The Mediterranean diet (MD) is recognized worldwide as a healthy and effective aid to weight management and overall health. A recent study published in Advances in Nutrition explores the available evidence on how consumption of MD during pregnancy affects perinatal health.
Study: Association between maternal Mediterranean diet and perinatal outcomes: a systematic review and meta-analysis. Image credit: NDAB Creativity / Shutterstock.com
The health benefits of MD
MD is associated with high consumption of whole grains, vegetables, legumes, nuts, fish, olive oil and fruit. Rich in antioxidants and anti-inflammatory compounds, MD has been shown to prevent and treat cardiovascular disease (CVD), metabolic disease, autoimmune conditions, poor mental health and cancers. MD also reduces overall mortality rates and promotes a healthy aging pattern.
Maternal diet can significantly affect the health of both mother and fetus during pregnancy and beyond. Thus, an adequate and high-quality maternal diet is essential for fetal development and metabolic and physiological homeostasis.
Many studies have investigated the importance of nutrition and nutritional status during pregnancy, which can help prevent conditions such as gestational diabetes mellitus (GDM), preterm birth and perinatal diseases.
Previous studies have shown improved metabolic health when following MD. However, there is a lack of meta-analyses on this topic. Furthermore, not all available randomized controlled trials (RCTs) have been included.
The combined use of interventional, observational, prospective, and cross-sectional studies has raised concerns about the potential impact of recall bias and reverse causality. As a result, there is limited evidence regarding the association of MD with metabolic health in pregnancy, which motivated the current study.
Study findings
In the current study, researchers reviewed 23 articles, including five RCTs and 18 cohort studies, in their systematic meta-analysis. These studies included 107,355 people from 10 different countries, including the United Kingdom, Spain, China, the United States, Greece, Norway, Denmark, Australia, and the Netherlands. Specifically, almost every study relied on the food frequency questionnaire (FFQ) to obtain information on dietary intake.
The five RCTs reported a significantly reduced risk of GDM and small for gestational age (SGA) babies. Similar results were observed in the cohort studies, in which MD was associated with a reduced risk of GDM, gestational hypertension, preeclampsia, preterm birth, low birth weight (LBW) and intrauterine growth restriction (IUGR). , along with increasing gestational age at delivery. A significant association was also observed between maternal MD and the incidence of preterm birth.
The greatest uniformity was observed for the association between MD adherence and pregnancy-associated hypertension, preterm birth and LBW. In two studies that accounted for confounders, the likelihood of pregnancy-related hypertension was reduced by 30% among those with MD. This was also observed in non-Mediterranean countries, but not when only Mediterranean countries were included.
Similarly, the risk of preterm delivery among mothers who followed MD was significantly reduced after controlling for potential confounders. However, the other parameters failed to show significant associations after such adjustment.
Pooled results demonstrate that attending MD during pregnancy reduces the risk of GDM and SGA in intervention studies. Cohort studies show that MD produces positive effects on almost all outcomes, including better metabolic health, reduced risk of gestational hypertension, increased birth weight, and higher gestational age at delivery.
The underlying mechanisms responsible for the perinatal benefits of MD may include the high antioxidant and anti-inflammatory content of this diet. Importantly, a low-carb plant-based diet helps achieve satiety earlier, thus supporting healthy weight management, particularly during pregnancy. By reducing systemic inflammation, this may help reduce the risk of preterm birth and high blood pressure during pregnancy, as well as GDM.
conclusions
Our meta-analysis focuses exclusively on strong evidence from RCTs and cohort studies, providing a comprehensive perspective on potential associations between maternal MD and both maternal and offspring outcomes..”
Future studies should include different types of evidence to determine the role of other confounders not considered in the studies included in the current meta-analysis. Larger study samples are also crucial to ensure the ability to detect these effects and guide clinical recommendations for diet during pregnancy.
Journal Reference:
- Xu, J., Wang, H., Bian, J., et al. (2024). Association between maternal Mediterranean diet and perinatal outcomes: a systematic review and meta-analysis. Advances in Nutrition 15(2). doi:10.1016/j.advnut.2023.100159.
