Melanoma is one of the most common cancers in the US and is the leading cause of skin cancer death. The National Cancer Institute estimates there will be 74,000 new cases in 2015. Currently, the only established lifestyle risk factor for this disease is exposure to ultraviolet radiation (UVR), primarily from sun and tanning beds.
Now, a new analysis from the NIH-AARP Diet and Health Study links coffee drinking with lower risk for the most aggressive form of melanoma. The study used data from 1/2 million non-Hispanic whites who were cancer-free and aged 50-71 when the study began in 1995.
The researchers looked at participants’ daily coffee intake – none; one cup or less; 2-3 cups or 4 or more cups. They found that those drinking 4 or more cups of coffee a day had a 20% lower risk for the aggressive type of melanoma – called malignant melanoma – compared to non-coffee drinkers. Then, they looked at whether participants drank decaf or caffeinated coffee. They did not find a significant difference in malignant melanoma risk for decaf drinkers compared to non-drinkers, but for those who drank regular coffee, there was a 25% lower risk compared to non-coffee consumers.
Previous population studies looking at this link have had mixed results. But this new study had a larger number of cases of skin cancer than previous studies, so the authors say this may have helped in finding a link. And there are cell and animal studies showing that substances in coffee, especially caffeine, can protect against skin cancer caused by UV radiation. These substances can protect against DNA damage, cause cancer cells to die, and reduce inflammation in skin cells.
In analyzing the data the authors took into account sun exposure and potential variables like age, body mass index, physical activity, alcohol and smoking, but found that differences in these lifestyle factors did not account for the coffee drinkers’ lower risk.
The authors note some caveats about the study – they had to estimate sun exposure for each participant based on measures of UVR in their location. The original study questionnaire did not ask participants about how long they spent i the sun and if they used tanning beds. They also had no information on risk factors like fair skin and family history.
Keep in mind though, that the most important steps you can take to lower risk for skin cancer are to limit the time you spend in the sun, use sunscreen and avoid tanning beds.
The AICR/WCRF Continuous Updates have found coffee to be protective against endometrial and liver cancers. You can read more about the research and what’s in coffee in AICR’s Foods that Fight Cancer.
Find more information on melanoma from the National Cancer Institute.
The study was supported by the National Institutes of Health/National Cancer Institute and by the Yale-National Cancer Institute training grant.