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.
Professor Lammert “ working together with his colleagues Dr. Frank Gr nhage, Maja Walier and Professor Dr. Thomas Wienker as well as scientists at the University Clinic of Cluj-Napoca in Romania “ has been searching for the specific genes involved. And he has succeeded, thanks to a study covering 178 women and men from 84 families. They all suffer from gallstones. In 21.4 per cent of cases the subjects were found to be carrying a particular gene variant. In healthy individuals studied as a control group, this variant also occurred, but only at a frequency of 8.6 per cent.
Cholesterol pump at full speed
"The mutation concerns what is known as the ABCG8-gene," Dr. Gr nhage explains. "It contains the instructions for building a pump responsible for transporting the blood lipid cholesterol from the liver into the bile ducts." Most of the gallstones consist to a high degree of crystallised cholesterol. The medical researcher concludes that, "The genetic alteration probably makes the pump run permanently at high speed."
The researchers now hope that their finding will have positive consequences for prevention and therapy. Professor Lammert thinks that, "It may be possible for certain patients to be helped with drug treatments in future, thus avoiding the need for an operation." However, the genetic contribution to the common problem of gallstones has not been fully explained by this study: "We believe there are at least three or four other gene variants that increase gallstone risk," says the medical scientist.
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