The majority of people today are more conscious about the food they eat. But nothing makes a woman question what she puts in her mouth more than hearing the words, “You’re pregnant.” While folic acid and calcium may be the first nutritional needs that come to mind, there is another that’s just as important and sometimes overlooked: docosahexaenoic acid, or DHA.
What is DHA?
“DHA is one type of polyunsaturated fatty acid,” says Toru Moriguchi, Ph.D., senior researcher at the Healthcare Research Institute, Wakunaga Pharmaceutical Co. in Japan. “Fatty acids consist of saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids.” The polyunsaturated fatty acids can be separated into two groups: omega-3 and omega-6. Omega-6 fats are derived from seeds, nuts and polyunsaturated oils. Omega-3 fats are mainly found in oily fish.
When it comes to the health of the fetus, DHA, an omega-3, ranks high in importance.
According to Moriguchi, DHA is “essential rather than beneficial” for pregnant women. DHA is found throughout the body and in high amounts in the brain and eyes. “It is important for development of not only the brain and nerves, but also the retina,” he says.
DHA may also help moms deliver bigger babies. A clinical trial, conducted by researchers at the University of Adelaide in Australia and published in the American Journal of Clinical Nutrition, found that women given fish oil containing 1 gram of DHA daily vs. women given a placebo from their 30th week extended the pregnancies by four days and gave birth to bigger babies.
The importance of DHA does not stop with fetal development, but can affect Mom as well. “The baby is fed by the nutrients in the mother’s blood via the umbilical cord,” says Moriguchi. “So by not consuming essential fatty acids, both Mother and Baby suffer.”
“DHA and other omega-3 fat sources are also important for the mother’s health during pregnancy, in particular as it is known that the mother’s blood becomes depleted in DHA as a result of the supply to the fetus,” says Dr. Norman Salem, Jr., chief at the Laboratory of Membrane Biochemistry & Biophysics, National Institutes on Alcohol Abuse & Alcoholism and National Institutes of Health in Rockville, Md. DHA is passed from the mother to the fetus throughout the pregnancy, but especially during the third trimester due to Baby’s brain growth at this time. If the mom-to-be is not getting enough DHA, neither will her unborn baby.
Even if You’re Not Pregnant…
“All women should have a balanced intake of omega-3 and omega-6 fats for proper health and avoidance of chronic disease prevalent in the Western World,” says Dr. Salem.
According to the American Dietetic Association, eating polyunsaturated fats in place of saturated fats – found in animal products, butter and tropical oils – decreases LDL cholesterol (bad cholesterol) levels. Research has found that diets high in omega-3 fatty acids can help prevent conditions such as diabetes, heart disease and arthritis pain. And research also has found that people who eat diets low in omega-3 and high in omega-6 have a higher rate of heart disease. Finding the right balance is the key.
“These fats (omega-3) compete with the omega-6 type of fats,” says Dr. Salem. “We are overdosing on these fats, from corn oil, safflower oil, etc. Even though these (omega-6) are also essential, we must reduce their intake in concert with increasing omega-3 fats.”
Low levels of DHA have been associated with memory loss, depression and vision problems.
Sources of DHA
“Fish is the primary source of dietary DHA,” says Dr. Salem. “Marine phytoplankton are the key originators of the omega-3 fatty acids in the food chain.” Dr. Salem says that in the United States, poultry is a secondary source of DHA because we feed poultry a diet containing menhaden oil (fish meal protein).
Mark A. Baugh, a doctor of pharmacy currently working as a pharmacist-in-charge in San Francisco, Calif., says fish oils are the richest natural source of DHA. This includes cod liver oil, herring oil, menhaden oil, sardine oil and whale oil.
But Baugh warns that extreme caution must be exercised by the consumer, and education in this area is of paramount importance. “All polyunsaturated oils are extremely sensitive to destruction by atmospheric oxygen and can lead to oxidation products that can induce certain cancers in laboratory animals,” he says. “Although these oils contain vitamin E as a preservative, the amount of vitamin E present when these oils are harvested and the amount left in the bottle the consumer purchases are unknown without chemical analysis.” If you have questions about the fish oil you purchase, consult your pharmacist or healthcare provider.
