Cut Heart Risk by Eating Less Salt
Studies Show a Lower-Salt Diet Lowers Risk of Heart Disease and Stroke
April 19, 2007 -- Even modest reductions in salt intake can dramatically
lower heart disease risk, new research shows.
In an extended follow-up of two rigorously designed trials, people who
reduced their dietary sodium while participating in the studies saw 25%
reductions in heart disease and stroke risk 10 to 15 years later, compared with
people who ate their usual diets.
Most people in the intervention arm of the studies -- where participants
reduced the sodium in their diet -- lowered their sodium intake by 25% to 30%,
researcher Nancy Cook, ScD, of Brigham and Women's Hospital and Harvard Medical
School, tells WebMD.
"This was not salt restriction, it was salt reduction," she says.
"These people ate normal diets, but we taught them how to look out for
hidden salt and avoid it."
The findings are the strongest evidence yet linking dietary salt intake to
heart disease, Cook says. It is the first intervention trial to assess
cardiovascular risk long term.
Participants were between the ages of 30 and 54 when recruited for the two
salt-reduction studies, which were conducted between 1987 and 1995. All also
had slightly elevated blood pressures, but none had heart disease at
During the initial trials, roughly half of participants were taught to
identify, select, and prepare low-salt foods and asked to reduce the salt in
their diets. The rest were not asked to lower the salt in their diets. One
study lasted for 18 months and the other study lasted for 36-48 months.
Ten to 15 years after the end of the original trials, participants in the
intervention arms of the two studies were found to have lower cardiovascular
risk and a slightly lower risk of death from all causes than participants who
ate their usual diets.
"Americans consume much more sodium than is necessary, and it comes
mostly from processed foods and the foods we eat in restaurants," Cook
says, adding that initiatives aimed at lowering dietary sodium will have a
bigger impact if they target the food industry and not individuals.
Calling for Change
Last summer, the American Medical Association (AMA) called for a minimum 50%
reduction in sodium in processed foods, fast foods, and non-fast-food
restaurant meals within a decade. The group also called on the FDA to work
harder to educate consumers about the health risks associated with a
Texas cardiologist J. James Rohack, MD, who was on the AMA board that issued
the directives, says 150,000 lives could be saved in the U.S. annually if
everyone cut their sodium consumption in half.
Most people eat much more salt than they realize, he says, because
restaurant meals and processed foods have replaced home cooking in the American
diet. The American Heart Association recommends that healthy adults should not
exceed 2,300 milligrams of sodium a day. This is equal to about 1 teaspoon of
table salt, but sodium is found in many processed and pre-packaged foods.
"The average American is eating three times as much salt as is healthy
every day -- the equivalent of 2 to 3 teaspoons instead of no more than 1,"
he says. "The assumption tends to be, 'If I don't use my salt shaker much,
I'm probably OK,' but that just isn't true."