The ratio of omega-6 to omega-3 was also found to be higher in infertile men, according to findings from a study with 150 men in Iran in the peer-reviewed journal Clinical Nutrition.
“These results suggest that research should be performed to assess the potential benefits of omega-3 fatty acid supplementation as a therapeutic approach in infertile men,” wrote the researchers, led by Mohammad Reza Safarinejad from Shahid Beheshti University in Tehran, Iran.
“To our knowledge, this is the first study evaluating the association of omega-3 and omega-6 fatty acids on semen quality, and seminal plasma anti-oxidant capacity in infertile and fertile men,” they added.
Being the first such study, the researcher noted that “there is a need for future, large, prospective studies to confirm the results of the present study”.
The study adds to a small but growing body of evidence supporting the importance of balance between omega-3 omega-6 fatty acids.
Safarinejad and his co-workers measured levels of polyunsaturated fatty acids in the blood plasma and spermatozoa of 82 infertile men who suffered from defective production of spermatozoa, and 78 fertile men.
Specifically, they looked at levels of the omega-3 fatty acids, including alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and the levels of omega-6 fatty acids, such as linoleic acid (LA) and arachidonic acid (AA).
According to their results, fertile men were found to have higher blood and sperm levels of all three omega-3 fatty acids. Furthermore, infertile men had significantly higher blood ratios of omega-6 to omega-3 fatty acids.
Levels of AA were higher in the infertile men, added the researchers, while the ratios of AA to DHA and EPA were also higher.
The AA to DHA or EPA ration was also linked to lower sperm counts, and decreased sperm motility.
“A high proportion of omega-6 fatty acids in the spermatozoa is a distinctive feature of infertile men. There is a growing body of evidence that the fatty acid composition of sperm membranes, determine their physiological characteristics,” wrote the researchers.
“The data tend to support a possible beneficial effect of omega-3 fatty acid supplementation among patients with [defective production of sperm],” said the researchers.
The findings are biologically plausible, noted the researchers, with DHA, for example, known to be present in the membranes of spermatozoa.
The researchers note that the results of this study are limited to Iranian men and therefore cannot be generalised to other populations. They also note that no data was collected about dietary or supplemental intakes of fatty acid-containing foods.
Source: Clinical Nutrition
Published online ahead of print, doi: 10.1016/j.clnu.2009.07.008
"Relationship of omega-3 and omega-6 fatty acids with semen characteristics, and anti-oxidant status of seminal plasma: A comparison between fertile and infertile men"
Authors: M.R. Safarinejad, S.Y. Hosseini, F. Dadkhah, M.A. Asgari