A new study suggests that eating less salt and exercising more may keep our brains smarter longer–in case you needed further motivation to put down the Doritos and head to the gym. This isn’t the first time that physical activity has been linked to better brain function, but the bit about sodium is something that might surprise you. Researchers didn’t investigate the mechanism by which salt makes us stupid (if that’s really true); they found a strong correlation between sedentary lifestyle, high sodium consumption and declining cognitive function. So should you put down the salt shaker?
If you love salty foods but you don’t love to exercise, the short answer is: yeah. The link between salt and brain function is hazy; researchers simply analyzed data from the Longitudinal Study on Nutrition and Successful Aging, and found a strong correlation between sodium intake, low physical activity and a decline in brain function with age. And that’s even after controlling for other factors like education level and overall diet. The researchers don’t claim that salt itself is responsible for eroding grey matter; they mainly see it as a marker that heralds poor overall health: Sodium is linked to blood pressure, and many think it also impacts bone health and overall cardiac health. But “this is has been proven to cause high blood pressure.
But there is some good news in all this, especially for anyone who’s highly active. According to the researchers, your workouts could earn you a free salt pass. Says lead study author Carol Greenwood, a nutrition scientist and interim director of the Baycrest Kunin-Lunenfeld Applied and Evaluative Research in Toronto:
People who were physically active were protected, regardless of their sodium intake. What’s important is maintaining the integrity of the cardiovascular system, and the benefits of exercise are going to outweigh any negative effects we see with salt.
And Dr. David Katz, director of Medical Studies in Public Health at Yale University, adds:
It stands to reason that people who are more active, and fitter, and thus healthier overall, would better ‘withstand’ the potential harms of excess sodium than those lacking this immunizing benefit.
But at the end of the day, Katz reminds us:
Whether or not dietary sodium directly affects cognitive function in older people, its intake should be restricted to recommended levels, best achieved by eating fewer processed foods, and more foods direct from nature.