Low DHA Omega-3 Intake Found in Men with Impaired Sperm Motility
Eslamian , G. et al., Fertility and Sterility, 103: 190-198 , 2015
Depts. of Community Nutrition and Clinical Nutrition and Dietetics, Shahid Beheshti University of Medical Sciences, Tehran, Iran
‘Asthenozoospermia’ is the medical term for impaired sperm motility. This condition is involved in a considerable portion of men exhibiting infertility. Published research from our department at the University of Guelph (Conquer et al., Lipids, 34: 793-799 (1999) reported significantly lower levels of DHA omega-3 fatty acid in the total ejaculate, sperm, and seminal plasma of asthenozoospermic men in comparison to normozoospermic men. The present study was conducted to determine if a relationship could be found between the types of dietary fatty acids consumed and the occurrence of asthenozoospermia. For this purpose , food frequency assessments were conducted on 107 men having asthenozoospermia versus 235 normozoospermics (average age for all men being 33 years) and the corresponding nutrient and fatty acid compositions of the foods/diets were determined from governmental food composition tables.
For almost all lifestyle/other characteristics, no significant differences were found between the two groups. However, the mean values for total and progressive sperm motility were lower by 56-58 % in the asthenozoospermic men relative to the normozoospermic controls with the differences being highly significant statistically. Whereas the dietary intake of the short-chain omega-3 fatty acid (alpha-linolenic acid) mainly from plant food sources was not different between the two groups, significantly lower intakes of both long-chain omega-3 fatty acids (DHA – docosahexaenoic acid and EPA – eicosapentaenoic acid) mainly from fish were found in the asthenozoospermic men relative to the controls (normozoospermic men). After fully adjusting the data for confounding variables, those men in the top third with respect to DHA omega-3 intakes had significantly reduced odds (by 47 %) of having asthenozoospermia.
The present findings are supportive of previous published reports that the DHA content of sperm has been positively related to sperm motility. The unique physico-chemical properties of DHA (imparting cell membrane fluidity, enhancing cell permeability) and its conversion to bioactive products may play important roles in sperm motility and function. It is noted that the median intakes of DHA and EPA in the control men (normozoospermics) in this population were estimated to be 390 mg and 310 mg, respectively, per day. Such intakes are considerably higher that current intakes in North America and most countries. It remains to be studied in lengthy research trials if much higher intakes of fish/seafood , functional foods, and supplements containing DHA/EPA can have favourable impacts in reducing the prevalence of asthenozoospermia and male infertility.