Drinking Alcohol in Excess Increases Cancer Risk
The Scientific Evidence that Supports the Link
Aug 19, 2009
Dr. Andrea Benedetti of McGill University and her colleagues, Drs. Marie-Elise Parent and Dr. Jack Siemiatycki of the University of Montreal found that people who regularly consume alcoholic drinks in excess develop increased risks of esophageal cancer (sevenfold); colon cancer (80%); and lung cancer (50%).
They also found statistically significant relationships between heavy drinking of beer and distilled beverages and six different types of cancers. By comparison, moderate drinking, that is less than daily consumption of ethanol did not show similar effects.
"We looked at the data in two ways. We compared people who drank heavily to our reference group, who abstained or drank only very occasionally. We also looked for trends across our categories: non-drinkers, weekly drinkers, and daily drinkers. We saw increased risk for esophageal cancer, stomach cancer, colon cancer, liver cancer, pancreatic cancer, and prostate cancer. The strongest link was for esophageal cancer and liver cancers. This study crystallizes many strands of evidence from different studies on different types of cancer and alcohol consumption."
The study showed that people who drink everyday or drink many times a day are at higher risk, compared to those who drank lightly who showed little effects from ethanol consumption. Their findings were published in the current issue of Journal Cancer Detection and Prevention.
How Alcohol or Ethanol Promotes Cancer
There is existing evidence that lymphoid cells offer resistance to cancer. Lymphoid cells are a type of white blood cells found in the blood. They are also found in the lymph-vascular system where they control the body's immunity to disease. Natural killer cells (NK) may offer resistance to the development of tumors in vivo (in living) since they have the ability to spontaneously "lyse" or "dissolve" tumor cells. Antibodies could also serve as important components of the host defense mechanism.
Changes in antibody production are frequently seen in the late stages of cancer and may play an important role in reduced resistance to malignancy.
Alcohol (ethanol) may induce cancer through the following effects:
- During metabolism, ethanol generates lipid peroxidation products (products of fat metabolism). These substances are highly unstable and reactive and de-stabilize other compounds.
- Ethanol may depress or suppress levels of DNA repair enzymes and create favorable conditions for a secondary cancer-forming event needed for tumor promotion.
- Ethanol is cytotoxic or poisonous to cells. This cytotoxicity followed by cell proliferation provide critical conditions for clonal expansion of initiated cells.
- By causing immune suppression and dysfunction, ethanol creates conditions where immune surveillance is weakened which furthers the carcinogenic process.
Appropriate Daily Alcohol Recommendations
Health authorities have tried to set acceptable limits for most healthy people. For healthy adult men, a moderate amount consists of not more than 2 drinks per day; and not more than one drink per day for a healthy adult woman. (Pregnant women are advised to abstain/not drink alcohol).
A drink is any alcoholic beverage that contains 1/2 ounce of pure ethanol. It is equivalent to one of the following:
- 5 ounces of wine
- 10 ounces of wine cooler
- 12 ounces of beer
- 1.5 counces of distilled liqour (80% proof whiskey, scotch, rum, or vodka)
Note: Taken in moderation, alcohol may be compatible with good health, with a strong emphasis on moderation.
References
Benedetti A et al. "Heavy Drinkers of Beer and Spirits Face Significantly Higher Cancer Risk" Journal Cancer Detection and Prevention August 2009
Watson RR Alcohol and Cancer CRC Press 1992
Weschler H et al. "College Binge Drinking in the 1990s: A continuing problem- Results of the Harvard School of Public Health 1999 College Alcohol Study" Journal of American College Health 2000;199-210
Whitney EN & Rolfes SR "Alcohol and Nutrition" Understanding Nutrition, Ninth Edition 2002, Wadsworth
pp: 230-239
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