Men have been advised to dramatically increase their abstinence from alcohol before conception

The negative effects of alcohol consumption on the male reproductive system last longer than thought, American scientists have found out. They recommended that men take this into account when preparing for fatherhood.

The state of women's health before conception is traditionally considered the main factor affecting the course of pregnancy and the development of the child. Alcohol consumption by expectant mothers has always been a concern for doctors because of its association with fetal alcohol syndrome (FAS). This is the name given to a complex of congenital mental and physical abnormalities in children whose mothers drank alcohol before and during pregnancy. Possible defects include abnormal facial features, low birth weight and/or height, attention problems, hyperactivity and poor coordination.

The responsibility for preventing a child from being exposed to alcohol and developing FAS has previously always been placed on women. Only recently has the father's alcohol use come to be seen as another contributing factor to fetal alcohol syndrome.

Previous studies have shown that sperm cells contain a lot of epigenetic information that can be altered by stressors, including alcohol. In the new paper, which was published in the journal Andrology, scientists from Texas A&M University (USA) looked at how alcohol consumption affects sperm, what epigenetic changes it causes and how long those changes persist.

To find out how long it takes for the effects of alcohol on sperm to subside, the researchers used male laboratory mice of the C57BL/6J line. For 10 weeks, the subjects were given a six- and 10-percent solution of ethanol to drink, while the animals in the control group were given plain water.

After 10 weeks of ethanol exposure, some of the mice in the alcohol group were killed immediately to have their tissues and semen analyzed. The remaining and control animals were left for another four weeks, after which they were also killed. The researchers then used RNA sequencing to examine gene expression patterns in the epididymis, the testicular appendage where sperm mature and accumulate.

The researchers observed that alcohol led to changes in genetic processes related to mitochondrial function, oxidative stress and the overall stress response in the epididymis. These effects persisted even a month after alcohol cessation.

"We thought things would return to normal relatively quickly, but it turned out not to be the case. The process took more than a month," said one of the authors of the project, Professor of Veterinary Physiology and Pharmacology Michael Golding (Michael Golding).

He explained that during withdrawal, the liver experiences constant oxidative stress and sends a signal to the entire male body telling it that a very strong oxidative stressor is present. Reacting to this, the body decides: future offspring must be programmed to adapt to such an environment. Golding suspected that these changes are what could lead to problems like FAS.

The researcher warned that you don't have to be an alcoholic to experience withdrawal syndrome. Regularly drinking three to four beers a few days a week is enough to cause withdrawal effects after stopping this behavior.

Although Golding and his colleagues are still continuing their research to clarify the effects of parental drinking, the scientist offered advice to expectant fathers. According to him, you should abstain from drinking for at least three months before conceiving, given that sperm is produced for 60 days, and the body needs at least four weeks to recover from alcohol.