The study – published in Cancer Research – suggests that increasing the number of cups of caffeinated coffee you drink could lower your risk of developing basal cell carcinoma – the most common form of skin cancer.
"Our data indicate that the more caffeinated coffee you consume, the lower your risk of developing basal cell carcinoma," said Dr Jiali Han, of Harvard Medical School and Harvard School of Public Health, USA.
"These results really suggest that it is the caffeine in coffee that is responsible for the decreased risk of basal cell carcinoma associated with increasing coffee consumption," said Han, though the researcher added that he would not recommend increasing coffee intake based solely on data from the new study.
"However, our results add basal cell carcinoma to a list of conditions for which risk is decreased with increasing coffee consumption. This list includes conditions with serious negative health consequences such as type 2 diabetes and Parkinson's disease."
Han and his colleagues analysed data from the Nurses' Health Study, a large and long-running study to aid in the investigation of factors influencing women's health, and the Health Professionals Follow-up Study, an analogous study for men.
Of the 112,897 participants included in the analyses, 22,786 developed basal cell carcinoma during the more than 20 years of follow-up in the two studies.
An inverse association was observed between all coffee consumption and risk of basal cell carcinoma.
Similarly, an association was found between intake of caffeine from all dietary sources – including coffee, tea, cola and chocolate – and risk of skin cancer. However, Han noted that consumption of decaffeinated coffee was not associated with a decreased risk of basal cell carcinoma.
"This would be consistent with published mouse data, which indicate caffeine can block skin tumour formation,” he said. “However, more studies in different population cohorts and additional mechanistic studies will be needed before we can say this definitively."
In contrast to the findings for basal cell carcinoma, neither coffee consumption nor overall caffeine intake were associated with the two other forms of skin cancer – squamous cell carcinoma and melanoma.
Han said the finding for other forms of skin cancer could be due to the lower incidence of the conditions within the study population – meaning any association between intake and incidence was more difficult to see.
"As the study participants are followed for a longer time, the number of cases of these conditions is likely to increase. We may be in a position in 10 years' time to better address this issue," he noted.
Source: Cancer Research
Published online ahead of print, doi: 10.1158/0008-5472.CAN-11-3511
“Increased Caffeine Intake Is Associated with Reduced Risk of Basal Cell Carcinoma of the Skin”
Authors: F. Song, A.A. Qureshi, J. Han