Infertility is a global health concern affecting 48 million couples and 186 million individuals worldwide. Infertility creates a significant economic and social burden for couples who wish to conceive and has been associated with suboptimal lifestyle factors, including poor diet and physical inactivity. Modifying preconception nutrition to better adhere with Food-Based Dietary Guidelines (FBDGs) is a non-invasive and potentially effective means for improving fertility outcomes. While several dietary patterns have been associated with fertility outcomes, the mechanistic links between diet and infertility remain unclear. A key mechanism outlined in the literature relates to the adverse effects of inflammation on fertility, potentially contributing to irregular menstrual cyclicity, implantation failure, and other negative reproductive sequelae. Therefore, dietary interventions which act to reduce inflammation may improve fertility outcomes. This review consistently shows that adherence to anti-inflammatory diets such as the Mediterranean diet (specifically, increased intake of monounsaturated and n-3 polyunsaturated fatty acids, flavonoids, and reduced intake of red and processed meat) improves fertility, assisted reproductive technology (ART) success, and sperm quality in men. Therefore, integration of anti-inflammatory dietary patterns as low-risk adjunctive fertility treatments may improve fertility partially or fully and reduce the need for prolonged or intensive pharmacological or surgical interventions.

There are conflicting results on the effect of diet on fertility. This study aimed to assess the effect of different dietary patterns on fertility outcomes in populations who conceive spontaneously and those requiring assisted reproductive technology (ART). A systematic search and meta-analysis were performed for studies investigating dietary patterns or whole diets in reproductive aged women requiring ART or conceived naturally. Outcomes were live births, pregnancy rates and infertility rates. In amount of 15,396 studies were screened with 11 eligible studies. Ten different diet patterns were grouped broadly into categories: Mediterranean, Healthy or Unhealthy. For the Mediterranean diet, on excluding high risk-of-bias studies (n = 3), higher adherence was associated with improved live birth/pregnancy rates in ART [OR 1.91 (95% CI 1.14–3.19, I² 43%)] (n = 2). Adherence to various Healthy diets was associated with improved ART outcomes (ProFertility diet and Dutch Dietary Guidelines) and natural conception outcomes (Fertility diet). However, due to the variability in Healthy diets’ components, results were not pooled. Studies demonstrated preliminary evidence for the role of dietary patterns or whole diets in improving pregnancy and live birth rates. However, due to heterogeneity across the literature it is currently unclear which diet patterns are associated with improvements in fertility and ART outcomes.

Background: Nutrient supplements are widely used for type 2 diabetes (T2D), yet evidence-based guidance for clinicians is lacking. Methods: We searched the four electronic databases from November 2015–December 2021. The most recent, most comprehensive, high-ranked systematic reviews, meta-analyses, and/or umbrella reviews of randomised controlled trials in adults with T2D were included. Data were extracted on study characteristics, aggregate outcome measures per group (glycaemic control, measures of insulin sensitivity and secretion), adverse events, and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) assessments. Quality was assessed using A Measurement Tool to Assess Systematic Reviews Version 2.0 (AMSTAR 2). Results: Twelve meta-analyses and one umbrella review were included. There was very low certainty evidence that chromium, Vitamin C, and omega-3 polyunsaturated fatty acids (Ω-3 PUFAs) were superior to placebo for the primary outcome of glycated hemoglobin (HbA1c) (Mean Difference/MD −0.54, −0.54 and ES −0.27, respectively). Probiotics were superior to placebo for HbA1c (Weighted Mean Difference/WMD −0.43%). There was very low certainty evidence that Vitamin D was superior to placebo for lowering HbA1c in trials of <6 months (MD −0.17%). Magnesium, zinc, Vitamin C, probiotics, and polyphenols were superior to placebo for FBG. Vitamin D was superior to placebo for insulin resistance. Data on safety was limited. Conclusions: Future research should identify who may benefit from nutrient supplementation, safety, and optimal regimens and formulations.

Although inflammation may disrupt immunoendocrine crosstalk essential for female reproductive function, causal links to disorders like polycystic ovary syndrome (PCOS) and endometriosis remain unestablished. This study aimed to utilise Mendelian randomisation (MR) methods to explore causal associations between serum inflammatory markers and common reproductive disorders, aiming to identify novel mechanisms and potential avenues for treatment. Total causal effects of serum inflammatory markers (interleukins, monocyte chemoattractant protein-1, etc.) on female reproductive disorders in large sample cohorts of Finnish ancestry were assessed using univariable two-sample MR methods, including the inverse variance weighted (IVW) method as the primary analysis, with relevant quality assessments (e.g., leave-one out, heterogeneity, and horizontal pleiotropy testing). The main outcome measures were PCOS (642 cases and 118,228 controls) and endometriosis (8288 cases and 68,969 controls) from the FINNGEN cohort. Monocyte chemoattractant protein-1/C-C motif chemokine ligand demonstrated a positive causal association with polycystic ovary syndrome (odds ratio [95% CI]: 1.48 [1.10, 2.00], p = 0.0097), while higher interleukin-9 levels were positively associated with endometriosis (1.15 [1.02, 1.30], p = 0.0277), both via the IVW method. These markers should be investigated as key candidates for future research into the mechanistic pathways underpinning these conditions.

Background: Nutrient supplements are widely used for type 2 diabetes (T2D) yet evidence-based guidance for clinicians is lacking. Methods: We searched the four electronic databases from November 2015–December 2021. The most recent, most comprehensive, high-ranked systematic reviews, meta-analyses and/or umbrella reviews of randomised controlled trials in adults with T2D were included. Data were extracted on study characteristics, aggregate outcome measures per group (glycemic control, measures of insulin sensitivity and secretion), adverse events, and GRADE assessments. Quality was assessed using AMSTAR-2. Results: Twelve meta-analyses and one umbrella review were included. There was very low certainty evidence that chromium, Vitamin C and omega-3 polyunsaturated fatty acids (-3 PUFAs) were superior to placebo for the primary outcome of HbA1c (MD -0.54%, -0.54% and ES -0.27 respectively). Probiotics were superior to placebo for HbA1c (WMD -0.43%). There was very low certainty evidence that Vitamin D was superior to placebo for lowering HbA1c in trials of <6 months (MD -0.17%). Magnesium, zinc, Vitamin C, probiotics and polyphenols were superior to placebo for FBG. Vitamin D was superior to placebo for insulin resistance. Data on safety was limited. Conclusions: Future research should identify who may benefit from nutrient supplementation, safety, and optimal regimens and formulations.