Are Organic Foods Healthier?

Organic Fruits & Vegetables

Author: Dr. Stephen Chaney

 fruits-vegetables

Are organic foods healthier for us than conventionally grown foods, specifically fruits and vegetables? The controversy about the benefits of organically raised produce continues. In fact, about the only thing that all sides agree on is that:

  • Organic foods have lower pesticide and herbicide residues and cause less environmental pollution.
  • Organic foods generally cost more.

But that is where all agreement ends.

  • Some experts argue that the pesticide levels on conventionally grown fruits and vegetables are within safe levels and that any risk from the pesticides is outweighed by the health benefits of the fruits and vegetables themselves.
  • Some studies have suggested that organic foods, fruits and vegetables, are healthier because they have higher antioxidant levels, while other studies have reported no nutritional differences between organic and conventionally grown fruits and vegetables.

Benefits of Organic Food?

The present study (Baranski et al, British Journal of Nutrition, doi: 10.1017/S0007114514001366) tried to overcome the shortcomings of many of the previously published reports.

To begin with this study was a meta-analysis that combined the results from 343 of the best designed previous studies to increase the statistical power of the analysis. In addition, the investigators utilized a type of statistical analysis that was superior to previously published studies. In short, it was a very good study. It does show some benefits of organic food.

organic-farms

The results were fairly clear cut:

  • Pesticide residues were four-fold lower in the organically raised produce than the conventionally raised produce. This result has been consistently seen in all of the previously published studies, and is probably the #1 reason that people choose organic produce. It is also one of the most agreed upon benefits of organic food.
  • Polyphenol antioxidant levels were significantly higher in the organically raised produce. The percent increase ranged from 19% to 69% depending on the polyphenolic compound tested. This increase has not been seen in all previously published studies, but would represent a side benefit if true.
  • Levels of the toxic metal cadmium were significantly less in the organically grown fruits and vegetables. The authors speculated that the cadmium found in conventionally grown produce came from the inorganic fertilizers that were used.

Should You Choose Organic Supplements?

natural-medicine

If organic foods are better for you than conventionally grown foods, does that mean that you should also choose organic supplements? While that idea sounds logical, the reality is actually more complex.

While organic foods clearly have less pesticides and toxic metals than conventionally grown foods, the level of those contaminants is not zero – even in foods with organic certification. The problem is that our environment is so polluted that no farm is contaminant free. A farmer can use the best organic practices, but if their groundwater is contaminated or pesticides from neighboring farms blow on to their farm, some of those toxic residues will end up in their “organic” crops.

 

So with supplements, “Organic” certification is not an absolute guarantee of purity. Instead you should insist on getting your supplements from a company with a very rigorous quality control program and a policy of rejecting any raw materials that contain contaminants of any kind.

The Bottom Line

1)     The latest study shows that pesticide residues are four-fold lower in the organically raised produce than the conventionally raised produce. This result has been consistently seen in all of the previously published studies, and is probably the #1 reason that people choose organic fruits and vegetables.

2)    Polyphenol antioxidant levels were significantly higher in the organically raised produce. The percent increase ranged from 19% to 69% depending on the polyphenolic compound tested. This increase has not been seen in all previously published studies, but would represent a side benefit if true.

3)    While one of the benefits of organic foods is they are less likely to be contaminated than conventionally grown foods, an organic certification is not a sufficient proof of purity when you are choosing supplements.You should insist on getting your supplements from a company with a very rigorous quality control program and a policy of rejecting any raw materials that contain contaminants of any kind.

 

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.

VTE

Benefits of Omega-3

Author: Dr. Stephen Chaney

venous-thomboembolism

 When a blood clot ends up in your lungs, it can be deadly. But that blood clot didn’t start out in your lungs. It initially formed in your veins where it is referred to as a thrombus. Then it broke off and migrated to your lungs – a process called venous thromboembolism or VTE. Venous thromboembolism is the third most common form of cardiovascular disease, killing around 100,000 Americans each year.

What if something as simple as adding more omega-3 fatty acids to your diet could dramatically decrease your risk of VTE? That’s exactly what a recent study (Hansen-Krone et al, J. Nutr., 144: 861-867, 2014) has suggested. It claims that one of the benefits of omega-3 in your diet may be to help prevent venous thromboembolism.

What Is Venous Thromboembolism or VTE?

As described above, venous thromboembolism starts when a blood clot (also called a thrombis) forms in a vein. About 2/3 of the time, the blood clot forms in the deep veins in the leg (called deep vein thrombosis or DVT) and stays there before eventually dissolving. The symptoms of deep vein thrombosis or DVT are generally leg pain and swelling.

About 1/3 of the time, the clot breaks loose and travels to the lung where it blocks blood flow to a portion of the lung (a process called pulmonary embolism). The symptoms of pulmonary embolism are severe shortness of breath, chest pain when breathing or coughing, and death! While the first two symptoms are pretty frightening, it’s the last symptom (death) that we’d really like to avoid.

Why Might Omega-3s Prevent Venous Thromboembolism or VTE?

One of the benefits of Omega-3s is they have been shown to reduce inflammation and platelet aggregation, two of the most important risk factors for venous thromboembolism. So it is logical to think that omega-3s might help reduce the risk. However, good scientists don’t rely on logic alone. They test their hypotheses by doing clinical studies.

Unfortunately, the results of previous clinical studies have been mixed. One study showed a protective effect of omega-3s, but two other studies found no correlation between omega-3 fatty acid intake and VTE. However, these studies had some significant limitations:

benefits-of-fish-oil-pills

  • They were all performed with populations in the United States where fish consumption is relatively low and many of the fish have low omega-3 content. As a consequence omega-3 fatty acid intake was low and there wasn’t much of a range in intake.
  • Some of the studies did not ask about the use of omega-3 supplements. In a country where 37% of the population takes fish oil supplements, that is a huge omission.
  • They did not measure omega-3 fatty acid levels in the blood to verify that their dietary surveys were accurate.

