It has long been theorised that taking B vitamins may lower your risk of Alzheimer’s. A new study shows how this theory came about, and whether or not it works.
A blood compound called homocysteine appears in high levels in the blood of those who suffer from Alzheimer’s disease. Healthy individuals who also have high levels of homocysteine have been shown to have an increased risk of Alzheimer’s disease.
So it makes sense that if you could lower your levels of this compound, your risk of Alzheimer’s would drop, right? This is what scientists proposed with the ‘homocysteine hypothesis’. They had discovered that taking folic acid and vitamin B-12 would lower the level of homocysteine in the body, and they hypothesised that taking B vitamins could reduce a person’s risk of Alzheimer’s because of this effect.
So, to prove it, researchers assembled the data of all the best clinical trials focussing on this effect. They considered data from 22,000 people, and looked at whether those taking B vitamins and those taking a placebo differed in the decline of their mental function.
Unfortunately they were able to determine, with a high degree of accuracy, that there was no difference between those who took B vitamins and those who did not. It didn’t change the rate of mental decline and it didn’t prevent Alzheimer’s, even though those taking B vitamins saw a reduction of homocysteine in their blood tests by around a quarter.
“It would have been very nice to have found something different,” said Dr Robert Clarke of Oxford University, who led the research. “Our study draws a line under the debate: B vitamins don’t reduce cognitive decline as we age. Taking folic acid and vitamin B-12 is sadly not going to prevent Alzheimer’s disease.”
“Taking supplements like B vitamins doesn’t prevent heart disease, stroke or cognitive decline,” says Professor Clarke. “About 25% of the adult population [in the UK] take multi-vitamins, often with the idea that they are also good for the heart or the brain, but the evidence just isn’t there. Much better is to eat more fruit and vegetables, avoid too much red meat and too many calories, and have a balanced diet.”
You can read more about this study at the ScienceDaily website.