Omega 3 VS. Mercury: How To Manage Risk Prenatally

A new study suggests that exposure to mercury during pregnancy may increase the risk for attention deficit hyperactivity disorder (ADHD), while eating fish may reduce this risk.

So it seems to be a toss up – Risk exposing your unborn baby to a toxic heavy metal, or deprive them of omega-3?

Mercury has an effect on the brain development of unborn children, infants and children. Methylmercury is the most toxic form to humans, found mainly in fish. The mother’s consumption of methylmercury, while relatively low, may negatively affect the brain and nervous system. This can also affect children for memory, attention, language and other skills when exposed to it in the womb.

This latest study assessed the potential relationships between prenatal mercury exposure and fish consumption in children who developed ADHD. It was published this month in the Archives of Pediatric and Adolescent Medicine.

The researchers found that mercury exposure was linked to greater risk of inattentive and hyperactive behaviors in children. However, eating fish more than twice a week was linked to a decreased risk for ADHD-related behavior.

While it is important to have omega-3 in the diet for proper brain development, getting it from fish carries the risk of mercury exposure. The source of food for a pregnant woman should be considered carefully. Low mercury fish that are still a source of omega-3 (sardines, mackerel, anchovies, etc.) are the best choice during pregnancy. The NRDC provides a useful wallet card as a resource http://www.nrdc.org/health/effects/mercury/walletcard.pdf, while suggesting that certain fish be avoided altogether, and up to a year prior to becoming pregnant. Flax and chia (with the necessary nutrient co-factors to boost conversion), or a pharmaceutical grade fish oil, screened for mercury, can also be included to avoid the mercury and still get the essential brain fat for the baby’s development.

Markham Integrative Medicine provides assessment (blood mercury and hair analysis for Mom), detoxification and a diet plan for guiding families that are planning pregnancy. We suggest a first office visit, and a nutrition plan particularly for mom, up to a year prior to conception.

1. Sagiv SK, Thurston SW, Bellinger DC, et al. Prenatal Exposure to Mercury and Fish Consumption During Pregnancy and Attention-Deficit/Hyperactivity Disorder-Related Behavior in Children. Arch Pediatr Adolesc Med. 2012 Oct 8:1-9.