 

Do Omega-3s Prevent Venous Blood Clots or DVT?

pulmonary-embolism

The current study (Hansen-Krone et al, J. Nutr., 144: 861-867, 2014) followed 23,631 people aged 25-97 from Tromso, Norway for 16 years.

  • The participants filled out a comprehensive dietary survey at the time of enrollment where they indicated the number of times per week they ate fish and how often they used fish oil supplements.
  • The scientists in charge of the study verified the estimated omega-3 intake from the dietary analysis in a subgroup of the population by measuring omega-3 fatty acid levels in their blood.
  • Finally, they utilized Norway’s excellent health records to determine how many of the people in their trial experienced a venous thromboembolism – either fatal or non-fatal.

The results were pretty impressive:

  • Blood level measurements of omega-3 fatty acids verified the omega-3 intake estimates from the dietary survey. There was a direct correlation between estimated intake and blood levels of the omega-3 fatty acids.
  • Those participants who ate fish most often (≥3 times/week) were 22% less likely to experience a VTE than those who ate fish least often (1-2 times/week). That difference was borderline significant.
  • Those participants who ate fish most often and took fish oil supplements were 48% less likely to experience a venous thromboembolism than those who ate fish least often and took no fish oil supplements. That difference was highly significant.

 

Strengths & Weaknesses of the Study

Since not all of the previous clinical studies have reached the same conclusion, it is important to look at the strengths and weaknesses of the study compared to the previous studies.

Strengths of the Study:

  • Tromso is located on the northeast coast of Norway, so fish consumption is high and most of the local fish are excellent sources of omega-3 fatty acids. Consequently, omega-3 intake was relatively high, which significantly increases the chance of seeing an effect if one exists. Fish consumption in the US is generally lower and not all of the fish consumed are good sources of omega-3s.
  • The study also took into account the use of omega-3 supplements. Some of the US studies did not.
  • The estimates of omega-3 intake from the dietary survey were verified by blood analysis of omega-3 fatty acids.

Weaknesses of the Study:

  • The amount of omega-3 fatty acids in the supplements was not recorded, so it is unclear what level of omega-3 fatty acid intake was required to see a significant decrease in VTE risk. This will make it difficult for future investigators to repeat the study.
  • They did not measure other nutrients that might affect the venous thromboembolism risk.

 

The Bottom Line

1)     VTE is a serious condition with a high rate of mortality.

2)     A recent study suggests that a combination of high fish consumption and fish oil supplement use may significantly decrease the risk of venous thromboembolism.

3)     It is interesting to note that even three servings/week of omega-3 rich fish was not enough to cause a significant decrease in venous thromboembolism risk. It required additional omega-3s from fish oil supplements before the decreased risk was significant.

4)     Not all previous studies have come to the same conclusion. So while the most recent study had several improvements in design compared to previous studies, the case can’t be considered closed. More studies are clearly needed.

5)     This study suggests that omega-3 fatty acids may help prevent VTE from occurring. You should not consider them to be a treatment for the condition. If you are experiencing symptoms of venous thromboembolism (leg pain and swelling for deep vein thrombosis (DVT) or shortness of breath and pain when breathing for pulmonary embolism), don’t reach for your fish oil capsules. Call your doctor right away.

 

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?

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.

Does Grilled Meat Increase Prostate Cancer Risk?

Author: Dr. Stephen Chaney

 Want Cancer With That Burger?

 backyard-bbq

Its summer and you have most likely already visited a backyard bbq. One question that you probably won’t hear from your host or hostess is “Would you like some cancer with that burger?” But, perhaps that is exactly the question that they should be asking.

You probably already knew that red meat consumption may increase your risk of cancer. But, did you know that grilling that red meat may increase your risk of cancer even more?

  • You probably didn’t really want to know that when fat from the meat hits the hot coals, carcinogens form that are deposited on the meat.
  • You probably also didn’t want to know that when you cook meat to high temperatures the amino acids in the meat combine to form cancer causing substances.
  • And you really didn’t want to know that a recent study showed that people who consume well-done red meat were 60% more likely to develop advanced pancreatic cancer.

Does Grilled Meat Increase Prostate Cancer Risk?

This study compared 531 people ages 40-79 who had recently been diagnosed with advanced prostate cancer with 527 matched controls. Both groups were asked about their dietary intake of meats, usual meat cooking methods and doneness of the meat.

The results were quite striking:

  • Increased consumption of hamburgers was associated with a 79% increased risk of advanced prostate cancer.
  • Increased consumption of processed meat was associated with a 57% increased risk of advanced prostate cancer.
  • Grilled red meat was associated with a 63% increased risk of advanced prostate cancer.
  • Well done red meat was associated with a 52% increased risk of advanced prostate cancer.

However, those percentages are a little bit difficult to compare, because “increased consumption” was defined relative to what the usual consumption or cooking practice was. So put another way, weekly consumption of…

  • 3 or more servings of red meat or…
  • 1.5 or more servings of processed meat or…
  • 1 or more servings of grilled or well done red meat…

…were associated with a 50% increased risk of advanced prostate cancer.

In contrast, consumption of white meat was not associated with increased cancer risk, no matter what the cooking method was used.

how-you-can-reduce-cancer-risk

Is It Possible To Enjoy Your Cookouts Without Increasing Cancer Risk?

Our local newspaper recently carried some tips by Dr. Denise Snyder from the Duke University School of Nursing in Durham, NC on how you could reduce the risk of giving your guests cancer the next time you are the chef at your backyard bbq.

