Folic Acid May Suppress Allergies, Asthma

BALTIMORE—Folic acid, or vitamin B9, may suppress allergic reactions and lessen the severity of allergy and asthma symptoms, according to new research from the Johns Hopkins Children’s Center.

The research examined the link between blood levels of folate – the naturally occurring form of folic acid — and allergies, and found evidence that folate can help regulate inflammation. Recent studies, including research from Hopkins, have found a link between folate levels and inflammation-mediated diseases, including heart disease. A report on the Hopkins Children’s findings appears in the Journal of Allergy & Clinical Immunology.

The researchers reviewed medical records of more than 8,000 people ages 2 to 85 and tracked the effect of folate levels on respiratory and allergic symptoms and on levels of IgE antibodies, immune system markers that rise in response to an allergen. People with higher blood levels of folate had fewer IgE antibodies, fewer reported allergies, less wheezing and lower likelihood of asthma. People with the lowest folate levels (below 8 nanograms per milliliter) had 40 percent higher risk of wheezing than people with the highest folate levels (above 18 ng/ml).

The current recommendation for daily dietary intake of folic acid is 400 micrograms for healthy men and non-pregnant women. Many cereals and grain products are already fortified with folate, and folate is found naturally in green, leafy vegetables, beans and nuts.

The Hopkins team is planning a study comparing the effects of folic acid and placebo in people with allergies and asthma.