Improved IVF success with the Mediterranean diet, study shows

By Dr. Liji Thomas, MDReviewed by Benedette Cuffari, M.Sc.Aug 27 2024

Study: The Role of the Mediterranean Diet in Assisted Reproduction: A Literature Review. Image Credit: Tatjana Baibakova / Shutterstock.com

Mediterranean Diet may improve clinical pregnancy and live birth rates in women undergoing assisted reproductive technology

In a recent study published in the journal Nutrients, researchers at the National and Kapodistrian University, Athens, Greece, reviewed how the Mediterranean diet promotes fertility.

The health benefits of the Mediterranean diet

The Mediterranean Diet involves increased consumption of olive oil, whole grains, legumes, and nuts, moderate fish and white meat intake, and little red meat or processed foods.

The Mediterranean diet's cardioprotective effects are well established, as is its association with reduced rates of metabolic syndrome, diabetes mellitus, and some cancers. Some studies also suggest that this diet increases fertility and promotes better outcomes in couples using assisted reproduction technology (ART).

Infertility is diagnosed in 15% of couples in their reproductive years. ARTs, which include procedures like in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI), have become increasingly used to overcome barriers to conception; however, these treatments are both expensive and invasive.

The Mediterranean diet has been shown to improve semen and quality, embryo morphology and development, and the implantation environment, all synergistically enhancing fertility outcomes following ART. Although individual nutritional elements have been investigated for their impact on fertility, nutrients in a diet act together to produce their effects.

About the study

The current review examines the role of the Mediterranean diet in relation to reproductive outcomes in couples undergoing ART. Seven studies were included in the current review, all of which used various food frequency questionnaires (FFQs) to estimate the degree of adherence to the Mediterranean diet.

The study results were heterogeneous, with adherence levels ranging significantly across the studies. This observation emphasizes the importance of developing standardized protocols and methods for future food research. ART protocols also varied between studies, with different hormonal agents used alone or in combination.

How does the Mediterranean diet affect reproductive outcomes?

Overall, the reviewed studies reported that couples with better adherence to the Mediterranean diet were 40-100% more likely to achieve clinical pregnancy. Egg number or embryo quality was not associated with dietary adherence. Live birth rates were 2.5 times higher with better Mediterranean diet adherence; however, no dose-response relationship was reported.

Other studies failed to show positive associations between the Mediterranean diet and better reproductive outcomes, as well as better oocyte number and embryo quality. In fact, one study reported 70% poorer ovarian responses to ART in women consuming the Mediterranean diet.

Age may be involved in these associations, as one study found that live birth rates and clinical pregnancy rates significantly improved in women 35 years of age and younger. Conversely, a second study indicated a marginally reduced risk of failure to achieve clinical pregnancy in women older than 35 years who reported intermediate adherence to the Mediterranean diet.

Conclusions

The Mediterranean diet appears to have a favorable effect on ART outcomes, specifically clinical pregnancy and live birth rates. Nevertheless, additional research is warranted, as these associations were non-linear and failed to show a dose-response relationship.

The current study identified a 65% agreement rate between the different scoring methods used. While this is credible, it stresses the need for standardized assessment tools in this area.

The Mediterranean diet's components enhance endometrial receptivity, favor implantation, promote placental development in the embryo, and support a healthy pregnancy due to its qualitative nutritional input, including its antioxidant and anti-inflammatory activity.

Furthermore, the Mediterranean diet reduces systemic inflammation, combats oxidative stress, and promotes healthy glucose metabolism. These effects result in a healthier endometrial microenvironment to improve the likelihood of implantation and embryonic development.

Couples who express interest in ART should be informed about the potential benefits of the Mediterranean diet. If they follow this diet, these couples should be monitored as part of future research programs to provide additional evidence for or against these tentative and sometimes conflicting conclusions. Adjusting individual dietary components according to personal and medical restrictions could also improve adherence.

In the future, rigorous studies are needed to obtain definitive conclusions about the benefit of the Mediterranean diet in couples on ART. More specifically, larger multicenter studies should be conducted to ensure statistical power to detect changes in outcomes, as well as an adequate follow-up period. Objective methods must also be developed for these assessments.

Researchers can also improve data quality through virtual meetings, biomarker analysis, and consultations with experts through phone or digital platforms. Genetic markers could also be included in these analyses to improve dietary recommendations.