Here are her suggestions:

  • Grill fruits and vegetables instead of meat. That was her idea, not mine. My editorial comment would be that grilling white meat (fish or chicken) is also OK.
  • Use the lowest temperature that will cook your food thoroughly and keep the grill rack as high as possible.
  • Use a meat thermometer so that you can make sure that as soon as the meat is thoroughly cooked you remove it from the grill. We usually overcook the meat to make sure that it is done.
  • Shorten your grill time by microwaving the meat first, using thinner leaner cuts of meat or cutting up the meat and making kabobs.
  • Trim as much fat from the meat as possible before you cook it.
  • Line your grill rack with aluminum foil poked with holes. This allows the fat to drip down but minimizes the exposure of the meat to the carcinogens formed when the fat hits the coals.
  • Marinate your meats before grilling. That has been shown to reduce the formation of cancer causing chemicals.
  • And, of course, avoid processed meats like hot dogs and sausage completely because they have been shown to increase the risk of cancer and diabetes (British Journal of Cancer, 106: 603-607, 2012; American Journal of Clinical Nutrition, doi: 10.3945/ajcn.111.018978, 2011) no matter how they are cooked.

So here’s to a healthier backyard bbq. Bon appétit!

The Bottom Line

1)     You already knew that red meat and processed meats may increase your risk of cancer, but how you cook your red meat also matters. Grilling your meat and/or cooking it until it is well done appear to significantly increase your risk of developing advanced prostate cancer.

2)     In contrast, consumption of white meat was not associated with increased cancer risk, no matter what the cooking method was used.

3)    I’ve included several tips on how you can reduce the cancer risk associated with grilling red meats in the article above so you can enjoy both your cookouts and your health.

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 Diet Sodas Make You Fat?

Why Do Sodas Cause Obesity?

Should You Kick the Diet Soda Habit?

Author: Dr. Stephen Chaney

Do Sodas Cause Obesity?We are consuming ever increasing amounts of diet sodas to combat the obesity epidemic. In 1960 14% of the U.S. population was obese and 3.3% of us consumed diet sodas. By 2010 41% of the U.S. population was obese and 20% of us were consuming diet sodas. It’s pretty clear that diet sodas aren’t helping us solve the obesity epidemic, but are they actually part of the problem?

You’ve probably seen the headlines questioning whether diet sodas actually help you lose weight. In fact many of the headlines imply the diet sodas will cause you to gain weight. Two of the more sensational headlines I came across said “Think diet sodas help you lose weight? Not so, Purdue study finds”, and “Can diet sodas actually cause more weight gain than regular sodas?”

Let me start with the first headline. The Purdue publication referred to in the headline (Swithers, Trends in Endocrin. & Metab., 24: 431-441) wasn’t really a study, it was an opinion piece. That simply means that it was a review where the references were selected on the basis of the author’s opinion. That’s OK if you clearly label it as an opinion piece, which Dr. Swithers did.

Now for the second headline: There is no good evidence that diet sodas will cause you to gain more weight than regular sodas. However, a number of published studies suggest that consumption of diet sodas is associated with weight gain – sometimes just as much weight gain as consumption of the sugar sweetened sodas they replace.

Do Diet Sodas Make You Fat?

The evidence that Dr. Swithers (Trends in Endocrin. & Metab., 24: 431-441) cited was pretty impressive.

For example, the San Antonio Heart Study recorded consumption of diet sodas and regular sugar sweetened sodas in 3,862 adults (average age 44) and measured the increase in BMI (a measure of obesity) over the next 7-8 years. That study found:

  • Individuals consuming >21 diet sodas/week were almost 2-fold more likely to become overweight or obese than individuals consuming no sodas.
  • There was a clear dose response effect, with a 41% increased risk of becoming overweight or obese for each can or bottle of diet soda consumed/day.
  • The increase in weight associated with diet soda consumption was just as great for those who were at normal weight at the beginning of the study as it was for those who were obese at the beginning of the study.
  • In this study the increase in weight associated with soda consumption was greater for diet sodas than it was for regular sodas.

Another major study (Circulation, 116: 480-488, 2007) recorded diet and regular soda consumption in 6039 participants in the Framingham Heart Study (average age 53) and measured the increase in obesity (along with other parameters associated with metabolic syndrome or pre-diabetes) over the next 4 years. This study found:

  • Individuals consuming one or more sodas/day had a 48% increased risk of becoming obese compared to people with infrequent soda consumption.
  • In this study the weight increase associated with soda consumption was virtually the same for diet sodas and regular sodas.

Are These Studies True?

Diet SodaThese, and similar studies have been criticized because they are looking at associations, which do not prove cause-and-effect. For example, it’s not always clear whether the people in those studies gained weight because they were consuming diet sodas or consumed diet sodas because they were overweight.

That argument is less persuasive for the San Antonio Heart Study, because the weight gain associated with diet soda consumption was also seen with people who were at normal weight at the beginning of the study. Still there is a need for good double blind, placebo controlled intervention studies.

There have been very few intervention studies in which one group of subjects were told to drink only diet sodas and the other group only regular sodas. Unfortunately, in those studies the total caloric intake of the diet soda group was also restricted. So while the diet soda group did lose weight, it’s not clear whether that weight loss was due to the diet sodas or the overall caloric restriction of the diet.

You may have also seen the recent headlines from a study showing that people consuming diet sodas gained no more weight than people consuming water (Obesity, 22: 1415-1421, 2014). But once again, both groups were given detailed instructions on how to restrict total calories. Almost any diet will work if you have a dietitian looking over your shoulder and telling you how to restrict calories.

So what is the average consumer to think? On the one hand, dietitians and health professionals are telling you to drink diet sodas if you want to lose weight. On the other hand, you keep seeing these headlines saying the diet sodas may not help you lose weight or may even cause you to gain weight.

Of all the recent blogs and online articles on the topic, the only one I actually recommend reading is from WebMD (http://www.webmd.com/diet/features/diet-sodas-and-weight-gain-not-so-fast).

WebMD often adheres to the AMA line, but I found this to be a very balanced analysis of the science behind the question of whether diet sodas help or hinder weight loss.

How Could Diet Sodas Possibly Cause Weight Gain?

