Daily supplements of folic acid could improve the memory and brainpower of elderly people, say experts.
Dutch researchers from the University of Wageningen gave a group of 818 volunteers aged 50-70 either low dose folic acid supplements or a dummy drug for three years, said the online edition of BBC News.
The folic acid group had significantly better memories and were faster at processing information, the researchers found. They had similar mental abilities to contemporaries almost five years younger, The Lancet study found.
But experts said this benefit must be balanced against other risks - an increase in folic acid can mask a vitamin B12 deficiency in older people. This causes anaemia and can lead to serious health problems, like nerve damage.
Further research is needed to reach a more definitive answer on the benefits and effects of folic acid supplementation, the experts said.
Both folic acid and vitamin B12 are essential for good health and good levels of both can be achieved by eating a healthy, balanced diet. Green vegetables are rich in folic acid, while B12 is found in foods such as eggs and meat.