Grapes and green tea for good breast health?

Illustration of grapes

The breast is 90% fat tissue, and while some of the hormones produced by the breast's fat cells are harmful, one such hormone acts as a "guardian angel" against breast cancer.

The hormone adiponectin appears to protect against the effects of obesity on metabolism, the heart, and blood vessels. Researchers at the Winship Cancer Institute of Emory University have found that adiponectin also can reduce the ability of cancer cells to migrate from the breast and invade other tissues.

"What kills someone with breast cancer is that the cancer cells learn to get away from the basement container," says hematology researcher Dipali Sharma. "They learn to migrate to the lung, liver, and beyond."

The key to translating this research for patient care lies in finding a way to increase a person's adiponectin, Sharma says. Anti-diabetic drugs known as thiazolidinediones increase adiponectin's activity, but they have toxic side effects. Also getting adiponectin to where it needs to go is a challenge, Sharma says, along with determining what an injection of a high level of adiponectin might trigger.

What can increase adiponectin is weight loss. Obese people have lower levels of adiponectin than people of normal weight, and as a consequence, those with obesity have an increased risk of breast cancer. The Emory researchers also found low levels of adiponectin in patients with aggressive breast cancer tumors.

Currently, Winship scientists are testing a molecule found in certain foods that appears to mimic the effects of adiponectin. The molecule is found in grapes, cabbage, and green tea.

The hormone leptin also is under investigation by breast cancer researchers. Although leptin is a satiety hormone, it is found in high levels in obese people, leading scientists to theorize that obese people may be resistant to the hormone. Studies in mice predisposed to breast cancer show that when leptin is turned off, the cancerous tumors cease to grow. 

"We've only scratched the surface," Sharma says. "We might find a gold mine of molecules that may inhibit leptin or enhance adiponectin." —Kay Torrance

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Emory Health - Winter 2010