New research examines the effects of consuming a high-sugar diet on fertility in healthy young men.
Male fertility includes both sperm quantity and sperm quality, which is the ability of sperm to reach an egg. High-quality sperm are generally high-motility sperm, as they move the fastest. Many lifestyle factors influence sperm quality, including cigarette smoking, consumption of alcohol, caffeine, illegal drugs, and stress.
Risk factors for poor-quality sperm include obesity and type two diabetes. A diet high in added sugars can increase the risk of developing obesity and type two diabetes and can thereby affect fertility indirectly. To examine the direct effects of excess sugar consumption on sperm quality in humans, a Swedish study published in PLOS Biology determined the effects of a high-sugar diet on male fertility for healthy young men.
A total of 15 healthy young men who did not smoke were allocated to a researcher-controlled diet for two weeks. The diet for the first week corresponded to the Nordic Nutrition Recommendations for healthy eating. The diet for the second week was the exact same as the previous week, however, researchers added a large amount of sugar to the diet. The amount of sugar consumed was equivalent to 3.5 litres of cola or 450 grams of candy. Sperm quality was measured at the beginning of the study, as well as after the first and second week of the study.
After the study, all men had a normal level of sperm motility. This is a significant rapid improvement in sperm motility given that one-third of the participants had low sperm motility, which is consistent with the low sperm motility rate of the general population. This is surprising because sperm quality was expected to decrease after heavy sugar consumption rather than increase.
The results of this study suggest that diet could be strongly associated with sperm quality, and the effects of diet on sperm quality can be very rapid. More research is needed to determine whether this effect is causal, as the study group only consisted of 15 men. Moreover, it was unclear whether or not it was the sugar that improved sperm motility as any of the healthier aspects of the administered diet could have this effect.
Written by Avery Bisbee
Natt, D., Kugelberg, U., & Casas, E. (2019). Human sperm displays rapid responses to diet. PLOS Biology. doi: 10.1371/journal.pbio.3000559
Diet has rapid effects on sperm quality. (2019, December 27). Retrieved December 30, 2019, from https://www.eurekalert.org/pub_releases/2019-12/lu-dhr122719.php.
Durairajanayagam, D. (2018). Lifestyle causes of male infertility. Arab Journal of Urology, 16(1), 10–20. doi: 10.1016/j.aju.2017.12.004
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