Scientists have known that alcohol has been promoting cancer for several decades. The World Health Organization classified alcohol consumption as causing cancer in 1987. Experts say that all types of alcoholic beverages can increase the risk of cancer because they all contain ethanol, which can cause DNA damage, oxidative stress and cell proliferation. Ethanol is metabolized by the body into another carcinogen, acetaldehyde, and can influence the risk of breast cancer by raising estrogen levels.
But research continues to show that most people remain unaware of the risks. When the American Cancer Research Institute interviewed Americans two years ago to assess their awareness of the different cancer risk factors, the results were surprising: less than half were aware of the link between alcohol and cancer.
Experts say one reason for the lack of awareness is the popular idea that moderate consumption of alcohol, especially red wine, is good for heart health, which drowned out public health messages about the impact of alcohol on risk cancer. But, although moderate alcohol consumption has long had a health halo, recent studies suggest that it may not be beneficial. The American Heart Association states that “no research has established a cause and effect relationship between alcohol consumption and better heart health”, and that people who drink red wine may have lower rates of heart disease for other reasons, such as healthier lifestyles, better diets or higher socioeconomic status.
Other analyzes have found that moderate drinking may seem beneficial in large population studies because the “non-drinkers” used for comparison often include people who do not drink because they have serious health problems or because they are heavy drinkers. When studies take these factors into account, the apparent cardiovascular benefits of moderate alcohol consumption disappear.
For this reason, the federal government’s Dietary Guidelines for Americans, which previously promoted moderate consumption of alcohol for heart health, no longer make this claim. A panel of scientists who helped shape the latest edition of the guidelines asked the government to lower the recommended daily limit on alcohol consumption to just one drink per day for men and women, citing evidence that higher levels of alcohol intake increase the risk of premature death.
But the alcohol industry pushed fiercely against this change, and the latest guidelines, published in December, did not include the lowest drink recommendation. The guidelines, however, for the first time included strong language about alcohol and cancer, warning that even moderate drinking can “increase the overall risk of death from various causes, such as various types of cancer and some forms of cardiovascular disease”.
“For some types of cancer,” say the new guidelines, “the risk increases even with low levels of alcohol consumption (less than one drink a day). Caution, therefore, is recommended. “