Folic acid intake in pregnancy linked to asthma

Folic acid is thought to impede the growth of proteins connected to the body's immune system making it more sensitive to allergens and hence increasing the likelihood of asthma.

To reach this conclusion, researchers from the Univerity of Adelaide in Australia studied 550 mothers.

These mothers were questioned about their folic acid supplement intake, diet and lifestyle habits like smoking.

Asthma’s link to folic acid found
The researchers found that women who took folic acid supplements between 16 to 30 weeks of the pregnancy were 30 percent more likely to give birth to a child who could develop breathing problem like asthma by the time he reaches three years of age.

On the other hand, women who took the folic acid supplements prior to conception or just few weeks after conception had no such risk.

“We believe that this is the first published study in humans to demonstrate that increasing consumption of folic acid, and specifically supplemental folate during late pregnancy, significantly increases the risk of physician-diagnosed asthma in the child at 3.5 years, persistent asthma (at 3.5 and 5.5 years), and possibly asthma at 5.5 years," wrote the authors, led by associate professor Michael Davies of the Research Centre for the Early Origins of Health and Disease at the University of Adelaide in Australia.

Previous studies conducted on mice also suggest similar results that folic acid intake is linked to asthma.

Expert advise intake of folic acid
Folic acid is commonly found in green leafy vegetables, legumes and some nuts. It is often recommended to pregnant women as it is believed to prevent neural defects in the unborn babies during the first weeks of pregnancy.

Health experts suggest that folic acid should be taken a month before conception and during the first trimester of pregnancy.

“We see a substantial proportion of women taking these folate supplements throughout pregnancy, and it may be because people think it is entirely benign," said Davies.

"Folate is incredibly important because of its role in preventing neural tube defects (like spina bifida). But because it is so important, and so bioactive, it needs to be treated with some respect as well," Davies further said.

The study appears in the American Journal of Epidemiology.