Obesity and Male Infertility: Role of Fatty Acids in the Modulation of Sperm Energetic Metabolism

Obesity in men of reproductive age is increasing worldwide, impacting negatively on reproductive potential, sperm function, and assisted reproduction outcomes. Changes in modern eating behaviors are needed to invert the negative correlation between lifestyle and sperm quality. It is known from the literature that fatty acids are able to modulate lipid metabolism by complex mechanisms involving a sequence of interdependent and cross‐regulated molecular events. Although a great deal of data is currently available on the dietary modulation of lipid metabolism, little is known about the nutritional regulation of sperm energetic metabolism. In this review, major data from the literature about the role of some dietary fats as modulators of sperm function and quality are described. Moreover, biochemical mechanisms responsible for an impairment or improvement in sperm bioenergetics are critically analyzed. It is noteworthy that both quantitative and qualitative aspects of dietary fats influence sperm function. The administration of a high‐fat diet, low in polyunsaturated fatty acids, caused a significant increase in body weight hyperglycemia, hyperinsulinemia, and dyslipidemia, along with a significant reduction in sperm quality. In contrast, unsaturated fatty acids are able to positively influence sperm quality and function. The understanding of the biochemical mechanisms underlying the development of male infertility related to obesity led us to depict a possible framework for the molecular action of fatty acids on sperm quality during dysmetabolic conditions. Practical Applications : In this review major data from the literature about the spermatozoa targeting of dietary fatty acids are described and critically analyzed, because now dietary fatty acids are the current focus of research in the field of nutrition and reproduction in males. Such knowledge will eventually translate into the development of new attractive therapeutic approaches for male infertility related to alterations in lipid metabolism. Dietary fatty acids are involved in the nutritional modulation of sperm energetic metabolism. Diets rich in saturated fatty acids (SFA) and low in polyunsaturated fatty acids (PUFA) seem to correlate with defective sperm energy metabolism and reduced sperm quality. Administration of PUFA, especially n‐3 PUFA, determines an increase in sperm concentration, and motility, associated to an increase in the activities of mitochondrial enzymes involved in gamete energetic metabolism and to a reduction in oxidative damaeg