Antioxidants tied to lower risk of preterm birth

Pregnant women who eat plenty of red- and orange-hued fruits and vegetables may have lower odds of giving birth prematurely, a new study suggests.

In the study, among more than 5,300 women the one-half of mothers-to-be with the highest blood levels of certain carotenoids including beta-carotene and lycopene were 30 percent to 50 percent less likely to deliver prematurely than women with lower levels (1).

The researchers said that the findings do not prove cause-and-effect. There may be other things about women with high carotenoid levels that explain the association with lower preterm-birth risk. If carotenoids do help prevent premature delivery, the reasons are not clear. The scientists speculated that it could be related to protection from any ill effects of environmental toxins, like air pollution, or exposure to bacteria or other infectious agents. However, the findings do fit in with the recommendation to eat a well-balanced diet during pregnancy.

In contrast to the case with carotenoids, high blood levels of another antioxidant – vitamin E – were linked to an increased risk of preterm birth. Similarly, women with the highest blood levels of certain dietary fats, including unsaturated fats, showed a somewhat higher risk of preterm birth. Omega-3 fatty acids, found largely in fish, were unrelated to preterm delivery. The reasons for those connections are also unclear, and the findings could have been due to chance, the researchers note. They said the results are too preliminary to make any recommendations.

1. Kramer MS et al. Antioxidant vitamins, long-chain fatty acids, and spontaneous preterm birth. Epidemiology. 2009; 20(5):707–13.