Another ‘Heart-Healthy’ Diet Study Fails

Last week the disappointing outcome of a major study made the news.  Here are some quotes from an article in the Washington Post titled Moderate weight loss alone doesn’t lower heart disease risk in diabetics, study shows:

Losing a small amount of weight doesn’t appear to lower the risk of heart attacks and strokes in people with diabetes who are already getting good medical care, according to a long and expensive clinical experiment whose results were announced Friday.

While modest weight loss has benefits in how overweight diabetics feel, sleep and move, whatever benefit it may confer in preventing cardiovascular disease — which is what most diabetics die from — is too small to measure, the study found.

“We were hoping that a weight-loss program would help reduce cardiovascular disease, but now we have the answer that it doesn’t,” said Mary E. Evans, a physician at the National Institute of Health’s National Institute of Diabetes and Digestive and Kidney Diseases, which paid for the study.

The researchers recruited 5,145 people with Type 2 diabetes, which is the form that generally comes on in adulthood and is strongly associated with being overweight. Type 1 diabetes, an auto-immune disease, is the opposite. It comes on in childhood, and its sufferers are usually thin.

Half of the people were randomly assigned to get intensive dietary counseling on how to limit their calories. They were provided meal substitutes such as Slimfast drink. They were also urged to exercise more and instructed how to do so safely. They met weekly in support groups and once a month with a counselor, although that amount of attention was eventually reduced to a monthly visit and a monthly phone call.

In the first year, the people with the intensive counseling lost 8 percent of their weight. They gained some back, but over the decade of the study maintained an average 5 percent reduction from their starting weight — about 10 pounds. The people in the less-intensive “arm” of the study lost, on average, about 1 percent of their body weight.

By the end of 11 years, there was no difference between the two groups in the rate of heart attack or stroke.

When I read this story, I of course immediately wondered what kind of intensive dietary advice these people were given.  I followed some links and eventually found a copy of the study protocol online.  Here’s the section on diet:

Restriction of caloric intake is the primary method of achieving weight loss. In order to aim for a weight loss of 10% of initial weight, the calorie goals are 1200-1500 kcal/day for individuals weighing 250 lbs (114 kg) or less at baseline and 1500-1800 kcal/day for individuals who weigh more than 250 lbs. These goals can be reduced to 1000-1200 kcal/day and 1200-1500 kcal/day, respectively, if participants do not lose weight satisfactorily. These calorie levels should promote a weight loss of approximately one to two lbs/week.

The composition of the diet is structured to enhance glycemic control and to minimize cardiovascular risk factors. The recommended diet is based on guidelines of the ADA and National Cholesterol Education program and includes a maximum of 30% of total calories from total fat, a maximum of 10% of total calories from saturated fat, and a minimum of 15% of total calories from protein.

BINGO!  It wasn’t losing weight that failed to prevent cardiovascular disease, it was losing weight on the ADA’s crappy low-fat, calorie-restricted diet.  If participants were indeed consuming 30% fat and 15% protein, that leaves 55% of their calories from carbohydrates – just what a diabetic needs, eh?  Hope Warshaw would approve.

Diabetics are three to four times more likely to die of heart disease than non-diabetics.  Thanks to the arterycloggingsaturatedfat theory, this sad fact causes so-called experts like the medical wizards at the ADA to recommend exactly the wrong diet.  The logic goes like this:  Well, since we know a fatty diet causes heart disease and diabetics are prone to heart disease, they need to eat a low-fat diet.

They can’t seem to bring themselves to consider an obvious alternate theory:  What if diabetics are prone to heart disease because high blood sugar causes heart disease?  What if heart disease begins with damage to a coronary artery and high levels of blood glucose can cause that damage?

If you look at it that way, then it’s clear that diabetics absolutely, positively should not be eating the kind of high-carb, low-fat diet the ADA recommends.  They should be eating a diet that keeps their blood sugar down – every day, every hour.  Since fat is the only macronutrient that doesn’t raise blood sugar, that would be a moderate protein, high-fat diet.

I found this section of the NIH press release about the study interesting:

“Look AHEAD found that people who are obese and have type 2 diabetes can lose weight and maintain their weight loss with a lifestyle intervention,” said Dr. Rena Wing, chair of the Look AHEAD study and professor of psychiatry and human behavior at Brown University. “Although the study found weight loss had many positive health benefits for people with type 2 diabetes, the weight loss did not reduce the number of cardiovascular events.”

Why was a psychiatrist chairing the study?  Probably because the NIH believes overeating is a psychological problem.  People are gluttons, being gluttons makes them fat, and being fat turns them into diabetics.  Then they get heart disease because they’re diabetics.  Cure their gluttony with intensive dietary counseling, and they’ll lose weight and suffer fewer cardiovascular problems as a result.

Except it didn’t work out that way, did it? After 11 years and $220 million spent, this large study failed to show that the diet promoted by the ADA, the USDA and countless doctors prevents heart disease in a population prone to heart disease.  With that in mind, perhaps the psychiatrist can come up with an explanation for this quote in the Washington Post article:

The results will probably surprise many physicians and patients but are not likely to change the advice they give and get.

Well, of course not.  You wouldn’t want failure to inspire a change in your beliefs, much less in your strategy.