The million dollar question is: How could diet sodas possibly cause weight gain? After all, they contain no calories. I think the most useful perspective from the Web MD article is that it’s probably not the diet sodas themselves that cause weight gain. It’s what we eat with the diet sodas that cause the weight gain. Here are a couple of quotes I found particularly enlightening.

Dr. Barry Popkin, a colleague from the University of North Carolina, calls it the “Big Mac and Diet Coke” mentality. He says: “Especially in America, we have a lot of people who eat high-fat, high-sugar diets, but also drink diet sodas.”

Why is that? Dr. David Katz from Yale University has research suggesting that artificial sweeteners may condition people to want to eat more sweet foods. He says: “Our taste buds don’t really differentiate between sweet in sugar and sweet from, say, aspartame. The evidence that this sweet taste is addictive is pretty clear. What I have seen in my patients is that those who drink diet soda are more vulnerable to processed foods with added sugars.”

There is some independent evidence to back up that hypothesis. For example, one recent study showed that rats given artificially sweetened yoghurt with their rat chow ate more rat chow and gained more weight than rats fed sugar-sweetened yoghurt with their rat chow (Behavioral Neuroscience, 122: 161-173, 2008). Another study in humans showed that consumption of artificial sweeteners activates a portion of the brain associated with cravings for sweets (Physiology & Behavior, 107: 560-567, 2012).

However, this viewpoint is controversial. Some experts think that the association between diet sodas and weight gain is psychological rather than physiological. Simply put, when people consume diet drinks they feel that they can splurge elsewhere.

The Bottom Line

  • Once again there is no magic bullet. There is no good evidence that diet sodas will help you lose weight unless you carefully control the calories in everything else you eat. And, diet sodas may just cause you to gain weight because they make you crave the very foods that are worst for your waistline.
  • In addition, there may be other good reasons not to consume diet sodas. For example, recent studies have shown that consumption of diet sodas may be linked to increased risk of metabolic syndrome or pre-diabetes (Circulation, 116: 480-488, 2007) and heart disease (see Does Sugar Cause Heart Disease? and Can Soft Drinks Cause Heart Disease?
  • My recommendations are to drink water, herbal teas, unsweetened tea & coffee or unsweetened mineral water or seltzer – perhaps with a splash of fruit juice.
  • Finally, there is no substitute for a healthy, calorie controlled diet; exercise; and lifestyle change if you want to lose weight and keep it off.

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 Sugar Cause Heart Disease?

Is Sugar No Longer Your Best Friend?

Author: Dr. Stephen Chaney

SugarSugar has gotten a lot of bad press in recent years. You’ve probably already heard that high sugar intake is associated with inflammation, obesity and diabetes. As if that weren’t bad enough, the latest headlines proclaim that added sugar may also increase our risk of fatal heart disease. Are those headlines true? And if they are true, what should you do about it?

Sugar Basics – The Truth About Sugar

There are three facts about sugar that almost every expert agrees with:

  • The sugars that occur naturally in foods like fruits and vegetables are generally not a problem unless you are a diabetic. It is the added sugars in our diet that we should be concerned with.
  • The amount of added sugars in the American diet has increased dramatically since the founding of this country. Based on data from the US Department of Commerce and the USDA, the amount of added sugar in the American diet has gone from 6.3 pounds/year in 1822 to over 100 pounds/year in 2000. Put another way, we have gone from consuming the amount of sugar in a 12 oz soda every 5 days in 1822 to every 7 hours in 2000.
  • The lion’s share of that added sugar is coming from sodas and similar sugary beverages. The amounts are: sodas and other sugar-sweetened beverages (37.1%), grain-based desserts (13.7%), fruit drinks (8.9%), dairy desserts (6.1%) and candy (5.8%).

Beyond that there is little agreement among experts. When I was a young man the sugar “villains” were glucose and sucrose. Then it was sugar alcohols. Today it is high-fructose corn syrup and maltodextrin. Tomorrow it will be something else.

In reality there are no sugar heroes and no sugar villains. The harmful effects of added sugars are based almost entirely on:

  • The amount of added sugars in the diet…and…
  • The type of foods those added sugars are found in.

For more information, watch my video “The Truth About Sugar”.

Does Sugar Cause Heart Disease?

The study behind the headlines (Yang et al, JAMA Internal Medicine, 174: 516-524, 2014) followed 11,733 participants in the 3rd National Health And Nutrition Examination Survey (NHANES III) for an average of 14.6 years. (NHANES studies are designed to represent a cross section of the adult US population). Sugar intake was based on the average of two dietary surveys for most of the participants, and cardiovascular deaths were determined from the NHANES III Linked Mortality Files.

The average intake of added sugar in the American population was around 16% of total calories (compared to around 1% of total calories in 1822). For comparison purposes, the authors divided the population into three groups based on added sugar consumption:

  • Those consuming less than 10% of calories from added sugar (28.6% of the population).
  • Those consuming between 10% and 25% of calories from added sugars (46.4% of the population).
  • Those consuming more than 25% of calories from added sugars (25.0% of the population).

When the groups with the 10-25% and >25% of calories from added sugars were compared to the <10% group with respect to cardiovascular deaths, the results were pretty striking.

  • The group consuming 10-25% of calories from added sugars had a 30% increased risk of dying from heart disease
  • And the group consuming >25% of calories from added sugars had a 275% increased risk of dying from heart disease!

This association between added sugar consumption and risk of cardiovascular death was independent of age, sex, race/ethnicity, educational attainment, physical activity, HEI score (a measure of overall diet quality and BMI (a measure of obesity).

The Strengths And Weaknesses of This Study

Strengths:

  • This was a particularly large, well designed study.
  • This study is consistent with a number of early studies suggesting that added sugar intake increases the risk of cardiovascular death. See, for example “Can Soft Drinks Cause Heart Disease?

Weaknesses:

  • The main weakness of this study is that it measures associations only. It does not prove cause and effect.

Should You Switch To Diet Sodas?

