Sperm size and shape in young men affected by cannabis use

http://www.eurekalert.org/pub_releases/2014-06/uos-ssa060414.php

PUBLIC RELEASE DATE: 4-Jun-2014
Contact: Amy Pullan
University of Sheffield
Sperm size and shape in young men affected by cannabis use

World's largest study investigating how lifestyle affects sperm

Young men who use cannabis may be putting their fertility at risk by inadvertently affecting the size and shape of their sperm according to research published today (Thursday 5 June 2014).

In the world's largest study to investigate how common lifestyle factors influence the size and shape of sperm (referred to as sperm morphology), a research team from the Universities of Sheffield and Manchester also found that sperm size and shape was worse in samples ejaculated in the summer months but was better in men who had abstained from sexual activity for more than six days.

However, other common lifestyle factors reported by men, including smoking cigarettes or drinking alcohol, appeared to have little effect.

----- [But cigarette smoking and alcohol use by men can have other adverse effects on their future children]

Previous research has suggested that only sperm with good sperm morphology are able to pass into the woman's body following sex and make their way to the egg and fertilise it. Studies in the laboratory also suggest that sperm with poor morphology also swim less well because their abnormal shape makes them less efficient.

----

Although the study failed to find any association between sperm morphology and other common lifestyle factors, such as cigarette smoking or alcohol consumption, it remains possible that they could correlate with other aspects of sperm that were not measured, such as the quality of the DNA contained in the sperm head.

Professor Nicola Cherry, originally from the University of Manchester but now at the University of Alberta, commented on a recent companion paper published by the group in the Journal of Occupational and Environmental Medicine4: "In addition to cannabis exposure shown in this paper, we also know that men exposed to paint strippers and lead are also at risk of having sperm with poor morphology."