In a first of its kind study, German scientists report that excess salt significantly impairs immune function. The scientists first conducted an experiment in mice, feeding the mice a high salt diet and assessing how the high salt diet impacted neutrophil function. Neutrophils are critical immune cells that target dangerous bacteria. They found that mice that consumed the high salt diet accumulated excessive glucocorticoids in their bodies. Glucocorticoids, like the drug cortisone, suppress immune function at high levels.

The scientists then fed human subjects a high salt diet for a period of one week to see if it affected them in a similar fashion. The level of salt consumed was roughly equivalent to two fast food meals a day. The results? After a week of consuming excessive salt, the study subjects experienced a marked decrease in neutrophil function. According to the lead researcher, “We have been able to prove for the first time that excessive salt intake weakens an important arm of the immune system.”

Over 90 percent of Americans consume excessive salt in their diets. Most of the salt in the US diet (upwards of 75 percent!) comes from processed and restaurant food. Give your immune system a much-deserved lift by going easy on the salt. Click here for my best guidance for reducing your salt intake.

Science Translational Medicine, 2020 DOI: 10.1126/scitranslmed.aay3850