Many of us can’t imagine starting our day without a cup of coffee. If you’re one of the 62% of Americans who drinks coffee every day, you may not have thought about how caffeine affects your fertility. It’s true that lifestyle choices and dietary habits can influence sperm health and improvement. But before you throw out your favorite bag of beans, find out how coffee affects male fertility and sperm health, how it compares to other caffeinated beverages, and some guidelines on how much is safe to drink (if you can’t fathom giving up your morning cup).
What is caffeine?
Found naturally in the fruits, leaves, and beans of coffee, cacao, tea, and guarana plants (among others), caffeine stimulates the central nervous system to promote wakefulness and mental focus. Research shows that caffeine is rapidly and completely absorbed in humans, with 99% being absorbed within 45 minutes of ingestion. Caffeine can be found in a wide variety of foods and drinks beyond coffee, including tea, energy drinks, sodas, chocolate, and supplement powders. Even some “decaf” coffees and teas contain low doses of caffeine.
How caffeine affects male fertility
How bad is caffeine for sperm? The evidence is mixed. Some research shows that caffeine is associated with a decrease in sperm quality, especially when consumed in excess; other studies demonstrate that moderate caffeine consumption might actually be good for sperm.
Caffeine intake may negatively impact a couple’s chances of conception. A 2016 study showed that consuming caffeinated sodas and energy drinks, specifically, reduced fertility in males. The study also showed that females who consumed caffeinated tea beverages were less likely to conceive.
A 2010 study showed that those who drank caffeinated cola had decreased average semen volume, sperm concentration, total sperm count, and percentage of spermatozoa compared to non-cola drinking men. The same study showed that when caffeine intake exceeded 800mg from all sources (including coffee), sperm count was also lower — but the association between caffeinated cola and poor semen parameters was stronger.
This is backed up by another study that looked specifically at coffee consumption. Of 1,321 men, the 204 participants who drank more than 3 cups of coffee a day had similar sperm concentration, but lower sperm quality than those who drank fewer than 3 cups of coffee per day. Surprisingly, researchers in this study noted that caffeine appeared to have an even more damaging effect on sperm quality than alcohol and smoking.
And while human studies are limited in this area, some animal research shows that caffeine exposure during sexual maturation may alter the anatomy of the testicles, even in small doses. Furthermore, caffeine may interfere with testosterone production, possibly delaying the onset of sexual maturation (puberty) — especially crucial information for young coffee drinkers.
The good news about caffeine and sperm
Interestingly, some studies show that caffeine may actually have a positive influence on sperm health.
A study from 1976 examined the effect of caffeine on sperm “in vitro,” or in the lab. Researchers found that caffeine stimulated motility, the “swimming” movement of sperm, and helped sperm stay alive longer. Animal research has since boosted this correlation between caffeine and sperm motility, finding that exposing mouse sperm to caffeine improved motility, vitality, and oocyte (egg) fertilization rates.
Does this work “in vivo” (in the body)? One Brazilian study says yes. Researchers found that average sperm motility increased alongside coffee consumption, and that even participants who drank more than six cups of coffee per day (yes, *more than six* per *day*) had higher sperm motility, on average, than those who drank no coffee. Semen volume and sperm concentration did not seem to be affected.
But before you take up a possibly unhealthy level of coffee addiction: not many studies have found this positive correlation between caffeine and fertility, at least not among IVF patients. A comprehensive study from an Italian fertility clinic showed no statistically significant association between caffeine intake and implantation, fertilization, or live birth in a cohort of fertility patients. Researchers in this study concluded by advising a conservative approach (i.e., limiting caffeine intake) until more human research is available.
The sugar question
Why do some studies show that caffeine affects male fertility negatively, while others demonstrate a positive effect? One plausible explanation is the sugar found in many caffeinated beverages like soda and energy drinks. While soft drinks like these typically contain less caffeine than a cup of coffee (less than 30 mg), experts report that soft drinks are the single largest source of calories and added sugar in the U.S. diet, containing up to 40 grams of sugar.
Excess sugar consumption is notorious for its negative impact on male fertility, affecting everything from sperm count to testicular function. This could be the driving factor behind the negative impact that soda and other sugary drinks have on sperm, or could be compounding the impact of caffeine. Learn more about sugar and male fertility.
Is there a specific amount of caffeine that’s safe for sperm?
Does coffee affect male fertility if you only drink one or two cups per day? The good news for many is that low (101–200 mg) to moderate (201–800 mg) of daily caffeine consumption was not associated with a reduction in semen quality, according to the 2010 study mentioned above. The exception: if that caffeinated beverage was cola — again, possibly due to the compound effect of caffeine and sugar.
An average cup of coffee contains 96 mg of caffeine, so one to two cups per day should not have an effect on most people’s fertility health.
The bottom line: evidence around caffeine and male fertility is mixed, so we still recommend moderating caffeine intake and avoiding added sugars.
Caffeine intake may have a negative impact on male fertility, including sperm count and testicular function, especially when used in excess and when found in sugary beverages like cola and energy drinks. Though some limited research suggests that caffeine may increase sperm motility, most fertility experts agree that caffeine intake should be low to moderate (and consumption of added sugar should be minimal) for the best chance of producing healthy sperm.