Mediterranean diet linked to lower risk for adverse pregnancy outcomes

Women with greater adherence to the Mediterranean diet had a nearly 30% lower risk for preeclampsia compared with women with lower adherence, according to a new study published in JAMA Network Open.

The Mediterranean diet — which includes high intake of fruits, leafy green vegetables, nuts, cereal and extra virgin olive oil and moderate intake of dairy products, fish and other meat — has previously been linked to improved cognition and a lower risk for frailty. It has also been named the best overall diet by U.S. News & World Report over the past several years.

Nour Makarem, PhD, MS, an assistant professor of epidemiology at Columbia Mailman School of Public Health, and colleagues conducted the current study to better understand “whether concordance to a Mediterranean diet pattern around the time of conception” impacted the risk for adverse pregnancy outcomes (APOs).

The analysis included data from 7,798 pregnant people. A total of 19.5% of the individuals were obese, 16.6% were Hispanic and 9.7% were aged 35 years or older. Makarem and colleagues scored each mother on a scale from zero to nine points based on their adherence to the diet, with six to nine points constituting a “high Mediterranean diet score.”

Overall, the researchers found that greater adherence to the Mediterranean diet was associated with a lower risk of APOs — which were defined as developing preeclampsia or eclampsia, preterm birth, gestational diabetes, gestational hypertension, stillbirth or delivery of a small-for-gestational-age infant — “with evidence of a dose-response association,” suggesting that “women with the highest concordance to this diet pattern prior to conception had the lowest risk of developing APOs.”

The mean score, they found, was 4.3 points. Around the time of conception:

• 30.6%, or 2,388 participants, had high concordance to the diet;
• 31.2%, or 2,430 participants had moderate concordance; and
• 38.2%, or 2,980 participants, had low concordance.

A high vs. low score was linked to 37% lower odds of gestational diabetes (adjusted OR = 0.63; 95% CI, 0.44-0.9), 28% lower odds of preeclampsia or eclampsia (aOR = 0.72; 95% CI, 0.55-0.93), and 21% lower odds of any APOs (aOR = 0.79; 95% CI, 0.68-0.92).

The researchers did not find any significant differences by race, ethnicity and pre-pregnancy BMI but did note that “associations were stronger among women aged 35 years or older” (aOR = 0.54; 95% CI, 0.34-0.84).

“This multicenter, population-based study validates that a healthier eating pattern is associated with a lower risk of adverse pregnancy outcomes, the most exciting being a 28% lower risk for preeclampsia,” Natalie Bello, MD, MPH, senior and corresponding author of the study and director of hypertension research in the Smidt Heart Institute in Los Angeles, said in a press release. “Importantly, this connection between the Mediterranean diet and lower risk of adverse pregnancy outcomes was seen in a geographically, racially and ethnically diverse population.”

The researchers concluded that “intervention studies are needed to assess whether dietary modification around the time of conception can reduce risk of APOs and their downstream associations with future development of cardiovascular disease risk factors and overt disease.”

“Taken together, our findings demonstrate that in U.S. women, adoption of a Mediterranean diet pattern may represent an important lifestyle approach for the prevention of APOs, particularly in women with advanced maternal age among whom risk for APOs is elevated,” they wrote. “Our findings add to the growing body of evidence demonstrating that the Mediterranean diet pattern may play an important role in preserving the health of women across the lifespan, including during pregnancy.”

References:

• Makarem N, et al. JAMA Netw Open. 2022;10.1001/jamanetworkopen.2022.48165.
• Mediterranean diet linked to lower preeclampsia risk. https://www.cedars-sinai.org/newsroom/mediterranean-diet-linked-to-lower-preeclampsia-risk/. Published Dec. 22, 2022. Accessed Dec. 22, 2022.