Dietary supplement may reduce preeclampsia

A dietary supplement containing the amino acid L-arginine and antioxidant vitamins can decrease the incidence of preeclampsia in women at high risk of the condition, a new study finds.

The randomized, blinded, placebo-controlled clinical trial, published online May 19 in the British Medical Journal, followed a group of pregnant women at high risk of preeclampsia (based on personal history or having a first-degree relative with the condition) from 14 to 32 weeks’ gestation until delivery at a Mexico City hospital. The women were randomized to 3 groups: 228 who ate daily food bars containing 6.6 g of L-arginine and antioxidant vitamins, 222 who received food bars with vitamins only, and 222 who received placebo bars. The participants’ blood pressure and L-arginine levels were measured every 3 to 4 weeks.

Among those women in the L-arginine plus antioxidants group, 12.7% developed preeclampsia compared with 22.5% of women in the vitamins-only group, and 30.2% of the placebo group.

In addition, supplementation with L-arginine plus antioxidant vitamins was found to significantly decrease the overall rate of preterm birth, although not spontaneous preterm births (ie, premature rupture of membranes or preterm labor).

“The results of this trial support the proposed hypothesis that supplemental L-arginine can reduce the risk of preeclampsia,” the researchers conclude. A deficiency of L-arginine, which directly affects blood pressure, is believed to contribute to development of preeclampsia.

“This relatively simple and low-cost intervention may have value in reducing the risk of preeclampsia and associated preterm birth,” the authors write. They caution, however, that more research is needed to determine whether their findings are replicable and clarify “the relative contributions of L-arginine and antioxidant vitamins to the observed effects of the combined treatment.”