Drinking coffee may do more than just help you wake up in the morning. In recent years, studies have not shown coffee drinking to demonstrate consistent results in the prevention of various types of cancer. (1) However, a study in 2006 of over 77 thousand women showed that “daily consumption of six or more cups of caffeinated coffee was associated with a 30 percent reduction in non-melanoma skin cancer.” (1). Can these results be a reason to drink more than a cup or two of java each day?
The study was lead by Dr Ernest Abel and his team as a cross-sectional analysis of 77,373 post menopausal Caucasian women aged 50-79 who were enrolled in the Women’s Health Initiative (WHI) between the years of 1993 and 1998. Only caffeinated coffee was found to offer this benefit, decaffeinated coffee did not show a correlation.
The women in the WHI study had filled in questionnaires regarding their lifestyle and other characteristics of their lives including coffee drinking habits and whether they had ever had skin cancer. Researchers found that about eight in every 100 women reported having had non-melanoma skin cancer.
“Daily consumption of caffeinated coffee with was associated with a dose-related decreased prevalence of NMSC (non-melanoma skin cancer) of nearly 5 percent for each cup.” Thus the calculation of 6 cups associated with a 30 percent reduction.
In looking at the results of a study like this it is important to note that it was a cross-sectional study. This means that it only looks at data collected during one point in time so it is not able to establish what events may cause a result or track trends in the women’s behavior.
This study had asked women about how much coffee they drank during the previous three months. While it is likely their coffee habits are not recent, we don’t know how many months or years they may have been drinking coffee in that amount, nor did someone really verify how much coffee the women actually drank.
The study also only looked at Caucasian women because they have a higher incidence of non-melanoma skin cancers so women from different ethnic groups may well have different results.