Macular pigment optical density during pregnancy and its relationship to the diet
Women, compared to men, are at higher risk for age-related macular degeneration (AMD), the leading cause of blindness in the elderly. The accumulation of dietary carotenoids, lutein (L) and zeaxanthin (Z) within the macula make up macular pigment and provide important protection to the retina. Macular pigment optical density (MPOD) gives a measure of macula pigment density. MPOD has been shown to be influenced by fruit and vegetable L and Z and docosahexanoic acid (DHA, 22:6n-3), cold water marine fish being the dietary source. A high MPOD may protect against AMD. Intake of DHA by women is low (40-120 mg/d) and transfer of DHA during pregnancy to the fetus tends to deplete their stores. To date, MPOD for pregnant women has not been evaluated. We posed the question: ¡§Is MPOD decreased during pregnancy?¡¨ MPOD was measured for 22 women using a macularmetrics densitometer at 18-23, 24-26, 30, and 36-38 weeks of pregnancy. Dietary information was collected using repeated food frequency questionnaires and 24-hour dietary recalls. Women consuming a prenatal supplement containing DHA/fish oil during the third trimester tended to have a higher MPOD than those not supplementing (0.41 vs. 0.28). While MPOD did not decrease from late second to third trimester in this small sample (MPOD, LSM ¡Ó SE: 0.34„b 0.03, 0.34„b 0.03, 0.35„b 0.04, 0.31„b0.04), our data provided the opportunity to calculate that with a power of 80% and a significance of 0.05 a sample size of 121 participants is required to assess difference over pregnancy. MPOD was positively correlated with L and Z, the consumption of fruits and vegetables high in L and Z (p-value<0.02) and weekly seafood intake (p-value<0.01). In conclusion, seafood as a source of DHA and dietary L and Z were associated with increased MPOD during pregnancy and prenatal supplements with DHA/fish oil may be important in maintaining MPOD during pregnancy.