  • Loss of muscle mass and gain of fat mass is a normal part of aging. However, you can slow or reverse the age-related loss of muscle mass with an exercise program and enough protein and leucine in your diet to maximize the effects of that workout program (details above).
  • You can prevent or get rid of excess belly fat by:
  • Following the exercise program and nutritional support of that exercise program described above.
  • Making food choices that replace saturated fats with monounsaturated fats and polyunsaturated fats, especially omega-3 polyunsaturated fats.
  • Replacing foods high in sugar and simple carbohydrates with fresh fruits and vegetables and whole grains in moderation.

 

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

Does Genetics Determine Weight?

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Does Genetics Cause Obesity?

Author: Dr. Stephen Chaney

Overweight & Skinny WomenIt’s frustrating. Try as hard as you might, you just can’t seem to lose weight. Even worse you suspect that your friends – and maybe your doctor – assume that you are cheating on your diet. It just doesn’t seem fair.

Perhaps there is a simple explanation. Maybe your genes are keeping you from losing weight. Does genetics determine weight?  It has been hypothesized that some of us have a “thrifty” phenotype when it comes to weight loss while others are “spendthrifts”. The theory is that people with a “thrifty” phenotype hold on to weight more tightly when they are “fasting” (i.e. trying to lose weight) and gain weight more readily when they are “feasting” (i.e. eating excess calories).

The metabolism of the “spendthrifts” is exactly the opposite. They lose weight rapidly when fasting and gain weight slowly when feasting. Those would be all of your skinny friends who just can’t seem to understand why you have such difficulty losing weight.

Those experts who favor the “thrifty” phenotype hypothesis point out that it would have provided a tremendous survival advantage in prehistoric times when food was scarce. That’s why some of those same experts think that up to 80% of the population has the “thrifty” phenotype. When you couple the thrifty phenotype with the typical American diet and lifestyle it becomes easy to understand why we have an obesity epidemic in this country.

Is the “thrifty” phenotype hypothesis true? Could it explain why you have such difficulty losing weight? A recent study suggests the answer to those two questions may be yes. I will outline the evidence below.

Then I will address what are probably the two most important questions for you: “If the thrifty phenotype hypothesis is true and you have the thrifty phenotype, are you destined to be overweight? Is there anything you can do about it?

How The Study Was Designed

medical studyThis study (Reinhardt et al, Diabetes, 64: 2859-2867, 2015) was truly a remarkable study. 15 healthy, but obese volunteers were put in a metabolic ward for a total of 11 weeks. In the metabolic ward every aspect of their metabolism was closely controlled and measured.

  • They were given diets that were precisely calibrated to provide a predetermined caloric (energy) input.
  • Urine and feces were collected and analyzed in an instrument called a bomb calorimeter to determine calorie (energy) output.
  • They were limited to primarily sedentary activity for the duration of the experiments, and the temperature of the metabolic ward was maintained constant. This eliminated variation in energy expenditures due to activity and temperature.
  • Metabolic energy expenditure was calculated by placing them in a special room designed to precisely measure oxygen consumption and CO2 production by the subjects over a 24 hour period. Don’t worry about the details. Just know that this is the gold standard for measuring energy expenditure.

Here is what the subject’s 11 weeks in the metabolic ward looked like:

  • During the first 3 weeks the subjects were provided with a diet designed with just enough calories to maintain their weight based on their weight and sex. If weight gain or loss was observed the calories were adjusted accordingly.
  • During one 24 hour period in week 3 the subjects were place on a diet that decreased their calories by 50%, (defined as “fasting” in this study) and the resulting decrease in metabolic energy expenditure was measured as described above.
  • During another 24 hour period in week 3 the subjects were place on a diet that increased their calories by 200% (defined as “overfeeding” in this study), and the resulting increase in metabolic energy expenditure was measured.
  • During the next 6 weeks the subjects were placed on calorie restricted diet that only provided 50% of the calories they needed to lose weight.
  • During the final 2 weeks the subjects were placed on a diet designed to provide the calories needed to maintain their new weight, whatever it was.

How Does Genetics Determine Weight?

do genetics cause obesityThe results of the study were quite interesting:

  • All of the subjects lost weight, but the amount of weight loss ranged from 5% to 12% of the original body weight.
  • Their starting weight did not influence their rate of weight loss during calorie restriction, but their metabolic response to fasting and overfeeding significantly affected their rate of weight loss. Specifically:
  • The subjects with the smallest decrease in energy expenditure during fasting and the largest increase in energy expenditure during overfeeding (the spendthrifts) lost significantly more weight during the 6 week caloric restriction period (what most of us call a diet).
  • The subjects with the largest decrease in energy expenditure during fasting and the smallest increase in energy expenditure during overfeeding (the thrifty) lost significantly less weight during the 6 week caloric restriction period.
  • The amount of caloric restriction needed to lose one pound of weight ranged from 1,558-2,993 depending on whether the subjects displayed the spendthrift or thrifty phenotype. That’s almost a 2-fold difference.

