Could hormone residues be involved?

The effect of dietary habits on oocyte/sperm quality

The effects of diet and nutritional habits on reproductive cells can be categorized in a variety of ways. In this review, the literature is divided, based on the dietary consumption effects on oocytes and sperm. Topics on dietary patterns and the intrauterine effect of maternal nutrition are covered. In general fruits, vegetables, whole greens, fish, legumes, and also dietary sources containing unsaturated fats can improve reproductive germ cell quality. In epidemiological studies, the food intake frequency questionnaire is one of the most common methods to assess diet. Due to methodological heterogeneity in dietary assessment and inadequacy in the measurement of dietary intake in the questionnaires used, several unreliable results may be reported. Thus, the quality of evidence needs to be improved, since nutritional diets may not be so simply objective and they are inadequate to explain obvious underlining mechanisms. In addition, various compounds that may be ingested can affect molecular mechanisms, influenced by other external factors (drugs, pesticides, smoking, alcohol) and changes in human nutritional parameters. Artificial Intelligence has recently gained widespread interest and may have a role in accurate analysis of dietary patterns for optimal nutritional benefit. Therefore, future prospective randomized studies and objective measurements, consisting of molecular level analysis of the impact on cells and clear-cut methods are needed for accurate assessment of the effect of dietary habits on reproductive treatment.

Dietary Patterns and Their Relationship With Semen Quality

Diet is a complex exposure variable, which calls for multiple approaches to examine the relationship between diet and disease risk. To address these issues, several authors have recently proposed studying overall dietary patterns by considering how foods and nutrients are consumed in combinations. The aim of the study was to investigate the associations between dietary patterns, semen quality parameters, and the level of reproductive hormones. The study population consisted of 336 men who attended the infertility clinic for diagnostic purposes and who had normal semen concentration of 20 to 300 mln/ml or slight oligozoospermia (semen concentration of 15-20 mln/ml). Participants were interviewed, and a semen sample was provided by them. Diet was assessed via food frequency questionnaire, and dietary patterns were identified by factor analysis. Men were classified into three groups according to scores of each dietary pattern: Western, Mixed, or Prudent. A positive association was observed between sperm concentration and Prudent dietary pattern, and level of testosterone and Prudent dietary pattern ( p = .05, p = .03, respectively). Additionally, Prudent dietary pattern was identified to decrease the DNA fragmentation index ( p = .05). The results were adjusted for sexual abstinence, age, smoking, past diseases, and alcohol consumption. Higher consumption of a Prudent dietary pattern was associated with higher sperm concentration and higher level of testosterone. Sperm chromatin structure was inversely related to higher consumption of a Prudent dietary pattern. Further research is needed to confirm these findings and extend these results to other populations.

Endocrine-disrupting chemicals: associated disorders and mechanisms of action

The incidence and/or prevalence of health problems associated with endocrine-disruption have increased. Many chemicals have endocrine-disrupting properties, including bisphenol A, some organochlorines, polybrominated flame retardants, perfluorinated substances, alkylphenols, phthalates, pesticides, polycyclic aromatic hydrocarbons, alkylphenols, solvents, and some household products including some cleaning products, air fresheners, hair dyes, cosmetics, and sunscreens. Even some metals were shown to have endocrine-disrupting properties. Many observations suggesting that endocrine disruptors do contribute to cancer, diabetes, obesity, the metabolic syndrome, and infertility are listed in this paper. An overview is presented of mechanisms contributing to endocrine disruption. Endocrine disruptors can act through classical nuclear receptors, but also through estrogen-related receptors, membrane-bound estrogen-receptors, and interaction with targets in the cytosol resulting in activation of the Src/Ras/Erk pathway or modulation of nitric oxide. In addition, changes in metabolism of endogenous hormones, cross-talk between genomic and nongenomic pathways, cross talk with estrogen receptors after binding on other receptors, interference with feedback regulation and neuroendocrine cells, changes in DNA methylation or histone modifications, and genomic instability by interference with the spindle figure can play a role. Also it was found that effects of receptor activation can differ in function of the ligand.