For hundreds of years, doctors have been telling their patients to reduce their salt intake, believing it caused high blood pressure that could lead to heart disease.
Turns out they were wrong.
Not only does too much sodium not cause hypertension, scientists now say, but too little salt can induce a host of puzzling health problems, from insulin resistance to dehydration.
“There is no longer any valid basis for the current salt guidelines,” said Andrew Mente, a professor at McMaster University in Ontario, Canada, and co-author of a major study published last year by the New England Journal of Medicine.
Medical professionals, including the American Heart Association, recommend a daily maximum intake of 2.4 grams of sodium, or slightly less than one teaspoonful. However, Dr. James DiNicolantonio, a cardiac research scientist at Saint Luke’s Mid-America Heart Institute, pointed out in a May Daily Mail op-ed that other cultures around the world eat what Americans would consider shockingly high-salt diets, yet have some of the lowest hypertension and heart disease rates in the world.
The average Korean, for example, eats more than 4 grams of sodium a day — nearly twice what American doctors recommend. However, South Korea has one of the lowest heart-disease death rates on earth.
The dangers of eating too little salt, however, are well documented. Sodium is an essential element of nearly every liquid in the human body — blood plasma, tears, lymphatic fluid and even amniotic fluid — and is necessary for transmitting nerve influences and supporting healthy brain cells. Without sufficient amounts of salt, the brain is thought to produce dangerous hormones leading to everything from reduced sex drive and insulin resistance to dehydration and weight gain.
Kat Merck is a freelance writer and editor based in Portland, Oregon. An amateur naturalist who studied forestry and natural resources at Cal Poly State University in San Luis Obispo, she writes on a wide range of topics for local and national publications.