Posts Tagged ‘alcohol consumption’

Modest Alcohol Consumption Lowers Semen Quality

Drinking modest amounts of alcohol may affect the sperm quality of young men, according to a new study.

“Young men should try to avoid habitual alcohol intake of more than 5 units weekly and especially more than 25 units weekly, which may be beneficial not only for their general health but their semen quality as well,” said Tina Kold Jensen, Professor of Research at the Department of Environmental Medicine, University of Southern Denmark, Copenhagen, Denmark.

One unit of alcohol was defined as the equivalent to 1 beer, 1 glass of wine, or 1 shot of alcohol.

“We also found that increasing alcohol consumption the week preceding the visit was associated with changes in reproductive hormones, especially a significant increase in serum free testosterone and reduction in sex hormone binding globulin,” Dr. Jensen said.


This appears to be the first study among healthy young men with detailed information on alcohol intake.

Dr. Jensen said, “Previous studies have not found adverse effects of low alcohol intake (more than 5 units per week), however, they only assessed average intake.

We assessed daily intake the week preceding the semen delivery.”

She added: “We think we found a strong association because we asked the men about intake last week and then extrapolated to a normal week.

We know that normal sperm take 3 months to mature.

Normal consumption is a better marker than just last week’s consumption.”


The cross-sectional, population-based study asked 1221 men to fill out a questionnaire on whether the previous week was a “normal” week of alcohol consumption and then studied the 553 who stated that it was.

These men, age 18 to 28 years, all had undergone a medical examination between 2008 and 2012 to assess their fitness for military service, which is compulsory in Denmark.

Sperm concentration, total sperm count, and percentage of spermatozoa with normal morphology were negatively associated with increasing habitual alcohol intake.

This association was observed in men reporting at least 5 units in a typical week but was most pronounced for men with a typical intake of more than 25 units per week.

Men who had a typical weekly intake of more than 40 units had a 33% reduction in sperm concentration compared with men who had an intake of 1 to 5 units per week.

Binge drinking was not independently associated with semen quality.

“We do not know how much of a direct effect on semen quality was due to the adverse effect of alcohol on spermatogenesis, but we adjusted for other lifestyle factors, such as smoking, diet, and exercise,” said Dr. Jensen.

“But it may be a certain lifestyle associated with alcohol intake that is harmful to semen quality.”

The researchers think that even moderate alcohol consumption could be a contributing factor in the low sperm counts reported among young men.

Whether semen quality is restored if alcohol intake is reduced remains to be seen, they stated.

The researchers reported their results in the October 2, 2014 issue of the British Medical Journal Open.

Heavy Drinking Hastens Cognitive Decline in Men

Men who are heavy drinkers show a faster cognitive decline compared with men who consume light to moderate amounts of alcohol, according to a new study.

The middle-age men who averaged 3 or more drinks per day showed faster 10-year declines in cognitive function than did lighter drinkers.

“The detrimental effect of heavy alcohol consumption on health is well documented.

This study adds a new argument against heavy drinking, showing that it is also detrimental for cognitive aging, with effects evident as early as age 55 years,” said lead author Séverine Sabia, PhD, from the Department of Epidemiology & Public Health at University College London.

“For example, heavy drinking men aged 60 years old show a decline in memory comparable to men aged 66 years old,” she noted.

The researchers published their results online on January 15, 2014 in the journal Neurology.

Lifestyle Questionnaires Assess Alcohol Consumption

Dr. Sabia and colleagues analyzed data from more than 7000 British civil servants, average age 56 years, who had agreed to complete lifestyle questionnaires and to undergo a physical examination beginning in the 1980s.

About two-thirds of the participants were men.

Alcohol consumption was assessed 3 times in the 10 years preceding the first cognitive assessment in the late 1990s.

Cognitive tests were repeated twice more in the 2000s.

The cognitive test battery included 4 tests that assessed memory and executive function.

The participants were stratified into 6 groups according to drinking status, including complete abstainers; those who stopped drinking entirely at some point during follow-up; “occasional” drinkers (their average daily alcohol consumption was not quantified); and light, moderate, and heavy regular drinkers.

Almost two-thirds of the men were light drinkers, just under 20% were moderate drinkers, and just under 10% were heavy drinkers.

The researchers used the light drinkers as the reference group to analyze drinking and cognitive decline.

Heavy Drinking = Cognitive Declines

Compared with the declines observed in the light drinkers, declines in cognitive scores were statistically higher in the heavy-drinking men but did not differ for the other groups.

The scores on 4 tests of short-term memory and executive function dropped the most in the heaviest male drinkers.

“Although we cannot completely exclude confusing effects from an unhealthy lifestyle, we did take into account fruit and vegetable consumption, physical activity, and smoking in the analyses,” said Dr. Sabia.

“The mechanisms underlying the association between alcohol consumption and cognition are complex.

The main hypothesis focuses on cerebrovascular and cardiovascular pathways, involving effects that play out over an extended period of time.

Heavy alcohol consumption is associated with higher risk of vascular disease which, in turn, may increase the risk of cognitive impairment.”

In addition, Dr. Sabia noted that “heavy alcohol consumption has detrimental short-term and long-term effects on the brain, including direct neurotoxic effects, pro-inflammatory effects, and indirect impact via cerebrovascular disease and vitamin deficiency.”

Dr. Sabia added, “Our findings are in agreement with previous studies showing that moderate alcohol consumption is probably not deleterious for cognitive outcomes, but they also show that heavy alcohol consumption in midlife is likely to be harmful for cognitive aging, at least in men.”