A study published by scientists at Harvard University mentioned that women drinking 4 or more cups a day had a 20% lower risk of suffering from depression.
According to a number of studies, coffee appears to have a protective effect against certain types of cancer, including colorectal and liver cancer. Statistics showed a 40% lower incidence of liver cancer and a 15% lower incidence of colorectal cancer in coffee drinkers.
Although coffee increases blood pressure, this effect is only temporary and there is some evidence that female coffee drinkers have a lower risk of heart disease while coffee drinkers of both genders have a 20% lower risk of stroke according to some studies.
Two very large studies have shown that over a period of 18-24 years, drinking coffee was associated with a 20% and 26% lower risk of death in men and women respectively. The boost to longevity that coffee provides appears to be particularly strong in those suffering from type 2 diabetes, who were shown to have a 30% lower risk of death during a 20-year study.