Scarf down a pile of French fries or bag of chips and you'll sack your system with a crazy amount of salt – not good. But if your body tends to retain sodium, it's even worse, because rather than getting flushed out by the kidneys, that salt enters the bloodstream, increasing your overall sodium load and potentially jacking up blood pressure.
Fries aside, stress can have the same impact on salt retention, it turns out. According to new findings from the Institute of Public and Preventive Health at Georgia Health Sciences University, when frazzled or anxious, 30 percent of African-Americans hold onto as much sodium as if they'd just polished off a salt-saturated snack. Researcher Gregory Harshfield says that this extended retention – which happened many times throughout the day as various stressors occur – caused the participants' blood pressure to stay elevated, even during sleep, when their bodies should've been recovering from the day. This in turn heightens the risk of serious heart troubles and stroke, he adds.
Harshfield says he examined African-Americans because previous studies have shown they have greater salt retention (up to 37 percent) than Caucasians (20 percent) in response to stress. He's unclear as to why race factors in, but it does. "In general, some people's kidneys are more adept at retaining salt because of their genetic makeup or heritage," he says. "In environments where salt is scarce, this trait is beneficial, but it becomes a problem with our salt-heavy diets."
Regardless, Harshfield believes these results are ultimately not race-specific and can be generalized to anyone who is "salt sensitive," meaning anyone whose blood pressure increases when they consume lots of salt – or when stress levels skyrocket. Of course, unless you're in the habit of checking your own blood pressure daily, you won't know whether or not you're salt sensitive. But Harshfield says weight can also factor in, so if you're carrying extra pounds, you should be especially careful to avoid excess salt and do your best to de-stress.
Or, you could always lose the extra weight (you wanted to anyway, right?) to give your body a better shot at properly flushing out salt. "Since fat cells secrete angiotensin II, the hormone that promotes sodium retention, losing weight will reduce it," Harshfield says. "That said, I suspect anything that improves fitness would have a beneficial impact."