A recent study within the journal Nutrients evaluates whether adherence to the Mediterranean weight-reduction plan (MD) affects sperm parameters.

Study: Observational Cross-Sectional Study on Mediterranean Weight loss plan and Sperm Parameters. Image Credit: losinstantes / Shutterstock.com

Background

In Western countries, 15-25% of couples experience infertility problems. Previous research has shown that about 50% of infertility cases might be attributed to male aspects.

Along with congenital problems, other aspects that impact male fertility include diabetes, hypertension, insulin resistance, obese/obesity, and atherosclerosis. Cigarette smoking, excessive alcohol consumption, and lack of physical activity also negatively affect male fertility.

Recent studies have also provided latest insights into how an unhealthy weight-reduction plan influences male fertility. For instance, preserved and processed meat, alcohol, sugary beverages, and foods with high levels of saturated fatty acids negatively impact sperm quality.

Male reproductive health is significantly benefitted from a low intake of trans fats and saturated fats and a high consumption of omega-3 fatty acids, carotenoids, polyphenols, vitamins, and antioxidants. Fish, whole grains, poultry, vegatables and fruits, seafood, and low-fat dairy products improve sperm quality.

Typically, a Western weight-reduction plan involves a high intake of ultra-processed foods that contain a big amount of sugars and fats. The regular intake of those foods creates dietary imbalance and introduces excessive calories.

A high-calorie weight-reduction plan causes obesity, which has been linked to insulin resistance, particularly hyperinsulinemia and hyperglycemia. Obesity induces changes in glucose metabolism within the sperm. Impaired glycolysis enhances oxidative stress, which affects sperm quality and male reproductive function.

Many studies have highlighted the positive effects of MD against non-communicable diseases, including cardiovascular diseases (CVDs). MD involves the high consumption of seasonal vegetables and fruits, fish, nuts, cereals, legumes, a moderate amount of wine, and a low intake of meat and dairy products.

MD is wealthy in antioxidants and anti inflammatory molecules, monounsaturated fatty acids, fibers, and low in saturated fat. Each anti-inflammatory and antioxidant molecules function as a gene modulator and reactive oxygen species (ROS) scavenger. Previous studies have shown that natural dietary components improve sperm parameters, including sperm motility, viability, and concentration.

Concerning the study

The present study hypothesized that higher MD adherence would positively profit male reproductive health and sperm parameters. The current observational cross-sectional study evaluated the association between MD adherence and sperm parameters.

Individuals who were referred to the Andrology and Reproductive Medicine Unit, University Hospital of Padova, between September 2022 and July 2023 for semen evaluation were considered for this study. All participants were between 18 and 45 years of age and didn’t have a history of varicocele, testicular cancer, endocrinopathies, genetic causes of infertility, and semen infections. Semen samples were collected from participants after two to seven days of sexual abstinence and were analyzed.

The body mass index (BMI) of all participants chosen on this study was estimated. Adherence to MD was assessed using a validated 14-point a priori Mediterranean Weight loss plan Adherence Screener (MEDAS) within the presence of a dietitian. 

Study findings

A complete of 300 non-obese males were enrolled on this study, and their mean age was 34.6 years. About 32%, 36.7%, and 31% of the cohort reported low, medium, and high adherence to MD, respectively. Notably, smokers and non-smokers showed different MD adherence.

The extent of MD adherence significantly correlated with sperm parameters. Being obese or obese negatively influenced the hypothalamic-pituitary-gonadal axis and affected spermatogenesis and energy metabolism. Adherence to MD prevented metabolically unfavorable phenotypes in men.

As a result of the low levels of saturated fatty acids and trans fatty acids, in addition to adequate levels of polyunsaturated fatty acids fraction (PUFA) and monounsaturated fatty acids, MD is positively correlated with male fertility status. All major predictors of fertility potential, including sperm motility, morphology, viability, and count, were significantly and positively correlated with the MEDAS rating. This finding strongly highlights that nutrition regimen might be a possible biomarker of sperm abnormalities, particularly in those that remain idiopathic.

Participants who belonged to the bottom tertile of MD adherence rating exhibited poor sperm motility, count, and concentration as in comparison with those with a high MD adherence rating. In keeping with the findings of a previous study, the present study revealed that MD is positively related to sperm parameters, particularly sperm count and concentration.

Conclusions

A key strength of this study is its sample size. The exclusion of known andrological conditions and the homogeneous evaluation of the MD regimen by a single dietitian are other strengths of this study.

The present study also has some limitations, including its cross-sectional and observational design, which made it difficult to discover the causal factor linking MD adherence to semen parameters.

Despite these limitations, the study findings indicate that higher adherence to MD promotes higher semen quality in males, whereas reduced MD adherence alters semen parameters, particularly sperm count. Due to this fact, dietary intervention might be an efficient and non-invasive strategy for men with poor sperm quality.