The Mediterranean diet delivers plenty of health dividends, and new research now discovers it may lower complications during pregnancy.

Specifically, women who stuck to the diet had a 21% overall reduced risk of preeclampsia, gestational diabetes, preterm birth, delivery of a small baby and stillbirth, researchers report.

“We know adverse pregnancy outcomes are becoming more common in the United States,” said lead researcher Dr. Natalie Bello, director of hypertension research at the Smidt Heart Institute at Cedars-Sinai Medical Center in Los Angeles.

These bad outcomes can have serious consequences for mom and baby, Bello said.

“While we still need more information, it seems like the adoption of a Mediterranean-type diet could be an important lifestyle approach to preventing these adverse outcomes,” she added.

The Mediterranean diet is rich in vegetables, fruits, nuts, whole grains, legumes and fish, while it is low in red and processed meats and alcohol. “This diet is associated with lower blood pressure, and more favorable profiles of glucose levels, so lower sugar levels and less insulin resistance,” Bello said.

Bello noted this study can’t prove that this diet caused the lower risk of complications, only that it was related to a reduced risk.

“Our thoughts are that you have a healthier background going into pregnancy,” Bello said. “Pregnancy can be a stress test for the body. A lot of people who eventually develop heart disease may have manifestations during their pregnancy in the form of these adverse pregnancy outcomes. And so perhaps it lowers your baseline levels of inflammation and if you go in healthier, you can withstand the stresses of pregnancy better,” she suggested.

For the study, Bello and her colleagues collected data on nearly 7,800 women who took part in a major study of pregnant women. These women, who were all having their first baby, completed a questionnaire about their diet during their first trimester.

Specifically, those who followed a Mediterranean diet saw their risk for preeclampsia and eclampsia drop by 28%, while the risk for gestational diabetes dropped by 37%.

Preeclampsia, dangerously high blood pressure during pregnancy, puts stress on the mother’s heart. If untreated, it can cause complications, such as weakened kidney and liver function, and decreased blood supply to the fetus, the study authors noted.

Surprisingly, the association between the benefits of a Mediterranean diet and the lower risk of pregnancy complications was strongest among women aged 35 and older, Bello said.

“In general, women over the age of 35 have a much higher risk of developing preeclampsia,” she noted. “If anything, I would say it’s encouraging.”

The findings were published online Dec. 22 in JAMA Network Open.

“It is not surprising that adhering to a more plant-based diet like the Mediterranean diet improves pregnancy outcomes,” said Samantha Heller, a senior clinical nutritionist at NYU Langone Health in New York City.

“Research has found that this type of dietary pattern helps promote health and reduce the risk of chronic diseases due to the many varied compounds contained in plants such as fiber, vitamins, minerals, and phytochemicals,” explained Heller, who was not involved with the new study.

A lifestyle before and during pregnancy that includes a more plant-based, balanced diet and regular exercise is good for mother and baby, she said.

“In fact, research suggests that a healthy lifestyle preconception is also good for the father and can affect sperm health and motility,” Heller added.

More information

For more on the Mediterranean diet, head to the American Heart Association.

SOURCES: Natalie Bello, MD, MPH, director, hypertension research, Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles; Samantha Heller, MS, RD, CDN, senior clinical nutritionist, NYU Langone Health, New York City; JAMA Network Open, Dec. 22, 2022, online

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