A new study shows that drinking alcohol, even in moderation, may increase the risk of Study Shows Moderate Alcohol Consumption May Increase Breast Cancer Risk (dateline May 29, 2001) | Breast Health News | Imaginis - The Women's Health & Wellness Resource Network

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Study Shows Moderate Alcohol Consumption May Increase Breast Cancer Risk (dateline May 29, 2001)

A new study shows that drinking alcohol, even in moderation, may increase the risk of breast cancer in post-menopausal women. While several previous studies have linked alcohol consumption to breast cancer risk, this study examined how alcohol might contribute to a higher risk of breast cancer. After following over 50 women for eight-week periods, the researchers noticed that women who consumed alcohol had higher levels of hormones that have been linked to breast cancer. However, because drinking in moderation has been associated with a lower risk of heart disease, the researchers suggest that women discuss the benefits and risks of modest drinking with their physicians.

Even having one alcoholic beverage per day could increase a woman’s risk of breast cancer, according to lead researcher Joanne Dorgan, MPH, PhD and her team from the Fox Chase Cancer Center in Philadelphia, Pennsylvania. Dr. Dorgan and her colleagues followed 51 post-menopausal women who were not taking hormone replacement therapy. The women were followed through three eight-week periods during which they consumed either 15 grams or 30 grams of alcohol each day or were given an alcohol-free beverage (15 grams to 30 grams is equal to approximately one to two alcoholic drinks, such as beer or wine).

After the eight-week cycles, the researchers measured the levels of estrogen, progesterone, and testosterone in the women’s blood. They found that among the women who drank 15 grams of alcohol per day (approximately one beverage), the levels of a breakdown product of estrogen (called estrone sulfate) increased by 7.5%. Among the women who drank 30 grams of alcohol per day, their levels increased by 10.7% compared to the women who did not drink any alcohol. This increase in the level of an estrogen byproduct could increase the risk of breast cancer.

The study involved following women who consumed alcoholic beverages on a daily basis as opposed to those who drank occasionally. Previous studies have also linked daily alcohol intake to a slight increase in the risk of breast cancer. For example, in a study published in the February 18, 1998 issue of the Journal of the American Medical Association, researchers found that consuming at least 10 grams of alcohol (0.75 to 1 drink) per day slightly increased the risk of developing breast cancer. Lead researcher Stephanie A. Smith-Warner, PhD and her colleagues suggested that reducing daily alcohol consumption could reduce breast cancer risk.

However, other studies suggest that the relationship between alcohol and breast cancer risk is less clear. For example, in a new study that will be published in the July 2001 issue of Epidemiology, researchers found that consuming more than one half of a glass of alcohol per day and having low amounts of the B vitamin folate may increase the risk of breast cancer. Folate is found in green leafy vegetables, orange juice, dried beans and peas, and some cereals. While Dr. Thomas Sellers of the Mayo Clinic and his colleagues note that alcoholic beverages slightly increase the risk of breast cancer, they suggest that an adequate intake of folate might help counteract the risk.

Because moderate drinking is linked to a lower risk of heart disease, Dr. Dorgan and her colleagues suggest that each woman’s situation be assessed by a physician. As a woman ages, her risk of breast cancer increases. However, her risk of heart disease and stroke also increase with age. Currently, heart disease kills more women in the United States each year than breast cancer and all other health conditions. The risk of heart disease is more likely to be reduced by changes to diet and exercise and other measures, such as taking medicines to treat high cholesterol.

To help detect breast cancer in its earliest stages when the chances of successful treatment and survival are the greatest, women should follow these guidelines:

  • Women 20 years and older should practice monthly breast self-exams and have physician-performed clinical breast exams at least every three years.
  • Beginning at age 40, women should begin receiving yearly screening mammograms in addition to monthly breast self-exams and yearly clinical breast exams.
  • Women at high risk of breast cancer, such as those with a strong family history of breast cancer, should talk to their physicians about beginning yearly screening mammograms before age 40.

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