Can Eating Seafood Prevent Alzheimer’s Disease?

There’s now evidence to support the possibility that regularly eating seafood can reduce someone’s risk of later having Alzheimer’s disease or suffering from other forms of dementia.

A study recently published in the Journal of the American Medical Association suggests that older people with a genetic predisposition for Alzheimer’s were less likely to get the disease if they ate at least one serving of seafood each week. Research demonstrated that their brains exhibited fewer manifestations of brain changes associated with Alzheimer’s disease, according to the Mirror.

There are, however, remaining questions about whether the study should be used as a template for everyone—including those who aren’t at greater genetic risk for getting the disease.

“This study links moderate seafood consumption with lower levels of Alzheimer’s-related brain changes in elderly people who carry a risk gene for the disease,” explained Alzheimer’s Research UK’s Dr. Laura Phipps. “But we must be careful when drawing conclusions about the wider population.”

Study participants all carried the APOE-4 gene, which has been linked to a greater risk of developing Alzheimer’s disease. A high-seafood diet may well be advantageous for those without the gene, but such a conclusion would require further research.

Some have also raised concerns that the mercury found in fish could actually be bad for the brain given its toxicity at high levels. But the study’s lead author and director of nutrition nutritional epidemiology at Rush University Medical Center, Martha Clare Morris, now suggests otherwise.

“The findings were very striking,” she said. “Our hypothesis was that seafood consumption would be associated with less neuropathology, but that if there were higher levels of mercury in the brain, that would work against that. But we didn’t find that at all.”

Given previous research into the health value of seafood, the new findings aren’t entirely shocking.

“The omega-3 fatty acids found in oily fish are an important part of a balanced diet, and previous studies suggest they could play an important role in keeping the brain healthy,” said Dr. Phipps. “Current research is underway to investigate the benefits of a diet rich in omega-3 fatty acids in those at risk of memory and thinking problems. But at this time there is no evidence to suggest fish oil supplements could prevent dementia.”

Not yet, anyway. Still, Dr. Phipps welcomed the new study’s findings with respect to the apparent harmlessness associated with low levels of mercury.

“While higher seafood consumption is linked to greater levels of mercury in the brain, it is encouraging to see that this did not appear to be associated with Alzheimer’s changes in the brain in this study,” she added.

The recent study was conducted by surveying older adults who lived in the Chicago area, focusing on questions about their diets. Between 2004 and 2013, 286 of the participants passed away, and brain autopsies later analyzed, “the levels of mercury and whether there was neurological damage indicative of dementia,” according to CNN.

Some believe the study fits into a broader body of evidence supporting the importance of seafood to one’s diet. James T. Becker is a professor of psychiatry and associate director of the Alzheimer’s Disease Research Center at the University of Pittsburgh, and he told CNN that, “The evidence is quite clear that people who consume healthier forms of fish [which are baked or broiled rather than fried] are going to end up with healthier brains.”

Unfortunately, the recent study seems to suggest that there are some diminishing returns associated with the brain benefits of seafood. In other words, eating more than one serving of seafood per week didn’t appear to yield any additional advantages for the brains that were analyzed.

More importantly, there are still a number of other factors that can contribute to someone’s risk of developing Alzheimer’s or other kinds of dementia.

“Dementia risk is a complex mix of age, genetics and lifestyle factors,” explained Dr. Phipps. “The best current evidence suggests that what’s good for your heart is good for your head and that getting plenty of exercise, eating a healthy balanced diet, not smoking and keeping blood pressure and cholesterol in check could help reduce dementia risk.”

Put simply, a regular dose of seafood may well be a start for healthy living. But there’s far more to it.