A new study published in the Archives of Internal Medicine links intake of beta-carotene (a pre-form of vitamin A found in carrots) to improved cognitive performance in later life. We have appreciated the benefits of vitamin A in brain development for a long time. But until now, the beneficial role in the adult brain has been less obvious.

The power of the new study is that it followed participants in a controlled study for 18 years, from about 55 to 73 years old on average. This provides the ability to really look at long-term affect.

Time is Too Short

The difficulty with many nutrition studies, especially those looking at cognitive health, is that they are too short. Many vitamins probably help maintain brain health due to their anti-oxidant properties, allowing them to prevent or slow age-related decline of the brain. These affects may take many years or even decades to be become apparent because your brain doesn't go belly-up overnight.

Several studies in the past have failed to show the cognitive benefits of vitamin supplements, but most of them were only a few years long. Grodstein et al., who authored the new study, actually looked at groups that participated anywhere from 1 to 18 years.

Although they found no observable cognitive benefit of vitamin A supplementation after 5 years, the benefit was clear by 15 years. Most other controlled studies have been much shorter, with a few making it to the 9-year mark at best. This may be a reason for lack of positive results in the past.

There are many 'observational' studies that support the cognitive benefits of taking vitamins, but these are typically plagued with other possible explanations. For example, people who take vitamins also exercise more, smoke and drink less, eat better, and generally limit their vices to a number they can count on one hand.

Control Freaks (make good scientists) The new study by Grodstein et al. is exciting because it presents some of the first data with a controlled study, large groups of people, and a long time course. The researchers looked at about 1,000 people per group for the short-term study (1-3 years) and about 2,000 people per group for the long-term study (up to 18 years).

Although the authors did not directly link vitamin supplementation to reducing Alzheimer's disease, the cognitive skills they measured are relevant to those that decline in dementia. Also, previous studies in animals have shown that vitamin A may help prevent some of the problems in the brain that are associated with Alzheimer's disease progression.

Too Much of a Good Thing

There is no magic bullet for preventing disease, but the new study suggests that vitamin A is beneficial for life-long brain health. This doesn't mean you should dose up on vitamin A, however, because it is toxic at high levels. A safe form found in quality nutritional supplements is beta-carotene, which the body converts to vitamin A as it is needed.

Still, no nutrients work all by themselves. A good quality multi-vitamin that contains optimal levels of beta-carotene along with all the other essential vitamins is a good way to go.

Copyright (c) 2007 BrainFit For Life