Go Ahead and Shake It: For Most of Us, Salt Is Good

Josh Mitteldorf, for the Shuttle

After decades of doctors’ advice, low-sodium foods, health labels and warnings, it has come out that it was all a mistake: Salty foods never did cause heart attacks.

This isn’t the first time the health researchers have done an about-face. Years ago, extra dietary iron was recommended by everyone from Jack Barry (remember Geritol?) to Popeye. Saturated fats were supposed to be the cause of clogged arteries, and margarine was healthier than butter. Hormone replacement therapy was supposed to lower the risk of post-menopausal heart disease. All these claims were reversed after brave scientists persisted in questioning the conventional wisdom until the evidence was re-evaluated.

It has been known for 100 years that high blood pressure is a risk factor for heart attacks. Eating salt raises your blood pressure. So it was obvious: Avoiding salt lowers your blood pressure, so it must lower your heart-attack risk. But this logic never was sound. 

The missing link in the logic is plaques in the artery walls. People who develop plaques, a buildup of fatty deposits inside their arteries, have high blood pressure because the plaques narrow the arteries. Meanwhile, inflamed plaques can crumble, and with really bad luck, a broken piece can lodge in a major artery, causing a heart attack or stroke. So it is the plaques that cause high blood pressure, and plaques that cause heart attacks.

But what if your high blood pressure is caused not by plaques but by a diet of pickles and salted nuts? Your blood pressure goes up because of osmotic pressure, otherwise known as swelling. This is a purely temporary effect, as your body excretes excess salt within a day. Your blood pressure goes up and down daily with the amount of salt you consume. If you habitually eat a lot of salt, then your blood pressure will habitually be elevated — but not your risk of heart attack! For most Americans, eating salt more liberally may even lower heart-attack risk, according to recent research.

The Centers for Disease Control is the federal agency that keeps such statistics. Several years back, the CDC commissioned a review of the data and issued a report saying that the average amount of salt consumed by Americans posed no risk. The dam was breached, and soon more studies started pouring over the top: People on low-salt regimens actually had higher rates of heart disease than people in the same condition, same age, who didn’t restrict their salt. 

Last year, a “meta-analysis” of data from 25 studies over the last 40 years by scientists from Copenhagen and the Einstein Medical Center in New York concluded that, compared to the American average, people who ate less salt were more likely to have heart attacks, and people who ate more salt were not at increased risk. Only at unusually high intake levels did salt start to show up as a risk factor.

So salt your food to taste. If you’re feeling a need for salty food, you can trust your body’s message. No need to hold back on the sauerkraut, kim chee or miso soup. 

If you need something to worry about, worry about sugar.

Josh Mitteldorf, a Weavers member for 35 years, maintains a page of health recommendations at AgingAdvice.org.