Nutrition and infertility: Fertile field of research and intervention with preventive value
The growing scale of infertility has prompted the World Health Organization to recognize this phenomenon as a social disease, which affects about 13-17% of couples of reproductive age . Definitely, success in treatment of infertility requires a professional teamwork of various specialists who consider wide range of multiple underlying causes. Large body of evidences reinforces direct and indirect impact of specific dietary factors upon fertility status in female and male [3, 4]. In fact, hormonal and neuroendocrine controls of energy balance, appetite control, insulin sensitivity and reproduction are closely intertwined. Proper nutritional modification based on comprehensive nutrition assessment, adjuvant to invasive treatments can influence both ovulation induction and improve sperm profile via hormonal and metabolic axis, antioxidant capacity and fatty acids flux in the body [6, 7]. At present, many artificial reproductive treatment (ART) centers do not integrate nutrition counseling in their treatment protocols, or nutrition counseling is only limited to obese or very underweight amenorrhoeic cases, whereas, there are many infertile subjects with normal body weight, who suffer from degrees of dietary imbalances [8, 9]. Also, at hypothalamic level the effects of dietary composition override the effects of body weight which directly and indirectly impact fertility and optimum responsiveness to infertility treatments. Type of protein intake, quality and quantity of carbohydrates are proven to have important impact on ovulation[10, 11]. According to the latest reports, nutrient deficiencies (vitamin D, Fe, Zn,B vitamins), low antioxidant intake, inappropriate dietary patterns and mal dietary habits such as meal skipping and false dieting, are not uncommon among infertile couple[11-16]. The wide array of dietary influences on ovulatory dysfunction suggests a complex balance of nutrition for optimal fertility and confirms the dictum that there is no “one size fits all” dietary intervention to boost fertility. Thereby, specialized nutrition counseling is highly necessary to be considered for infertile female as they attend for treatment. Additionally, the deleterious effects of dietary factors can impair spermatogenesis, sperm concentration, motility, and increase sperm DNA damage. Especially, infertile obese male with diabetes, dyslipidemia or metabolic syndrome are at increased risk of oxidative stress in the testicular microenvironment or excurrent ductal system [17, 18]. Although, number of nutritional therapies and antioxidants as, zinc, selenium, vitamin B12 , Vitamin C, Vitamin E, Glutathione and Coenzyme Q10 , carnitine and arginine have been shown to improve sperm count and motility , none of these interventions can provide optimum support without complete assessment of food intake and appropriate dietary modifications. Therefore, providing timely optimal paternal diet therapy can promote sperm and embryo quality and eventually the rate of live birth success. Finally, succession in infertility treatment is not finalized only in pregnancy, but the ultimate aim has to be producing a child with optimum neurodevelopment and lowest susceptibility to chronic diseases during its life span [20, 21]. Hence, improving metabolic condition and nutrient demands of infertile couple, at least three months prior initiation of reproduction treatment cycle is definitely crucial opportunity for developing healthy generation. Conclusively, scientific based approaches on setting standards of nutrition care during ART program need to receive more attention in infertility treatment package worldwide.