Regular consumption of pomegranate juice may enhance the quality and mobility of sperm, suggests a new study with male rats.
The link between the antioxidant-rich juice and male fertility could see pomegranate seen as much more than a heart healthy food, if the new results published in Clinical Nutrition can be translated to humans.
"The results of this study demonstrated, for the first time, that daily consumption of PJ for seven weeks caused increased spermatogenic cell density, epididymal sperm concentration, sperm motility and decreased abnormal sperm rate related with decreased lipid peroxidation in male rats," wrote lead Gaffari Turk from Firat University in Turkey.
The health-benefits of pomegranate have focussed almost exclusively on the pulp and juice of the fruit, most notably in fruit form although extracts are also gaining increasing attention. The antioxidant-rich fruit have been linked to improved heart health, and claims that it may offer protection against prostate cancer, Alzheimer's, and may slow cartilage loss in arthritis.
It is these antioxidants, and particularly compounds like punicalagin, which accounts for about half of the fruit's antioxidant ability, that are reportedly behind the proposed health benefits.
The new study suggests the health benefits of the fruit may also extend to improving fertility, and comes only months after a pilot study reported that pomegranate juice may help manage erectile dysfunction (International Journal of Impotence Research, doi: 10.1038/sj.ijir.3901570).
Turk and co-workers divided 28 male Wistar rats into four groups, and assigned them to drink one millilitre of distilled water (control group), 0.75 mL water plus 0.25 mL pomegranate juice (PJ), 0.50 mL water plus 0.50 mL PJ, or one mL PJ daily for seven weeks.
At the end of the experiment, the researchers report that levels of malondialdehyde (MDA), a reactive carbonyl compound and a major end product of lipid oxidation, significantly decreased as a result of PJ consumption, with the a 48.5 and 63.5 per cent decrease in the serum and sperm of the animals drinking the concentrated juice, respectively, compared to controls.
"Spermatozoa are especially susceptible to peroxidative damage because of the high concentration of polyunsaturated fatty acids which are involved in regulation of sperm maturation, [and] spermatogenesis," explained the researchers.
Levels of antioxidant enzyme activities increased as a result of PJ, report Turk and co-workers, with sperms activities of glutathione (GSH), glutathione peroxidase (GSH-Px) and catalase (CAT) increasing by 4.5, 12.5 and 52.9 per cent, respectively.
Moreover, the researchers report: "In the present study it was observed that epididymal sperm concentration and sperm motility of rats that received different doses of PJ were significantly higher than those of the control."
"Additionally, only a high dose of PJ significantly decreased total abnormality of sperms when compared to the control," they added.
Significant further research is necessary to investigate if such observations would be reproducible in humans, and the necessary doses required to illicit such improvements. Mechanistic studies would also help identify the active ingredients in the pomegranate and their direct mode of action.
Consumption of pomegranate juice has been on the rise, particularly in the UK where sales have rocketed in the last year thanks to media coverage of the antioxidant-rich fruit that has commonly been linked to improved heart health, as well as claims that pomegranate could protect against prostate cancer and slows cartilage loss in arthritis.
Source: Clinical Nutrition (Elsevier)
Published online ahead of print, doi:10.1016/j.clnu.2007.12.006
"Effects of pomegranate juice consumption on sperm quality, spermatogenic cell density, antioxidant activity and testosterone level in male rats"
Authors: G. Turk, M. Sonmez, M. Aydin, A. Yuce, S. Gur, M. Yuksel, E.H. Aksu, H. Aksoy