What Does This Study Mean For You?

life-is-sometimes-unfairLife isn’t fair. You probably already suspected that. Your skinny friends actually do have a much easier time losing weight than you do. In fact, they may be able to lose up to twice the amount of weight with exactly the same amount of caloric restriction.

However, the good news is that weight loss is possible – even for you. Everyone in the study lost weight – even those subjects with the thriftiest phenotype. So the question becomes what can you do to lose weight successfully? Here are 5 simple tips.

#1: Don’t give up. Stick with it. Pounds may come off slowly for you, but this study shows they will come off. You just have to keep the faith and be consistent.

#2: Watch what you eat very carefully. The researchers in this study controlled every morsel of food the subjects ate. People always lose weight more rapidly when they are in a metabolic ward. My recommendation is to track what you eat daily using one of the many available tracking apps.

#3: Be consistent with your exercise. The subjects in this study were not allowed to exercise, but that is one of the best ways to increase energy expenditure. Aerobic exercise gives you a small increase in energy expenditure during and immediately following the exercise. Weight bearing exercise gives a long term increase in energy expenditure because it increases muscle mass, and muscle burns calories faster than any other tissue.

#4: Choose a diet that preserves muscle mass (High Protein Diets and Weight Loss ) while you are losing weight.

#5: Avoid all those diets with herbal and pharmaceutical stimulants. They are dangerous and they may just kill you.  Check out  Are Dietary Supplements Safe.

 

The Bottom Line

A recent study (Reinhardt et al, Diabetes, 64: 2859-2867, 2015) did a very careful metabolic analysis and divided subjects into what they characterized as either a “thrifty” or “spendthrift” phenotype based on their changes in metabolic energy expenditure in response to fasting and overfeeding. They then looked at how those phenotypes affected weight loss during a 6 week period of caloric restriction. Does genetics cause obesity or help determine weight?  Here’s what they found:

  • All of the subjects lost weight, but the amount of weight loss ranged from 5% to 12% of the original body weight.
  • Their starting weight did not influence their rate of weight loss during caloric restriction, but their metabolic response to fasting and overfeeding significantly affected their rate of weight loss. Specifically:
  • The subjects with the smallest decrease in energy expenditure during fasting and the largest increase in energy expenditure during overfeeding (the spendthrifts) lost significantly more weight during the 6 week caloric restriction period (what most of us call a diet).
  • The subjects with the largest decrease in energy expenditure during fasting and the smallest increase in energy expenditure during overfeeding (the thrifty) lost significantly less weight during the 6 week caloric restriction period.
  • If you struggle to lose weight, this is a good news – bad news study.
  • The bad news is that life isn’t fair. You probably already suspected that. Your skinny friends actually do have a much easier time losing weight than you do.
  • The good news is that weight loss is possible – even for you. Everyone in the study lost weight – even those subjects with the thriftiest phenotype. So the question becomes what can you do to lose weight successfully? I’ve given you 5 simple tips in 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.

Artificial Sweeteners And Diabetes

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Another Myth Bites The Dust

Author: Dr. Stephen Chaney

 

artificial sweeteners and diabetesArtificial sweeteners and diabetes; is there a relationship?

Once again, artificial sweeteners have come up empty. They were supposed to help you lose weight, but several recent clinical studies have suggested that artificially sweetened beverages are just as likely to lead to weight gain as sugar sweetened beverages, see  Do Diet Sodas Make You Fat.

What about type 2 diabetes? There have been several clinical trials that have suggested that excess consumption of sugar sweetened beverages may increase your risk of developing type 2 diabetes (For example, Basu et al, Am J Pub Health, 103: 2071-2077, 2013; Malik et al, Diabetes Care, 33: 2477-2483, 2010).

As a consequence if you are at risk of developing type 2 diabetes, you’ve probably been advised by your doctor or dietitian to switch from sugar sweetened beverages to artificially sweetened beverages or natural fruit juices. But, does that really work? Maybe not.

In fact, some studies have suggested that excess consumption of artificially sweetened beverages or fruit juice may be just as likely to lead to type 2 diabetes as consuming sugar sweetened beverages (For example, Greenwood et al, Br J Nutr, 112: 725-734, 2014; Xi et al, PloS One, 9:e93471, 2014).

A Systematic Study Of Beverage Consumption And Diabetes Risk

However, this has been a very controversial topic. The problem is that it is devilishly difficult to design studies that provide definitive answers to these important questions.

To start with there are problems with confounding factors. For example,

  • It is pretty well established that consumption of sugar sweetened beverages leads to obesity and obesity leads to type 2 diabetes, but many of the studies did not adjust the data for obesity.
  • In addition, many people who are overweight often switch to artificially sweetened beverages in the mistaken belief that they will help them lose weight. Once again, many of the published studies did not correct for that.

