The study, done in France, compared the diets of more than 1,600 people 65 and older with scans of their brains. Volunteers younger than 75 who ate two or more servings of fish per week, had fewer telltale signs of vascular illness, such as plaque, which often leads to cognitive decline and dementia.

“It's really exciting to see a new, solid study with brain imaging that those folks who actually have eaten more fish are clear of plaque,” said Judy Simon, a clinical dietician with UW Medicine, who was not involved in the research.

While the study, reported in the In the Nov. 3 issue of Neurology, does not prove fish protects your brain, it’s easy to see why it would help.

“Fish is an excellent source of polyunsaturated fat omega three, which is made up of two types of fatty acid,” Simon explained. “And what they do is they reduce inflammation in the vessels, so in those small vessels of our brain and our heart, so they’re a lot more flexible – healthy, good blood flow, which is helps prevent plaque buildup.”

Simon’s takeaway from the study: Everyone, both young and old, should eat more fish. Most Americans don’t eat enough.

More Info: Fish on Your Plate May Keep Your Brain Sharp