Omega-3s delivered umbilically in the weeks before birth appear more critical than omega-3s supplied by nursing
by Craig Weatherby
The medical literature offers a wealth of evidence that babies benefit when their mothers’ diets are rich in omega-3s during pregnancy and breastfeeding.
In fact, there is no longer any doubt that mothers who consume ample amounts of omega-3s help ensure healthy pregnancies and optimal brain and eye development in their fetuses and infants.
- Findings confirm that babies’ brains benefit when mothers consume omega-3s from fish.
- Prenatal omega-3s proved far more important than omega-3s supplied in breast milk.
- Difference between pre- and post-natal omega-3s probably stems from the timing of critical brain and eye developments in the 3rd trimester.
Now a U.S.-Canadian team has published the results of a study conducted among Inuit (Eskimo) women in Quebec’s Arctic region.
Their findings affirm the hypothesis that mothers who consume ample fish-borne omega-3s during pregnancy give their babies measureable advantages in intelligence, vision, and coordination.
This applies especially to DHA, the omega-3 fat that abounds in—and is critical to— the brains and eyes of fetuses and adults alike.
As the authors wrote, “This study, which is the first to examine the effects of naturally occurring variability in prenatal DHA intake on cognitive and motor development, complements findings from maternal dietary supplementation studies about the beneficial effects of increased maternal DHA intake during pregnancy.”
The results also indicated that, compared with omega-3s obtained via breast milk, the babies gained greater benefits from omega-3s supplied in the womb during the last two to three months before birth.
Prenatal omega-3s beat out omega-3s from breast milk
The new findings come from a collaboration between researchers at Detroit’s Wayne State University School of Medicine and Quebec’s Laval University.
The third trimester of pregnancy—from week 28 of pregnancy to delivery at 38 to 42 weeks—is a crucial period for the development of neurons (brain cells) and light-receptor cells in the retina.
This final trimester is also characterized by a spurt in the formation of bridges between brain cells (synaptogenesis).
And the levels of DHA in an infant’s umbilical cord provide a good measure of the amounts of omega-3s he or she received during this critical period.
The US-Canadian study involved 109 Inuit infants in Nunavik, the northernmost portion of the Province of Quebec, which includes 14 coastal Inuit villages.
The international team measured the levels of omega-3 DHA in three places:
- The infants’ umbilical cords.
- The mothers’ blood.
- The mothers’ breast milk.
Probably because of these coastal-dwelling women’s fish-rich diets, the average levels of omega-3 DHA in their blood and breast milk were higher than those found in recent studies of women who follow a standard Western diet.
The DHA concentrations in the Inuit mothers’ blood and breast milk were similar to those seen in Finland, where fish provides a comparably substantial part of people’s diets.
Testing infant intelligence.
The Bayley scales are the most widely used of all infant/toddler development tests, and include non-verbal tests, such things as looking for hidden objects.
A growing interest in the foundations of intelligence led researches to devise newer tests that can assess information-processing skills in the very young using measures that are culture-neutral.
One of these is the Fagan test of infant intelligence, which was used in the study reported here.
The Fagan test is valuable because it elicits similar performance from infants of different cultures, and because its results reliably predict those of intelligence tests taken years later.
The scientists then administered standard tests used to measure brain, coordination, and vision development at six and 11 months of age:
- Visual acuity (Teller Cards).
- Memory and cognitive development and future intelligence (Fagan Test of Infant Intelligence).
- Cognition and coordination (Bayley Scale II).
They adusted the results to account for differences in several potentially influential factors:
- The mothers’ education and income levels.
- The mothers’ habits with regard to smoking and intake of alcohol and drugs.
- The levels of contaminants (PCBs, mercury, and lead) in the mothers’ blood and breast milk and in their babies’ umbilical cord blood.
The results gave another boost to the notion that babies are more likely to achieve optimal brain and eye development when their mothers consume adequate fish and omega-3s during pregnancy:
The infants who had higher levels of DHA in their umbilical cords at birth showed better performance on all of the intelligence, visual acuity, and coordination tests.
Surprisingly, the infants who received higher levels of DHA from breast-feeding than their peers did not score better on any of the cognitive, visual, or coordination tests.
In addition to the greater developmental importance of the prenatal period, the authors attributed the failure to detect any significant benefit from higher DHA levels in breast milk to the taking of only one sample of breast milk (as with umbilical and maternal blood).
Unlike blood levels of DHA, which are slower to change, levels of DHA in breast milk can vary widely in response to daily variations in diet.
Accordingly, compared with DHA blood tests, a single breast milk sample is a much less accurate measure of a mother’s average post-natal DHA intake.
Conclusions support emphasis on seafood for mothers
The U.S.-Canadian team came to this logical conclusion: “The association of higher [umbilical] cord DHA concentration[s] with more optimal visual, cognitive, and motor development is consistent with the need for substantial increases in this critically important fatty acid during the third trimester…”
The international team expressed their views in a press release from Université Laval:
“A diet rich in omega-3s during pregnancy can't be expected to solve everything, but our results show that such a diet has positive effects on a child's sensory, cognitive, and motor development. Benefits from eating fish with low contaminant levels and high omega-3 contents, such as trout, salmon, and sardines, far outweigh potential risks even during pregnancy.”
For more on this topic, search our newsletter archive for “child” or “development”.
- Jacobson JL, Jacobson SW, Muckle G, Kaplan-Estrin M, Ayotte P, Dewailly E. Beneficial effects of a polyunsaturated fatty acid on infant development: evidence from the inuit of arctic Quebec. J Pediatr. 2008 Mar;152(3):356-64. Epub 2007 Oct 22.
- Université Laval. L’avantage oméga-3. Le journal de la communauté universitaire Édition du 10 Avril 2008; Volume 43, numéro 27. Accessed online April 12, 2008 at http://www.aufil.ulaval.ca/articles/avantage-omega-7132.html