Nov. 15, 2010 (Chicago) -- Cutting salt intake among U.S. teens by just half a teaspoon a day would prevent up to 120,000 deaths, 64,000 heart attacks, and 28,000 strokes by the time the adolescents reach age 50.
So say researchers who used computer models and clinical data to predict the health effects of a 3-gram -- or half a teaspoon -- daily reduction in salt intake by U.S. teens.
Adolescents get more salt each day -- an average of more than 1 1/2 teaspoons, or more than 9 grams -- than any other age group, says Kirsten Bibbins-Domingo, MD, PhD, associate professor of medicine and epidemiology at the University of California, San Francisco.
The American Heart Association (AHA) recommends no more than 1,500 milligrams of sodium daily, which would be the equivalent of eating between 1/2 and 3/4 teaspoon of salt. One teaspoon of salt equals 2,300 milligrams of sodium.
About 80% of the salt we eat comes from processed or prepared foods, with about one-third of that from cereals, breads, and pastries, Bibbins-Domingo says.
The biggest culprit among teens: Pizza. "You have the salty bread, the salty sauce, the salty cheese -- all before you add the pepperoni," she tells WebMD.
Other fast foods, like chicken products and burgers and snacks like french fries, are also near the top of the list, Bibbins-Domingo says. And condiments like ketchup are packed with salt, she says.
Cutting Salt Prevents High Blood Pressure
Using the computer model, the researchers project that a 3-gram reduction in salt intake by teens translates to a 44% to 63% decrease in the number of hypertensive teenagers and young adults. Put another way, that means 380,000 to 550,000 fewer teens with high blood pressure.
By the time the teens reach age 50, cutting back on salt today will translate to up to 3.9 million fewer adults with high blood pressure, the model shows.
AHA spokesman Robert Eckel, MD, of the University of Colorado in Denver, says that although computer modeling is "desk math ... the data speak fairly convincingly about the impact of salt reduction on improving health outcomes."
The findings were presented here at AHA's annual meeting.
Researchers Call for Salt Reduction in Processed Foods
Even though only about 5% of our daily salt intake is sprinkled during cooking, Bibbins-Domingo says parents can do their part by preparing fresh foods -- with little to no salt added - whenever possible.
But no real progress will be made until food manufacturers stop putting so much salt into processed foods, Bibbins-Domingo says.
She said she would like to see a program modeled after the British efforts.
"In 2003, the federal agency in the U.K. started working with food companies to lower the salt content in 75 products. The idea was to do it gradually," and it resulted in a 10% reduction in salt intake in the United Kingdom over four years, she says.
Physiological studies suggest that if you cut back on salt gradually, you begin to prefer less salt in your food, she says. "Things that used to taste normal start to taste salty," Bibbins-Domingo says.
In the U.S., the New York City Department of Health is leading the effort to regulate salt in prepared foods, and a number of major companies like Kraft and Starbucks have signed on, she says.
Bibbins-Domingo says she doesn't think salt-reduction efforts will work in the U.S. "unless there is some regulation."
Mandatory efforts are opposed by the Salt Institute, a trade association representing the salt industry.
“Salt is an essential nutrient. Need for salt varies based on multiple factors, including genetics, health status, overall diet, activity level, exercise, and climate, so requirements vary from individual to individual and from day to day. Population-wide sodium reduction strategies are reckless and not based on the whole body of science,” Salt Institute President Lori Roman said in a news release after the Institute of Medicine called for mandatory sodium reductions earlier this year.
This study was presented at a medical conference. The findings should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.