There are also problems with study design. For example, many of the studies did not directly compare sugar sweetened and artificially sweetened beverages in the same population group. If the population groups are different enough between studies, it can be a little like trying to compare apples to oranges.

Because of these limitations an international team of experts designed a major systematic review and meta-analysis (Imamura et al, Br J Med, doi: 101136/bmj.h3576, 2015) of all reasonably well designed prospective studies that measured the effect of beverage consumption on the development of type 2 diabetes over time.

They evaluated the data from 17 studies that represented 38,253 people who developed type 2 diabetes over a period of at least two years. They used the most rigorous statistical analysis methods available, and they interpreted their results very cautiously.

In short, this was a major study. So, what did the study show?

Is There a Relationship Between Artificial Sweeteners And  Diabetes?

On face value, the data appeared to be fairly clear:

  • prevent diabetesAn additional one serving per day of a sugar-sweetened beverage increases your risk of developing type 2 diabetes by 18%. When you correct for obesity, the increased risk is 13%. (Note: we are talking about an 8 ounce serving here, not a 32 ounce Big Gulp or 64 ounce Double Gulp).
  • An additional one serving per day of an artificially-sweetened beverage increases your risk of developing type 2 diabetes by 25%. When you correct for obesity, the increased risk is 8%.
  • An additional one serving per day of fruit juice increases your risk of developing type 2 diabetes by 5%. When you correct for obesity, the risk actually increases to 7%.

In short, if you want to decrease your risk of developing type 2 diabetes, none of these options is a particularly good choice.

How Were These Data Interpreted

Of course, the strength of any meta-analysis is limited by the quality of the studies that were included in the meta-analysis. It is the old GIGO (garbage in, garbage out) principle. The authors acknowledged that limitation and analyzed in great detail the quality of the individual studies included in their meta-analysis. Their conclusions were as follows:

  • garbage in garbage outThe quality of the data on sugar sweetened beverages was strong enough that they could conclude that “habitual consumption of sugar sweetened beverages is associated with a greater incidence of type 2 diabetes, independent of obesity”. In short, you want to stay away from sugar sweetened beverages. They can cause obesity AND they can cause type 2 diabetes.
  • They also said that “…artificially sweetened beverages and fruit juice also showed positive associations with incidence of type 2 diabetes”, but did not feel the existing data were strong enough to make a definitive conclusion. They felt that more studies are needed.
  • However, they did feel that the existing data were strong enough to conclude that “neither artificially sweetened beverages nor fruit juice are suitable alternatives to sugar sweetened beverages for the preventing of type 2 diabetes.” In short, consumption of artificially sweetened beverages and fruit juice may not cause type 2 diabetes, but they clearly don’t prevent it.

 

The Bottom Line

If you are overweight or otherwise at risk of developing type 2 diabetes, you have probably been advised to switch from sugar-sweetened beverages to either artificially sweetened beverages or fruit juices. A major study has just turned that advice on its head!

This study (Imamura et al, Br J Med, doi: 101136/bmj.h3576, 2015) was a systematic review and meta-analysis of 17 previously published clinical studies that measured the effect of beverage consumption on the development of type 2 diabetes over time. Based on a very careful analysis of the data from this meta-analysis the authors concluded:

  • The quality of the data on sugar sweetened beverages was strong enough that they could unequivocally state that “habitual consumption of sugar sweetened beverages is associated with a greater incidence of type 2 diabetes, independent of obesity”. In short, you want to stay away from sugar sweetened beverages. They can cause obesity AND they can cause type 2 diabetes.
  • They also said that “…artificially sweetened beverages and fruit juice also showed positive associations with incidence of type 2 diabetes”, but did not feel the existing data were strong enough to make a definitive conclusion. They felt that more studies are needed.
  • However, they did feel that the existing data were strong enough to conclude that “neither artificially sweetened beverages nor fruit juice are suitable alternatives to sugar sweetened beverages for the preventing of type 2 diabetes.” In short, consumption of artificially sweetened beverages and fruit juice may not cause type 2 diabetes, but they clearly don’t prevent it.

So what kind of beverages should you consume if you don’t want your beverage intake to contribute to type 2 diabetes?

  • Water is always the first choice.
  • Milk, protein shakes and similar beverages can also be an excellent choice as long as you take the calories into account. The protein content of those beverages generally slows the rate of sugar uptake. Look for products with a low glycemic index.
  • High intensity or long endurance exercise requires a lot of carbohydrate, so sugars in rehydration or recovery sports supplements are well tolerated. However, those same sports drinks would be a concern if used as part of a sedentary lifestyle.
  • Finally, tea, coffee, and non-caffeinated herbal teas are excellent choices as long as you learn to enjoy them without adding sugar or artificial sweeteners.

