Cola and unhealthy lifestyle lower sperm count

Mar 31, 2010 by Lin Edwards report

(PhysOrg.com) -- A Danish study suggests drinking a lot of cola regularly could men’s lower sperm count by almost 30 percent. The culprit does not appear to be caffeine, since coffee did not have the same effect, even though it contains even more caffeine than cola.

Leader of the research team, Professor Tina Kold Jensen of the University Department of Growth and Reproduction at the Rigshospitalet in Copenhagen, said the results of previous studies on the effect of on had been unclear, and the study participants had usually been carefully selected, often because they were infertile or about to undergo vasectomy. The current study included 2,554 young men and aimed to find out how the increasing consumption of soft drinks containing caffeine by young people in Denmark might affect male reproductive health.

The participants were recruited in the period 2001 to 2005 when they were having their compulsory physical examination to determine if they were fit for . They were asked to complete a questionnaire about lifestyle and diet, including information on their intake of caffeine from various sources including , and they also delivered a semen sample.

The results were that those with low to moderate total and cola consumption (up to 800 mg/day caffeine and up to 14 x 0.5 liter bottles of cola per week) showed no link with semen quality in terms of sperm concentration and sperm count, while those with high intake of total caffeine and/or cola (over 800 mg/day and more than 14 x 0.5 liter bottles/week) had reduced sperm count and concentration, but this was only significant for the cola intake. Those with low to moderate consumption (the vast majority) had higher sperm counts (average 56 million/ml) than those who drank cola. In the 93 men who drank a liter (a quart) or more a day the sperm counts were much lower (35 million/ml). Even the lower count is within the World Health Organisation’s reported normal limits, but a reduced sperm count increases the risk of eventually becoming infertile.

The study found no link between caffeine in tea or coffee and the lowered sperm count, which meant the effect may be produced by other ingredients in the , or other factors related to lifestyle, but the authors said they could not “exclude the possibility of a threshold above which cola, and possibly caffeine, negatively affects semen quality”. The researchers also found that those who drank cola had unhealthier lifestyles, ate less fruit and vegetables, and more fast foods than those who did not. It is therefore unclear if one or more of the cola’s ingredients, the unhealthy lifestyle, poor diet or a combination of these factors is responsible for the reduced sperm quality.

The study findings are published in the American Journal of Epidemiology.

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More information: Tina Kold Jensen et al., Caffeine Intake and Semen Quality in a Population of 2,554 Young Danish Men, American Journal of Epidemiology, doi:10.1093/aje/kwq007

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Yellowdart
1 / 5 (3) Mar 31, 2010
Gee over 800 mg a day is insane. Thats like drinking 8 20oz mountain dews a day. Anything in massive excess isnt good for you anyway, even water.
damnfuct
1 / 5 (1) Mar 31, 2010
Unhealthy lifestyles should make a person less healthy, and it makes sense that sperm counts would drop. If it were the caffeine causing the problem, would it not affect coffee drinkers as well (seeing as coffee has 3x-6x the caffeine of cola)?
Though the findings are notable, the article is not as conclusive as the headline suggests.
intarctanxdx
4.7 / 5 (3) Mar 31, 2010
people who drink a lot of cola tend to have other major problems with their diets, which is probably the actual reason why their sperm count was lower. flawed experiment - they should have used only individuals with regular sperm counts and tested their semen at different levels of cola intake. that way they're testing roughly the same diets.
Alec_Rawls
2.2 / 5 (6) Mar 31, 2010
Did they control for masturbation? That turned out to be the explanation for the supposed decreasing sperm counts since WWII, and one can easily see this behavior being correlated with soda pop consumption.
fixer
1 / 5 (1) Mar 31, 2010
If you drink all that coke you will probably be awake most of the night anyway, gotta do something to pass the time...
skelly
1 / 5 (1) Apr 01, 2010
Clearly the researchers have not looked at the UK where the cola swigging non-working fraternity seem to be the only area of the population who are breeding. Perhaps their resistance to the effects of cola lie in their preference for baseball caps.