Dementia benefits of B vitamins shot down
Taking B vitamins to stave off mental decline and Alzheimer's is likely to be a waste of time, research has shown.
Scientists said people would be better off eating more fruit and vegetables as part of a balanced diet.
This is despite earlier evidence suggesting that B vitamins may protect the brain.
Vitamins B9 – also known as folic acid – and B12 are known to reduce blood levels of a compound called homocysteine that has been linked to Alzheimer's.
According to the "homocysteine hypothesis", taking supplements of the vitamins could reduce the risk of developing the disease.
But a new study bringing together data from 11 trials involving 22,000 people suggests the theory is unfounded.
Although B vitamins did reduce blood levels of homocysteine by around a quarter, this had no effect on the mental abilities of participants.
Measures of mental processes such as memory, speed and executive function were the same for those taking the vitamins and dummy placebo pills.