04/06/2007 – Folic acid supplementation is best known as a means of protecting unborn children against birth defects, but research suggests that it could also be beneficial to adults and significantly reduce their risk of suffering a stroke.
A meta analysis published this week in The Lancet concludes that people can cut their risk of a stroke by a fifth by increasing their intake of folic acid.
Xiaobin Wang from the Children’s Memorial Research Center in the US and colleagues analyzed data from eight randomized trials looking at the link between intake of folic acid and the risk of suffering a stroke.
They found that people who regularly took a supplement of folic acid reduced their relative risk of stroke by an average of 18 per cent.
An even greater risk reduction of 30 per cent was seen when the treatment lasted more than 36 months; if the individual had no past history of stroke, folic acid supplementation reduced their risk by 25 per cent.
Wang’s team recommended that more research should be carried out among individuals with no history of stroke from regions without grain fortification, with a follow-up period of four years or longer.
The board of the UK’s Food Standards Agency agreed last month that either bread or flour in the UK should be fortified with folic acid to reduce the risk of neural tube defects (NTDs) in the early states of pregnancy.
A mandatory policy of fortification appears to have been a success in the US and Canada, where NTD-affected pregnancies are reported to have fallen by 26 per cent since the measure was introduced in 1998.
However, there are concerns that mandatory folic acid fortification could mask vitamin B12 deficiency, particularly in the elderly. While the symptoms of B12 deficiency are alleviated by folic acid, its effects – including cognitive decline – are not.
In Australia and New Zealand the proposal has been particularly opposed by organic bakeries, which claim they cannot add a synthetic vitamin to their products that are by definition free of all additives.
Others in the baking industry say the proposal ignores both up-to-date information on women’s diets and adequate knowledge of the risks to others in the population from consuming more folic acid.
As well as evidence showing that folic acid could mask deficiency of other B vitamins in the elderly, there are also fears of the effects of large amounts of folic acid in young children.
Natural source of folic acid or folate, include green vegetables and oranges.
Source: The Lancet
2 June 2007, Volume 369, Issue 9576
Efficacy of folic acid supplementation in stroke prevention: a meta-analysis
Authors: X Wang, X Qin, H Demirtas, J Li, G Mao, Y Huo, N Sun, L Liu, X Xu