The roles of omega-3 and omega-6 fatty acids in idiopathic male infertility

Abstract

mega-3 fatty acids found in some foods have a wide-range of health benefits. The omega-3 supplementation results in higher antioxidant activity in human seminal fluid and enhanced sperm count, sperm motility, and sperm morphology. Considerable number of infertile men with idiopathic oligoasthenoteratozoospermia might be benefit from omega-3 fatty acids administration.Infertility caused by idiopathic oligoasthenoteratozoospermia(OAT) syndrome without any female factor represents one of the biggest patients group in the daily practice of urologists. Despite great advances in the field of infertility, still many cases of male infertility are diagnosed as idiopathic and remained untreated. In low-income communities where health service resources are restricted and basic health needs are unmet, health resources are not used to provide expensive technologies for the treatment of infertility. Social and family consequences of infertility, especially in developing and under developed communities are devastating. A decrease in male fertility has been occurred over the years. 1 Sperm density had fallen by 40% over the past 50 years. 2 One of the reasons for the impaired semen parameters over the years is dietary factors. 3,4 The significant effects of dietary fatty acids (FAs) on male fertility have been well documented both in animal and human studies. 5,6 There are three types of natural FAs: saturated, monounsaturated and polyunsaturated. Polyunsaturated fatty acids (PUFAs) are essential FAs, because they cannot be synthesized by the human body. Docosahexanoic acid (DHA), eicosapentanoic acid (EPA) and alinolenic acid are the main omega-3 PUFAs.Linoleic acid, c-linolenic acid and arachidonic acid (AA) are the main omega-6 PUFAs. The first mechanism by which omega-3 and omega-6 PUFAs affect spermatogenesis, is by the incorporation into spermatozoa cell membrane. Omega-3 and omega-6 PUFAs are structural components of cell membranes. 7 The lipid bilayer of cellular membranes is maintained by the presence of these PUFAs. 8 The successful fertilization of spermatozoa depends on the lipids of the spermatozoa membrane. 9 Deleterious health effects of increased dietary omega-6/omega-3 ratios have been documented in many studies. 10 The ideal ratio is 1:1. During the past 100 years, omega-6 PUFAs of Western diets have increased dramatically. This has resulted in an omega-6/omega-3 ratio of 25:1 to 40:1. 11 Increased omega-6/omega-3 ratio in spermatozoa has also been implicated in impaired semen quality in oligozoospermic and/or asthenozoospermic men. 12 Spermatozoa from asthenozoospermic and oligozoospermic men exhibit decreased concentrations of DHA compared with those from normozoospermic men. Conquer et al. 13 demonstrated that, compared with normozoospermic men, spermatozoa from asthenozoospermic men have diminished concentrations of DHA and higher concentrations of oleic acid. Safarinejad et al., 14 investigated PUFA composition of the blood plasma and spermatozoa in men with idiopathic OAT. They found that, fertile men h...

Effect of different dietary omega-3/omega-6 fatty acid ratios on reproduction in male rats

“…Accumulating evidence from studies in men [4,22] and animals [1,6,7] indicated that consumption of n-3 fatty acids was beneficial to male reproductive capacity, but the appropriate ratio of n-3/n-6 PUFAs for male reproduction was still not known.…”

“…The lipid composition, the degree of PUFA unsaturation, and the proportion of sperm PUFA have been shown to affect sperm quantity [2-4]. Animals cannot synthesize n-6 or n-3 fatty acids de novo because of a lack of the appropriate fatty acid desaturase enzymes.…”

“…Studies in men [4] and boars [1,6,7] have demonstrated the benefits of n-3 fatty acids on male reproductive capacity. While, other studies in humans [8] and boars [9] did not show any effect of n-3 PUFA supplementation on semen quality or quantity post-ejaculation.…”

Histomorphometric study on testes in rams fed with linseed oil rich in omega-3 and -6 polyunsaturated fatty acids

“…Experiments carried out by other scientists demonstrated that the intake of n-3 fatty acids was beneficial to male reproductive capacity, resulting in histological and ultra-structural changes in the testis and sperm, better spermatogonial development, a larger number of germ cell layers (5), an increased total number of sperm per ejaculation, greater sperm quality, density and motility, as well as an increased membrane integrity of sperm in humans and animals (4,18,22,23,25,28), which may be related to changes in hormone metabolism (16 …”

Male fertility: modifiable and non-modifiable risk factors (a review)

“…Позитивный эффект может быть связан с при-сутствием некоторых эссенциальных элементов, в частности, полиненасыщенных жирных кислот (ПНЖК) семейств ω-3 и ω-6 [25]. Эти кислоты явля-ются структурными компонентами мембран сперма-тозоидов, от которых во многом зависит их оплодо-творяющая способность.…”