Tofu-Rich Diet May Help Women With Lung Cancer
Chinese study found eating high amounts before diagnosis boosted survival rates
The authors reported that about 450 women were diagnosed with lung cancer during the study. They were divided into three groups according to the amount of soy food they had eaten before their lung cancer diagnosis. The highest intake levels of tofu were equal to about 4 ounces a day, while the lowest soy consumers ate less than 2 ounces daily.
During the study, more than 300 of the lung cancer patients died, Yang said. Sixty percent of the women in the highest soy-eating group and 50 percent in the low soy consumer group were alive twelve months after diagnosis. A patient's risk of death decreased with increasing soy intake, but leveled off at 4 ounces of daily tofu consumption.
"Patients with the highest soy food intake had better overall survival compared with those with the lowest intake," said Yang, who described the association as "linear."
What is in soybeans that might have cancer-slowing properties? It contains isoflavones that can act like selective estrogen modulators (SERMS), similar to the breast-cancer-fighting drug tamoxifen, Patel said.
"These SERMS may have a protective effect in lung cancer because we know that estrogen receptors are present in lung cancer and are important in lung development," Patel said.
Elisabetta Politi, nutrition director at the Duke Diet and Fitness Center in Durham, N.C., said the study is promising, but it raises a lot of questions too: Does the age at which soy is consumed play a role in how well it fights cancer later? Are certain soy foods better than others at fighting cancer? Would the results translate to a non-Chinese population?
"Maybe soy is important to eat before puberty," Politi said, noting that some studies suggest breast cancer risk is linked to earlier puberty. She said most American women don't eat soy before puberty, though. "It's not a typical staple in the American diet."
The new research also only collected information on soy intake before a lung cancer diagnosis, Politi said. People who already have lung cancer may wonder if adding tofu or soymilk to their daily diets could help.