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Adverse pregnancy outcomes may be reduced by Mediterranean diet (MD) adherence in a White population, according to a recent review published in the American Journal of Obstetrics & Gynecology.
- Adhering to a Mediterranean diet appears to be associated with a reduction in adverse pregnancy outcomes, particularly in White populations.
- The study emphasizes the significant impact of reproductive health on overall women's health. Lifestyle factors, obesity, and environmental chemicals have raised concerns globally,.
- The MD involves high consumption of fruits, vegetables, nuts, legumes, whole grains, and healthy fats (olive oil), along with moderate intake of fish, poultry, and dairy. Red and processed meat consumption is limited.
- The systematic review and meta-analysis included 32 studies, consisting of 22 cohort studies, 9 randomized controlled trials (RCTs), and 1 nested case-control study. Most RCTs were conducted in predominantly White populations, while cohort studies were mainly carried out in European countries or the United States.
- Women with higher adherence to the MD showed improved fertility outcomes, including enhanced embryo development, higher live birth rates, and reduced difficulty conceiving. Additionally, pregnancy-related outcomes such as gestational diabetes mellitus, preterm birth, gestational hypertension, and preeclampsia were also observed to be improved in those adhering to the MD during pregnancy
Reproductive health significantly impacts overall health in women. Increased rates of suboptimal lifestyle, obesity, and environmental chemical factors have led to concerns about female reproductive health worldwide, with rates of female reproductive disorders including up to 30% for irregular menstruation and 20% for polycystic ovarian syndrome.
The MD is a dietary style involving 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. Red and processed meat consumption is limited in individuals on the MD.
The MD targets inflammation, oxidative stress, and hormonal balance mechanisms, which are also associated with female reproductive outcomes. However, the potential impact of MD on female reproductive health has not been evaluated until now.
To assess the association between MD and female reproductive health, investigators conducted a comprehensive systematic review and meta-analysis. Databases evaluated included 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.
Search terms were developed by 2 independent reviewers and included “Mediterranean diet” as well as keywords related to female reproductive outcomes. Studies included female participants and evaluated major female reproductive outcomes.
Included studies were prospective cohort studies, case-control studies, or randomized controlled trials(RCTs). Titles and abstracts were independently screened by 2 reviewers, after which selected full texts were evaluated.
Data extracted in RCTs included study characteristics, population characteristics, study design, and outcome data. Data extracted in cohort or case-control studies included study characteristics, population characteristics, exposure assessment, outcome assessment, effect sizes of outcomes, and adjusted covariates and matching factors.
There were 32 studies included in the final analysis, of which 22 were cohort studies, 9 RCTs, and 1 a nested case-control study. Most RCTS were conducted in predominantly White populations, and most prospective cohort studies were conducted in European countries or the United States.
An RCT evaluating the impact of MD on fertility outcomes found improved embryo development in a MD group vs control group, with live birth rates of 41.5% and 32.7%, respectively. Other studies evaluated success of implantation, clinical pregnancy, and live birth among women receiving infertility treatment, with risk ratios (RRs) of 1.07, 1.13, and 1.34, respectively.
Healthy women with a greater adherence to MD also had reduced difficulty conceiving, with a reported odds ratio of 0.56. Pregnancy related outcomes were also improved in women adhering to MD, with an RR of 0.74 for gestational diabetes mellitus, 0.45 for preterm birth, 0.71 for gestational hypertension, and 0.82 for preeclampsia observed in RCTs.
These results indicated potential decreased risk of certain adverse reproductive outcomes in patients with greater adherence to a MD during pregnancy. Investigators recommended further studies to evaluate the impact of a MD on other female reproductive outcomes.
Yang J, Song Y, Gaskins AJ. Mediterranean diet and female reproductive health over lifespan: a systematic review and meta-analysis. American Journal of Obstetrics & Gynecology. 2023;229:6(617-631). doi:10.1016/j.ajog.2023.05.030