Research presented at the 2018 American Academy of Allergy, Asthma & Immunology (AAAAI) and World Allergy Organization (WAO) Joint Congress suggests folic acid exposure during pregnancy could have an effect in determining whether children develop food allergies.
The research comes from the Boston Birth Cohort, which was an ongoing study that followed mother-baby pairs from birth to childhood from 1998 to 2013. One of the focuses of the study was the causes of food allergies in children.
What Did The Study Find?
Researchers tested newborns at birth and early life for levels of unmetabolised folic acid, which occur when the level of folic acid is too high and overwhelms the liver’s capacity to metabolise it.
Newborns who had high levels of unmetabolised folic acid had a higher risk for food allergies later in life, compared with newborns with lower folic acid levels.
Of the 1,394 children included in the study, 507 had a food sensitisation and 78 had a food allergy.
The researchers believe increased levels of unmetabolised folic acid could be due to increased exposure to folic acid in utero or to underlying genetic differences.
But Isn’t Folic Acid Necessary During Pregnancy?
Women are routinely told to supplement folic acid at the time of conception and during early pregnancy.
In the 1980s, scientists looked at the blood results of women who had babies with neural tube defects, such as spina bifida. The researchers found the mothers were deficient in folate.
Further research found supplementing with folate before conception reduced the occurrence of neural tube defects.
Read more about this in Folate – Why It’s So Important Before And During Pregnancy.
Folate is a naturally occurring B-vitamin, found in dark leafy vegetables, whole grains, animal livers, and orange-red fruits.
It wasn’t long before it became standard, mandatory practice, in many countries, to fortify flour and grain products with a synthetic version of folate, called folic acid.
Women who are in their childbearing years are also recommendedo take a folic acid supplement.
You can read more in Folic Acid – What You MUST Know Before You Take It.
Folate Versus Folic Acid Metabolism
Folate is a general name used for a group of compounds that have similar nutritional properties.
Folate is a naturally occurring form of vitamin B9. Before it enters the bloodstream, the digestive system converts folate into a biologically active form of B9, called 5-MTHF.
Folic acid is a synthetic B9. When it enters the body, it isn’t converted into the active form of vitamin B9 very well. As a result, there can be a build-up of unmetabolised folic acid circulating in the bloodstream.
It’s been shown a daily dose of 400mcg can be responsible for causing unmetabolised folic acid to build up in the bloodstream. This is the same amount as the recommended daily dose for women who are planning to conceive or are pregnant.
Recent research has also shown taking folic acid late in pregnancy can increase the risk of allergies in babies after birth.
Read more about this in Folic Acid In Late Pregnancy Can Increase Risk Of Allergies.
What’s The Bottom Line For Folic Acid?
Health experts agree vitamin B9 is important for the prevention of neural tube defects.
Obviously, the best form of this vitamin is that found in natural sources, such as spinach, avocados, asparagus and other foods.
However, if you’re concerned about not having enough vitamin B9 in your diet, and want to take a supplement, it’s best to choose one which doesn’t contain the synthetic form of folic acid.
Some supplements containing 5-MTHF or methyl folate would be worth considering instead of the standard folic acid.