Published: Monday, October 18, 2021, 11:30 a.m. U.S. Eastern Time
Media Contact: Kara Flynn, 202.257.8424, press@ashg.org
ROCKVILLE, MD – Alcohol and tobacco use are associated with increased “epigenetic age” in adults and heavy alcohol use in men was associated with increased epigenetic age acceleration in their offspring, according to new research presented by Wei Zhao, PhD, an assistant research scientist at the University of Michigan, at the American Society of Human Genetics 2021 Annual Meeting.
It is well documented that alcohol and tobacco use can impact an individual’s health, as well as the biological health of their offspring through epigenetic changes. Epigenetic changes are alterations that affect gene expression but do not change the DNA sequence and “epigenetic age” is an estimate of biologic age based on epigenetic patterns along the genome. In the new study, researchers used data from the Michigan Longitudinal Study, the world’s longest-running study on the development of substance abuse, to examine how alcohol and tobacco use affected epigenetic age.
One epigenetic mechanism used by cells to control whether genes are turned on or off is DNA methylation. DNA methylation levels change as people age and are associated with many biologic metrics of aging. Methylation is also influenced by environmental and behavioral factors across the lifespan, making methylation a molecular mechanism by which external stimuli can influence health and disease.
To examine whether alcohol and tobacco use affect DNA methylation in individuals and their offspring, Dr. Zhao and her colleagues analyzed genomic DNA from saliva samples of 42 parents and 45 offspring taking part in the Michigan Longitudinal Study. The researchers estimated four measures of accelerated epigenetic age (difference between chronological age and epigenetic age) across many age-associated methylation sites.
The researchers found that in female parents, but not male, a higher number of alcoholic drinks per month was associated with increased epigenetic age acceleration. Sex-specific effects were also found for tobacco use, with male parents who were current tobacco smokers, but not female, showing an increased epigenetic age.
In addition, the researchers asked whether parental tobacco and/or alcohol use when their offspring were young impacted the epigenetic age of offspring as adults. They found that heavy alcohol use by fathers when their offspring were 12 years old or younger was associated with increased epigenetic age acceleration upon reaching adulthood, even after correcting for the offspring’s own alcohol and tobacco use. These findings suggest that substances not only directly affect the individuals who use them, but could also affect their offspring — either directly, such as through secondhand smoke, or indirectly, such as through psychosocial stress associated with the family environment.
Dr. Zhao and her colleagues caution that this is a pilot study with a small sample size, and this may have contributed to the lack of findings for sex-specific effects of alcohol use in men and/or parental smoking effects. The researchers plan to expand their study to include additional participants in order to answer more questions about substance use and DNA methylation in individuals and across generations.
“The implications of this research are that alcohol use and tobacco smoking have an adverse impact on the epigenome, and some of that impact may differ by sex, which might lead to different health outcomes between men and women and their offspring,” says Dr. Zhao.
“Another important finding is the suggestion that parental alcohol use during the offspring’s early childhood may lead to persistent biologic changes that influence children into young adulthood,” Dr. Zhao said. “The most important takeaway message is that heavy alcohol use and tobacco smoking do not only affect one’s own health but could also have a long-term impact of one’s offspring.”
Media Interest: To learn more about Dr. Zhao’s work or set up an interview, please contact press@ashg.org to coordinate.
Reference: Zhao, W., Carter, A., Bares, C., Lin, L., Reed, B.G., Bowden, M., Zucker, R.A., Smith, J.A., and Becker, J.B. (October 18, 2021). Abstract: Sex-specific and generational effects of alcohol use and tobacco smoking on epigenetic age acceleration in the Michigan Longitudinal Study. Presented at the American Society of Human Genetics 2021 Annual Meeting.
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