 

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.

What Is Epigenetics

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Can What We Eat Affect Our Kids?

Author: Dr. Stephen Chaney

 

what is epigeneticsWhat is epigenetics?  For me, the first stages of understanding came a while back.  When I was a young graduate student (which is more than just a few years ago), I was taught that all genetic information resided in our DNA. During conception, we picked up some DNA from our dad and some from our mom, and that DNA was what made us a unique individual.

We knew that environmental influences such as diet, lifestyle and exposure to toxic chemicals could affect our health personally. However, we never dreamed that the effects of those environmental influences could actually alter our gene expression, and that those genetic alterations could be passed on to our children.

Today we know that environmental influences can actually modify our DNA and that those modifications can be passed on to our offspring – a process called epigenetics.

What Is Epigenetics & How Does It Affect Gene Expression?

Simply put, epigenetics involves modifications to our DNA. DNA can be methylated or acetylated and the proteins that bind to our DNA can be modified in multiple ways. That is important for two reasons:

  • These alterations can turn genes on and off. That means that epigenetic modifications can alter gene expression.
  • These alterations can be influenced by our environment – diet, lifestyle, and exposure to environmental chemicals

In a previous “Health Tips From the Professor” article titled “Can Diet Alter Your Genetic Destiny?”  I discussed recent research suggesting that a healthy diet and lifestyle causes epigenetic changes in the DNA that may reduce your risk of heart disease, cancer and diabetes.

That alone was a monumental discovery. Even more monumental is the recent discovery that at least some of those epigenetic changes can be passed on to our children, which brings me to the question I posed in the title of this article: “Can what we eat affect our kids?”

Animal Studies Showing That Epigenetic Changes Can Be Inherited

epigenetic changes are inheritedAs is often the case, the first definitive study showed that epigenetic changes were heritable was an animal study. This study was done with a mouse strain called agouti (Waterman and Jirtle, Mol. Cell. Biol. 23: 5193 – 5300, 2003). Agouti mice can have two remarkably distinctive phenotypes. They can either have a yellow coat, become obese as adults and be prone to cancer and diabetes as they age or they can have a brown coat and grow up to be lean and healthy.

It had been known for some time that these phenotypic differences were controlled by the epigenetic methylation of a specific gene called the agouti gene. The agouti gene codes for a genetic regulator that controls coat color, feeding behavior, and body weight set-point, among other things. When the agouti gene is under methylated it is active. As a consequence the mice have yellow coats and are prone to obesity. When the agouti gene is highly methylated it is inactive. The mice have brown coats and are lean and healthy.

Moreover, methylation of the agouti gene is not a purely random event. Mothers with the yellow, obese phenotype tended to produce a preponderance of offspring with the same phenotype and vice-versa. In short, the epigenetic methylation pattern of the agouti gene could be passed from generation to generation. It was heritable.

Waterman and Jirtle’s research broke new ground by showing that the methylation of the agouti gene could be strongly influenced by what the mother ate while the fetal mice were still in the womb.

When they fed agouti mothers a diet with extra folic acid, B12, betaine and choline (all nutrients that favor DNA methylation) during conception and pregnancy the agouti gene of their offspring became highly methylated. A high percentage of those offspring had brown coats and grew up to be lean and healthy.

However, when Waterman and Jirtle put agouti mothers on a diet that was deficient in folic acid, B12, betaine and choline during conception and pregnancy the agouti gene of their offspring was under methylated. Many of those offspring had yellow coats and grew up to be fat and unhealthy.

Subsequent studies from the same laboratory have shown that:

  • Addition of genistein, a phytonutrient from soy, to the maternal diet also favors methylation of the agouti gene and protects against obesity in agouti mice (Dolinoy et al, Environmental Health Perspective, 114: 567-572, 2006).
  • The addition of the environmental toxin bisphenol A to maternal diets causes under methylation of the agouti gene and predisposes to obesity in agouti mice, but this effect can be reversed by also feeding the mother genistein or folic acid and related nutrients during pregnancy (Dolinoy et al, PNAS, 13056-13061, 2007).

The agouti mice studies provide a dramatic example of how diet and environmental exposure during pregnancy can cause epigenetic changes in fetal DNA that have long term health consequences for the offspring. However, they are animal studies. Does the same hold true for humans?

Diet, Epigenetic Changes, and Obesity in Humans

diet-epigenetic-changes-obesityWith humans, it is really difficult to determine whether epigenetic changes that occur during conception and pregnancy affect our children. That is because when you measure an epigenetic effect in a child or adult, it is difficult to sort out how much of that effect was caused by what the mom ate during pregnancy and how much was caused by how the family ate as the kids were growing up.

