New studies raise questions about vitamin D, omega-3 fish oil and glucosamine pills in some people.
People tend to think about supplements the way they think about food: Things that are inherently good or bad for you. Green beans are good. Potato chips are bad. Vitamin D and fish oil belong, presumably, on the green-bean side of the ledger.
But the aging brain may change the calculation, putting some of America’s most popular supplements under new scrutiny.
Recent research is raising a largely overlooked question: Can something that benefits (or is at least neutral to) a young, healthy brain become less helpful — or even harmful — as the brain ages?
In January, researchers reported an association between vitamin D supplement use and faster cognitive decline among older adults who already had normal vitamin D blood levels. In April, another study found that adults 55 and older taking omega-3 supplements showed greater cognitive deterioration over time than nonusers. Then, in June, researchers reported that people taking glucosamine, used for joint pain, appeared to have a much higher likelihood of progressing from mild cognitive impairment to dementia over five years than their peers who were not taking it.
“I was stunned,” said Ramon Sun, a professor of biochemistry and molecular biology at the University of Florida and the lead author of the glucosamine paper.
The findings are preliminary, contradict other research in places and far from proof that the supplements lead to cognitive decline.
The studies are mostly observational, meaning they don’t prove causation, and those links with mental deterioration may be because of the supplements or something else entirely.
But together they point toward a possibility that researchers are beginning to take seriously: Aging changes how the brain handles fats, calcium and glucose, and how it responds to inflammation, which could alter how nutrients and drugs reach brain tissue in the first place.
Full story: Scientists are investigating whether popular supplements could harm the aging brain, WaPo
