Zeynep Madak-Erdogan is associate director for education at the Cancer Center at Illinois and a professor of food science and human nutrition at the University of Illinois Urbana-Champaign. Madak-Erdogan’s research explores the impact of hormones and metabolism on breast cancer and individuals’ responses to treatment. She spoke with News Bureau research editor Sharita Forrest about the links between alcohol consumption and cancer.
The former U.S. Surgeon General Dr. Vivek Murthy recently released an advisory indicating that alcohol causes genetic mutations that trigger several forms of cancer. What are the mutations that occur?
There are no specific mutations that alcohol consumption cause. Mutations occur randomly. However, if these mutations affect genes that control cell proliferation and/or inhibit cell death or DNA repair signaling programs, they can give cells a distinct advantage to become cancerous.
For cells to be transformed into cancer cells, multiple mutations are typically needed. If DNA repair genes are mutated, for example, cells can more easily acquire additional mutations since the system that would normally repair these mutations is compromised.
Are there ways to determine if a person is more susceptible to these mutations? And if they are, should they completely abstain from drinking alcohol?
Yes, genetic testing can identify mutations that predispose individuals to certain cancers, such as mutations in BRCA genes or DNA repair genes. If individuals carry these inherited mutations, they are indeed more likely to develop cancer earlier in life.
While abstaining from all types of alcohol, not just liquor, would reduce their risk of acquiring additional mutations, the decision should be made in consultation with health care providers who can assess individual risk factors and family history.
Some companies are marketing at-home test kits that use a cheek swab to collect DNA samples and assess users’ genetic susceptibility. Are such tests reliable?
Many direct-to-consumer genetic tests are technically reliable for detecting known mutations in established susceptibility genes. However, their clinical utility depends on several factors. These tests typically only screen for specific known mutations, not all possible genetic variants.
For comprehensive genetic risk assessment, medical-grade testing ordered by health care providers along with professional genetic counseling for result interpretation remain the gold standard. Over-the-counter tests should be viewed as preliminary screening tools rather than definitive medical diagnostics.
The advisory indicates that women are significantly more likely to develop these alcohol-related cancers — i.e., 5 women versus 3 or more men out of 100 consuming two drinks per day. Why are women at greater risk at the same level of alcohol consumption?
Women are more vulnerable to alcohol’s effects for several reasons. One major mechanism involves enzyme competition: Alcohol metabolism uses the same enzymes that the body uses to metabolize and clear estrogens. With chronic alcohol consumption, levels and activity of these enzymes change, leading to altered estrogen metabolism and increased levels of circulating estrogens in the body.
Since breast cancer risk is closely related to elevated estrogen levels, this creates greater susceptibility to alcohol’s carcinogenic effects in women.
Additionally, women generally have lower body water content and different fat distribution than men , which might result in higher blood alcohol concentrations from the same amount of alcohol consumption. Also, for women, alcohol gastric metabolism is smaller, which might result in higher blood levels of alcohol.
Both alcohol and smoking are linked with cancer, but recent research suggests that in combination they may be particularly toxic. Why is that?
In addition to their individual harmful effects, alcohol and smoking can be particularly dangerous when combined. While smoking exposes the body to numerous carcinogens, our body’s protective cell layers normally help shield us from these harmful chemicals. However, alcohol consumption weakens these protective layers, allowing more carcinogens from smoking to enter the body. This means that people who both drink and smoke may expose their bodies to significantly higher levels of cancer-causing substances than those who only smoke or only drink.