Folic acid could protect against strokes

时间:2019-03-02 08:04:12166网络整理admin

By Roxanne Khamsi Folic acid supplements can reduce the risk of stroke by 30%, according to a review of eight studies involving nearly 17,000 participants. The new findings will add fuel to growing calls for the B vitamin to be routinely added to flour or bread – to protect against birth defects – in countries such as the UK where this is not already practice. Opponents point out that an increase in folic acid can mask a vitamin B12 deficiency which can be dangerous in the elderly. Xiaobin Wang at the Children’s Memorial Research Center in Chicago, Illinois, US, and colleagues combined existing data from trials looking at the vitamin’s effect on cardiovascular disease. The studies, in which people aged around 60 received either placebo pills or daily folic acid supplements, followed participants for between two to six years. Those taking supplements in the trials received between 0.5 milligrams and 15 mg. Health officials in the US recommend a daily intake of at least 0.4 milligrams of folic acid – about the amount in a bowl of fortified cereal. The analysis revealed that taking any amount of folic acid lowered the risk of stroke by 18%. Another analysis looking specifically at the effect in countries that do not fortify grain with folic acid, such as Norway, China and Italy, found a 25% drop in stroke among those taking the supplement. When Wang analysed a subgroup of those who took the supplements for at least three years, she found that folic acid reduced the risk of stroke by almost 30%. Unexpectedly, those who received the smallest dose of folic acid benefited just as much as those who received the largest amounts. Wang believes this is because the body needs only a certain crucial amount of the vitamin. “If you have a person who has never had a stroke before, they may benefit,” says Cynthia Carlsson of the University of Wisconsin School of Medicine in Madison, US, who was not involved in the study. She cautions, however, that people with a history of cardiovascular disease might want to steer clear of folic acid supplements, since previous studies have suggested it may slightly elevate the risk of heart attack. How folic acid protects against stroke remains unclear. It is known that the vitamin helps the body excrete homocysteine, a by-product of protein breakdown that effects small blood vessels, and which has been linked to heart disease and dementia. Journal reference: Lancet (vol 369,