Strong links have already been found between how susceptible an individual is to alcohol use disorders and the drinking habits of their parents, but a new study examining mice suggests that a father's excessive alcohol consumption could influence the effects of his son's drinking, even before their conception.
Earlier this year, Medical News Today wrote about a drive from the Centers for Disease Control and Prevention (CDC) to increase levels of alcohol screening and counseling in order to combat high levels of drinking in adults. The CDC reported that at least 38 million Americans drink too much, a figure that includes binge drinkers, those with high weekly alcohol use, and any alcohol use by pregnant women and those under 21.
Research indicates that genetic factors do influence alcoholism. The National Institute on Alcohol Abuse and Alcoholism (NIAAA) state that the children of alcoholics are about four times more likely than the general population to develop alcohol problems.
Grants from the NIAAA funded the new study from the University of Pittsburgh School of Medicine, which was published in PLOS ONE this week. The study aimed to test the authors' hypothesis that alcohol drinking and neurobiological sensitivity to alcohol are influenced by ancestral alcohol exposure.
The study was carried out by regularly exposing male mice to intermittent ethanol vapor over a period of 5 weeks. This led to the mice having blood alcohol levels slightly higher than the legal limit for human drivers. Afterward, the mice were mated to females who had not been exposed to any alcohol.
An inherited vulnerability to alcohol?
The male offspring of mice who had been exposed to alcohol were more susceptible to its effects.
The results found that the adult male offspring of the mice who were exposed to alcohol consumed less alcohol when it was made available and were less likely to choose to drink it over water, compared with mice whose fathers had not been exposed.
However, they were more vulnerable to the effects of alcohol on control of the body and anxiety reduction.
Dr. Gregg E. Homanics, Ph.D., senior investigator, said their study showed that it is possible for alcohol to modify the father's otherwise normal genes and influence consumption in his sons, but surprisingly not his daughters.
Lead author Dr. Andrey Finegersh acknowledged that there was some uncertainty with the outcome of their research:
"We suspected that the offspring of alcohol exposed sires would have an enhanced taste for alcohol, which seems to be the pattern for humans. Whether the unexpected reduction in alcohol drinking that was observed is due to differences between species or the specific drinking model that was tested is unclear."
The researchers now plan to investigate why female offspring appear to be unaffected, how alcohol modifies the genes and to examine alternative drinking models such as binge drinking.
The NIAAA state that alcoholism is not solely determined by the genes inherited from parents; more than 50% of all children of alcoholics do not become alcoholic. There are many other factors that influence the risk of developing alcoholism, some raising the risk and others lowering it.
The outcome of the study suggests, though, that caution should always be exercized when drinking, due to the far-reaching consequences of heredity.
The CDC offer the following recommendations on alcohol consumption on their Alcohol Screening and Counseling web page:
- Do not start drinking or drink more often because of potential health benefits.
- If you do choose to drink, do so in moderation. This is defined as up to 1 drink a day for women or 2 for men.
- Do not drink at all if you are under age 21, pregnant or may be pregnant, or have health problems that could be made worse by drinking.
Written by James McIntosh