11 May 2000 Salt: If you read nutrition warnings, you know a little dab'll do ya, and a big dab will put you on the road to high blood pressure, and perhaps a painful, early death.
Hypertension -- excess pressure in your arteries -- makes you a sitting duck for heart disease, brain stroke, even damaged kidneys (half of kidney dialysis patients had high blood pressure, according to hypertensionist Clarence Grim of the Medical College of Wisconsin). You name your ailment, and salt can cause it, or so you'd think after reading books like "Get the Salt Out," which contends that "table salt should be avoided because it is, without a doubt, hazardous to human health."
No question, hypertension kills too many, too young. As the National Heart, Lung and Blood Institute (NHLBI) says: "This is serious business: heart disease is the number one killer in the United States, and stroke is the third most common cause of death."
But after 20 years of hearing the good public-health doctors tell us to cut, cut, cut salt consumption, some scientists are questioning the indictment. After correcting what they deem major problems with major studies, these scientists say the issue is muddier than "salt: less is more." Most people, they argue, have little to worry about. They even contend that the largest multi-national, multi-cultural study on hypertension and salt consumption failed to find the expected association between the two!
Like the asteroid controversy, it's a classic example of scientists drawing opposite conclusion from the same data. These doubting scientists say that far from trying to cut salt consumption -- which most people find difficult anyway -- we should not fret about salt -- unless we have hypertension and are sensitive to salt.
Note that we haven't
even mentioned food or physiology! But as any lover of French fries or
fish and chips knows, salt brings out flavor. Salt plays an even more
critical role in the body, where sodium is the major ion that accepts
electrons. Sodium helps maintain the balance of electrolytes, the level
of fluids, and the electrical conductivity of tissues.
In other words, without sodium, mainly from salt, we'd quickly slide from cramped muscles to dead meat. And our natural cravings tell us as much, according to Australian neuroscientist Derek Denton, who wrote the book "Hunger for Salt." "So universal has been its use that it may be called the cosmopolitan condiment. So great is the craving for it ... that a love of it is one of the most potent of our natural instincts and salt itself is necessary to the health and even the life of man."
'n water, hold the salt
But history, no matter how salty and colorful, can't tell us how much sodium we really need, and how much is harmful. Those questions move us from history to the far more contentious realm of modern science.
Countless millions have been spent on thousands of studies about health and salt (the chapter on salt and blood pressure in Denton's book listed about 350 references -- back in 1982! -- yet no resolution is in sight. Indeed, judging from talks at the 2000 meeting of the American Association for the Advancement of Science, the danger zone has shifted. The crusaders against salt, say some researchers, ignored evidence that people live longer if they eat more salt. Huh?
That evidence has not persuaded the crusaders, who call the mineral a public health menace -- a cause of preventable heart attacks, strokes and kidney disease.
You can bet your bottom dollar The Why Files ain't solving this one for you, but we bet you'll agree that it's a fascinating and illuminating scientific squabble.
Salt: it's poison. Salt: the dangers are overhyped. You pays your money, and you takes your choice!
There are 1 2 3 4 5 6 7 pages in this feature.
Bibliography | Credits | Feedback | Search