Fetal Brain Development and the Omega-3 Fatty Acid Connection

You might not even know that you are pregnant when fetal brain development first begins. Just three weeks after conception, the baby's nervous system, which includes the brain and spinal cord, starts to form. That is one of the reasons that good nutrition is important, before you even become pregnant.

Without the proper nourishment, things can go wrong. For example, if folic acid (vitamin B9) is missing from the mother's diet, the neural tube along the baby's back may not close. A birth defect called spina bifida, in which the tube never fully closes, is attributed to lack of folic acid in the mother's diet. The tube begins to close just four weeks after conception.

The importance of folic acid has been well known for many years, but the importance of omega-3 fatty acids in a pregnant woman's diet is a relatively new subject. Research indicates that a lack of omega-3s during pregnancy contributes to problems in later life that result from fetal brain development abnormalities. Those problems include poor verbal skills and behavioral problems.

Research has also shown that when Mom's diet is rich in omega-3 fatty acids, her children develop visual acuity more quickly and are less likely to have asthma and allergies. Omega-3s play a role in normal immune system function and are necessary building blocks for the light gathering mechanisms within the eyes.

Many obstetricians now recommend an omega-3 supplement, along with other prenatal vitamins. Most infant formulas are fortified with DHA or Docosahexaenoic acid, a specific omega-3 that is abundant in breast milk, but until recently, was missing from infant formulas.

That DHA is essential for normal fetal brain development is accepted as fact by most scientists and researchers. There may still be a few groups that say the omega-3 found in vegetable oils (alpha-linolenic acid or ALA) is an acceptable substitute for DHA, but their arguments are being disproven one by one.

They have said that the body can convert ALA, the shortest of the long-chained polyunsaturated fatty acids, to DHA, the longest. But, before ALA is converted to DHA, it must first be converted to EPA, Eicosapentaenoic acid. In fact, the primary importance of ALA in the diet is simply to be converted to EPA, which is important for fetal brain development and for other developing organs.

The percentage of ALA that will inevitably be converted to DHA varies between 0 and 4%. Studies have shown that supplements containing ALA do not increase a woman's DHA blood levels and the level is seriously depleted just before delivery. That may be a factor in post-partum depression, because research has shown that depressed individuals typically have low blood levels of the nutrient.

Only fish oil and some types of marine algae contain EPA and DHA. Pregnant women are advised to limit their consumption of fish, because of mercury contamination. The simplest solution is to take a fish oil supplement that has been proven free of mercury by independent laboratory analysis. They can do that with supplements, but not with individual fishes.

Many other factors can have a negative effect on fetal brain development, but normal function is simply not possible without DHA. Whether you are pregnant or just thinking about it, consider dietary supplementation. It's good for you and good for the baby.