Don't Believe What Dietitians Tell You About Diet

In just the past year, I've seen a lot of articles in mainstream publications refuting long-cherished dietary doctrine, and supporting many of the ideas put forward by "alternative" health systems. Here are a few.

First, according to Scientific American: "It's Time to End the War on Salt. The zealous drive by politicians to limit our salt intake has little basis in science." They cite articles in the American Journal of Hypertension and the Journal of the American Medical Association pointing to this, and go on to say that "the evidence linking salt to heart disease has always been tenuous".

Next, the LA Times comes around to the idea that carbs are the problem, not fat: "A reversal on carbs. Fat was once the devil. Now more nutritionists are pointing accusingly at sugar and refined grains… 'The country's big low-fat message backfired,' says Dr. Frank Hu, professor of nutrition and epidemiology at the Harvard School of Public Health… Some…would argue that we haven't evolved to adapt to a diet of refined foods and mass agriculture—and that maybe we shouldn't try."

The New York Times brings us an article arguing that counting calorie intake is not an effective way to lose weight. It matters more what we eat than how much we eat. "'There are good foods and bad foods, and the advice should be to eat the good foods more and the bad foods less,' (a cited doctor) said. 'The notion that it’s O.K. to eat everything in moderation is just an excuse to eat whatever you want.'". The "worst" food, by their measure, was french fries; the "best" was yogurt, with nuts close behind. (I guess I can keep eating yogurt with nuts for breakfast!)

Finally, a study showing that bacterial imbalance in the large intestine may affect the brain. "For the first time, researchers at McMaster University have conclusive evidence that bacteria residing in the gut influence brain chemistry and behaviour." (Citation.) Of course, Natasha Campbell-McBride has been saying this for years. (For much more on this subject, check out this post on Food Renegade's blog.)

Here are my (perhaps rhetorical) questions:

1. In the case of salt, how and why was the salt-hypertension connection elevated from a tenuously-supported hypothesis to a "fact"? And in the case of fat and carbs, what led to the promotion of the low-fat, high-carb diet? What went wrong with our scientific process?

2. How long will it take for the above-cited research to affect, say, the low-fat, high-carb food that patients are given in hospitals? The french fries and bread that kids are given in schools? How long will it be before educators, dietitians, and regulators catch up to the true best practices in the field of nutrition?

I am not asking these questions to be negative or show how clever and cynical I can be—I am asking them to open the door to questioning dietary authorities like the USDA and the various medical guilds. "Alternative" nutrition movements, while by no means perfect, are sometimes way ahead of the mainstream on important issues.

(This post is part of Health Home Economist's Monday Mania blog carnival. Please visit her great blog!)