Bacon Cheeseburgers and Other Health Foods
Posted on January 26, 2011
The past decade has seen a remarkable sea change in the medical and scientific consensus about the alleged dangers of fat in our diet. In part, this is from a re-evaluation of old research, such as that done in the '60s in Africa. Vanderbilt University scientist George Mann, MD, found that Masai tribesman in Kenya and Tanzania who lived primarily on red meat and whole milk were also very lean, had extremely low cholesterol levels, and were virtually free of heart disease.
In addition, a newly critical light has been shed on some research that seemed to support the hypothesis that eating lots of saturated fat raises your risk for cancer and heart disease. In 1953, physiologist Ancel Keys published an influential paper titled "Atherosclerosis, a Problem in Newer Public Health." He compared fat intake and the rate of heart disease in 6 countries: the United States, Canada, Australia, England, Italy and Japan. He found a correlation: nations with high levels of fat intake also had high levels of heart disease.
Turns out, however, that Keys pulled a fast one. First of all, he "cherry-picked" his data. Statistics about fat intake and heart disease were actually available for 22 countries. If you analyze all 22, the apparent link between fat consumption and heart disease disappeared. For example, the death rate from heart disease in Finland was 24 times that of Mexico, even though fat-consumption rates in the two nations were similar.
The other problem with Keys' study is one that frequently bedevils researchers: correlation is not causation. In other words, maybe fat had little to do with the high rates of heart disease in the US, which had the highest level of fat intake of all. Maybe it was the fact that US citizens didn't exercise very much, or smoked a lot, or ate a lot of something else that was bad for the heart.
That "something else" is now generally agreed to be refined carbohydrates such as white sugar, white flour and high-fructose corn syrup. This has led to a number of smart approach low carb diets such as that espoused by the late Robert Atkins, MD. Recent research suggests that if you want to lose weight, you're better off on a low-carb diet than a low-fat diet. When people on low-carb diets have been compared head-to-head with those on low-fat diets, the low-carb dieters typically scored significantly better on markers of heart disease, including both LDL and HDL cholesterol and triglycerides.
The key idea in all of this is that your body makes fat from carbohydrates. It works like this: when you eat carbs (particularly starches and sugar), your blood sugar level rises. This triggers the release of insulin, which, in turn, signals the liver to start converting excess blood sugar to triglycerides, or fat.
So what's the bottom line? If you're trying to lose weight, then I think a low-carb approach makes sense, combined, of course, with exercise. If you're already at a good weight and are otherwise healthy, then stay away from processed foods and unnecessary carbs, but relax and eat what you want with moderation. I like the advice of writer Michael Pollen: "Eat food. Not too much. Mostly vegetables." His point is to eat normal food, the kind your grandmother was likely to cook - not stuff that's full of added sugars and other ingredients.
I also think Julia Child had the right idea. She suggested that we all have an imaginary shelf labeled "Indulgences" which contained things like "the best butter, jumbo-sized eggs, heavy cream, marbled steaks, sausages, and gooey chocolate cakes." These are not "everyday" foods, she once wrote, but for special occasions, and "when that occasion comes, we can enjoy every mouthful." Amen. And bon appétit!