Unfortunately, there is a tragic human experiment that shows that the same kind of epigenetic changes are heritable in humans. I’m referring to what is known as the “Dutch Hunger Winter”. This was a period of starvation during 1944-1945, the final year of World War II, when the Germans set up a blockade that prevented food from reaching western Holland. During that few months even pregnant women were forced to live on food rations providing a little as 500 calories a day.

This was an event without parallel in human history. Holland is not a third world country. Once the blockade was lifted children born during the Hunger Winter had the same plentiful supply of food as every other Dutch citizen. This has allowed generations of research scientists to ask what were the effects of a brief exposure to malnutrition during conception and pregnancy.

The health consequences were dramatic. 50 years later individuals who were conceived during the Hunger Winter weighed about 14 pounds more, had waists about 1.5 “ larger, and were three times more likely to have heart disease than those born to mothers who were in their second or third trimester of pregnancy during that time. By the time they reached age 63, they experienced a 10% increase in mortality.

What caused those health consequences? Could the cause have been epigenetic? Recent research suggests that the answer might be yes.

A recent study analyzed epigenetic changes in DNA from blood samples of survivors born during the Hunger Winter that had been collected when they were 59 years old (Tobi et al, Int. J. Epidemiology, doi: 10.1093/ije/dyv043, 2015). This study showed:

  • A distinct pattern of DNA methylation was observed in survivors who were conceived during the Hunger Winter. This pattern of DNA methylation was not observed in survivors who were in their second or third trimester during the Hunger Winter. It was also not seen in people who were conceived immediately before or after the Hunger Winter.
  • Some of the genes with distinctive methylation patterns were genes that affected things like cholesterol levels and insulin sensitivity, which have the potential to increase disease risk.
  • Other genes with distinctive methylation patterns were genes that affected metabolism. They were “thrifty” genes that increased the efficiency of metabolism. Increased efficiency of metabolism is beneficial when calories are scarce, but can lead to obesity when calories are plentiful.

That is a truly remarkable finding when you think about it. If these data are true, they suggest that starvation during early pregnancy caused the fetus to make epigenetic changes to its DNA that allowed it to become more efficient at energy utilization, and those epigenetic changes have lasted a lifetime – even when food was abundant throughout the rest of that lifetime.

What Is Epigenetics And Can What We Eat Affect Our Kids?

can what we eat affect our kidsThe studies I featured in this article are powerful “proof of concept” that diet and environmental exposure during conception and pregnancy can result in epigenetic changes to the DNA of the offspring that can persist throughout their life and dramatically affect their health. However, it is not yet clear how they apply to you and me.

  • Agouti mice are a very special strain of mice. It is not yet clear what effect folic acid, genistein and bisphenol A have on epigenetic modification of specific human genes, and whether those epigenetic modifications will have health consequences in humans.
  • The specific circumstances of the Dutch Hunger Winter are unlikely to be repeated on any significant scale. The closest approximation I can envision would be a woman who becomes pregnant while on a very low calorie fad diet.

There are, of course, many other examples of heritable epigenetic modifications. For example:

  • When female rats are maintained on a “junk-food diet” high in fat and sugar during pregnancy and lactation their offspring show a marked preference for high fat foods (Ong & Muhlhausler, FASB J, 25: 2167-2179, 2011). They also show epigenetic alterations of the central reward pathways that may pre-condition them to require higher intakes of fat to experience pleasure from eating.
  • When rats are fed diets deficient in omega-3 fatty acids, adolescent rats from the second and subsequent generations display marked increases in hyperactivity and anxiety (For more details, see my “Health Tips from the Professor” article titled “The Seventh Generation Revisited”.
  • In a clinical trial of 162 obese Canadian mothers who had children before and after weight loss surgery, the children born after weight loss surgery were half as likely to grow up overweight or obese as the children born before the weight loss surgery (Smith et al, Journal of Clinical Endocrinology & Metabolism 94: 4275-4283, 2009), and this correlated with epigenetic modification of genes that play a role in obesity, diabetes, cancer and heart disease (Guernard et al, PNAS 110: 11439-11443, 2013).

Taken together, the existing data suggest that our diet and environmental exposure during conception and pregnancy can cause epigenetic changes to our children’s DNA that may affect their future health in ways that we can only begin to understand at present. It is a sobering thought.

 

The Bottom Line

 

  • The term epigenetics describes modifications to our DNA that turn our genes off and on.
  • In this article I discussed two powerful “proof of concept” studies, one in rats and the other in humans, showing that diet and environmental exposure during conception and pregnancy can result in epigenetic changes to the DNA of the offspring that can persist throughout their life and dramatically affect their health.
  • The health consequences of these epigenetic modifications include obesity, diabetes, cancer, heart disease, hyperactivity, anxiety and many more.
  • This is a new paradigm. Most prenatal nutrition advice is currently based on what it takes to have a healthy baby – not on what it might take for your child to experience better health throughout their life.
  • Of course, the science of epigenetics is relatively new. It will be many years before we will be able to make specific recommendations as to what your diet should be like during pregnancy and lactation if you wish to make beneficial modifications to your baby’s DNA.
  • However, you should be aware that what you eat during pregnancy & lactation may influence the health of your children – not just at the time of their birth – but throughout their life, and that a high calorie, “junk-food” diet or a fad weight loss diet just may not be your best choice.

