Reduced Salt: Bad for Your Health?

Hold onto your pickles. The great American nanny state is at it again. This time the government wants to make sure you don’t eat too much salt.

Most people would readily agree there is too much salt in processed foods. That an increase in salt corresponds to an increase in blood pressure. And that Americans, as well as citizens of most other western nations, consume more salt than their government recommends.

Millions of dollars have been pumped into numerous studies in an attempt to prove the negative impact of this orgy of excess salt on human health. The assumption is that because there appears to be a relationship between salt and high blood pressure, that there is a corresponding relationship between cardiovascular disease and mortality.

Based on this assumption, the FDA sponsored a report by the Institute of Medicine (IOM) titled “Strategies to Reduce Sodium Intake in the United States,” released on April 20th. While the FDA insists it’s seeking only voluntary cutbacks by the food industry at this time, FDA spokeswoman Meghan Scott also declared, “Nothing is off the table.” She continued, “Everyone’s in agreement that something needs to be done… We just don’t know what it’s going to look like.”

That might be a little less than honest. You’ll find this little gem buried on page 253 of the IOM’s report: “While efforts to reduce the sodium content of the food supply can result in considerable progress toward reducing sodium intake, supporting strategies are needed to ensure that consumers achieve current recommendations.”

In other words, the American public must “voluntarily” comply with the FDA’s target salt consumption or they’ll force you. The report then goes on to outline recommendations for the FDA to actively regulate salt usage and to set mandatory national standards for sodium content in foods.

Again, where the rubber meets the road here is on the assumption that salt intake is responsible for increased disease and mortality. The preface of the report itself states that “High sodium intake puts the whole population…at risk for hypertension and subsequent cardiovascular events such as heart failure and stroke.”

Is that right? Do the facts really support that contention, or is it merely a case of repeating something often enough until you finally believe it? One study from the University of Helsinki in Finland frequently pointed to by advocates of mandatory salt reduction is a good case in point.

The authors of the study noted a one-third decrease in average salt intake over three decades among the Finnish population due to an aggressive salt reduction program, similar to the one now advocated for the United States . At the same time a significant drop in blood pressure and a nearly 80% decrease in stroke and coronary heart disease mortality was accomplished.

The authors then compared the Finnish drop in salt usage with the United States increase in salt consumption of roughly 55% between the mid-80s and late-90s due to a lack of an aggressive salt reduction campaign.

There you go. Decreased salt consumption, lower death rates. Increased salt consumption, higher death rates? Not so fast.

What the study authors failed to note is that even while U.S. citizens consumed more salt, their ischaemic heart disease mortality rate per capita declined faster than Finland’s. Same with Italy, Sweden, Denmark, the United Kingdom, and even Canada which reduced its mortality rate by double the rate of Finland’s — all with no claimed drop in dietary salt intake.

Almost looks to me like eating less salt increases your mortality rate compared to those who continue eating more salt. I’m not the only one who notices something amiss.

Dr. Michael Alderman, an epidemiologist and professor at the Albert Einstein College of Medicine in New York, believes that while salt reduction may reduce average blood pressure by mid-low single digits, he worries it could also lead to “unintended consequences.” Side effects of sodium restriction include increased insulin resistance, activation of the renin-angiotensin system (which itself can increase blood pressure), and increased sympathetic nerve activity (which induces the body’s stress response mechanism).

What really takes the cake is his careful review of the large-scale Third National Health and Nutrition Examination Survey which actually found lower sodium was associated with higher mortality. He cautions that these were modest rates of higher mortality, but at the same time, it certainly indicates “higher sodium is unlikely to be independently associated with higher cardiovascular disease or all-cause mortality.”

Dr. Alderman’s findings are good enough for me. The salt shaker remains on the table. Perhaps the FDA should review a few more studies before taking the IOM’s drastic recommendations to heart as well.

Related references:

Karppanen, H, Mervaala E. Sodium intake and hypertension. Progress in cardiovascular diseases. 2006 Sep-Oct;49(2):59-75.
Satin, M. Health Outcomes Lessons From Finland’s Salt Reduction. Salt & Health. Summer 2007. Vol. 2 No. 3.
Alderman MH. Evidence relating dietary sodium to cardiovascular disease. Journal of the American College of Nutrition.. 2006 Jun;25(3 Suppl):256S-261S.
Cohen HW, Hailpern SM, Alderman MH. Sodium intake and mortality follow-up in the Third National Health and Nutrition Examination Survey (NHANES III). Journal of general internal medicine. 2008 Sep;23(9):1297-302.