DHA is short for docosahexaenoic acid, which is an omega-3 fatty acid. While omega-3 fatty acids are essential to health and normal cellular function, and appear to have anti-inflammatory properties in the general population, they're particularly important to fetal development. Omega-3 fatty acids in general, and DHA in particular, foster brain development in growing babies.
Significance
Of the two well-known classes of essential fatty acids--omega-6 fatty acids and omega-3 fatty acids--the omega-3s are much harder to obtain in diet. They come primarily from walnuts and cold water fish such as salmon--while flax has some omega-3 fatty acid in it, the fats aren't in a form that the body can use easily. As such, many individuals turn to supplement pills or vitamins that contain omega-3 fatty acids such as DHA, particularly during pregnancy.
Features
The molecule DHA consists of a very long hydrocarbon chain, meaning a long chain made up of atoms of hydrogen and carbon. At one end of the chain, there are two atoms of oxygen, and the overall chemical formula is C22H32O2. DHA has some carbon-carbon double bonds in the molecule that cause a kinked shape, making the molecule a liquid even at very low temperatures, explain Drs. Reginald Garrett and Charles Grisham in their book "Biochemistry."
Function
DHA has several uses in the body that have lead to research for potential medical application of the molecule. It's an anti-inflammatory and appears to help reduce the symptoms of Alzheimer's, arthritis and heart disease. It also helps foster brain development, explain Drs. Michael Roizen and Mehmet Oz in their book "You: Having A Baby." Drs. Roizen and Oz note that it is no coincidence that evolutionarily, the human brain grew largest when humans began eating seafood, which is rich in DHA.
Considerations
A woman's body naturally supplies her fetus with DHA, not only during pregnancy, but also during breastfeeding. However, the human body can't make DHA--it must be obtained from food. As such, for a woman to make it available to her baby, she must eat it, and the richest food source is cold water fish. Many women aren't able to eat enough fish to ensure adequate DHA to support their baby's growing brain, explain Drs. Roizen and Oz, so many prenatal vitamins contain the oil.
Expert Insight
One further reason to seek out DHA from vitamin pill sources rather than exclusively from food sources is that many of the fish that contain high levels of DHA can also be contaminated with mercury. In her book "Conception, Pregnancy and Birth," Dr. Miriam Stoppard notes that while salmon is relatively safe, tuna--which also contains DHA--can have high levels of mercury and can be dangerous to a developing baby. For this reason, DHA vitamin supplements, which don't contain mercury, may be safe sources of the oil.
References
- "Biochemistry"; Reginald Garrett, Ph.D. and Charles Grisham, Ph.D.; 2007
- "You: Having A Baby"; Michael Roizen, M.D. and Mehmet Oz, M.D.; 2009
- "Conception, Pregnancy and Birth"; Miriam Stoppard, M.D.; 2008