Diet SodaYou may be thinking that you should switch to diet sodas – and perhaps artificially sweetened snacks and desserts as well. It only makes sense that if sugar is the problem, artificial sweeteners must be the answer. Wrong! The latest research suggests that diet sodas may be just as bad as the sugar-sweetened sodas.

I have already shared one study with you that linked consumption of diet sodas with increased risk of heart disease (see “Can Soft Drinks Cause Heart Disease?”). The link between diet sodas and heart disease has now been supported by another major clinical study reported by Dr. Ankur Vyas from University of Iowa, March 30, 2014 at the American College of Cardiology’s 63rd Annual Scientific Session.

This study followed 60,000 women with an average age of 62.8 years who were enrolled in the Woman’s Health Initiative Observational Study for 9 years. They reported that compared to women who never or rarely drank diet sodas, those who consumed two or more diet sodas/day were:

  • 30% more likely to suffer heart attacks and strokes…and…
  • 50% more likely to die from cardiovascular disease.

What Can You Drink?

By now you are probably asking yourself: “If regular sodas, diet sodas, other sugary and diet beverages, and even most fruit juices are out, what else can I drink? Is there anything left?”

It’s not quite as daunting as it seems at first. It may take some time to re-educate your taste buds, but your health is worth it. Here are some healthy alternatives:

  • My #1 recommendation is always water. If you crave some flavor, add lemon, mint, or your favorite fruits. Herbal teas are another flavorful, healthy choice.
  • If you crave caffeine, go for green tea, regular tea or coffee – without sweeteners, of course.
  • If you crave the carbonation, start with unsweetened mineral water or seltzer and add you favorite flavorings.

The Bottom Line:

1)    The evidence is getting stronger every day that too much added sugar in our diet is linked to increased risk of death from cardiovascular disease. If you are consuming >25% of calories from added sugars the increased risk is almost 3-fold!

2)    The evidence from this study suggests that it would be prudent to keep added sugars below 10% of calories. For most Americans this represents around 200 calories/day from added sugars. That compares with the World Health Organization’s recommendation that added sugars be <10% of calories, the Institute of Medicine’s recommendation that added sugars be <25% of calories, and the American Heart Association’s recommendation that added sugars be <100 calories for women and <150 calories for men.

3)    There are no sugar heroes and villains. The amount of added sugar in the diet is much more important than the kind of sugar. The food that the sugar is found in is also very important, with sodas and similar sugar-sweetened beverages being the worst offenders (See my video “The Truth About Sugar” for more information).

4)    Artificial sweeteners are not the solution. A recent study with postmenopausal women suggests that consumption of as few as two diet sodas a day increases the risk of heart attacks and strokes by 30% and cardiovascular death by 50%.

5)    Don’t despair. You won’t have to go thirsty. There are lots of healthy alternatives available (see 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.

Are The Benefits Of Resveratrol A Myth?

Is Resveratrol Dead?

Author: Dr. Stephen Chaney

Red WineIt seems like just a few years ago that the headlines were proclaiming that resveratrol, a polyphenol found in red wines, grapes and chocolate, was the latest “super nutrient”. It was going to make you younger, smarter and healthier. You probably knew that all of the claims being made at the time could not be true.

But the latest headlines are claiming that resveratrol health benefits are all a myth. Has the resveratrol bubble burst? Was it all just hype?

Before you decide that resveratrol supplements are just a waste of money, let me take you behind the scenes and evaluate the latest study objectively. Let’s talk about what it showed, and didn’t show. But, before we look at the study, let’s review the history of resveratrol.

How Did The Resveratrol Story Get Started?

The resveratrol story started in the 1990’s when Dr. Serge Renaud at Bordeaux University coined the term “French Paradox” to describe the fact that cardiovascular disease incidence was relatively low in the French population despite the fact that they consumed diets high in saturated fat and cholesterol.

People immediately started asking what could possibly explain this discrepancy between the US and French populations? In other words, what could be protecting the French population from their high fat diet? One obviously difference between the French and Americans is that the French consume a lot more red wine – or at least they did before the “French Paradox” publicity turned red wine into a health food. Based on that difference, Dr. Renaud proposed that the French Paradox was due to the high red wine consumption in France.

But, red wine is an alcoholic beverage and overconsumption of alcoholic beverages is a major health problem for many people. And, while alcohol does have some cardiovascular benefits, alcohol consumption was pretty constant across countries.

So the next logical question was what other ingredients in red wine might explain their supposed health benefits. Polyphenols appear to have numerous health benefits, and resveratrol is the major polyphenol in red wine. So resveratrol became the “poster child” for the health benefits of red wine.

Even so, for years resveratrol was a “niche” supplement. It had a loyal following, but it wasn’t a big player in the nutritional supplement market. All that changed in 2009. Dr. David Sinclair at Harvard University had been studying genes that slow the aging process. He had screened thousands of naturally occurring small molecules in hopes of finding some that could turn on those anti-aging genes.

He announced that resveratrol and a few related polyphenols were the most potent activators of those anti-aging genes, and he went on to publish studies showing that resveratrol could help obese mice live longer and lean mice be healthier. All of a sudden resveratrol became a superstar.

But, does resveratrol also work in humans? There are many clinical studies that suggest it does. That’s why I was surprised by the recent headlines proclaiming that the supposed health benefits of resveratrol were myths. So once again, let’s look at the study behind the headlines.

Are The Benefits Of Resveratrol a Myth?

The study behind the headlines (Semba et al, JAMA Internal Medicine, doi: 10.1001/jamainternalmed.2014.1582) followed 783 men and women aged 65 years or older from the Chianti region of Italy for 9 years. None of the participants were taking resveratrol supplements. The investigators estimated resveratrol intake by measuring the concentrations of resveratrol metabolites in the urine.

The investigators measured all cause mortality and the prevalence of heart disease and cancer over the 9 year period and found no correlation between those outcomes and urinary resveratrol metabolites. From those data the authors concluded that “Resveratrol levels achieved with a Western diet did not have a substantial influence on health status or mortality risk of the population in this study.”

