Coffee may slash breast cancer risk: study

Researchers from Lund University and Malmo University in Sweden looked at the coffee-drinking habits of about 460 breast cancer patients, and found that the potential protective effects of the beverage were dependent on variations in a gene called CYP1A2, which codes for an enzyme that metabolises both oestrogen and coffee. Half of the women had a variant called A/A, while the others had either A/C or C/C. "This study is the first to report an association between coffee consumption, CYP1A2 genotype, and breast cancer characteristics, and our results warrants confirmation,"​ wrote the researchers in the journal Cancer Epidemiology, Biomarkers and Prevention​. "Because coffee is widely consumed and the CYP1A2 A/A genotype is present in half of the population, our findings may have important implications with regard to breast cancer given that coffee consumption is a potentially modifiable factor." ​ Coffee, one of the world's largest traded commodities produced in more than 60 countries and generating more than $70bn in retail sales a year, continues to spawn research and interest, and has been linked to a range of health benefits, including a reduced risk of diabetes, improved liver health, and potential protection against ovarian and liver cancer. New data ​ The women completed questionnaires in order to assess their coffee consumption habits. The average age of the participants at diagnosis was 59.6, while their average BMI was 24.5 kg per sq. m. Lead researcher Helena Jernstrom said: "Those women who had one of the C variants, and who had drunk at least three cups of coffee a day, developed breast cancer considerably more seldom than women with the A/A variant with the same coffee consumption. Their cancer risk was only two thirds of that of the other women. ​​"A/A women who had drunk two or more cups of coffee a day received more ambiguous help from their coffee consumption. On the one hand, their cancer appeared considerably later than among women who had seldom or never drunk coffee at a mean age of 58 years instead of 48 years, unless they had taken hormone replacement therapy for menopausal symptoms,"​ she added. The researchers related the effects to the female sex hormones, oestrogens. Jernstrom and co-workers noted that certain metabolic products of these hormones are known to be carcinogenic, and components of coffee improve the configuration of various oestrogens. Moreover, the caffeine content may also hamper the growth of cancer cells. Jernstrom stressed, however, that dietary recommendations regarding coffee consumption were not possible based on these preliminary results. "This is new information that needs to be corroborated in other studies before we can issue any recommendations. If coffee does in fact provide some protection against breast cancer, then women in such a coffee-drinking country as Sweden ought to have fewer cases of cancer than other countries. This is also the case, at least compared with the U.S. There the proportion of breast cancer cases in the population is considerably higher, and there people drink both more decaffeinated coffee and less coffee in general,"​ she said. Over one million women worldwide are diagnosed with breast cancer every year, with the highest incidences in the US and the Netherlands. China has the lowest incidence and mortality rate of the disease. Hormone-sensitive oestrogen-receptor (ER) positive and progesterone-receptor (PR) positive tumours are said to be the most common type diagnosed among breast cancer patients in the US. Source: Cancer Epidemiology, Biomarkers & Prevention​ 2008, Volume 17, Pages 895-901 "Coffee Consumption and CYP1A2*1F Genotype Modify Age at Breast Cancer Diagnosis and Estrogen Receptor Status" ​Authors: E. Bageman, C. Ingvar, C. Rose, H. Jernstrom