Coffee consumption and disease specific mortality

A 2019 meta-analysis suggested a non-linear inverse association between coffee consumption and mortality from respiratory disease and diabetes, while a linear inverse association was found for mortality from non-CVD and non-cancer causes⁵. A further 2021 meta-analysis supported these findings suggesting that there was a significant inverse association between coffee consumption and the risk of CVD, type 2 diabetes, endometrial cancer, melanoma and nonmelanoma skin cancer, with the largest risk reduction being observed for 3-4 cups per day (∼120 mL/cup)⁶.

Cardiovascular disease

Research into coffee consumption and CVD has largely suggested that a moderate intake of coffee may reduce CVD mortality risk^3,6,12,13, although some studies have given varying results. Moderate coffee consumption can be defined as 3-5 cups per day, based on the European Food Safety Authority’s review of caffeine safety⁷.

Specifically in relation to coronary heart disease, some studies propose a protective effect at intakes of approximately 3-5 cups per day with the association resembling a U-shaped curve^12,13.

Studies reviewing associations between coffee consumption and stroke have suggested that a moderate intake is associated with a reduced risk of stroke, particularly in women^14,16.

• A number of studies have suggested that a moderate intake of coffee may reduce incidences of cardiovascular diseases (CVD), and CVD mortality risk^2,3.
• A 2019 meta-analysis found that an intake of coffee of 2.5 cups per day was associated with a 17% reduction in CVD mortality⁵.
• Additionally, a UK Biobank study proposed that drinking 4 to 5 cups of coffee per day was associated with a significant reduction in incident arrhythmia, including atrial fibrillation (AF), cardiovascular disease (CVD), coronary heart disease (CHD) and ischemic stroke¹³.
• However, a 2018 population study suggested that in men, coffee was associated with an increased risk of cancer and cardiovascular mortality, and a reduced risk of respiratory and other causes of death¹⁶.

Cancer

In 2016, the International Agency for Research on Cancer (IARC) reviewed all available research on coffee and cancer, including research published since its original review in 1991, and found no clear association between coffee intake and cancer in any area of the body. In some cases, research suggested coffee drinking is associated with a reduced occurrence of certain cancers. IARC classified coffee in Group 3 alongside agents which are not considered to pose risk of “carcinogenicity to humans”¹⁷. However, IARC classified beverages consumed at very high temperatures (defined as over 65°C) as “probably carcinogenic to the human oesophagus”¹⁷. It should be noted that 65°C is however significantly hotter than the temperature at which most people can comfortably drink coffee without scalding their mouth and tongue^18,19.

• A 2017 review of 39,685 men and 43,124 women suggested that increased frequency of coffee consumption was associated with a lower risk of cancer incidence in both men and women. Coffee consumption frequency was also associated with reduced mortality from cancer²⁰. In contrast a 2018 population study found that coffee was associated with an increased risk of cancer in men¹⁶.
• A 2019 meta-analysis suggested that the lowest relative risk for cancer mortality was seen at an intake of 2 cups per day, while additional intakes were not associated with further lower mortality⁵.
• Additionally, a 2021 meta-analysis proposed that a moderate intake of coffee (3-4 cups per day) was associated with a reduced risk of endometrial cancer, melanoma and nonmelanoma skin cancer⁶.

For further information on the effects of coffee consumption on cancer, please visit ISIC’s Health Conditions webpages.