The Strengths And Weaknesses of The Study

There are really two important questions – what are the strengths and weaknesses of the study and what does the study actually show?

What are the strengths and weaknesses of the study?

  • A major strength of the study was the measurement of urinary resveratrol metabolites rather than relying on the less accurate dietary recall – although it should be noted that the assays used are relatively new and could benefit from further validation.
  • The main weakness is that it was a relatively small study in a relatively homogeneous population. Most of the resveratrol consumed by this population came from red wine and even the group with the lowest resveratrol intake was drinking 2-3 glasses of red wine per week (You don’t find many teetotalers in the wine growing regions of Italy).

What does the study actually show?

  • The level of resveratrol metabolites in this population directly correlated with alcohol consumption. And, the authors of the study concluded that since the study was done in the Chianti region of Italy, most of the resveratrol came from red wine. So the study actually suggests that red wine consumption has no effect on heart disease, cancer or longevity – in direct contradiction to Renaud’s French Hypothesis.
  • The conclusion that the amount of resveratrol one can obtain from diet alone is unlikely to provide health benefits needs to be replicated in a much larger population group with a wider range of resveratrol intakes from a wider variety of foods before it can be considered definitive.
  • Even if the amount of resveratrol in food does offer no significant health benefits, that information provides little or no guidance when we consider resveratrol supplements, which generally provide much higher levels of resveratrol.

The Bottom Line:

1)    Don’t pay too much attention to the headlines saying that the health benefits of resveratrol are a myth. The study behind the headlines was a small study in a relatively homogeneous population. If anything, it debunked the hypothesis that red wine consumption is responsible for the French Paradox.

2)    The study did suggest that the amount of resveratrol one can obtain from diet alone is unlikely to provide significant health benefits. While that may be true, it is irrelevant when considering resveratrol supplements because they provide much higher amounts of resveratrol.

3)    The clinical studies on resveratrol supplements are very encouraging, but not yet definitive (see, for example, my “Health Tips From the Professor” article on resveratrol and blood sugar control. That’s to be expected at this stage. It generally takes decades of studies before the scientific community reaches consensus on anything. In the meantime you will continue to see alternating headlines proclaiming the miracles and the myths of resveratrol.

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 Chocolate Help You Lose Weight?

A Candy a Day Keeps The Weight Away?

Author: Dr. Stephen Chaney

chocolateSometimes you come across news that just seems too good to be true. The recent headlines saying that you can lose weight just by eating chocolate are a perfect example. Your first reaction when you heard that was probably “Sure, when pigs fly!”

But, it’s such an enticing idea – one might even say a deliciously enticing idea. And, in today’s world enticing ideas like this quickly gain a life of their own. Two popular books have been written on the subject. Chocolate diet plans are springing up right and left. A quick scan of the internet even revealed a web site saying that by investing a mere $1,250 in a training course you could become a “Certified Chocolate Weight Loss Coach” earning $50,000/year.

If you like chocolate as much as most people you are probably wondering could it just possibly be true?

Can Eating Chocolate Help You Lose Weight?

The idea that chocolate could help you lose weight does have some support. There are actually three published clinical studies suggesting that chocolate consumption is associated with lower weight (European Journal of Clinical Nutrition, 62: 247-253, 2008; Nutrition Research, 31: 122-130, 2011; Archives of Internal Medicine, 172: 519-521, 2012).

While that sounds pretty impressive, they were all cross-sectional studies. That means they looked at a cross section of the population and compared chocolate intake with BMI (a measure of obesity). Cross sectional studies have a couple of very important limitations:

1)    Cross sectional studies merely measure associations. They don’t prove cause and effect. Was it the chocolate that caused the lower weight, or was it something else that those populations were doing? We don’t really know.

2)    Cross sectional studies don’t tell us why an association occurs. In many ways this is the old chicken and egg conundrum. Which comes first? In this case the question is whether the people in the studies became obese because they ate less chocolate – or did they eat less chocolate because they were obese and were trying to control their calories? Again, we have no way of knowing.

If Pigs Could Only Fly

If Pigs Could FlyChocolate is relatively rich in fat and high in calories. It’s not your typical diet food. On the surface it seems fairly implausible that eating chocolate could actually help you lose weight.

Scientists love to poke holes in implausible hypotheses, so it is no surprise that a recent study (PLOS ONE, 8(8) e70271) has poked some huge holes in the “chocolate causes weight loss” hypothesis.

This study analyzed data from over 12,000 participants in the Atherosclerosis Risk in Community (ARIC) Study. This was also a cross sectional study, but it was a prospective cross sectional study (That’s just a fancy scientific term which means that the study followed a cross section of the population over time, rather than just asking what that population group looked like at a single time point).

The authors of the study assessed frequency of chocolate intake and weight for each individual in the study at two separate time points 6 years apart. The results were very interesting:

  • When they looked at a cross section of the population at either time point, their results were the same as the previous three studies – namely those who consumed the most chocolate weighed less. So the data are pretty consistent. Overweight people consume less chocolate. But, that still doesn’t tell us why they consume less chocolate.
  • However, when they followed the individuals in the study over 6 years, those who consumed the most chocolate gained the most weight. The chocolate eaters were skinnier than the non-chocolate eaters at the beginning of the study, but they gained more weight as the study progressed. And, the more chocolate they consumed the more weight they gained over the next 6 years. [No surprise here. Calories still count.]
  • When they specifically looked at the population who had developed an obesity related illness between the first and second time point, they found that by the end of the study those participants had:

– Decreased chocolate intake by 37%

– Decreased fat intake by 4.5%

– Increased fruit intake by 20%

– Increased vegetable intake by 17%

  • In short, this study is more consistent with the “obesity causes reduced chocolate intake” model than the “reduced chocolate intake causes obesity” model. Simply put, if you are trying to lose weight, sweets like chocolate are probably among the first things to go.

