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A new study suggests adhering to a Mediterranean diet during early pregnancy may lower the risk of adverse outcomes, especially for people over 35. Anna Malgina/Stocksy
  • T​he Mediterranean diet consists of minimally processed foods, including fruits, vegetables, poultry, and fish.
  • A​ recent study found that adhering to a Mediterranean diet during early pregnancy may reduce the risk of adverse pregnancy outcomes like preeclampsia, preterm birth, and gestational diabetes.
  • The findings show the benefits were highest among pregnant people ages 35 and older.
  • Pregnant people should follow the FDA’s recommendations for safe fish consumption during pregnancy.

Dietary recommendations during pregnancy continue to evolve as researchers gain new insights into the best nutrition for a pregnant person and their developing fetus.

As more data emerges, experts continue to recommend what’s safe to eat and not eat during pregnancy.

A​ recent study found that following a Mediterranean diet around the time of conception and during early pregnancy may decrease the risk for adverse pregnancy outcomes.

The results were published in JAMA Network.

Named “Best Diet Overall” for 6 consecutive years, the Mediterranean diet is an eating pattern that may offer certain health benefits.

Adherence to this eating pattern may improve blood glucose levels and help reduce the risk of certain chronic conditions, including adverse cardiovascular events.

The Mediterranean diet includes high levels of fruits and vegetable intake. People following this diet type consume fish as well as some dairy and poultry. The diet also emphasizes olive oil as a main source of fat.

Researchers are still working to understand how a Mediterranean diet may benefit pregnancy outcomes. One concern is fish intake during pregnancy because of the risk of consuming mercury.

N​on-study author and registered dietitian Aderet Dana Hoch, MS, RD, CDN, explained to Medical News Today:

“It’s recommended that women who are pregnant ensure they are getting enough omega-3 fats in their diet, EPA and DHA, typically found in foods like oily fish. But some fish sources can also have a high mercury content, and this should be avoided during pregnancy. Unfortunately, fish mercury contamination is a byproduct of our environment, and we don’t have proper monitoring systems in place. Mercury passes from mother to fetus and can impact the brain of the developing fetus. High levels of mercury are usually found in fish like shark, swordfish, tilefish, albacore tuna, and bass.”

To help prevent mercury contamination during pregnancy and postpartum, the Food and Drug Administration (FDA) offers recommendations for safe fish intake for people who are pregnant or nursing.

The institution recommends consuming 8 and 12 ounces of seafood each week during pregnancy. This intake should come from various seafood options that are low in mercury.

Examples of low-mercury fish options include catfish, clams, crab, crawfish, haddock, and scallops, among others.

With this caution in mind, there are many potential benefits to the Mediterranean diet that can still be explored.

T​he new research is based on a cohort study that included nearly 8,000 pregnant people.

Researchers recruited a diverse group for this study, which was helpful in the data collection.

They wanted to see if consuming a Mediterranean diet around the time of conception reduced the risk for adverse pregnancy outcomes.

Study author Dr. Natalie Bello, MPH, a physician scientist and multimodality imaging cardiologist at Cedars-Sinai Medical Center in Los Angeles, explained to MNT:

“Adverse pregnancy outcomes (APOs) are increasing in frequency in the United States and are associated with a heightened risk of adverse events for mom and baby in both the short- and long-term. Right now, we don’t have a lot of good strategies to reduce this risk. We do know that making healthy food choices prior to conception and in pregnancy is important for the health of mother and baby.”

To evaluate the potential effects of a Mediterranean diet during early pregnancy, researchers measured adherence to the eating pattern using a special scoring system. They evaluated the intake of the diet’s components like vegetables, fish, and whole grains.

A​ higher score meant a higher adherence to a Mediterranean diet.

Researchers then examined the association between adherence to this diet and the risk for several adverse pregnancy outcomes.

The results show that higher adherence to a Mediterranean diet during early pregnancy was associated with a lower risk for adverse pregnancy outcomes.

The researchers further found that the benefits of eating a Mediterranean diet may be highest for pregnant people of advanced maternal age (35 and older) whose risk for adverse pregnancy outcomes is elevated.

Dr. Bello explained the study’s key findings to MNT:

“Higher compliance with an ‘Alternative Mediterranean Diet (aMed)’ score was associated with a 21% lower risk of any adverse pregnancy outcome (preeclampsia, preterm birth, gestational HTN [hypertension], gestational DM [diabetes mellitus], small for gestational age infant or stillbirth), 28% lower risk for preeclampsia and 38% lower risk of gestational diabetes. Women of all races, ethnicities, and body weights (BMI) benefited equally. We did find that women aged ≥35 years had evidence of a stronger benefit from this diet.”

Despite the positive implications, the study has some limitations to consider.

First, the data did rely on self-reporting from participants about diet, which is not always reliable. Some participants had access to certain prenatal care that may have influenced the associations.

In addition, researchers could only do limited subgroup analysis, indicating the need for further studies. The study cannot establish causality, and researchers noted that there is still the risk of residual confounding.

D​r. Bello noted the following areas for further research:

“Next steps will include testing the benefits of a Mediterranean diet prospectively prior to conception and in early pregnancy to see if adverse pregnancy outcomes can be prevented. We are looking forward to piloting a randomized trial at Cedars-Sinai in the near future.”

Those in early pregnancy and those seeking to become pregnant can work with doctors and nutrition experts to establish healthy eating patterns during critical periods.

“Following specific dietary recommendations is not easy to do on our own,” Hoch noted. “It’s best to find support — this can mean downloading a health app that can help track intake and lifestyle.”

Hoch added that some people may benefit from working with a dietitian during pregnancy and postpartum, which will “give you the tools and accountability you need to follow dietary recommendations.”