Teenagers, with their innate drive to do things that will come as close as possible to killing them without actually doing so, eat a lot of salt. And that’s bad, kind of! As the thinking goes, a higher salt intake leads to higher blood pressure, which leads to a higher chance of being dead. However, according to a new study of teenage girls by Boston University’s School of Medicine, salt intake appears to have no effect on blood pressure. Potassium, however, does.
“It may be that potassium is more of a determinant of blood pressure than sodium is,” said Lynn L. Moore, the study’s lead author and an associate professor of medicine at Boston University. “The kids who consumed the most potassium had much lower blood pressures by the end of adolescence. What we need to focus on is increasing potassium intake rather than focusing on restricting sodium intake.”
The study tracked the eating habits and blood pressure of 9- and 10-year-old girls for up to 10 years. Their findings were surprising: Not only did a high sodium intake appear to have little negative effect on blood pressure, but some girls who consumed up to 3,500 mg of sodium per day had lower blood pressure than those who consumed 2,500 mg daily. The real determinant, they found, was potassium. Teenage girls who consumed more potassium routinely had healthier blood pressure levels.
The recommended daily intake of potassium is 4,700 mg per day, which is a lofty goal for most people to achieve. As the New York Times points out, though, there are plenty of teen-friendly foods with loads of potassium. Bananas are a well-known source, but avocados, potatoes, spinach and kale all have up to twice the potassium. Kiwis, nectarines, yogurt and papayas are all quality (and far tastier) sources of potassium as well.
The girls who ate the most potassium in the study still fell well below the recommended daily intake at around 2,400 mg, but still had the lowest blood pressure. The study also found that the girls in the group that consumed both the most sodium and the most potassium also consumed the most calories, as well as the most fruits, veggies, fiber and dairy.
Current American dietary guidelines stipulate that salt consumption for those under 50 should be limited to 2,300 mg per day. This latest study calls those guidelines into question.