Of course, even prospective cross sectional studies have their limitations. Double blind, placebo controlled studies are clearly needed to resolve this question. The only published study of this type has reported a slight weight gain associated 25 g/day of dark chocolate, but the study was too small and too short in duration to draw firm conclusions.

In summary, more studies are needed, but the current evidence does not support the “miracle diet food” claims for chocolate.

The Bottom Line:

1)    Pigs still haven’t learned how to fly. As enticing as it may sound, the weight of current evidence does not support the claims that chocolate is a miracle diet food or that eating chocolate every day is a sensible strategy for losing weight.

2)    On the other hand, dark chocolate is probably one of the healthier dessert foods. There is no reason not to enjoy an occasional bite of chocolate as part of a healthy, calorie-controlled diet.

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 Resveratrol Improve Blood Sugar Control?

Is The Promise of Resveratrol True?

Author: Dr. Stephen Chaney

blood sugar testIt was just a few years ago that resveratrol was the latest “miracle nutrient”. It was featured on Dr. Oz and on 60 Minutes. It was hot! Today you see dueling headlines. The headlines one week proclaim the benefits of resveratrol. Next week’s headlines say that it’s all hype. What’s a person to believe?

Let me take you behind the headlines to look at the actual studies and answer some important questions.

1)    What do we actually know about the benefits of resveratrol?

2)    Is the evidence for beneficial effects of resveratrol where it should be considering the number of clinical studies that have been published?

3)    What additional studies need to be done before we can be sure that resveratrol is beneficial?

4)    Should you wait until we are absolutely certain resveratrol is beneficial, before you start using it? This is perhaps the most important question of all.

To answer those questions, let’s examine the study behind one of the latest headlines, namely: “Resveratrol Improves Blood Sugar Control in Diabetics”. One of the promises of resveratrol has been that it might help diabetics and pre-diabetics who struggle with blood sugar control. However, this promise was based on animal studies. The study that generated the headlines in question was a meta-analysis of recently published human clinical trials in this area (Liu et al, Am. J. Clin. Nut., 2014, doi: 10.3945/ajcn.113.082024).

Does Resveratrol Improve Blood Sugar Control?

The meta-analysis included 11 published placebo controlled double blind clinical studies looking at the effects of resveratrol supplementation on fasting blood sugar levels, insulin levels, hemoglobin A1c (a measure of blood sugar control) and insulin resistance (a measure closely associated with type 2 diabetes).

A strength of this meta-analysis is the fact that it included 11 clinical studies. However, a weakness of this analysis is that these studies utilized a wide variety of resveratrol doses (10 mg/day to 1 gram/day), a wide variety of end points and both diabetic and non-diabetic patients. That means that there were only a few studies with common population groups, resveratrol doses, and end points.

The conclusions of the study (and the headlines you may have seen) were that:

•    Resveratrol appeared to improve blood sugar control (based on improvements in fasting blood sugar levels, insulin levels, hemoglobin A1c and insulin resistance) in diabetics.

•    No consistent effect of resveratrol on blood sugar control was seen in non-diabetics.

How Good Are These Studies?

While these studies are very promising, they are bot definitive.  There were only 3 published clinical studies in diabetics. While all 3 of the studies showed a positive effect of resveratrol supplementation:

•    The doses used were different in each study (ranging from 10 mg/day to 1 gram/day)

•    Each study measured different end points (one measured blood glucose, insulin levels, hemoglobin A1c and insulin resistance, one measured blood glucose and hemoglobin A1c and the third measured insulin resistance).

As a research scientist I would like to see more studies done at comparable doses and measuring the same end points – we scientists always want more studies.

Similarly, there was not enough consistency in the studies with non-diabetics to draw a firm conclusion. (3 were with obese patients, 3 were with patients with cardiovascular disease, 1 was with patients with metabolic syndrome and 1 was with perfectly healthy subjects.)

If you really wanted to see if something like resveratrol helps non-diabetics with blood sugar control, you would want to start with people who are already experiencing some difficulties with blood sugar control (pre-diabetics or patients with metabolic syndrome) and follow them for a couple of years to see if resveratrol reduces the number of them who become diabetic.

Are The Headlines Just Hype?

Newspaper HeadlinesDoes that mean that the blood sugar benefits of resveratrol are just hype? The answer is no. There is a difference between “very promising, but not yet definitive” and “hype”. We shouldn’t be surprised that human studies on the health benefits of resveratrol are not yet definitive. Science moves slowly. It often takes decades of scientific research before promising concepts are widely accepted by the scientific community.

When a research area is as young as this one, we sometimes need to go beyond the clinical studies and look at the totality of evidence. In this case:

•    In mice resveratrol exerts its beneficial effects by turning on a specific anti-aging gene called SIRT1 (Cell Metabolism, 15: 675-690, 2012). In humans, resveratrol appears to activate the same genetic pathways as in mice (Journal of Clinical Endocrinology & Metabolism, 96: 1409-1414, 2011).

•    In obese mice resveratrol improves markers of blood sugar control (Nature, 444: 337-342, 2006). Published clinical studies in diabetic humans also show improvements in blood sugar control (Journal of Clinical Nutrition, 2014, doi: 10.3945/ajcn.113.082024).

So while more and better clinical studies are needed to be absolutely certain that resveratrol helps improve blood sugar control, the evidence supporting that effect is substantial.

What Should You Do?

The ONLY important question for each of you is probably: “Should I wait a decade or two until we are absolutely sure about the health benefits of resveratrol before I take a resveratrol supplement?” That question is ultimately yours to answer. It’s all about benefits and risk.

Benefits – In animal studies resveratrol clearly improves blood sugar control. The human clinical studies published to date are consistent with the animal studies.

Risk – Current data suggest that resveratrol appears to be safe, even at high doses. For example, one recent study indicated that up to 5 gm/day is safe (Cancer Epidemiology BioMarkers & Prevention, volume 16:1246-1262, 2007), but I wouldn’t personally recommend exceeding 100-200 mg/day.

