We’ve known for a long time that a high-salt diet is linked with high blood pressure, and high blood pressure contributes to heart disease and stroke risk.
Now, there’s another reason to step away from the salt. An article published in Nature Neuroscience reports a connection between high salt intake and problems with memory and learning. It’s not triggered by high blood pressure, but by a link between the gut and the brain.
The study’s researchers fed mice a high-salt diet. And it wasn’t one of those thousand-times-above-normal-levels studies.
Costantino Iadecola, M.D., one of the study’s investigators and the director and chair of the Feil Family Brain and Mind Research Institute at Weill Cornell Medicine in New York, N.Y, points out that the salt levels studied were high, but they were comparable to levels sometimes seen in human diets.
The researchers found that, over time, these high-salt-eating mice performed more poorly on cognitive tests than mice on a normal-salt diet.
A new gut-brain connection
In investigating what was behind these results, the researchers discovered a new connection between the gut—specifically, the small intestine—and the brain.
The high levels of salt triggered immune changes in the gut. Those immune changes led to less blood flow to the brain. That, in turn, led to the cognitive declines.
For those of us of a certain age, there’s more bad news: Salt’s brain-busting effects started sooner, and were worse, in middle-aged mice compared to younger mice.
The good news? Once the mice stopped eating all the extra salt, their brain function returned to normal.
You know the drill
While more research is needed to confirm whether these results hold true for people, reducing salt intake probably isn’t a bad idea.
The American Heart Association recommends 2,300 milligrams a day of sodium or less. That’s about a teaspoon of salt. But Americans average about 3,400 milligrams a day, or almost 50% more than what’s recommended.
And, ideally, the AHA would like to see most adults at 1,500 milligrams a day or less.
To reduce your salt intake, cut back on processed and prepared foods—they’re responsible for more than 70% of the salt Americans consume. Watch out for these top culprits, according to the AHA:
- Bread. Bread might not taste salty, but a slice can pack up to 230 milligrams of sodium.
- Pizza. Just one slice of pizza might have 760 milligrams of sodium. Ask for extra veggies and light cheese to cut down on salt.
- Canned soup. With up to 940 milligrams of sodium per cup, you’re better off choosing low-sodium options, and adding extra veggies to cut salt per serving even more.
- Cold cuts and cured meat, which have salt added as a preservative.
- Poultry. Processed nuggets can be high in salt, and even fresh chicken might be injected with a salt solution.
- Sandwiches, burritos, and tacos. These go-to lunch options are often loaded with salt.
Prepare food at home, and you’re in control of the salt. But that’s not always feasible, so when you need to turn to processed or prepared foods, read the labels or ask for nutritional information. That way you can make lower-salt choices.