Alcohol and breast cancer risk: What to know

Can as little as one alcoholic drink a day raise your breast cancer risk?

Studies say yes. But does that mean you should steer clear of alcohol completely? And what about that glass of wine that’s supposed to be good for you?

Alcoholic drinks come in three choices: beer, wine and liquor. A drink is defined as 12 ounces of beer, 5 ounces of wine or 1.5 ounces of liquor. If you choose to drink, exceeding the recommended limit of one alcoholic drink a day increases your breast cancer risk.

“But that risk is very low,” says Therese Bevers, medical director of MD Anderson’s Cancer Prevention Center. “You need to be more concerned if it becomes a routine in which you drink more than one drink each day.”

More than 100 studies have looked at the association between alcohol consumption and breast cancer risk in women. These studies, although observational – meaning they draw on inferences from researchers - have consistently found an increased risk of breast cancer associated with alcohol intake.

“We always question the validity of observational data, but with this we’re seeing it over and over again,” Bevers says.

And while some studies show that one glass of wine a day can be good for your heart, you shouldn’t have more if you’re trying to stay healthy.

How does alcohol affect breast cancer risk?

So, why does alcohol intake increase breast cancer risk specifically?

“We don’t really know, but we do have a few guesses,” Bevers says.

Reasons why alcohol consumption may lead to breast cancer include:

• Alcohol is empty calories and can lead to unwanted weight gain. Excess fat can lead to increased cancer risk.
• Alcohol can increase levels of estrogen and other hormones associated with breast cancer.
• Alcohol users are more likely to have increased amounts of folic acid in their systems, which can lead to increased cancer risk.

Men should also limit their drinking, but not because of breast cancer risk. While men can develop breast cancer, alcohol consumption doesn’t really increase their risk for breast cancer.

“Breast cancer in men is so rare, if they do develop it it’s usually because of genetics, not diet or alcohol,” Bevers says.

Alcohol has been shown to increase risk for other cancer types, including head and neck, esophageal and liver cancers.

To cut back on your alcohol consumption and lower your breast cancer risk, follow these guidelines:

• Select low-calorie options to avoid unwanted weight gain.
• Stay away from 100-proof liquor. Researchers believe that it’s the ethanol or alcohol in beer, wine and liquor that causes increased cancer risk.
• Avoid alcohol as often as possible.

“You can still enjoy alcohol on occasion,” Bevers says. “Just don’t make it a routine.”