Alcohol, alcoholism, and cancer
Alcohol, specifically ethyl alcohol, is a widely consumed intoxicating substance produced through the fermentation of sugars. Alcoholism, or alcohol-dependence syndrome, manifests as a compulsive need to consume alcohol. Research indicates that alcohol consumption is linked to several types of cancer, including cancers of the mouth, throat, esophagus, liver, breast, and others. The Centers for Disease Control and Prevention (CDC) has warned that even moderate alcohol consumption can increase cancer risk, with higher risks observed at more significant intake levels. Ethyl alcohol undergoes metabolism in the body, primarily converting to acetaldehyde, a known carcinogen that can damage DNA and promote tumor growth. Genetic variations in enzyme activity related to alcohol metabolism can influence individual cancer risk. Furthermore, alcohol's cancer risk is compounded when combined with other risk factors, such as smoking. Despite its cultural prevalence and social acceptance, awareness of the connection between alcohol consumption and cancer remains limited, prompting calls for public education and warning labels on alcoholic beverages to enhance understanding and prevention efforts.
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Alcohol, alcoholism, and cancer
DEFINITION: Alcohol is a chemical that is generated during fermentation of sugar. Ethyl alcohol is the specific chemical that is generally referred to as alcohol. Alcohol is the most commonly used intoxicating agent around the world. Alcoholism (also called alcohol-dependence syndrome) is a phenomenon of continuous intake of alcohol, with a compulsive need to consume it. Alcohol has been linked to several cancers, but a direct causal relationship between the two has not been established. In 2024, the Centers for Disease Control and Prevention (CDC) warned that alcohol consumption of any kind, including beer, liquor, and wine, increases the risk of cancer of the mouth and throat, larynx, esophagus, colon and rectum, liver, prostate, and breast. The CDC also warned that drinking more than three drinks a day can be linked to stomach and pancreatic cancers. Other researchers caution that even one alcoholic beverage a day can increase cancer risk.
Alcohol as carcinogen: Intake of alcohol is considered a risk factor for developing various kinds of cancers, and therefore, alcohol has been classified as a carcinogen. Ethyl alcohol, the form in which alcohol is commonly consumed, undergoes an array of metabolic changes when ingested. The main enzymes that are involved in metabolism of alcohol are alcohol dehydrogenase and aldehyde dehydrogenase. A small amount (approximately 10 percent) is metabolized by microsomal cytochrome P4502E1 (CYP2E1). Alcohol dehydrogenase converts about 80 percent of ethanol to acetaldehyde. Acetaldehyde is a mutagen and a carcinogen and in 2022 the CDC cautioned that acetaldehyde was known to cause deoxyribonucleic acid (DNA) damage and inhibit the body's response to repair damaged DNA. When the DNA of a cell is damaged and unable to repair, there is a risk it will grow out of control and form a cancerous tumor.
Acetaldehyde is implicated in a variety of processes such as inflammation of the tracheal epithelium, delaying of cell cycle progression, induction of apoptosis, chromosomal damages and aberrations, and sister chromatid exchanges. Much of the carcinogenic effect of alcohol is attributed to this single metabolite. Direct association between the concentration of acetaldehyde in saliva and the development of cancer has been reported. Acetaldehyde covalently bonds with deoxyribonucleic acid (DNA) and forms structures called DNA-adducts. The most common DNA-acetaldehyde adduct is N2-ethyl-dG, which is not mutagenic. Acetaldehyde also induces the formation of the mutagenic DNA adduct called Cr-PdG (alpha-methyl-gamma-hydroxy-1, N2-propano-2′-deoxyguanosine). Polyamines are one of the basic molecules essential for cells and are implicated in cell growth and differentiation, nucleic acid synthesis, and protection against oxidative damage. Polyamines facilitate acetaldehyde-induced formation of Cr-PdG adducts. Cr-PdG adducts are highly mutagenic and interfere with DNA replication and repair, inducing cancer formation. Polyamines also react with acetaldehyde and form crotonaldehyde, which is highly carcinogenic.
Response to alcohol is individualistic and differs among people and races. This is because of polymorphisms in the genes for the enzymes alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH). Presence of the ALDH2*1/2 allele significantly increases the risk of upper aerodigestive tract cancer. In addition to these enzymes, oral bacteria also generate acetaldehyde. High amounts of acetaldehyde are detected in saliva after alcohol consumption. Saliva is directly in contact with the upper aerodigestive tract, and this contact is considered a possible mechanism for its carcinogenic effects.
