In the past, coffee was associated with adverse health effects, but that was when some studies of its impact didn’t consider many of its drinkers also smoked and had a sedentary lifestyle.
More recent research has discovered numerous health benefits from black coffee, though its high caffeine content does warrant caution for those sensitive to it or have acid reflux.
How coffee helps:
Promotes heart health — A 2013 review of 36 studies of the link between coffee and heart health by the journal Epidemiology and Prevention found a reduced risk of heart disease in those who drank three to five cups per day over those who drank no coffee or more than 5 cups per day.
Protects the liver — Several studies have found coffee drinkers are less likely to die from liver cirrhosis, have high amounts of harmful liver enzymes or suffer scarring from hepatitis C. A 2015 study found drinking one cup a day reduced risk of death from chronic liver disease by 15%, while drinking four cups reduced your chances by 71%.
Reduces skin cancer risk — A review of more than 445,000 white participants in the NIH-AARP Health Study published in 2015 by the Journal of the National Cancer Institute found cases of malignant melanoma were 20% lower in four-cup-a-day caffeinated coffee drinkers.
Protects against type 2 diabetes — A Harvard study published in 2014 followed more than 120,000 coffee drinkers for up to 20 years and reported that those who increased their coffee intake by more than a cup a day for four years had an 11% lower risk of developing type 2 diabetes. Conversely, those who decreased their coffee by one cup a day had a 17% higher risk of the disease.
Slows onset of dementia — A 2012 study from the University of South Florida took the blood caffeine levels of 124 adults with early symptoms of memory loss, then tracked progression toward dementia over the next four years. No participants found to have a blood caffeine level above 1,200 ng/ml had progressed to full-blown dementia. Coffee was the main source of caffeine.