The Bottom Line:

1)     Don’t get too excited about the headlines suggesting that resveratrol might help improve blood sugar control in diabetics. The few human clinical studies that have been published to date are consistent with previous animal studies. That is very promising, but more studies are needed before we can be absolutely confident that resveratrol supplementation is beneficial for diabetics.

2)     Similarly, don’t be discouraged by the headlines suggesting that resveratrol does not help with blood sugar control in non-diabetics. Those results are preliminary as well.

3)     That doesn’t mean that the headlines are just hype. It takes decades to accumulate definitive proof that any kind of food or nutrient offers proven benefits, and the bulk of human clinical research on reveratrol has occurred in the last couple of years. We are exactly where we should expect to be at this point in time.

4)     With something as promising as resveratrol, the real question becomes whether you can afford to wait a decade or two until you know whether the potential benefits have been definitely proven. That question is up to you. On the plus side, current data suggest that resveratrol is highly promising for blood sugar control. In addition, resveratrol appears to be safe, even at high doses, but I wouldn’t personally recommend exceeding 100-200 mg/day.

5)     We already know that weight control, exercise and a healthy diet improve blood sugar control. You should think of resveratrol as something you may wish to add to a healthy lifestyle, not as a substitute for a healthy lifestyle.

6)     If you are diabetic and decide to try a resveratrol supplement, be sure to work with your physician so they can modify your dose of insulin or blood sugar medication as necessary.

7)     Finally, you may be asking whether resveratrol supplements are even necessary. Can’t you just get all the resveratrol you need from a glass or two of red wine? Stay tuned. I’ll have the answer to that question in a couple of weeks.

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 Fish Oil Make Children Smarter?

When Do Omega-3 Supplements Make Sense?

Author: Dr. Stephen Chaney

Confused ChildWe know that the omega-3 fatty acids found in fish oil are critically important for brain development. But will they really help our kids learn better? Some studies suggest that they do, while other studies have come up empty. Why is this? More importantly, what does it mean for your children? Will fish oil supplements help or not?

I’ve selected today’s study (Portillo-Reyes et al, Research in Developmental Disabilities, 35: 861-870, 2014) because it sheds some light on those important questions.

Can Fish Oil Make Children Smarter?

This study looked at the effect of supplementation for 3 months with 360 mg of EPA + DHA on cognitive function of malnourished Mexican children, ages 8-12 years old. The children came from poor neighborhoods where foods rich in omega-3 fatty acids were seldom available. Low intake of omega-3 fatty acids was confirmed by a food frequency survey.

Cognition was assessed based on a battery of 16 standardized cognition tests at the beginning of the study and again 3 months later.

The results were fairly clear cut. The children receiving the fish oil supplements showed significant gains in mental processing speed, visual-motor coordination, perceptual integration, attention span and executive function compared to children receiving a placebo. In case you were wondering, the first three most strongly affect a child’s ability to learn and last two affect their tendency to display ADHD symptoms.

What Is the Significance of This Study?

There are a lot of things not to like about the study:

  • It was a small study (59 children total)
  • Blood levels of omega-3 fatty acids were not determined.
  • It was a short term study (12 months would have been better).
  • Measuring the ability to learn is difficult. Experts in the field differ about which cognitive tests are best. I’m not taking a position on the adequacy of the tests they were using because that is not my area of expertise.
  • Because it was done in a poor region of Mexico, one could argue that its applicability to children in this country is uncertain.

 

So why even mention this study? That’s because it illustrates an important principle – one that is often ignored in the design and interpretation of clinical studies.

Simply put, the principle is that not everyone will benefit equally from supplementation. It is the malnourished and the sick who will benefit most. When you focus your clinical studies on those groups you are most likely to observe a benefit of supplementation. When you focus your study on well nourished, healthy individuals it will be much more difficult to observe any benefit. And if you perform a meta-analysis of all studies, without evaluating the studies on the basis of need – nutrition status and health status – benefits will also be much more difficult to demonstrate.

This study is just one example of that principle. In an earlier “Health Tips From the Professor” (Can DHA Help Johnny Read?) I reported on a study looking at the effect of DHA supplementation on reading ability of English schoolchildren. In that study, it was the children who were most deficient in DHA and started with the lowest reading skills who benefitted most from DHA supplementation.

What does all of this mean to you?

  • If you are a parent, you may be asking if a study done with Mexican children eating poor diets has any relevance for your kids. In today’s world of pop tarts and pizza it just might. Most children don’t order sardines on their pizza. As a consequence, many American children don’t get enough omega-3 fatty acids in their diet.
  • Should your children be getting more omega-3s in their diet? A recent study concluded that most American children only get 20-40 mg/day of DHA from their diet. So if your child’s food preferences don’t include salmon, sardines and the like – and if your child is experiencing learning issues or problems with ADHD, you might consider adding fish oil supplements to their diet. There’s no need to megadose. The international standard is around 200 mg/day of DHA for children 7 or older.
  • If you are one of those people who is confused by conflicting headlines about the benefits of supplementation, you may want to look at the studies behind those headlines and ask if supplementation would have been likely to provide any benefit in the subjects studied.

The Bottom Line:

1)     A recent study reported that supplementation with fish oil significantly improved learning skills in children consuming a diet that was deficient in omega-3 fatty acids.

2)     If your children are not consuming foods rich in omega-3 fatty acids such as coldwater fish, you might wish to make sure that they are getting adequate levels of omega-3 fatty acids in their diet. Most experts recommend around 200 mg/day for children over 7.

3)     This study also illustrates the principle that supplementation is most likely to be of demonstrable benefit to those who have the worst diets and the greatest need. That doesn’t mean that supplementation won’t benefit everyone, but it does mean that it may be difficult to prove the value of supplementation in healthy people consuming a good diet.

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