With alcohol, the old adage is true: Everything in moderation.

To help put concerns into perspective, James Lacey, Ph.D., associate professor in City of Hope’s Division of Cancer Etiology, answers some questions about alcohol and cancer risk.

What cancer risks are associated with alcohol consumption?

Alcohol consumption has been reported to increase the risk of breast cancer in women. Alcohol also has been linked with increased risks of digestive tract cancers: oral and pharyngeal cancer, cancer of the larynx and some types of esophageal cancer.

The mechanisms aren't entirely understood, but the increase in breast cancer risk might be due to the ability of alcohol to increase circulating levels of estrogens, which are key factors in the development of breast cancer. For digestive tract cancers, there is some indication that alcohol's metabolism into acetaldehyde — which has carcinogenic and mutagenic properties — might be the mechanism at work.

Many studies compare moderate drinking and heavy drinking. What is considered moderate?

In most studies, "moderate" is defined as one drink per day, based on the standard unit equivalents of one beer, one glass of wine or one serving of hard liquor.

In most study results, heavy drinking is usually bad while moderate drinking can be either good or bad. If less is better, is not drinking at all the best?

There is no consensus answer to whether complete abstinence is better than moderate drinking. Moderate alcohol consumption has been reported to reduce the risk of coronary heart disease, which of course affects far more men and women than do breast cancers or the rare digestive tract cancers.

A real challenge with alcohol is that rarely is it consumed independently of other factors that affect health and disease. On the negative side, alcohol can accompany smoking or other less-healthy behaviors, so it's always tough to isolate how much of an observed effect is due to alcohol versus other related lifestyle factors.

The same can be said of alcohol's positive effects. Think of the Mediterranean diet or the French diet, where lower caloric intake and healthy eating habits often include more daily consumption of wine than is typically seen in U.S. diets.

As far as I know, there have not been good studies that attempt to quantify the overall effects of alcohol on multiple chronic disease endpoints — breast cancer, coronary heart disease, liver disease, for example — at the same time, although I am currently working on a research grant that will propose to do just that.

How can we celebrate but still be mindful of our health?

The old mantra "everything in moderation" still applies. There is certainly a place for good beer, fine wine or special champagne during special events [and] celebrations. Moderate consumption can help to make sure that the alcohol — just like a favorite meal or decadent dessert — adds to the occasion.

On the other hand, because most of the studies have looked at the benefits and risks of regular alcohol consumption, the person who usually doesn't drink alcohol but wants to join the toast should not have to worry about whether the alcohol they consume … is going to increase their risk of developing cancer.

Where can people go for more information about the risks and benefits of alcohol consumption?

If you want more info on the data on risks and benefits, try looking at the American Institute for Cancer Research or the American Cancer Society website.