AARP Hearing Center
- WHEREAS high blood pressure is an epidemic in this country, long linked to sodium intake.
- WHEREAS the average American adult consumes about 3,400 milligrams of sodium a day through a diet rich with salt.
- WHEREAS the federal government recommends that, to keep blood pressure in check, people 51 and older should consume less than 1,500 mg per day.
The State of Your Health (hereafter “you”) proposes to decrease daily salt intake by more than half. However, this adjustment is extremely difficult and requires highly vigilant dietary behaviors. And an increasing number of scientists are willing to testify that these targets are not supported by science.
The purpose of this hearing, then, is to determine whether such a move is supported by the weight of the evidence. Should you drastically cut down on salt?
Opening arguments
You have been told to cut back on sodium for decades. “The food supply is loaded with salt, which we know raises blood pressure,” says Lawrence Appel, M.D., a professor of medicine at Johns Hopkins University and spokesman for the American Heart Association. “The best advice for almost everyone is to cut back.”
That advice is even more pointed for older people. With age, the body’s ability to process sodium declines. Around menopause, women tend to begin to develop salt-sensitive high blood pressure. Men also become less efficient at metabolizing sodium, usually in their 60s and beyond.
But in recent years that long-accepted advice has come under fire. “The current recommendations are too extreme,” insists Suzanne Oparil, M.D., a hypertension expert at the University of Alabama at Birmingham School of Medicine. “There is zero evidence that cutting salt to very low levels like 1,500 milligrams is beneficial.”
Three studies have shown little or no indication that people are eating an unhealthy amount of sodium. One of those, a 2014 Danish study, set optimum sodium levels at between 2,645 and 4,945 milligrams.
The evidence
Why is one set of medical experts so certain about declaring salt guilty while another set is passionately defending it? One reason is that salt affects people differently. “It’s not how much salt you consume, but whether your body can process the sodium it contains,” says L. Gabriel Navar, chair of the Department of Physiology and director of the Center for Biomedical Research Excellence in Hypertension and Renal Biology at Tulane University Medical Center in New Orleans. “Operating efficiently, the kidneys can get rid of a huge amount of sodium — 5,000 milligrams or more.”
But not everyone can handle a lot of salt. About half of the population is salt sensitive: When they consume salt, their blood pressure climbs, usually about 10 points. Unfortunately, scientists have yet to develop an easy-to-administer test for salt sensitivity.