The Sleeper Curve Continues Apace

Everything bad is good for you. To recap:

• High-fat diets are good for you.
• High-fat diets help you lose weight.
• Steak and lard and bacon are good eats.
• Low salt diets increase the risk of death.
• Diet soda makes you fat.
• Salt helps your body get rid of bad cholesterol.

Last week we learned that exercise may increase heart risk.

By analyzing data from six rigorous exercise studies involving 1,687 people, the group found that about 10 percent actually got worse on at least one of the measures related to heart disease: blood pressure and levels of insulin, HDL cholesterol or triglycerides. About 7 percent got worse on at least two measures. And the researchers say they do not know why.

“It is bizarre,” said Claude Bouchard, lead author of the paper . . . .

Yes, bizarre. Because we're so smart. And the body is such a simple mechanism.

And yesterday Gary Taubes piled on. He questioned the need for a low salt diet in a New York Times opinion piece, citing "a slew of studies" that say a low salt diet is likely to do more harm than good.

The idea that eating less salt can worsen health outcomes may sound bizarre, but it also has biological plausibility and is celebrating its 40th anniversary this year, too. A 1972 paper in The New England Journal of Medicine reported that the less salt people ate, the higher their levels of a substance secreted by the kidneys, called renin, which set off a physiological cascade of events that seemed to end with an increased risk of heart disease. In this scenario: eat less salt, secrete more renin, get heart disease, die prematurely.

With nearly everyone focused on the supposed benefits of salt restriction, little research was done to look at the potential dangers. But four years ago, Italian researchers began publishing the results from a series of clinical trials, all of which reported that, among patients with heart failure, reducing salt consumption increased the risk of death.

Those trials have been followed by a slew of studies suggesting that reducing sodium to anything like what government policy refers to as a “safe upper limit” is likely to do more harm than good. These covered some 100,000 people in more than 30 countries and showed that salt consumption is remarkably stable among populations over time. In the United States, for instance, it has remained constant for the last 50 years, despite 40 years of the eat-less-salt message. The average salt intake in these populations — what could be called the normal salt intake — was one and a half teaspoons a day, almost 50 percent above what federal agencies consider a safe upper limit for healthy Americans under 50, and more than double what the policy advises for those who aren’t so young or healthy. This consistency, between populations and over time, suggests that how much salt we eat is determined by physiological demands, not diet choices.

. . .

Proponents of the eat-less-salt campaign tend to deal with this contradictory evidence by implying that anyone raising it is a shill for the food industry and doesn’t care about saving lives. An N.I.H. administrator told me back in 1998 that to publicly question the science on salt was to play into the hands of the industry. “As long as there are things in the media that say the salt controversy continues,” he said, “they win.”

Evil corporations. @GabrielMalor pointed out today that Mayor Bloomberg is using the same kind of defensive rhetoric: "Portion sizes of sugary drinks have ballooned not as result of consumer demand but corporate decisions." Whatevs. Silly rhetoric aside, the one thing that is clear is that scientists, politicians, and bureaucrats have underestimated the complexity of the human body, overestimated their own intelligence, and they have been telling people what to do based on flawed science and incomplete information. And unintended bad consequences have followed.

Besides . . .

"It's not salt. It's FREEDOM."
--Mary Katherine Ham

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posted by rdbrewer at 05:06 PM

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