UNDERSTANDING THE IMPORTANCE OF SALT IN YOUR DIET – Part I

Everybody is confused about salt, and with good reason. Not even the major health organizations in our country agree with one another on the proper amount of dietary salt. While their recommendations have continued to decline overall, the CDC (Centers for Disease Control) 2020-2025 guidelines recommend the average intake of sodium to be about 2,300 mg per day, which was revised down from a previous recommendation of 3,300 mg.

The USDA also says to consume less than 2,300 mg per day, while the American Heart Association recommends even more strict guidelines of less than 1,500 mg a day for general health and disease prevention. So, the Centers for Disease Control at one time recommended that you have twice as much as the American Heart Association.

The absolute minimum requirement for your body to function and sustain life is about 500 mg per day. This is due to the fact that sodium is a vital nutrient. Your cells maintain a sodium-potassium pump, which is very important for life. Sodium is also a major part of the fluid outside your cells, called extracellular fluid. It is necessary to help maintain the right volume of plasma for normal cell metabolism. And, because sodium is found in the blood and lymph fluids, it is especially important for cardiovascular health.

Salt also plays a very important role with chloride for nerve transmission within the nervous system, which aids in our movement and other necessary functions.

In 2011 the Journal of the American Medical Association did a study demonstrating a low-salt zone where stroke, heart attack and death are more likely. In their study, they followed 3,681 subjects for 23 years and found that those on a low-salt diet were more than 50% more likely to die from cardiovascular causes than those who consumed substantially more salt.

The researchers concluded that their findings “refute the estimates of computer models of lives saved and health care costs reduced with lower salt intake, and they do not support the current recommendations of a generalized and indiscriminate reduction in salt intake at the population level.” 

So, where did the government recommendations come from, and why are they still recommending salt restriction? Healthcare experts have been recommending salt restriction since the 70’s, when research conducted by Lewis Dahl reflected established proof that salt causes hypertension. 

In his research, he induced high blood pressure in rats by feeding them the human equivalent of over 500 grams (not milligrams) of sodium a day, which is 50 times more than the average intake in the western world. He also said cultures with higher salt intake tended to have higher blood pressure than those who consumed less.

However, major research from Intersalt, a study that showed no association between dietary salt and blood pressure, disagreed. Their study involved over 10,000 men and women aged 20-59 from 52 populations around the world.     

Intersalt’s results were disputed and re-analyzed, and they were found to stand. The results have been confirmed in other studies, as well. When Intersalt looked into other confounding factors (something Dahl didn’t do), the correlation between blood pressure and salt almost disappeared. But, for some reason, Dahl’s contradictory evidence is still used today to justify restricting salt intake.

Next week we will look at the type of salt to eat, and the benefits and uses of salt.