Alcohol may affect male’s role in reproduction
A solid body of medical literature calls on women to stop drinking alcohol while they’re trying to conceive a child. Now a related stream of research may persuade potential fathers to abstain as well.
Men who want to conceive a child may already know that a mother’s alcohol use raises the risk that she will have a child born with fetal alcohol syndrome, a leading cause of mental retardation. But these men probably don’t know about studies that link alcohol use to reduced male fertility and poor health among newborns.
Recognizing this link calls for understanding the work of a crucial system in a mans body. This system is an axis with three primary points: a region of the brain called the hypothalamus; the pituitary gland; and the gonads (testes).
All three secrete various hormones — chemicals that regulate growth, development and reproduction. One of these hormones is testosterone, which creates male sex characteristics and is needed to produce mature, healthy sperm.
This system is finely tuned: Hormones produced by the hypothalamus and pituitary gland will rise to adequate levels only when testosterone — produced in the testes — increases.
Research with animals indicates that alcohol disrupts this system. Studies have focused on male rats. In these animals, exposure to alcohol reduced testosterone. In turn, this lowered levels of hormones from the hypothalamus and pituitary gland. And this led to even lower testosterone levels, completing a feedback loop that damaged reproductive ability.
A review of this research was published last year in the journal Alcohol Research and Health (Vol. 25, No. 4) by authors Dr. Mary Ann Emanuele and Dr. Nicholas Emanuele, researchers at Loyola University Stritch School of Medicine in Maywood, Ill. Both have studied alcohol in male rats firsthand. And they describe the testosterone-lowering effect of alcohol as “profound,” both with long-term and one-time exposure to alcohol.
These authors also note that low levels of testosterone in adult men “have been associated with a variety of medical problems, including accelerated osteoporosis, decreased muscle and prostate function, altered immune function, and decreased reproductive ability.”
Men who want to continue drinking while trying to conceive children may dismiss these findings. After all, the studies involved rats, not men. However, three facts call on these men to reconsider their position:
- One is that animal studies in the past have yielded useful warnings about chemicals that can be toxic to humans. For ethical reasons, such studies are rarely replicated in human beings.
- Second, male rats have a reproductive system that mirrors the hypothalamus-pituitary-testes axis found in male humans — a striking similarity. Dr. Mary Ann Emanuele admits that research on the link between alcohol and male reproductive ability has not yet involved humans. However, because studies with rats mimic the human model, “there are human implications, certainly,” she says.
- Finally, alcohol may do more than alter hormone levels. One study exposed male rats to a single moderate or high dose of alcohol and then allowed the rats to mate. The results included reduced litter size and birth weights.
Applying these findings from animal studies to humans is difficult. For one, men who become fathers may use drugs other than alcoholand so may their sexual partners. Research might reveal that these other drugs are more threatening than alcohol to newborn health, or that the mother’s use is a greater concern.
Still, men who want to apply the spirit of Father’s Day to their health behavior can choose to abstain from drinking while trying to conceive children. Though the research backing this choice is still incomplete, the decision is certainly safe. Moreover, men who choose this option can form a supportive bond with women who have already decided to abstain for the sake of a child’s health.
[ Download PDF ]
Comments
Leave a Reply
