The online universe is even more chaotic. Google any common disease and you will likely find links to hundreds of thousands of sites, some legit and many just plain bogus. "There are a plethora of scientific studies, many of them very small," says Lauer. "You can almost always find at least one study that agrees with your point of view. Some interest groups will grab onto the study that agrees with them and promote it, but won't mention the other 99 studies that disagree with those results."

The two hormone studies presented last month at a breast-cancer conference both drew on earlier research, and neither was particularly surprising to scientists who follow the field. Doctors have known for a while that women who take estrogen and progestin for five years or longer are more likely to be diagnosed with breast cancer. When they stop taking hormones, their risk goes down within a year. Does that mean the estrogen causes the cancer?

That's not clear, says Dr. Ruth Freeman, a WHI investigator who runs a menopause treatment and research center at Montefiore Medical Center in New York. "There's no question that in cellular studies estrogen promotes growth of cancer cells," says Freeman, who is also a professor at the Albert Einstein College of Medicine. "But that doesn't mean it creates the cancer. It feeds it. Maybe that's the issue. But there's no definitive answer." And it's also not clear why hormone takers are only at risk for a less aggressive form of breast cancer. "What we can say is that estrogen plus progestin doesn't prevent breast cancer," Freeman says. The reason for the decline in breast cancer after women stop taking hormone is another continuing puzzle. "That's strange," says Freeman. "If estrogen were causing a doubling of breast cancer [as the study indicates], you wouldn't expect it to go down within one year."

At the moment, the best advice for women suffering from hot flashes is to try lifestyle changes first: lose weight, quit smoking and exercise more. If that doesn't work, you can talk to your doctor about taking the smallest effective dose for the shortest possible time. For many women, that means just a year or so to get them over the period around the time of menopause (the average age in the United States is 51) when hormone fluctuations are most extreme. Then, Freeman advises tapering off gradually to prevent more hot flashes in the withdrawal phase. Of all the medical decisions women may face, hormone therapy remains one of the most contentious. Many doctors feel strongly on one side or the other of this issue, and it's sometimes hard to know whether you're getting the most objective information. "If your doctor is willing to have a sophisticated discussion with you, giving you multiple points of view, I think you can have confidence," says Lauer. "I would be worried any time I'm hearing all pros and no cons."

For more information on hormone therapy, check out this National Institutes of Health site.

© 2009