Eating seafood at least once a week may protect against age-related memory problems, including Alzheimer’s.
Research into drugs that can prevent or treat Alzheimer’s disease and other forms of dementia are underway in labs around the world. So far, there’s no medication known to protect memory long-term. But there is hopeful news on the nutrition front.
Several studies suggest eating seafood containing omega-3 fatty acids on a regular basis can slow memory loss as we age. And consuming fatty fish with omega-3s weekly may be especially beneficial for those who have a genetic risk for developing Alzheimer’s, the most devastating form of dementia.
Last year, a team of Rush University scientists found the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet — which is rich in fiber, seafood containing omega-3 fatty acids, fruit, veggies, and olive oil — appeared to protect against memory loss. In fact, when the research participants followed this style of eating closely, it slashed their odds of developing dementia by fifty percent.
Another study by Rush scientists, working with colleagues at Wageningen University in the Netherlands, zeroed in on the impact of diets containing plentiful omega-3s on brain health. And they found more evidence eating seafood protects memory.
The researchers followed 915 people with an average age of 81 for almost five years. None of the elders had signs of dementia when the study began, and each volunteer was tested every year to see if their memory and thinking abilities declined or stayed the same. The research volunteers also completed questionnaires about how much fish they ate, especially omega-3-rich seafood.
The participants were divided into two groups — one comprised of those who ate the most seafood (about two servings a week) and another group that ate seafood less than once a week. Tests over the course of the study showed there wasn’t much difference in the cognitive decline between the groups when it came to short-term memory and visuospatial ability (comprehension of relationships between objects).
However, tests for other types of memory told a different story.
Overall, the seniors who ate the least amount of omega-3 seafood each week suffered more age-related memory loss and other thinking problems than those in the study who ate seafood regularly. Specifically, the study participants who consumed seafood-rich diets had far less decline in their semantic memory – how they remembered verbal information, including facts, meanings, concepts, and knowledge about the external world. They also had retained more ability to quickly and correctly compare letters, objects and patterns.
The results were the same even after the researchers looked for other factors that could affect memory and thinking skills, including how much the seniors exercised, their level of education, history of smoking, and whether they participated in mentally stimulating activities.
Seafood’s role in protecting the brain isn’t surprising because it’s the direct source of a type of omega-3 fatty acid (docosahexaenoic acid) that is the main structural component of the brain, the researchers pointed out. So eating more seafood (including salmon, tuna, and shellfish) is a proactive way to help keep memory problems at bay for as long as possible.
"This study helps show that while cognitive abilities naturally decline as part of the normal aging process, there is something that we can do to mitigate this process," said Rush nutritional epidemiologist Martha Clare Morris, ScD, who headed the research.
The results of the study also offer hope to people with a family history of Alzheimer’s disease. The impact of seafood’s memory protection was strongest for the seniors who carried the APOE gene, a known risk factor for developing Alzheimer's disease.
August 30, 2016
Janet O’Dell, RN