Fortifying cereals, grains, and flour with folic acid has not protected against the risk of certain birth defects as much as experts thought it would, a large, new study suggests.
At issue are neural tube defects, which include anencephaly, a fatal condition where the baby’s brain does not develop and a paralyzing spinal cord deformity known as spina bifida.
In the late 1990s, health experts found that low folic acid blood levels were linked to both birth defects. So, the U.S. Food and Drug Administration mandated that cereal and grain products be fortified with the B vitamin.
To measure just how effective that effort has been, investigators from Stanford University School of Medicine analyzed 1.3 million births across eight central California countries over two decades.
Between 1989 and 2010, there was an average of about 88 cases of neural tube defects for every 100,000 births.
But digging deeper, investigators found that the risk had already started to decline before the 1997 fortification mandate. There was a risk drop of nearly 9 cases per 100,000 births every year between 1969 and 1996 alone, the researchers said.
And that downward trend actually slowed after fortification, dipping be 1.7 cases for every 100,000 births annually between 1999 and 2010, the study authors said.
Study co-author Gary Shaw, associate chair of clinical research at Stanford’s department of pediatrics, said a number of unexamined factors might have played a role in the trend, including a notable rise in maternal obesity.
“And we now have to wonder if folic acid is the whole answer,” he said.
“What we do know, however, is that this is not a message to women that they should now do anything differently,” Shaw stressed. “I certainly do not want to convey that folic acid doesn’t work. We’re all very grateful that we found folic acid a while back. And it works.”
“The benefits of folic acid for the prevention of neural tube defects are well-documented,” said Laura Baldwin, a public health analyst with the U.S. National Center on Birth Defects and Developmental Disabilities, part of the Centers for Disease Control and Prevention. “The CDC continues to recommend that women capable of becoming pregnant should take 400 micrograms of synthetic folic acid daily, from fortified foods or supplements or a combination of the two, in addition to consuming food with folate from a varied diet.”
Shaw and his colleagues reported their findings online May 18 in the journal Birth Defects Research Part A.
The “whole answer” lies in our genetics. Both folate and folic acid are converted in the lining of the small intestine to 5-methyltetrahydrofolate. That is the active form of the vitamin. It is not found in nature and we are dependent of the cells lining the small intestine to perform this biochemical conversion.
You inherit two gene snippets to facilitate this chemical process, one from mom and one from dad. Eight percent of the population has impaired snippets from both parents and cannot ever convert folate or folic acid to 5-MTHF. An additional 25% have an impaired snippet from just one parent. This also limits conversion. Together, this is one in every three people suffering from impaired folic acid metabolism.
The Bottom Line:
The solution is simple – take 5-MTHF rather that the unconverted supplements noted above. You can also do simple genetic testing from saliva that will document this and many other metabolic genetic impairments – vitamin B6 and B12, the warrior gene, etc.
Source: May 20, 2016 National Institutes of Health