Coffee linked to reduced melanoma risk and heart‑health guidelines

A large prospective study by the National Cancer Institute (NIH‑AARP Diet and Health Study) followed more than 447,000 participants for ten years and found that drinking four or more cups of caffeinated coffee a day was associated with a 20% lower risk of malignant melanoma compared with non‑coffee drinkers. The effect was statistically significant only for caffeinated coffee.

Meta‑analyses involving over 844,000 people reported approximately a 4.5% risk reduction in melanoma for each additional cup of caffeinated coffee consumed. Laboratory research suggests caffeine may inhibit UV‑B‑induced DNA damage and promote the removal of damaged pre‑cancerous cells, while chlorogenic and caffeic acids suppress COX‑2 enzyme expression linked to melanoma development.

Separate research highlighted that up to 400 mg of caffeine daily—roughly five cups of coffee—is considered safe for most adults by the American Heart Association. Consuming up to five cups is linked to lower cardiovascular risk, including reduced incidence of heart failure, stroke, hypertension, and type‑2 diabetes. Professor Gregory M. Marcus of the University of California, San Francisco notes the lowest mortality risk occurs with two to four cups per day, provided no excessive sugar or high‑calorie additives are added.