Certain dietary patterns are associated with long-term brain health
Scientists have long known that certain nutrients are essential for brain development and function. There's also evidence that good nutrition can help stave off cognitive decline in older people. But studies of single nutrients have largely been disappointing, and research on the relationship between overall diet and brain function generally relies on food frequency questionnaires, which can be misleading because of faulty memories and the inability to take account of nutrient absorption. Now researchers have conducted the first study using nutrient biomarkers and brain imaging to analyze the effect of diet on cognitive function and brain volume. Their main finding is that higher blood levels of omega-3 fatty acids and vitamins B, C, D, and E are associated with better memory and thinking in older people. The study was published in Neurology (Jan. 24, 2012).
The study. Researchers at Oregon Health & Science University measured the blood levels of 30 nutrients in 104 people (64 of them women), average age 87, who were participating in the Oregon Brain Aging Study. For the Neurology study, the scientists administered tests of mental function (including memory, learning, and spatial relations), and, for a subgroup of 42 participants, used MRI imaging to measure cerebral brain volume.
The results. Eight specific nutrient biomarker patterns emerged, and three of them were associated with brain volume and cognitive measures. Participants with the highest blood levels of B vitamins (B1, B2, B6, folate, and B12) and vitamins C, D, and E scored the highest on mental tests, particularly in executive, attentional, and visuospatial ability. Compared with participants with the lowest levels of these nutrients, those with the highest levels also had larger brain volumes (suggesting less atrophy). Higher blood levels of omega-3 fatty acids were associated with better executive function but not with higher brain volume. According to the authors, these healthy fats (found mostly in fish) may act through a different means than staving off atrophy — possibly by improving blood vessel function. A nutrient pattern high in trans fats (unhealthy fats found mostly in commercial baked goods) was associated with worse cognitive function and smaller brain volume.