Western diet increases breast cancer risk in Asian women

Jul 11 2007

A study on the dietary habits of Chinese women has found that those who ate a Western diet increased their risk for breast cancer.

Although Asian breast cancer rates are lower than those in the West, that appears to be changing and experts suspect changing dietary habits in countries such as China may be a factor.

A study of 3,000 women in Shanghai, half of whom were diagnosed with breast cancer, showed those who ate a "meat-sweet" diet were twice as likely to develop the disease as those on a vegetable-based diet.

The research suggests a Western-style diet high in meat, white bread, milk and puddings may put Asian women at a higher risk of developing breast cancer.

The researchers from the Fox Chase Cancer Center in Philadelphia say however that the two-fold increase in risk for women on a Western-style diet was found to exist only among post-menopausal overweight women and those with a Body Mass Index (BMI) of over 25 were found to be most at risk.

They say for post-menopausal Asian women, low consumption of a western diet along with successful weight control may protect against breast cancer.

A "vegetable-soy" diet more traditionally followed in China uses a variety of vegetables, soy-based products and freshwater fish but experts say overall it is difficult to determine the effects of diet on breast cancer risk.

According to the Chinese Anti-Cancer Association (CACA) the incidence and death rates of breast cancer in China's major cities rose respectively by 37% and 38.9% during the 1990s.

It is thought better diagnosis partly explains the rise, but environmental factors - including dietary changes are also thought to be factors.

Western scientists have estimated that obesity causes around 10% of breast cancer cases and many studies show that post-menopausal women who are overweight or obese have a raised risk of breast cancer.

But experts agree that it is still very difficult to pinpoint factors and to determine the effects of diet on breast cancer risk.

They say the study did not appear to take into account issues such as having children at a later age, not exercising or taking the pill.

The study appears in Cancer Epidemiology, Biomarkers and Prevention.