Potassium-Enriched Salt Reduces Risk of Death

You might think that it's normal for people's blood pressure to increase as they age. Unfortunately, that's only true in cultures where the usual diet is high in salt - cultures with a usual diet that's low in sodium don't see this happen. As we mentioned last week, taking potassium can help reduce one's blood pressure when doing so won't raise your potassium intake to dangerous levels. So the fact that potassium chloride is a common salt substitute is probably a good thing, wouldn't you think?

Researchers in Taiwan, where the average daily intake of sodium in elderly men is about 5 grams (5,000 mg) per day, noted this and sought to find out if using a salt substitute high in potassium would measurably affect the risk of death from heart disease (Am J Clin Nutr 2006;83(6):1289-96).

A nearby veteran's retirement home was kind enough to allow the researchers to perform their study there. In this retirement community, each veteran is assigned to receive his meals from one of five kitchens, all serving the same menu each day. Each kitchen serves two "squads" of veterans and each squad includes about 200 men. Two of the kitchens were chosen randomly to switch to a salt substitute which was half sodium chloride and half potassium chloride, while the other three kitchens continued using plain salt (all sodium chloride). Over the course of about 2 1/2 years (on average), the researchers noted the cause of death for all veterans who passed away during that period and were also able to note the cost of health care administered to the veterans.

As you might expect if you've been reading our Health and Nutrition Bites for a while, those men who were assigned to the salt substitute were less likely to die of heart-disease-related illnesses than those in the regular salt groups. Interestingly, this effect was most strongly seen after the veterans had been on the low-salt, high-potassium diet for 3 months.

That reduced-sodium diet also resulted in lower expenditures on heart-disease-related health care: inpatient (hospital) treatment for those on the low sodium diet cost about 40% less than it did for those on the regular salt diet.

What this means for you

It's important to note that those veterans who participated in the study were not getting enough potassium in their diets before the study began, and the researchers were unable to determine with certainty whether their lower risk of death from heart disease was due to the potassium supplementation or the decrease in sodium. The veterans' diets were still high in sodium even when they were in the low-sodium group: their average daily intake was about 3.8 grams (3,800 milligrams), which is still high even if lower than their typical 5.2 grams.

Your take-home message here is that switching to a salt substitute, even if that does not reduce your actual sodium intake under the recommended 2,400 milligrams per day, may still help you reduce your risk of death from heart disease.

First posted: August 8, 2012