Mediterranean diet boosts fertility, averts poor pregnancy outcome

Keeping to a Mediterranean diet improves fertility and averts poor pregnancy outcomes in a comprehensive review and meta-analysis conducted by Singaporean researchers.  

Mediterranean diet involves a high consumption of fruits, vegetables, nuts, legumes, whole grains, and healthy fats with olive oil, as well as moderate consumption of fish, poultry, and dairy products, and limiting consumption of red and processed meat.

In this meta-analysis, women who adhered to a Mediterranean diet had improvements in fertility outcomes, including enhanced embryo development, higher live birth rates, and reduced difficulty in conceiving. [Am J Obstet Gynecol 2023;229:617-631]

Additionally, pregnancy-related outcomes such as gestational diabetes, preterm birth, gestational hypertension, and preeclampsia improved in those who adhered to the Mediterranean diet during pregnancy.

Diet and reproductive health: The connection

There are concerns about female reproductive health worldwide because of the increase in suboptimal lifestyle, obesity, and environmental chemical factors. However, the potential impact of the Mediterranean diet – aimed at targeting inflammation, oxidative stress, and hormonal balance – on reproductive health has not been investigated until this study.

To assess the association between the Mediterranean diet and female reproductive health, researchers from the Global Centre for Asian Women’s Health, Yong Loo Lin School of Medicine, National University of Singapore, Singapore identified studies from databases of PubMed, Embase, MEDLINE, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, National Knowledge Infrastructure, Wanfang Data, and Korean Studies Information Service System and Research Information Sharing Service.

Thirty-two studies comprising 22 cohort studies, nine randomized controlled trials (RCTs), and 1 nested case-control study were included in the meta-analysis. Most RCTs were conducted in predominantly White populations, while cohort studies were mainly carried out in the US and European countries.

Data extracted from RCTs included study and population characteristics, study design, and outcome data. Data extracted from cohort or case-control studies included study and population characteristics, exposure assessment, outcome assessment, effect sizes of outcomes, and adjusted covariates and matching factors.

One RCT found improvement in embryo development in the group adhering to the Mediterranean diet compared with the control group. Live birth rates were 41.5 percent vs 32.7 percent, respectively. Other studies evaluated the success of implantation, clinical pregnancy, and live births among women receiving infertility treatment, with risk ratios (RRs) of 1.07, 1.13, and 1.34, respectively.

Decreased risk of adverse outcomes

Healthy women with greater adherence to the diet also had reduced difficulty conceiving, with a reported odds ratio of 0.56. Pregnancy-related outcomes were also improved in those adhering to the Mediterranean diet (RR, 0.74 for gestational diabetes, 0.45 for preterm birth, 0.71 for gestational hypertension, and 0.82 for preeclampsia) in the RCTs.

These results suggest a decreased risk of certain adverse reproductive outcomes in patients who adhered to the Mediterranean diet. However, further studies are warranted to evaluate the impact of the diet on other female reproductive outcomes.