Low Folate May Be Linked to Allergies
Study Shows Low Folate Levels May Have Link to Risk for Allergy and Asthma
May 8, 2009 -- Early research suggests that low folate levels may be linked to an increased risk for allergy and asthma, but more study is needed to confirm the association.
Researchers from the Johns Hopkins Children's Center examined the blood folate levels of more than 8,000 people with and without asthma and allergies who were enrolled in a large, national health registry.
They found that those with the lowest serum folate levels were 31% more likely to have test-verified allergy and 40% more likely to have wheeze than people with the highest levels. They also found them 16% more likely to have diagnosed asthma, although the asthma finding wasn't statistically significant.
Pediatric allergist and study researcher Elizabeth C. Matsui, MD, MHS, tells WebMD that the relationship appeared to be dose-dependent, meaning that the people with the highest blood folate levels had the lowest incidence of wheeze and allergies and the people with the lowest folate levels had the highest incidence.
But she warns that it is too soon to recommend that people take folic acid -- the synthetic form of folate used in supplements -- in an effort to reduce their risk for allergy and asthma or to treat symptoms.
"That would be premature," she says. "Our findings are a clear indication that folic acid may indeed help regulate immune response to allergens, and may reduce allergy and asthma symptoms. But we still need to figure out the exact mechanism behind it, and to do so we need studies to follow people receiving treatment with folic acid."
Few Are Folate Deficient
Less than 5% of Americans have so little folate in their blood that they are considered deficient in the B vitamin, Matsui says.
That's because since 1996, the U.S. government has required folic acid to be added to cereals, flours, pastas, rice, and other grain products in an effort to ensure that pregnant women get enough of the vitamin to protect against certain birth defects.
Folate is also abundant in leafy green vegetables like spinach and turnip greens, citrus fruits, dried beans, liver, and many other foods.