Eating fish twice a week can help reduce the risk of dementia, including Alzheimer’s disease, primarily because fish is rich in omega-3 fatty acids, which are essential for brain health. Omega-3s, especially EPA and DHA found in fatty fish like salmon, mackerel, and sardines, support brain structure and function by maintaining nerve cell membranes, reducing inflammation, and protecting against brain damage that contributes to cognitive decline.
Research shows that omega-3 fatty acids play a crucial role in slowing down the progression of brain changes associated with dementia. For example, studies have found that older adults who consume omega-3s regularly tend to have fewer white matter lesions—areas of brain damage linked to cognitive decline—and better preservation of neuronal integrity, which is vital for memory and learning. This effect appears to be particularly important for people who have a genetic predisposition to Alzheimer’s, such as those carrying the APOE4 gene variant, as omega-3s may help slow the biological processes that lead to dementia.
Beyond omega-3s alone, diets that include fish as part of a broader healthy eating pattern, such as the Mediterranean diet, have been associated with a lower risk of dementia. This diet emphasizes not only fish but also vegetables, fruits, nuts, whole grains, and olive oil, all of which contribute to brain and cardiovascular health. The Mediterranean diet’s protective effects seem strongest in individuals with a higher genetic risk for Alzheimer’s, suggesting that eating fish twice a week within this dietary context can be particularly beneficial.
Women may especially benefit from omega-3 intake because their brains contain a high proportion of fat, much of which is omega-3. These fats are necessary for forming and maintaining nerve cells and for supporting the brain’s immune system, which fights inflammation linked to Alzheimer’s. Since many people consume diets high in processed foods and low in healthy fats, increasing omega-3 intake through fish or supplements can be a practical way to support brain health and potentially delay or reduce dementia risk.
The recommended intake to gain these brain benefits is roughly two servings of fatty fish per week, which provides about 500 milligrams of omega-3 fatty acids daily. For those who do not eat fish, omega-3s can also be obtained from nuts, seeds, or supplements, though fish remains the most direct and effective source.
In summary, regularly eating fish twice a week supplies the brain with essential omega-3 fatty acids that help maintain cognitive function, reduce brain inflammation, and slow the progression of dementia-related brain changes. This dietary habit, especially when combined with other healthy lifestyle choices, offers a promising approach to protecting brain health as people age.
