Moderate Weekly Intake of Alcohol Tied to Poor Sperm Quality
A new Danish study reveals that moderate weekly consumption of alcohol is strongly associated with reduced sperm quality among healthy young men.
This observational study focused on 1221 Danish men of ages 18-28. All of the participants underwent medical examination that assessed their fitness for military service between 2008-2012. During the assessment, they were asked about the amount of alcohol they consumed in the week prior to the medical examination- whether it was habitual drinking (typical) and how often they binge drank, and had been drunk in the preceding month.
"This is, to our knowledge, the first study among healthy young men with detailed information on alcohol intake, and given the fact that young men in the western world [drink a lot], this is of public health concern, and could be a contributing factor to the low sperm count reported among [them]," the study researchers said.
Binge drinking was defined as intake of over 5 units of alcohol in one sitting. The participants also submitted a sample of semen that was used to check the quality of sperm. Their blood samples were also collected to check the levels of reproductive hormones.
It was reported that the average number of units consumed in the preceding week was 11. Nearly 64 percent of them had indulged in binge drinking and 59 percent had taken alcohol more than twice during the preceding month.
Even after taking in to consideration certain influential factors, there was no significant association between sperm quality and recent alcohol consumption or binge drinking in the preceding month. However, intake of alcohol in the previous week was tied to alterations in the levels of reproductive hormone. These effects increased with the increase in the number of units.
The levels of testosterone rose and the sex hormone binding globulin dropped. Similar results were seen for the number of times the person had been drunk or had binge drink in the previous month.
For half of the men the quantity of alcohol consumed taken in previous week was typical of the weekly alcohol intake. Among these, higher the number of weekly units, lower was the quality of sperm. The effect was more evident after intake of 5 and more units, but apparent among those taking above 25 units every week.
Among those taking 40 units a week, the total sperm count was 33 percent lower and the proportion of the normal-looking sperm was 51 percent lower.
"It remains to be seen whether semen quality is restored if alcohol intake is reduced, but young men should be advised that high habitual alcohol intake may affect not only their general health, but also their reproductive health," the researchers said.
The finding was documented in the British Medical Journal.