Alcohol is often associated with helping the male population get lucky, but according to a new study, all this booze-fueled luck in the bedroom may compromise one of man’s most valuable attributes: sperm. A recent study from Denmark found the fertility of otherwise healthy men was significantly harmed by alcohol, and considering that the human race is currently facing a “sperm crisis” anyway, it may be time for guys to hold off on the booze.

In Denmark, as part of the required military examination, men are required to give samples of their blood and semen. Taking advantage of this already available information, a team of researchers decided to test the blood and semen samples from 1,221 Danish men between the ages of 18 and 28 for sign of fertility. The men’s drinking habits were also noted, with researchers marking down how much the men had drank in the week before their medical exam, whether this was habitual, and how often they binge drank, according to the press release.

Off the bat, the results of the study showed that Danish men sure like to drink. The mean number of units drunk in the week preceding the exam was 11. The study defined binge drinking as five units in one sitting. A total of 64 percent of the men admitted to binge drinking in the previous month, while 59 percent said they had been drunk more than twice in the month before their exam.

Results also showed that men who drank the most also experienced more harmful changes to their fertility. High amounts of alcohol consumption was associated with lower levels of the sex hormone, lower sperm count, and higher numbers of misshaped or oddly sized individual sperms. In total, the sperm count of men who drank 40 units of alcohol a week was 33 percent lower, and the proportion of “normal” looking sperm was 51 percent lower than men who drank between one and five weekly units.

“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," concluded the researchers in the press release.

This is not the first time scientists have suggested that alcohol may interfere with male fertility, although it is the first to study the fertility of healthy men with such detailed information on their alcohol intake. Since, according to The Wall Street Journal, the sperm concentration of men has decreased by nearly one-third between 1989 and 2005, the human race simply can’t afford losing any more sperm. "We’re producing pretty poor sperm compared with those of primates and other mammals,” said Gary Cherr, a reproductive toxicologist at the University of California, Davis, to Discover Magazine. “ Even in the most fertile men, there are quality issues.”

Male fertility is a complicated subject, and the reasons for why it is decreasing are even more complicated. Some experts say that exposure to pesticides and endocrine-disrupting chemicals like Bisphenol A are responsible, while others argue it's more likely down to lifestyle habits, such as lack of exercise, but the truth is scientists are really unsure of the exact root.

Even in this past study, researchers weren’t able to conclude if alcohol consumption was actually the cause of compromised fertility or if men with compromised fertility were simply more likely to drink more. Still, cutting down on your alcohol intake isn’t going to cause any harm, and as suggested by this study’s results, it may be the best bet for couples hoping to get pregnant.

Source: Jenson TK, Gottschau M, Madsen JOB, et al. Habitual alcohol consumption associated with reduced semen quality and changes in reproductive hormones; a cross-sectional study among 1221 young Danish men. BMJ. 2014.