The Impact of Obesity and Whole-Food Patterns
The strongest evidence in reproductive nutrition concerns the overarching effect of metabolic health. Obesity (BMI ≥30 kg/m2) is consistently associated with a 15% reduction in live birth rates in assisted reproduction, likely mediated by systemic inflammation and hormonal dysregulation. Conversely, adhering to high-quality dietary patterns—such as the Mediterranean or American Heart Association diets—has been linked to a significant reduction in miscarriage risk (OR 0.39–0.81).
These diets, characterized by high intake of seafood, vegetables, and complex grains, provide the substrate necessary for optimal mitochondrial function and reduced oxidative load, though their absolute ability to guarantee live birth remains variable across cohorts.
Antioxidants, Oxidative Stress, and Reductive Risk
The role of antioxidants like CoQ10, Vitamin C, and Vitamin E is frequently marketed as a means to improve oocyte and sperm quality. While preclinical evidence and small cohort studies suggest these supplements can increase follicular fluid antioxidant content, clinical results are inconsistent. There is an increasing recognition of the risk of 'reductive stress'—a state where excess antioxidants inhibit the physiological reactive oxygen species necessary for cell signaling and maturation.
Current protocols lack standardization, and the transition from animal-model efficacy to human fertility success is largely unproven for the majority of these compounds.