MONDAY, Dec. 12, 2005 (HealthDay News) -- Women who drink at least two cups of tea a day can reduce their risk of developing ovarian cancer by almost 50 percent, Swedish researchers report.
There has been some experimental evidence that green and black tea might lower the risk of some cancers, but this is one of the few studies that has looked at the ability of tea to reduce the risk of ovarian cancer, the researchers noted.
The report appears in the Dec. 12/26 issue of the Archives of Internal Medicine.
In their study, Susanna C. Larsson and Alicja Wolk, of the National Institute of Environmental Medicine at the Karolinska Institute in Stockholm, looked at 61,057 women who were 40 to 76 years old.
The women all participated in a population-based study called the Swedish Mammography Cohort. At the beginning of the study, 68 percent of the participants said they drank tea (mainly black tea) at least once a month. During 15 years of follow-up, 301 women were diagnosed with ovarian cancer.
"We found a lower risk of ovarian cancer associated with greater tea consumption," Larsson said.
Larsson and Wolk found that women who drank at least two cups of tea a day reduced their risk of developing ovarian cancer by 46 percent.
"Each additional cup of tea per day was associated with an 18 percent lower risk of ovarian cancer," the authors reported.
In addition, women who drank one cup a day cut their risk by 24 percent, and those who even drank less than one cup of tea a day reduced their risk by 18 percent compared with non-tea drinkers.
"The advice to women is to increase the consumption of tea," Larsson said. "There are no harmful effects of tea."
One expert sees this study as reason to look for the components in tea that may be protecting women from ovarian cancer.
"This manuscript continues to increase our optimism that lifestyle interventions can be successful in cancer prevention," said Dr. Robert Morgan Jr., section head of medical gynecologic oncology at City of Hope Cancer Center in Duarte, Calif.
"These interventions are particularly important in ovarian cancer because, while ovarian cancer diagnosed in early stage disease is very curable, screening interventions have been only minimally effective in this disease due to the non-specificity of symptoms of early ovarian cancer, as well as the location of the ovaries deep in the pelvis, making them difficult to examine directly," Morgan said.
Because of this, prevention strategies are very important, Morgan added.
"Much data has recently been published suggesting that lifestyle changes, including exercise and statins, may lead to decreased incidences of new diagnoses of cancer or cancer recurrences. This manuscript suggests that there are other natural products which may be capable of the same phenomenon," he said.
Since the reasons tea may be protective are not known, Morgan thinks this study could lead researchers back to the lab to uncover the mechanisms at work.
The National Cancer Institute can tell you more about ovarian cancer.