Your Fair Share of DHA
The National Institutes of Health (NIH) recommends 300 milligrams a day of DHA as Adequate Intake (AI) for pregnant and lactating women.
Meeting the NIH’s recommendation seems simple enough: Eat more fish. “Just have frequent meals during the month that contain marine fish like tuna, swordfish, shark, salmon, sardines, cod, etc.,” says Baugh. Another fish Baugh suggests is mackerel. “Mackerel is an oily fish and comes in cans. I frequently use it instead of tuna because it is cheaper, and you get more fish for your money with mackerel,” he says.
Although these choices are good for many women, a warning issued in January 2001 by the Food and Drug Administration (FDA) warned pregnant women of harmful mercury levels in some ocean fish. The fish most likely to contain high amounts of mercury are tuna, shark, swordfish, king mackerel and tilefish. Good choices for moms-to-be include cod, haddock, pollock, pink salmon, chum salmon, sockeye salmon, flounder and sole. Pollock, haddock and cod are considered the safest choices.
Other than fish, good choices that contain DHA include eggs, shellfish, shrimp, chicken livers, flax seed oil, crab and beef liver.
Another way to incorporate DHA into your diet is with supplements. “DHA can also be obtained as a nutritional supplement,” says Dr. Salem. “A variety of sources are available from various fish oils and plant sources. Supplements are a convenient way for Westerners in particular to meet their needs for omega-3 fat intake and may be obligatory for those who do not like fish or are allergic to fish, etc.”
“Supplements such as Kyolic-EPA have high-quality fish oil in it,” says Haru Amagase, Ph.D., director of research and development at Wakunaga of America Co. in Mission Viejo, Calif. “Therefore, it is a good source of DHA and EPA (another omega-3 fatty acid) in addition to odorless, aged garlic extract.” Kyolic-EPA contains 120 milligrams of DHA per capsule.
Remember: It’s important to consult your healthcare provider before taking any supplement.
And Again, Breast is Best
The need for DHA doesn’t stop once your baby is born. According to Moriguchi, the brain of a newborn baby is still immature after birth. “Mother has to continue to take DHA source, because the baby needs to be supplied with DHA from breast milk or baby formula,” he says.
Dr. Salem agrees that breast milk is the best source of DHA for the infant diet, but says that since American women have a very low intake of fish and other sources of omega-3 fats, their breast milk is also very low in DHA. “The level of DHA in American women has been reported in the past to be about 0.35 percent of totally fatty acids,” he says. “However, many women have levels of 0.1 percent and lower. This is below the level where randomized, controlled trials have been able to demonstrate a benefit. Therefore, breastfeeding does not assure that adequate DHA will be fed.” Dr. Salem adds that most women in the United States have inadequate levels of DHA in their breast milk.
Whether pregnant or not, DHA should be a part of your dietary plans. While DHA may not be the most talked about, “we need a lot more than we are getting in this country,” says Dr. Salem.
DHA and Infant Formulas
Research has shown that adding DHA to infant formula is beneficial to babies. In one study published in the journal Developmental Medicine & Child Neurology, infants fed formula enriched with DHA and ARA (arachidonic acid) had accelerated mental development by seven points on the Mental Development Index of the Bayley Scales of Infant Development II.
Infant formulas that contain DHA are now available in the United States. “This would be an excellent alternative for women who chose to not breastfeed,” says Dr. Salem.
However, he notes that there are many differences between breast milk and formula. “For lipids, the ease of digestion and the efficiency of the milk fat globule particle (the source of fat in human milk) cannot be duplicated by formula. Despite these limitations, infants that receive formulas that contain DHA have performed as well as breastfed babies in most randomized controlled trials where there was also this (uncontrolled) reference group.”
One such company which has several infant formulas on the market containing DHA is Mead Johnson. Their Enfamil Lipil line of infant formula is the first in the United States to include DHA and ARA in quantities similar to those found in breast milk, says the company.