April 4, 2012
Can what you eat help to protect the brain, and possibly help ward off Alzheimer’s disease? A growing body of evidence suggests nutritional factors can influence brain health, including a new report linking certain nutrients to good cognitive health.
Researchers measured blood levels of 30 key vitamins and nutrients in a sample of elderly men and women, all of whom also underwent memory tests. Some also underwent brain scans to measure their brain volumes and look for signs of Alzheimer’s disease.
Five nutrients were linked to good memory and thinking skills: omega-3 fatty acids, the kinds of fats found in fish, and vitamins B, C, D, and E. People who had high blood levels of these nutrients scored better on thinking tests than those who had low blood levels of these nutrients. Their brains also showed less shrinkage, a sign of brain health. People with Alzheimer’s typically have smaller brains than those without the disease.
The study also found that people with high levels of trans fats, an unhealthy type of fat found in packaged baked goods as well as fast, fried and frozen foods, scored lower on thinking and memory tests than those with low trans fat levels. Trans fats are also found in some types of margarine and have been banned in some locales. The findings appeared in Neurology, a journal from the American Academy of Neurology.
The study, part of the Oregon Brain Aging Study, involved 104 people whose average age was 87. Other than advanced age, they had few risk factors for Alzheimer’s disease or other forms of dementia. Over all, the participants were nutritionally sound, though 7 percent were low in vitamin B12, and 25 percent were deficient in vitamin D.
“These results need to be confirmed, but obviously it is very exciting to think that people could potentially stop their brains from shrinking and keep them sharp by adjusting their diet,” said study author Gene Bowman of Oregon Health and Science University in Portland.
Other studies have shown that deficiencies in individual nutrients, like vitamin B12, can lead to memory problems. And anyone with memory problems should be tested for that and other vitamin levels.
This study was the first to use nutrient levels in the blood to analyze the effect of diet on memory and thinking skills and brain volume. Blood measurements are considered more reliable than questionnaires to assess people’s diet, since people often forget exactly what they ate. Food surveys also do not account for how much of the nutrients are absorbed by the body, and poor absorption of certain vitamins and nutrients is often a problem in the elderly.
While dietary factors are complex and foods contain a balance of hundreds of nutrients, the study suggests these five may be especially important for brain health.
Omega-3 fatty acids: Other studies have shown that the oils found in fish are good not just for the heart, but for the brain as well. Oily fish like salmon, tuna, mackerel and trout are particularly high in omega-3s.
Vitamin B: There are many types of B vitamins, and all are important for nerve and brain health. B12 in particular has been shown to be protective against memory problems. After age 50, some people lose the ability to absorb B12 from foods, so supplements may be recommended. B12 is found in meats and other animal foods like fish, eggs and cheese. Some cereals are fortified with B vitamins as well.
Vitamin C: Most people know vitamin C from orange juice, but it’s also found in broccoli, red peppers, dark green vegetables, strawberries and kiwifruits.
Vitamin D: Called the sunshine vitamin because people make it through the skin on exposure to sunlight, vitamin D levels also tend to be low in older people. Milk has added vitamin D, but it’s also found in fatty fish.
Vitamin E: Since vitamin E is stored in fat, you don’t want to overload on it. But it is found in vegetable oils, nuts and seeds, leafy greens and whole grains. Wheat germ is also an excellent source of vitamin E.
Sources: Christy C. Tangney, Nikolaos Scarmeas: “The Good, Bad, and Ugly? How Blood Nutrient Concentrations May Reflect Cognitive Performance.” Neurology Vol 78 No 1, 2012.
G. L. Bowman, L.C. Silbert, D. Howieson, et al: “Nutrient Biomarker Patterns, Cognitive Funciton, and MRI Measures of Brain Aging.” Neurology Vol 78, No. 1, 2012.