Moderate Alcohol Consumption is Associated with Reduced Sperm Quality
In the first study among healthy young men with detailed information on alcohol intake, modest regular drinking of alcohol could be playing a major role in the abnormal semen analyses reported. In a study published in the British Medical Journal on October 2, 2014, Professor Tina Jensen and colleagues reported on 1221 young Danish men, aged 18-28, recruited for compulsory military service between 2008 and 2012.
As part of their medical assessment, the recruits were asked about total alcohol consumption in the week prior (recent drinking), usual drinking (habitual) and binge drinking. Semen and blood samples were obtained from the group to determine semen quality (volume, sperm concentration, total sperm count and percentages of motile and normal appearing sperm) and the concentration of certain reproductive hormones.
The average alcohol intake in the week prior to assessment was 11 units among the men who average age was 19 and whose favorite beverage was beer. Almost two-thirds (64%) had binged and 59% had been drunk at least twice in the thirty days prior to assessment.
Semen quality decreased with increasing recent alcohol consumption as well as binge drinking. The higher the number of units drunk, the lower was the semen quality in terms of total sperm count and the percentage of sperm of normal size and shape. This was true after accounting for other lifestyle factors. The effects were present from five plus units per week and beyond; however, the effects were most apparent among men who drank 25 or more units per week. Total sperm counts were 33% lower, and the percentage of normal sperm forms was 51% lower among those who drank 40 units per week relative to those who drank between one and five units.
Moderate habitual drinking was also associated with changes in reproductive hormones. Testosterone increased and its carrier protein (sex hormone binding globulin, SHBG) decreased with increasing recent alcohol intake.
The authors of this observational study conclude with “given the fact that young men in the Western world have a high alcohol intake, this is a public health concern and could be a contributing factor to the low sperm count reported among young man. It remains to be seen whether semen quality is restored if alcohol intake is reduced, but young man should be advised that high habitual alcohol intake may affect not only there general but also the reproductive health.”