*The agouti mice picture is by Randy Jirtle and Dana Dolinoy (E-mailed by author) [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons.

 

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.

7 Easy Ways To Spot Fad Diets

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dietIf It Sounds Too Good To Be True…

Author: Dr. Stephen Chaney

 

I think it was P. T. Barnum who said “There’s a Sucker Born Every Minute”. That’s particularly true in the diet world where hucksters seem to be all around us – especially this time of year.

You’ve seen the weight loss ads touting:

Pills or powders that suppress your appetite or magically prevent you from absorbing calories.

  • Fat burners that melt the pounds away.
  • New discoveries (juices, beans, foods) that make weight loss effortless.
  • The one simple thing you can do that will finally banish those extra pounds forever.

You already know that most of those ads can’t be true. You don’t want to be a sucker. But, the ads are so compelling:

Many of them quote “scientific studies” to “prove” that their product or program works.

  • Their testimonials feature people just like you getting fantastic results from their program. [You can do wonders with “computer enhanced” photographs.]
  • Many of those products are endorsed by well known doctors on their TV shows or blogs. [It is amazing what money can buy.]

So it is easy to ask yourself: “Could it be true?” “Could this work for me?”

Fortunately, the Federal Trade Commission (FTC) has stepped up to the plate to give you some guidance. Just in time for weight loss season, they have issued a list of seven claims that are in fact too good to be true. If you hear any of these claims, you should immediately recognize it as a fad diet and avoid it.

 

7 Easy Ways To Spot Fad Dietsfad diet

Here are the seven statements in ads that the FTC considers as “red flags” for fad diets that should be avoided:

  • Causes weight loss of two pounds or more a week for a month or more without changing your diet and exercise routine.
  • Causes substantial weight loss no matter what or how much you eat.
  • Causes permanent weight loss without lifestyle change even after you stop using the product.
  • Blocks absorption of fat or calories to enable you to lose substantial weight.
  • Safely enables you to lose more than 3 pounds per week for more than 4 weeks.
  • Causes substantial weight loss for all users
  • Causes substantial weight loss by wearing a product on your body or rubbing it on your skin.

I’m sure you have heard some of these claims before. You may have actually been tempted to try the products or program. You should know that the FTC said that it considers these to be “Gut Check” claims that simply can’t be true.

 

The Bottom Line

diet pillsThere are no magical pills or potions that will make the pounds melt away. You need to change your diet, change your activity level and make significant lifestyle changes if you want to achieve long term weight control.

For more science-based health tips visit https://www.chaneyhealth.com/healthtips

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.

Do Diets Work?

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dietingObesity in America?

Author: Dr. Stephen Chaney

If you are like most Americans, you are either overweight yourself or have close friends and family who are overweight. That’s because 69% of Americans are currently overweight, and 36% of us are obese. Worldwide the latest estimates are that 1.5 billion adults are overweight or obese.

A new report, How The World Could Better Fight Obesity,  estimates that obesity is a $2 trillion drain on the world’s economy. That is equivalent to the global cost of war & terrorism and of smoking – and is double the global costs of alcoholism and global warming!

If you are like most Americans you have tried a number of diets over the years. All of them promised that they had the “secret” to permanent weight loss. You lost some weight initially, but here you are a few years later weighing as much as ever.

You are probably beginning to wonder whether any diets work long term. According to the latest study, the answer may just be “no”.

Really, Do Diets Work?

This study (Atallah et al, Circulation Cardiovascular Quality and Outcomes, 7: 815-827, 2014) was a systemmatic review of all of the randomized controlled studies of the four most popular diet plans – Weight Watchers, Akins, Zone and South Beach.

In case, you are unfamiliar with these diets, here is their philosophy:

  • Weight watchers is a food, physical activity and behavior modification plan that utilizes a point system to control calorie intake and features weekly group sessions.
  •  Atkins is based on very low carbohydrate intake, with unlimited fat and protein consumption.
  •  South Beach is relatively low carbohydrate, high protein diet that focuses on low-glycemic index carbohydrates, lean proteins, and mono- and polyunsaturated fats.
  • Zone is a low carbohydrate diet that focuses on low-glycemic load carbohydrates, low-fat proteins and small amounts of good fats.

The investigators restricted their analysis to studies that were greater than 4 weeks in duration and either compared the diets to “usual care” or to each other. (The term usual care was not defined, but most likely refers to a physician giving the advice to eat less and exercise more).

