The research, published Tuesday by the American Institute for Cancer Research (AICR), indicates that 10 grams of alcohol daily — about the size of a small glass of wine or beer — can increase the breast cancer risk by 5% in premenopausal women and 9% in postmenopausal women.
“Some other individual studies had suggested that risk only started with 2 drinks per day or more,” said Anne McTiernan, lead author of the study. “But this meta-analysis, where we combined results from many large cohort studies, was definitive.”
Alcohol has long been established as a known human carcinogen (cancer-causing substance). The mechanisms by which alcoholic beverages increase risk the risk of cancer include:
- Metabolizing ethanol into acetaldehyde, a toxic chemical that can damage both DNA and proteins.
- Generating reactive oxygen species (chemically reactive molecules that contain oxygen) which can damage DNA, proteins, and lipids (fats) through a process called oxidation.
- Hindering the body’s ability to break down nutrients that may be associated with an increased cancer risk.
- Increasing blood levels of estrogen, a sex hormone linked to breast cancer.
It’s not all bad news for women who like to wet their whistle, fortunately. The study also found that a more vigorous exercise routine can lower the risk of breast cancer by up to 17% in premenopausal women and 10% in postmenopausal women.
Physically active people are more likely to maintain a healthy weight throughout their lifetime. Obesity increases the risk for many forms of cancers, and certain types of body fats release hormones that may lead to the disease.
However, the researchers cautions that exercising more and drinking less aren’t sure fire ways to avoid breast cancer.
“It’s not a guarantee,” McTiernan said. “I think of it like a seatbelt. It’s not a surety that you’ll be saved from injury in a car crash, but using a seat belt reduces your risk.”
Source: Washington Post