Today is International Beaver Day, doubtless to the consternation of Oregon Ducks fans. Nonetheless, here's wishing them a happy IBD as well.
And now to the Science:
The U.S. government's dietary guidelines indicate that Americans should consume no more than one teaspoon equivalent of salt per day, but a lot of scientists doubt that it's as bad for you as the government says. The current head of the Heart Association disagrees with them:
“The totality of the evidence strongly suggests that Americans should be lowering their sodium intake,” said Elliott Antman, the president of the American Heart Association. “Everyone agrees that current sodium intake is too high.”
If that's so, Elliott might want to have a word with former AHA president Suzanne Oparil:
“The current [salt] guidelines are based on almost nothing,” said Oparil, a distinguished professor of medicine at the University of Alabama at Birmingham. “Some people really want to hang onto this belief system on salt. But they are ignoring the evidence.”
What we do know is that if your blood pressure is 120/80 and you drop your salt intake to levels recommended by the feds, you might see a reduction down to as low as 117/79. That's insignificant. Moreover, the US recommendation fails to take even the most basic consideration into account: variability. Reduced salt intake might very well be beneficial to the extremely sedentary, but athletes and those who work out - or even ride their bicycles to and from work, as is increasingly encouraged by government greenies - likely need double or more the recommended intake; sweat, after all, sheds a lot of NaCl.
So it looks as though the science is a lot less settled than it supposedly was.
Many times, particularly in the past several decades of government grants and "peer review", valid ideas are dismissed because they contradict the preconceived views of government agencies or because the "expert" "peer reviewers" believe that they know better:
In 1991, for example, the evolutionary biologist Margie Profet argued that allergies fought toxins. Immunologists dismissed the idea, perhaps because Profet was an outsider.
I've had some experience with this phenomenon; in a paper describing the flehmen response in Asian elephants that was submitted to Science, a physical chemist with whom I was working had it rejected because the "expert" reviewer knew that elephants don't exhibit that behavior. In discussing the situation with her, I suggested that she refer to it as a "flehmen-like" response. Not only was the paper subsequently accepted, it was the cover story for that issue. Over the next couple of decades, it became universally accepted that indeed the flehmen response is an important component of chemical communication in elephants.
I've long believed that part of the issue was related to the fact that, as a physical chemist rather than a zoologist, she was also considered an outsider. So in a fairly real sense, ours was a fortuitous collaboration, as I had a background in zoology and she did not. In scientific circles, there are some very large egos involved. In this case, a simple four-letter modification to an accepted zoological/ethological term rendered an unacceptable paper suddenly acceptable - and contributed to our understanding of chemical communication in elephants.
