WASHINGTON (Reuters) - Post-menopausal Chinese women who eat a Western-style diet heavy in meat and sweets face a higher risk of breast cancer than their counterparts who stick to a typical Chinese diet loaded with vegetables and soy, a study found.
The researchers, writing on Tuesday in the journal Cancer Epidemiology, Biomarkers & Prevention, tracked about 3,000 women in Shanghai, about half of whom were diagnosed with breast cancer.
Post-menopausal women who ate a Western-style diet -- beef, pork, shrimp, chicken, candy, desserts and dairy products -- were 60 percent more likely to develop breast cancer than those eating a diet based on vegetables and soy, the study found.
The study found the increased risk most acute for cancer involving so-called estrogen-receptor positive tumors. The post-menopausal women with the Western-style diet experienced a 90 percent increased risk for this type of breast cancer.
One of the researchers, Marilyn Tseng of the Fox Chase Cancer Center in Philadelphia, said the study detected a much smaller increased breast cancer risk among younger women on a Western-style diet which was not statistically significant.
Tseng noted that breast cancer rates among Asian women traditionally have been low but have been rising in recent years. Some experts have suspected that the adoption of a more Western diet may be at least partly to blame.
"The increase in risk did appear to be due to the increase in red-meat intake," Tseng said in a telephone interview. "But we didn't do specific analyses to see if it could have been due to other parts of a western diet, like the high intake of desserts or high intake of dairy."
The findings also suggested such a diet may increase breast cancer likelihood by increasing obesity, the researchers said.
"We are the first to find evidence for an increased risk of breast cancer for a Western-style dietary pattern in an Asian population," the researchers wrote.
They detected two dietary patterns in the women, who were diagnosed with their cancer from 1996 to 1998 and were subsequently interviewed about what they ate.
One was a "vegetable-soy" pattern based on tofu, cauliflower, beans, bean sprouts and green leafy vegetables, with not much meat. The other was a "meat-sweet" pattern among women gravitating away from typical Chinese fare in favor of more Western foods.
"Most studies have tended to look at single dietary factors. And what was unique about this study is that we tried to describe patterns of intake -- foods that go together, that seem to occur together in the diet," Tseng said.