Twenty six studies met their inclusion criteria. Fourteen of those studies were short-term (< 12 months) and 12 were long-term (>12 months). Of the long-term studies, 10 compared individual diet plans to usual care and 2 were head-to-head comparisons between the diet plans (1 of Atkins vs Weight Watchers vs Zone and 1 of Weight Watchers vs Zone vs control). The majority of participants in these studies were young, white, obese women. Their average age was 45 years and their average weight at the beginning of the studies was 200 pounds.

What Did This Study Show?

If you have struggled with your weight in the past, you probably won’t be surprised by the result of the study.

  •  Short-term weight loss was similar for Atkins, Weight Watchers and Zone in the two head-to-head studies.
  •  At 12 months, the 10 studies comparing individual diets to usual care (physician’s advice to eat less and exercise more) showed that only Weight Watchers was slightly more effective than usual care (physician’s advice to lose weight). The average weight loss at 12 months was 10 pounds for Weight Watchers and 7 pounds for usual care. That is a 3 pound difference for all of the additional effort and expense of Weight Watchers!
  • When they looked at the two head-to-head studies at 12 months, there was no significant differences between the diets. Average weight loss in these studies was 7 pounds for Weight Watchers, 7 pounds for Atkins, 5 pounds for Zone and 5 pounds for usual care. There was only one study comparing the South Beach diets with usual care. It was a study comparing the results with severely obese patients following gastric bypass surgery, and it also found no difference between the diet program and usual care. Based on hype about these diets, you were probably expecting more than a 5 to 7 pound weight loss 12 months later!
  •  By 24 months 30-40% of the weight had been regained for the Atkins and Weight Watchers diets, which was comparable to the results for patients who were just told to eat less and exercise more. Not only was the weight loss modest, it also did not appear to be permanent.
  •  Finally, many of the studies included in this review also looked at improvement in other health parameters such as HDL cholesterol levels, LDL cholesterol levels, triglycerides, blood pressure and blood sugar control. The Atkins diet gave slightly better results with HDL levels, triglyceride levels and blood pressure in the short-term studies, but there was no significant differences for any of these parameters in the long-term head-to-head studies. None of the diets were any healthier than the others.

The investigators concluded: “Our results suggest that all 4 diets are modestly efficacious for short-term weight loss, but that these benefits are not sustained long-term.

A similar study in 2005 compared the Weight Watchers, Jenny Craig and LA Weight Loss diets (Tsai et al, Annals of Internal Medicine, 142: 56-66, 2005) and concluded “…the evidence to support the use of major commercial and self-help weight loss programs is suboptimal”.

weight loss and obesityA Weight Loss Diet That Actually Works?

My personal recommendation for the initial weight loss is a high protein diet – one that provides about 30% of calories from healthy protein and moderate amounts of healthy carbohydrates and healthy fats. The protein should be high enough quality so that it provides 10-12 gram of the essential amino acid leucine because leucine specifically stimulates muscle growth. The combination of high protein and leucine preserves muscle mass while you are losing weight. That is important because it keeps your metabolic rate high without dangerous herbs or stimulants.

However, the high protein, high leucine diet is still just a diet. It is an excellent choice for the initial weight loss, but what about long-term weight control?

The authors of this study said: “Comprehensive lifestyle interventions aimed at curbing both adult and childhood obesity are urgently needed. Interventions that include dietary, behavioral and exercise components…may be better suited to [solve] the obesity epidemic.” I agree.

The Bottom Line:

Your suspicions are correct. Diets don’t work!

A recent systematic review of 26 randomized controlled clinical trials of the Weight Watchers, Atkins, Zone & South Beach diets compared to the usual standard of care (recommendations to eat less and exercise more) concluded:

1) Contrary to what the advertisements promise, after 12 months all four diets gave comparable and very modest (5-7 pounds) total weight loss. The results with the diets were not significantly different than for patients who were simply told to eat less and exercise more.

2) By 24 months 30-40% of the weight had already been regained.

3) A previous systematic review of the Weight Watchers, Jenny Craig, and LA Weight Loss diet programs came to a similar conclusion.

4) My personal recommendation for the initial weight loss is a diet that is high in protein and the amino acid leucine because that type of diet preserves muscle mass.

5) For permanent weight control the authors of the recent systematic review recommended comprehensive lifestyle interventions that include permanent changes in diet, behavior and exercise. I agree. Diets never work long term – lifestyle change does!

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 Gut Bacteria Make You Fat?

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bacteria

bacteria

Gut Bacteria, Diet and Obesity

Author: Dr. Stephen Chaney

 

 

Can gut bacteria make you fat? It has been known for some time that the types of bacteria found in the intestines of obese people are different than those found in the intestines of lean individuals. But no one really knew the significance, if any, of that observation. Did obesity favor certain types of intestinal bacteria, or did certain types of intestinal bacteria favor obesity?

