Now researchers say teens ought to cut their salt intake to head off some of these diseases early on.
Using a computer simulation, researchers found that cutting teens' salt intake by 3 grams a day -- about half a teaspoon's worth -- would reduce by 100,000 the number of teens who get cardiovascular disease by age 50.
The findings were presented at the annual scientific meeting of the American Heart Association. Lead author of the study Kirsten Bibbins-Domingo, a researcher at University of California, San Francisco, tells Shots there are two reasons why there should be a lasting benefit from an early reduction in salt.
"We think that lowering salt in the diets of teenagers would have both immediate and tangible benefits, [leading to] slightly lower blood pressure -- which means less hypertension as teens age," Bibbins-Domingo says. "It also means that they start a pattern of healthier behaviors with regard to how much salt they're consuming."
Bibbins-Domingo led an analysis -- published earlier this year in New England Journal of Medicine -- that found that if adults cut their salt intake by 3 grams, it would save between 44,000 and 92,000 lives a year. An internist and an epidemiologist, Bibbins-Domingo was interested in looking at salt intake in teens because she's seen an increase of adults with heart disease.
"Part of that is related to the rising rates of obesity in teenagers," she says. "Those teenagers become young adults, and then I take care of them. And I have to see the results of things that start much earlier." She says her team used the same model and applied it to younger age groups.
Bibbins-Domingo says teens and young adults consume more salt than any other age group. That's because teens not only consume more calories, they also eat foods that have a higher salt content, she says. About 80 percent of the salt we eat comes from processed food, Bibbins-Domingo says. What's a major culprit? Pizza, she says.
"Pizza starts with salt in the crust of the bread, salt in the tomato sauce, salt in the cheese, and then any other toppings," she says. "And since teenagers tend to eat a lot of that food that's very high in salt, it's there."
A slice of a small thin-crust pepperoni pizza from Domino's has 525 milligrams of sodium. (Check for yourself here.)
The 3-gram decrease that Bibbins-Domingo's team recommended for teens puts them just short of the government's recommendation's for salt intake. Bibbins-Domingo says teens and young adults consume about 9.2 grams of salt per day (or 3,800 milligrams of sodium) -- but the government's recommendation is about 5.8 grams (that is, 2,300 milligrams of sodium).
This summer, a panel of experts who was reviewing the country's nutritional guidelines suggested that we change the standard and try to consume no more than 1,500 milligrams of sodium, which is what the AHA currently recommends.