Existing evidence suggests coffee’s benefits, among many, protect against non-melanoma skin cancers. But a new study published in the JNCI: Journal of the National Cancer Institute found consumption can reduce risk for malignant melanoma, the fifth most common cancer (and leading cause of skin cancer death) in the United States.

According to the American Academy of Dermatology, melanoma, if not caught early, spreads quickly throughout the body; the rapid spread is what makes it deadly. And until now, the research on coffee consumption and the risk of cutaneous melanoma has been limited, said Erikka Loftfield, of the Division of Cancer Epidemiology and Genetics, National Cancer Institute. She added, "coffee contains numerous bioactive compounds and may be associated inversely with melanoma."

So, Loftfield and her team used the data collected from 447,357 people who participated in the NIH-AARP Diet and Health Study. Each participant was cancer-free at the start of the study, and researchers measured for their coffee consumption, as well as “ambient residential ultraviolent radiation exposure, body mass index, age, sex, physical activity, alcohol intake, and smoking history.”

After a median follow-up of 10 years, 2,904 cases of malignant melanoma developed, plus 1,874 cases of melanoma in situ (early stages) were identified. Compared to non-coffee drinkers, participants who consumed coffee were at an overall lower risk of melanoma.

"We found that as compared with non–coffee drinkers, those who drank the most coffee (four cups per day) had a 20 percent lower risk of malignant melanoma but not of melanoma in situ, which may indicate different disease etiologies or an inhibitory role of coffee consumption in disease progression," researchers explained. "Statistically significant inverse associations were also found for caffeinated coffee intake and malignant melanoma but not for decaffeinated coffee intake."

Put it another way: Four cups of caffeinated coffee per day cut risk for deadly skin cancer by 20 percent. In addition to melanoma, previous studies have suggested drinking this much coffee per day reduces risk for Alzheimer's by 20 percent and type 2 diabetes risk by 25 percent.

It’s important to note the current study’s results are preliminary and will require additional research before researchers can say increased coffee consumption is a surefire way to prevent cancer.

The AAD believes the number of deaths from melanoma would be much lower if people knew the warning signs, how to check their skin, and took the time to, in fact, self-check. The ABCDEs of melanoma compile everything a person should look for, from asymmetry to evolution: “A mole or skin lesion that looks different from the rest or is changing in size, shape, or color.”

You can catch up on symptoms of skin cancer and how to recognize pre-malignant symptoms here and here.

Source: Loftfield E, et al. Coffee Drinking and Cutaneous Melanoma Risk in the NIH-AARP Diet and Health Study. JNCI: Journal of the National Cancer Institute. 2014.