Study: No Link Between Salt Intake, Heart Disease, Especially for Healthy Older Adults

A recent study finds no link between salt consumption and mortality or development of cardiovascular disease (CVD) or heart failure (HF) in healthy older adults. The study, by researchers at Emory University, is published online in JAMA Internal Medicine. The researchers looked at the association between dietary sodium intake and mortality, CVD and HF in a group of 2,642 healthy adults who ranged in age from 71 to 80. The authors analyzed 10-year follow-up data on the adults, who were participating in this community-based study, where dietary sodium intake was assessed at baseline with a food frequency questionnaire.

Study details

The researchers examined sodium intake at three levels: less than 1,500 milligrams of salt a day; 1,500 to 2,300 milligrams a day; and more than 2,300 milligrams a day. At the 10-year mark, 881 of the participants had died. Cardiovascular disease developed in 572 participants, and 398 developed heart failure. Categorized by level of sodium intake, mortality rates were lowest in the middle group at 31 percent, compared with 34 percent in the low-sodium group, and 35 percent in the high-sodium group, but the differences were not significant.

Emerging evidence

A number of recent studies are challenging the long-accepted thresholds of sodium intake. “There’s emerging evidence that salt is not as evil as many people have suggested,” says cardiologist Steven Nissen, MD. Dr. Nissen is Chairman of the Robert and Suzanne Tomsich Department of Cardiovascular Medicine at Cleveland Clinic. He did not participate in the study. While the study is not definitive, “several recent studies seem to show that in otherwise healthy patients, fanatical measures are not necessary to control their salt intake. What they are suggesting here falls in line with other studies,” Dr. Nissen says. Patients with other medical conditions will still need to modify their salt intake, he says. “There are obviously other people who cannot take salt, namely those with hypertension or who are pre-hypertensive, but not on medications. They should not be included in this group,” Dr. Nissen says. Dr. Nissen cited the food frequency questionnaire as a significant limitation of the study, noting that self-reported dietary intake has a high potential for inaccuracy.

More research needed

The Emory University researchers say more studies are needed, with stronger evidence, before changing the current daily sodium recommendations. Dietary Guidelines for Americans recommends everyone older than age 2 consume less than 2,300 milligrams of salt each day. The guidelines also limit salt intake to 1,500 milligrams daily for adults older than age 51, African-Americans and those with high blood pressure, diabetes or chronic kidney disease. Dr. Nissen says he will continue to recommend hypertensive or pre-hypertensive patients follow the DASH diet, which is low in salt and total fat from animal products and high in fruits, vegetables and low-fat dairy foods. “Research supports that the DASH diet lowers blood pressure, so that’s clearly an intervention worth considering for these patients,” Dr. Nissen says.