Women who eat chocolate are at decreased risk of developing preeclampsia, a potentially dangerous complication of pregnancy, a Yale study suggests.

The conclusions are reported in the current issue of the journal Epidemiology.

A team headed by Elizabeth Triche of the Yale Center for Perinatal, Pediatric and Environmental Epidemiology wanted to see if chocolate, particularly dark chocolate which had been previously linked to improved cardiovascular health, might also offer protection to pregnant mothers against preeclampsia. Preeclampsia is a disorder characterized by dangerously high blood pressure and protein in the urine. Pregnant women who suffer from the condition sometimes complain of swelling, sudden weight gain, headaches and vision problems.

The study looked at self-reported chocolate consumption and also at levels of a byproduct of chocolate consumption, called theobromine, in the cord blood of pregnant women. Although the study did not distinguish between dark and other kinds of chocolate, dark chocolate has higher levels of theobromine.

The study of 1,681 women showed that those who reported chocolate consumption of more than five servings a week had a lower risk of developing preeclampsia. Among the 1,346 women with cord blood data available, those with higher theobromine levels had significantly lower risk of developing preeclampsia than those who had low levels of theobromine.

Results were particularly dramatic for women with the highest levels of theobromine. Women who had levels in the top quartile for theobromine were nearly 70 percent less likely to develop preeclampsia than women in the lowest quartile for theobromine. Having the theobromine data available as a more objective measure of chocolate consumption was a strength of the study, Triche said.

Researchers have speculated that the presence of anti-oxidants called flavonoids in dark chocolate may confer cardiovascular benefits.

"This looks promising, but we need to do more research into how much and what type of chocolate is the most beneficial,'' Triche said.

Triche also cautioned that the study results do not mean pregnant women can eat all the chocolate they want. Excess consumption of all sweets can lead to weight gain and other health problems, she noted.

Citation: Epidemiology Vol. 19: 459-464 (May 2008)

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