Young Drinkers Damage DNA

To many teenagers and young adults weekend binge drinking seems like harmless fun. Having just a drink or two a day is even thought by some to be healthy.

But The National Institute on Alcohol Abuse and Alcoholism tells us that four out of five young adults of college age drink alcohol and 1,425 college students aged 18 to 24 die of unintentional alcohol poisoning every year. And a study conducted at two universities in Mexico even suggests that even moderate consumption of alcohol by young people can damage DNA in ways that accelerate aging and affect them the rest of their lives.

Oxidative Damage of Cell Membranes Caused by Alcohol Consumption

Researchers at the Unidad Profesional Interdisciplinaria de Biotecnología and the Autonomous University of Nayarit in Mexico tested two groups of young people aged 18 to 23. One group did not drink any alcohol at all, and then other consumed an average of 118 grams of alcohol per week, the equivalent of 3.3 liters of beer (1-1/2 cans per day, or drinking a couple of six packs on the weekend). In Mexico, it should be pointed out, consumption of alcohol by 18-year-olds is legal.

All of the participants in the study agreed to blood tests that determined that they were free of chronic disease and not addicted to drugs. The researchers measured a group of oxidative damage biomarkers that are usually measured in people who have been diagnosed with alcohol-related diseases such as cirrhosis of the liver.

Specifically, the researchers looked a chemicals that measure damage to cell membranes that can cause cells to break down prematurely. Oxidative damage to cell membranes can occur for a number of reasons, but the researchers found twice as many damaged cells in blood samples from the alcohol-consuming group.

See Also: Alcohol and Teen Drinking

Oxidative Damage to DNA Caused by Alcohol Consumption

The scientists measured DNA damage in white blood cells through a process called electrophoresis. This test measures damage to telomeres, the protective DNA once though to be junk DNA at the ends of chromosomes. This DNA does not transmit genetic information, but instead makes sure that the two strands that make up the double helix of each gene match up in the right order. When telomeres get too short, the cell simply stops replacing itself. When enough cells stop replacing themselves because their telomeres have been damaged, tissues begin to malfunction and die.

The researchers found that 8% of cells in non-drinkers had this form of DNA damage. Among the young adults who drink, however, 44% of cells had shortened telomeres that would keep them from being able replace themselves as they wore out. This suggests that young people who drink are setting themselves up for early aging as tissues all over their bodies simply wear out and cannot be renewed.

But Isn't a Drink or Two a Day Healthy?

These findings seem to fly in the face of well established science that suggests that a variety of health conditions are actually improved by taking a drink (for women) or two (for men). Is there any way to reconcile the apparently contradictory results of research?

Actually, there is, and the common connection is the immune system.

 Once such study was reported in the journal Vaccine in December of 2013. Dr. Ilhem Messaoudi of the School of Medicine at the University of California, Riverside led a group of researchers that kept two groups of rhesus monkey and allowed them access to either as much sugar water or as much alcohol as they wanted. Some monkeys, as you might imagine, kept themselves in an inebriated state, their blood alcohol levels averaging over 0.08%.

When Messaoudi and colleagues injected the monkeys with smallpox vaccine, which provokes a strong reaction by the immune system, they found that the reaction was stronger in the monkey that were allowed to drink alcohol. From this and similar studies, scientists conclude that moderate consumption of alcohol stimulates the immune system.

When cell DNA is damaged so much that the cell cannot replace itself and cannot function normally in a tissue, the cell becomes more vulnerable to immune attack, as if it were a germ instead of a human cell. When the immune system "takes out" this defective cell, it usually gets several of its neighbors in the process. 

When the cells surrounding the site of inflammation generated by the immune system also have damaged DNA, they cannot proliferate to repair the damage. The more active the immune system, the greater the malfunction caused by defective DNA.

By the time this damage has accumulated to the point it produces symptoms, the process is too far along to reverse. In younger persons, however, surviving cells could reproduce themselves in sufficient numbers to keep tissues in good repair, if DNA damage is stopped.

See Also: Parenting Advice: Talking with Kids about Drugs and Alcohol Abuse

It is not just the young, however, who suffer DNA damage due to alcohol consumption. The process does not stop just because someone is no longer a "party animal." It continues throughout life. Not everyone is affected equally by alcohol consumption, but drinking sets the stage for the eventual development of acute respiratory distress syndrome, chronic liver disease, and untreatable diseases of the central nervous system.

The takeaway from research seems to be that it is healthier, as the moralists are always telling us, not to drink at all. And if you must drink, don't drink every day, and don't go on binges. Less alcohol results in less damage and slower aging. Beer, wine, and spirits all damage the protective antioxidant glutathione that keeps cell membranes in tact, and all can cause oxidative damage to DNA.