Taking folic acid and vitamin B12 supplements can prevent memory loss in people aged over 60, an Australian study has found.
A team of researchers based at several universities across Australia studied about 900 people in Sydney, Canberra and in the southern NSW regional centre of Wagga Wagga.
But their findings had a different outcome to what they were originally looking for.
"The aim of the study was to look at the prevention of depression rather than cognitive decline", one of the study's authors, Helen Christensen, professor of Mental Health Research at the University of NSW and Director of the Black Dog Institute, said.
"We were interested in whether folate (the naturally occurring version of folic acid) was a mechanism by which we could reduce levels of depression in the community as a prevention measure."
The team monitored cognitive decline because some changes to memory function occur in people once they reach the age of 60.
Participants in the study were given a dose of 400 micrograms of folic acid and 100 micrograms of Vitamin B12 per day.
Prof Christensen said she was surprised at the outcome of the study.
"With respect to depression, we didn't find any effect of folate. So folate had no effect on whether people were more or less depressed."
However, there was an effect on cognitive decline.
"We found that those people who were taking folate did not seem to show the same level of cognitive change as those that were not taking folate."
Real results emerged after people took folate for at least 12 months.
And the improvement was specific to memory decline rather than other cognitive changes, such as speed or processing of ideas.
Prof Christensen stressed more study was needed.
"We would really think it was a great idea to replicate this with another group of people before we can be running around stridently suggesting that people should be making sure they have the folate in their food."
However, she was encouraged that a definite link has been made between taking the supplements and preventing memory loss.
Prof Christensen said using folate and Vitamin B12 was an inexpensive way for people to improve memory function.
"I didn't expect that such a small dose of folate supplement would have such an effect on cognitive levels," she said.
"All the (previous) evidence seemed to be pointing towards the use of folate as a way of reducing depression. So it was a nice result."
Folate and folic acid are both vitamins in the B group. They are closely related but are not the same.
Folate occurs naturally in food whereas folic acid is a synthetic form of the vitamin usually found in fortified foods such as cereals and vitamin supplements.