Obese individuals are often insulin resistant, and insulin resistance can cause higher sugar levels in the blood, urine and intestine. So it was easy to assume that obesity simply favored the growth of different types of bacteria in the intestine. However, recent studies have suggested that certain types of bacteria in our intestines may actually cause obesity.

Can Gut Bacteria Make You Fat?

For example, one study (Vijay-Kumar et al, Science, 328: 228-231, 2010) compared a strain of mice that are genetically predisposed to obesity with wild type (genetically lean) mice. They first looked at the intestinal bacteria. It turned out that the obese mice and lean mice had the same differences in intestinal bacteria that obese and lean humans have. And just like obese humans the obese mice ate more, displayed insulin resistance, and had elevated levels of triglycerides, cholesterol and blood sugar (They were pre-diabetic).

The investigators then decided to test the hypothesis that the particular bacterial strains found in the intestines of genetically obese mice might be causing their insulin resistance and obesity.

In the first experiment they killed off the intestinal bacteria in the genetically obese mice by putting high dose antibiotics in their food. Depleting the intestinal bacteria created some health problems for the mice, but it completely prevented the insulin resistance, overeating and obesity normally observed with this strain of mice.

In the second experiment they sterilized the intestines of the genetically lean mice and then colonized their intestines with intestinal bacteria from the genetically obese mice. When they did this, the genetically lean mice developed many of the characteristics of the genetically obese mice including insulin resistance, overeating, obesity and hyperglycemia.

insulin resistanceIn short, when their guts became colonized with bacteria from obese mice, the genetically lean mice became overweight and developed diabetes. Based on these experiments and other studies the scientists hypothesized that the wrong kinds of intestinal bacteria can make a significant contribution to insulin resistance, which in turn can lead to overeating and obesity. In short, they concluded that bad gut bacteria may make you fat.

The Battle of The Bacteria

In a second study (Walker et al, Science, 341: 1079-1089, 2013) the intestines of germ free mice were colonized with gut bacteria from lean and obese humans. The results were essentially the same as in the first study. That is, the mice who received gut bacteria from lean humans stayed lean and those who received gut bacteria from obese humans became obese.

But then the investigators asked two really interesting questions:

1) If you mixed the two types of bacteria, which one would win “the battle of the bacteria”?

For this experiment they took mice that had received gut bacteria from lean humans and mice that had received gut bacteria from obese humans and put them in the same cage. It turns out that since mice eat each other’s poop, they pick up each other’s intestinal bacteria. (No, I am not suggesting that you…)

The results of this experiment were (envelop please): The “lean” bacteria won out. They became the predominant bacteria in the intestines of all of the mice in the cage. Furthermore, none of the mice became obese – even the ones that had originally been inoculated with gut bacteria from obese humans.

2) Are the types of bacteria in the intestine influenced by diet?

In the previous experiment the mice were eating standard mouse chow – which is pretty healthy if you are a mouse. So the investigators decided to ask what would happen if they ate foods that were similar to really good and really bad human diets. They devised two types of diets for the mice – one that was high in fresh fruits & vegetable and low in fat (the good diet) and one that was high in fat and low in fresh fruits and vegetables (the bad diet).

On the good diet, the results were the same as in the previous experiment. On the bad diet the “lean” bacteria never grew in the intestines of the mice inoculated with bacteria from obese humans and those mice went on to become obese.

This study confirmed that the wrong kind of gut bacteria can cause obesity, but it also showed that diet can influence the type of bacteria that can grow in the intestine – something I talked about in an earlier issue of “Health Tips From the Professor”  Our Gut Bacteria Are What We Eat.

The Bottom Line

1) Does this mean that you should rush out and buy some probiotics (good bacteria) as part of your weight loss strategy? The simple answer is no. That would be premature. These studies were performed in mice. Although similar results have been reported in humans (for example, Jumpertz et al, Am. J. Clin. Nutr., 94: 58-65, 2011), those studies are very preliminary at present. In addition, genetics and diet obviously played a role in the results. In short, we are a long way from knowing to what extent intestinal bacteria might contribute to obesity in humans.

2) However, there are many very good reasons to make sure that you supply friendly bacteria to your intestinal track on a regular basis. For example, we know that bad bacteria in your intestine can compromise your immune system, convert foods that you eat to cancer causing chemicals, and cause chronic inflammation – which contributes to a number of major diseases.  Can gut bacteria make you fat?  We can’t yet say whether good bugs will help keep you slim, but we do know that they can help keep you healthy.

3) Finally, while we can’t yet say whether probiotic supplements can help you lose weight, it is becoming increasing clear that healthy diets (low fat, high fiber diets with lots of fresh fruits and vegetables) support the type of intestinal bacteria that can make you slim. This is yet one more reason why a healthy diet is so important if you want to stay slim and healthy.

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