Alcohol consumption, smoking reduce semen quality
Acute spikes in alcohol consumption and smoking lead to significant negative early and long-term effects on seminal quality, a new study shows.
Investigators administered questionnaires and collected semen samples from 36 healthy male volunteers of reproductive age (mean age 22±3 years) at three time points: before a 7-day academic festivities event, one week after the event and three months after the event.Information on medical history, alcohol and medication consumption, and smoking were collected.
Basic sperm parameters, expression of superoxide dismutase 1 (SOD1) and glutathione peroxidase 4 (GPx4), total antioxidant status, and presence of carbonyl groups and 3-nitrotyrosine (3-NT) were determined from the semen samples.
No histories of medication, drug use, comorbidities and pregnancies were reported at baseline. Between the first and second time points,the daily consumption of alcohol and nicotine increased by more than eight times (p=0.00) and two (p=0.00) times, respectively. Alcohol consumption returned to baseline levels during the third time point (p=0.00). [Sci Rep 2017;7:45457]
Between the first and second time points, semen volume dropped by 18 percent (p=0.02); between the second and third time points, volume dropped by 19 percent (p=0.04). Similarly, the concentration and total number of spermatozoa dropped by 25 (p=0.04) and 52 (p=0.00) percent, respectively, from the first to the third time point.
“As expected,” the investigators wrote, “alcohol and cigarette consumption increased during the academic festivities, when compared with values observed 1 week prior and 3 months after the academic festivities. This abrupt lifestyle change was concurrent with deleterious effects on semen quality, both at early and late short-term.”
Between the first and third time points, there were significant reductions in the amount of fructose (28 percent; p=0.02), activity of neutral α-glucosidase (46 percent; p=0.02) and amount of citric acid (36 percent; p=0.03).
Fructose and citric acid are biomarkers of the seminal vesicles and the prostate, respectively, the investigators explained. A decrease in their concentrations may imply an impairment of these organs and thus “explain the decrease in volume observed over the [time points],” they said.
Nonprogressive motile spermatozoa dropped by 40 percent (p=0.04) between the first and second time points, and by 50 percent (p=0.002) between the first and third time points. On the other hand, immotile spermatozoa decreased by 14 percent (p=0.05) between the first and second time points.
Compared with time points 2 and 3, there were more spermatozoa with normal morphology in time point 1 (p=0.00 for both). Defects in the midpiece and head were much more common in the second time point compared to the first and the third.
The decrease in morphologically normal sperm cells observed a week and 3 months after the acute lifestyle change implies that there is “an effect on already morphologically mature spermatozoa in the epididymis and on spermatozoa forming in the testicles,” the investigators said.
The oxidative stress marker 3-NT was 1.4 times greater (p=0.01) in the second time point compared to the third.
The increase of 3-NT a week after the event shows “that the acute lifestyle changes were responsible for increasing [reactive oxygen species] levels in spermatozoa and, consequently, for an effect on protein modifications by tyrosine nitration,” they explained.
“Excessive levels of protein nitration may lead to alterations in protein function and structure, which may result in a compromise of sperm function,” investigators added.
The findings, the investigators conclude, “[suggest] that specifically high alcohol and cigarette consumption are associated with decreased semen quality in healthy young men… Healthy men may therefore be advised that occasional acute lifestyle alterations may harm their reproductive health at short-term.”