Women who drink red wine may have a lower risk of breast cancer than women who drink white wine, a small new study suggests.

The results show that premenopausal women who drank 8 ounces of cabernet sauvignon every night for about a month had lower estrogen levels than women who drank white wine. Increased estrogen levels have been linked to breast cancer.

Much research has linked increased consumption of alcohol with an increased risk of breast cancer, the researchers say.

Still, previous studies have found that red grapes, grape juice, grape seed extract and red wine contain compounds called aromatase inhibitors, which can lower estrogen production. Drugs made from aromatase inhibitors are used to treat some types of breast cancer in postmenopausal women; this study was the first to examine whether red wine might also have an estrogen-lowering effect in younger women.

“I’d say that if someone is not a drinker, they shouldn’t start drinking,” said Dr. Glenn Braunstein, chairman of the Department of Medicine at Cedars-Sinai in Los Angeles and co-author of the study.”But if someone is a wine drinker, they should stick to red wine.”

Red vs. white

For the study, researchers recruited 36, healthy premenopausal women around age 36. The women were told to drink 8 ounces of either cabernet sauvignon or chardonnay each evening for three weeks, and then to drink the other type of wine each night for another three weeks.

The women did not consume any grape products, or other alcoholic drinks during the study. Throughout the study, researchers collected blood samples to measure hormone levels.

They found that during the three weeks of cabernet drinking, women showed a slight decrease in estrogen, and an increase in testosterone, which could mean that red wine may act as an aromatase inhibitor in younger women.

“The estrogen dropped about 10 percent, and free testosterone went up a little over 10 percent,” Braunstein said. Those changes were “all going in the direction you’d expect with aromatase inhibitors,” he said.

That degree of change in hormone levels is unlikely to bring unwanted side effects, according to Braunstein. “They had pretty normal hormonal changes. There would be no long-term effects, like osteoporosis, at these levels.”

Still, the findings are modest, he acknowledged.”We would have liked to have had more robust findings,” Braunstein said.  “We didn’t have enough subjects to see smaller changes.”

Does red wine have different effects on breast cancer than other alcoholic drinks?

Braunstein, and other doctors who were not involved in the study ,said that people should view the results with caution.

Braunstein would have liked to conduct the study for a longer period of time and have had more participants.

“Also, we asked people not to drink other alcohol or eat grapes or raisins, but we did not control their diets,” he said.

Dr. Wendy Chen, an assistant professor of medicine at Harvard Medical School who was not involved in the study, said she found fault with the study’s methodology.

“They used an unusual way of analyzing the data,” Chen said. Hormone levels can vary greatly between people, so researchers usually look at how one person’s levels change over time. Instead, the researchers averaged values for each group, she said.

Chen studies the relationship between alcohol and breast cancer, and recently published a study that found that women who drink frequently, regardless of the type of alcohol, have an increased chance of developing breast cancer.

Her findings are in line with many other studies showing that increased consumption of alcohol is linked with an increased risk of breast cancer.

“The big question is that there is plenty of data that links alcohol to breast cancer, but it is unclear if wine has the same effects as other types of alcohol,” Braunstein said. “I would posit that it doesn’t have the same effect.”

Pass it on: Drinking red wine instead of white may offer women a lower risk of breast cancer.

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