The Era Of The Lowfat Diet Is Coming To A Close

This very important article announcing the end of the low-fat era just appeared in the Daily Mail newspaper. Here are some choice quotes from the article:

"It is time to bust the myth of the role of saturated fat in heart disease and wind back the harms of dietary advice that has contributed to obesity." — Dr. Aseem Malhotra, interventional cardiology specialist registrar at Croydon University Hospital, London

Babies Need To Eat Fat, Says International Journal of Obesity

I came across this article the other day from the International Journal of Obesity, "reprinted" on the Nature.com website.

The editor concludes that babies who do not eat enough fat before age two tend to be fat as adults. The editor also suggests doing additional research to determine if a low fat diet might be problematic for folks over age two.

I think this is an excellent line of inquiry, and one that has too seldom been pursued in recent years.

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!)

Critique Of The China Study; The Nature Of Scientific Innovation

The China Study, sponsored by Cornell and Oxford Universities and conducted by T. Colin Campbell, PhD, concludes that consuming animal products causes chronic disease, and advocates a plant-based diet. It is often cited by people who favor plant-based diets.

Establishing causal relationships between diet and disease via statistics-based population studies can be difficult. Correlations in data are often mistaken for causation, especially when someone is trying to prove a point. Beyond that, there are always many variables to consider, and it's nearly impossible to control for them all.

Still, scientists and epidemiologists are experts at this sort of thing: it's what they're trained to do. Right?

I just read this excellent critique of The China Study, on Denise Minger's blog. Take a look and see what you think. I find no fault with it.

It is fascinating to me that an amateur (albeit a very smart one) can find fundamental problems with research sponsored and carried out by professionals with years of training and huge budgets.

Is T. Colin Campbell a careless scientist? Unlikely.

Do Cornell, Oxford, and T. Colin Campbell have an agenda that they are advancing, besides improving public health? Campbell may be motivated by financial considerations, but what about the others who reviewed his work?

Is it that the "plant-based diet" has become the flavor-of-the-day, and that scientists who want funding must cleave to this dogma?

The physicist Max Planck once said, "An important scientific innovation rarely makes its way by gradually winning over and converting its opponents. What does happen is that its opponents gradually die out, and that the growing generation is familiarized with the ideas from the beginning."

What Planck does not mention is that the validity or utility of a new scientific paradigm is not the only deciding factor in its acceptance. A powerful, multi-decade marketing campaign can affect the thinking of an entire generation of up-and-coming scientists and lay-people.

In physics, we have string theory, which is not verifiable and predicts nothing measurable, yet has dominated theoretical physics for decades. Many young physicists are "string theorists", having spent their professional lives working in string theory. They are invested, literally, in its continued popularity.

In nutrition theory, we have low-fat, which was promoted masterfully by Ancel Keys from the 1950s through the 1970s. Health in the US has gone sharply downhill in the forty years since low-fat hit the mainstream. Of course this is merely correlation, not necessarily causality, and of course there are many other variables involved. But modern nutritionists and dietitians are invested in the low-fat paradigm, and are reluctant to consider that it might be wrong.

Could it be that low-fat is grounded in marketing rather than good science?