Multivitamins don’t slow loss of brain function in older people
Taking a daily multivitamin, even over several years, doesn’t help slow the decline of brain functions in older people, according to a large study.
BMJ Group News
What do we know already?
Ageing populations in many countries are leading to increases in illnesses linked with old age, including dementia and Alzheimer’s disease. But even though most older people won’t have problems as serious as these, many will experience declining brain functions (called cognitive decline). For example, they might find that their memory isn’t what it once was, or that they forget the names of things now and then.
Like the rest of our bodies, our brains need to be regularly fed a cocktail of essential vitamins to keep them working properly. Many multivitamin supplements contain these vitamins, as well as minerals and other nutrients important for good health. We know that multivitamin supplements contain lots of good things. But it’s not clear whether taking vitamins in this form, rather than getting them from our diet, really does any good. So researchers in the US conducted a large study to try to find out whether taking daily multivitamins could help keep the brain working properly.
They recruited just under 6,000 US doctors into the study and divided them randomly into two groups. For the next 12 years, the doctors took either a daily multivitamin or a placebo (dummy) pill. The doctors in the study didn’t know which treatment they were taking - the vitamin or the placebo. The researchers contacted the doctors every few years, up to a maximum of four times each. Each time, they tested their brain functions, using measures such as memory and recognition tests. At the end of the 12-year study period they looked to see whether the people taking vitamins had better brain function than those who had taken placebos.
What does the new study say?
The study found no difference in the rate of slowing of brain functions between the two groups of people. People who took daily multivitamins did no better in the various tests than the people who had taken placebos.
How reliable is the research?
This was a kind of study called a randomised controlled trial, which is the best way of testing how treatments compare with each other. It was also a large study, which makes it more reliable. However, there are several reasons to be cautious about its results. The people in the study were all doctors, which means that they were probably well nourished to begin with - perhaps too well nourished, say the researchers, for multivitamins to make much difference. They were also all men and, as doctors, they were all well educated. So we don’t know whether the vitamins would have worked differently on women’s brains or on the brains of people who were less well educated.
What does this mean for me?
This isn’t the only recent study to cast doubt on the supposed benefits of multivitamins. But because of its very specific study group (male doctors), we can’t completely dismiss the possibility that vitamins might help slow cognitive decline in some people. For now, though, there is no evidence that taking vitamin supplements can help the brain work better. The best way to keep the body and mind healthy is still to eat a varied diet that includes plenty of fresh fruit and vegetables and to get plenty of exercise.
If you want to know more about dementia or about Alzheimer’s disease, talk to your doctor.