A Docosahexaenoic Acid-Functional Food During Pregnancy Benefits Infant Visual Acuity at Four but not Six Months of Age
Department of Nutritional Sciences , University of Conneticut, Storrs, CT. Department of Statistics, University of Conneticut, Storrs, CT.
The present study was conducted in view of the physiological essentiality of DHA (docosahexaenoic acid, 22:6n-3) in the retina of the eye for optimal visual acuity in infants and the generally low intakes of DHA particularly during the last trimester of pregnancy where accelerated DHA accumulation in the brain and retina of infants occurs. In this study, 30 pregnant women were assigned to either a placebo group or to a treatment group where a DHA–containing functional food was consumed in the form of a cereal bar from 24 weeks of pregnancy to delivery. The basal diet as consumed by the women provided approximately 80mg/day such that the placebo control group and the group on the DHA-functional food had total daily DHA intakes of approximately 80mg/day and 294 mg DHA/day (with 214mg of DHA coming from the cereal bar), respectively.
As seen in the figure below showing the results from this study for infants tested via acuity card procedure (ACP) as a measure of visual acuity, the visual acuity scores were significantly higher (by 19%) in the infants from mothers consuming the DHA-enriched diet (via the DHA-containing functional food) as compared to those mothers on the basal diet. No significant difference in visual acuity in the infants was found between the two groups at 6 months of age. The authors conclude based on their results that DHA supplemented during pregnancy may play a supportive role in the maturation of the visual system in infants.
It is of interest to point out that the daily DHA intake form the base diet of these American women (80 mg/day) is very close to the daily DHA intake of 82 mg/day reported by our group at the University of Guelph via direct assessment. (J. Nutr. 135: 206-211, 2005) Such low intakes are reflective of a very modest intake of DHA-containing fish during pregnancy in North America where the average consumption of fish is approximately only one serving every 10 days with many women having intakes well below 80-82 mg DHA/day. While some fish (example, swordfish, shark, some types of tuna, others) are considered unsuitable for regular consumption during pregnancy due to contaminants (including methyl mercury) many other fatty fish rich in DHA (eg, salmon, rainbow trout, others) consumed at the level of 2-3 times per week can provide an average daily intake of approximately 250-300mg DHA/day. For the majority of the population who chose not to increase fish consumption for various reasons, the availability of DHA-containing functional foods such as those employed by the present investigators can offer important alternative sources of DHA during pregnancy. In addition, supplementation with DHA as well as folic acid (for the prevention of spina bifida in infants) is becoming increasingly popular as a means of ingesting these important nutrients during pregnancy.