Alcohol and breast cancer: Alcohol is one of the most ancient intoxicants known to humankind. Consuming one or two drinks a day is not just common but is also a social custom in many cultures. However, research suggests that even one or two drinks a day could put women at a greater risk for developing breast cancer. A study conducted at the National Cancer Institute tested postmenopausal women for differences in hormone levels after alcohol consumption (15 or 30 grams of alcohol per day) for eight weeks. Results showed a significant elevation of estrone sulfate (an estrogen metabolite) and the hormone DHEAS (dehydroepiandrosterone sulfate). DHEAS is secreted by the adrenal glands, and increased levels of DHEAS indicate induction of a process called adrenal steroidogenesis, reflecting stimulation of the hypothalamic-pituitary-adrenal axis in the brain as a response to alcohol consumption.
Alcohol and liver cancers: Excessive consumption of alcohol leads to alcohol liver disease. One type of alcohol liver disease is called alcoholic cirrhosis of the liver, a condition in which normal liver tissue is completely destroyed. Cirrhosis of the liver is considered the primary risk factor for development of hepatocellular carcinoma (liver cancer). Even though alcohol does not seem to cause liver cancer directly, there is a strong association between alcohol and liver cancer.
Alcohol and other cancers: Research shows that drinking one alcoholic beverage a day increases the risk of oral and upper gastrointestinal tract (GI) cancers. Alcohol-related cancers include those of the mouth, esophagus, larynx, and the colon and rectum. The combination of drinking alcohol and smoking increases the risk of developing cancer more than drinking alone. Alcohol is addictive, and alcoholism leads to enhanced tolerance levels, loss of control, cravings for alcohol, and an inability to stop drinking even when people wish to stop or need to stop for their health. Evidence shows that the nutritional status of the body is also negatively affected by alcohol.
Perspectives and progress: According to World Health Organization statistics in 2022, alcohol is responsible for about 3 million deaths a year. An estimated 4 percent of all cancer diagnoses were attributed to chronic alcohol consumption in 2020. Experts believe that education to make people aware of the link between alcohol consumption and cancer will aid in prevention of such cancers, and efforts have been undertaken by interest groups in the twenty-first century to add cancer warning labels to alcoholic beverages. In 2022, the Canadian Broadcasting Corporation examined the awareness of the link between consuming alcohol and cancer and found that despite being listed as a "Group 1" carcinogen by the International Agency for Research on Cancer, only 25 percent of Canadians were aware that alcohol can cause cancer. As a result, medical professionals have argued that adding cancer warning labels to alcoholic drinks is an important first step in the fight to raise awareness of the link between alcohol consumption and cancer.
Bibliography
“Alcohol and Cancer.” CDC, 8 May 2024, www.cdc.gov/cancer/risk-factors/alcohol.html. Accessed 14 June 2024.
"Alcohol Tied to 750,000 Cancer Cases Worldwide in 2020." National Cancer Institute, 12 Aug. 2021, www.who.int/news-room/fact-sheets/detail/alcohol. Accessed 28 Feb. 2022.
Cho, Chi Hin, and Vishnudutt Purohit, eds. Alcohol, Tobacco, and Cancer. New York: Karger, 2006.
Dorgan, J. F., et al. “Serum Hormones and the Alcohol-Breast Cancer Association in Postmenopausal Women.” Journal of the National Cancer Institute 93 (2001): 710-715.
Roumeliotis, Ioanna, and Brenda Witmer. "Alcohol Should Have Cancer Warning Labels, Say Doctors and Researchers Pushing to Raise Awareness of the Risk." Canadian Broadcasting Corporation, 8 Jan. 2022, www.cbc.ca/news/health/alcohol-warning-labels-cancer-1.6304816. Accessed 28 Feb. 2022.
Seitz, H. K., B. Maurer, and F. Stickel. “Alcohol Consumption and Cancer of the Gastrointestinal Tract.” Digestive Diseases 23 (2005): 297-303.
Seitz, H. K., and F. Stickel. “Molecular Mechanisms of Alcohol-Mediated Carcinogenesis.” Nature Reviews 7 (2007): 599-612.
Yirmiya, Raz, and Anna N. Taylor, eds. Alcohol, Immunity, and Cancer. Boca Raton, Fla.: CRC Press, 1993.