Prenatal vitamins may prevent autism

Here's a super interesting article on a study done on pregnant moms to see if taking a prenatal vitamin (high in folic acid which prevents neural tube defects in babies) is associated with the incidence of an autistic spectrum disorder (ASDs - these disorders range the gamut from Asperger's Syndrome to full autism). An association between an adequate or high folate level and the decreased incidence of ASDs would greatly impact the field as folic acid is readily available in many foods we eat and as a cheap dietary supplement. Unfortunately, this association would not explain the cases that occur despite adequate folic acid intake by the mom. It appears that autism is a multifactorial problem - can be caused by genetics, environmental toxins (the science is still out on this) and possibly now by diet (or lack thereof). Read on for more info and have a fabulous weekend!

"Taking prenatal vitamins around the time of conception decreased the risk of autism in the children by almost half, finds a study of mom/child pairs from California. Mothers with specific genetic variants that hinder the breakdown of nutrients important to early brain development – like folate –  were further at risk if they didn't take prenatal vitamins.  The results – published in the journal Epidemiology – indicate that proper prenatal nutrition may be especially important  for susceptible individuals and may help prevent autism overall.

What did they do? Researchers used data from the Childhood Autism Risks from Genetics and the Environment (CHARGE) study – a population-based case control study of preschool children from California. In CHARGE,children are considered "cases" if they had received services for an ASD from one of the state's regional centers of the California Department of Developmental Services. 

Children aged two to five years old participated in the study. Autism was confirmed in the children based on results from two standardized clinical assessments. The controls were children without autism who were identified from state birth certificates.The controls were matched to the cases based on age, sex, and area of California where they lived.

Mothers were asked questions about their use of prenatal vitamins, multivitamins, other nutritional supplements and dry cereal to measure their intake of nutrients like folate that are important in early neurodevelopment.

Samples of DNA were collected from both the mothers and the children. The researchers examined 10 functional genetic variants – parts of genes that work to make proteins in the body – key to carbon one metabolism, which is primarily responsible for the breakdown and uptake of folate in the body.

The authors looked to see if moms and their children who had genes that did not work as well as other mom/child pairs to break down folate were at additional increased risk for autism if the mother did not take a prenatal vitamin or consume fortified foods to provide the vitamins important for brain and nerve development. They compared the risk of autism when taking prenatal vitamins before conception, later in pregnancy and regularly during pregnancy. 

What did they find? Mothers who took prenatal vitamins during the  three months before and the first month of pregnancy – called the peri-conceptional period – had nearly half the risk of having a child with autism when compared to mothers who did not take prenatal vitamins during this pregnancy stage. Later in pregnancy, there was not a detectable difference in risk between mothers who did and did not take prenatal vitamins.

The mothers who took prenatal vitamins more regularly during pregnancy had a lower risk of having a child with autism than those who didn't. The researchers found that those who reported taking a prenatal vitamin daily or taking one at least four days a week were the least likely to have a child with autism.

No change in autism risk was found for standard multivitamin use. Prenatal vitamins typically
contain more iron, vitamins B6 and B12 and twice as much folic acid – which are needed for proper brain and nerve development.

The results show genetic factors play a role as well. Mothers with gene variants that decreased their ability to metabolize nutrients were two to four times as likely to have a child with autism if they also did not take prenatal vitamins. One genetic variant identified in the child increased the risk of autism by seven times if the mother did not take prenatal vitamins.

What does it mean? Prenatal vitamins may help prevent autism, particularly when women take the supplements up to three months prior to conception and during the first month of pregnancy. In particular, taking a daily prenatal vitamin may be most beneficial for women who are planning to become pregnant to help decrease the risk of autism.

The study is the first to look at the relationship between prenatal vitamins and the risk of autism, according to the authors. The findings show prenatal vitamins taken before conception and daily throughout pregnancy can reduce the risk of the disorder.

Use of these supplements may also be more important among genetically susceptible individuals who may not be as able to metabolize important nutrients like folate.

While the underlying causes of autism and the biology which makes the disorder occur have not been deciphered, studies such as this one are important steps to understanding prevention of autism.

Future research on maternal diet throughout pregnancy and mechanisms by which this may work – like epigenetic effects – may help understand the findings of this study.  Replication in other samples is also needed to support these findings and address small samples present when looking for gene-environment interactions.''

Source: Environmental Health News
http://www.environmentalhealthnews.org/ehs/newscience/prenatal-vitamins-lowers-autism-risk/

Original article: Schmidt, RJ, RL Hansen, J Hartiala, H Allayee, LC Schmidt, DC Tracredi, F Tassone and I Hertz-Picciotto. 2011. Prenatal vitamins, one-carbon metabolism gene variants and risk for autism. Epidemiology http://dx.doi.org/10.1097/EDE.0b013e31821d0e30.