Confirming two earlier studies of the U.S. population in the federal government's Nutrition and Health Examination Survey (NHANES) parts I and II, a study by Drs. Hillel W. Cohen, Susan N. Hailpern and Michael H. Alderman in the new issue of the Journal of General Internal Medicine examined the relationship of dietary sodium and mortality in NHANES III. The NHANES sample represented 99 million non-institutionalized U.S. adults aged 30 and over. Dividing the population into quartiles the researchers found an inverse relationship between sodium consumption and mortality. The lowest quartile (averaging 1,501 mg/day sodium - coincidentally, the sodium target for sodium restriction advocates - had an 87% greater cardiovascular mortality than the highest sodium quartile (which averaged a hefty 5,497 mg/day). In the NHANES I analysis, the low-salt group was 20% more likely to die. In the NHANES II group, the low-salt group was 37% more likely to die. So the trend with the recent studies has been accelerating in the opposite direction than that predicted by authors of the government's dietary guidelines.
The data seem to be giving the public health nutrition establishment a slap in the face trying to wake it up. The lowest quartile was a good surrogate for the politically-correct social elite. They were, by far, the best-educated, smoked less, consumed the least salt, added the least salt at the table and had the lowest body mass, but still had non- significantly higher systolic blood pressure and, of course, they suffered vastly higher mortality outcomes."
The authors conclude that "These data are consistent with the hypothesis that lower sodium intake is associated with increased CVD and all-cause mortality." Although many associations lacked statistical significance, they "were remarkably consistent." They added: "In contrast, no analysis of the two mortality outcomes generated (Note: CVD and all-cause)any trend supporting the competing hypothesis that the highest sodium relative to the lowest sodium is associated with increased mortality."
Bottom line: "There are no randomized trial data linking sodium intake to CVD events or mortality." In fact, the findings, they declare, affirm "that for the broad general US population, higher sodium is unlikely to be independently associated with higher all-cause or CVD mortality."
