Coffee and skin cancer
There is no research to currently suggest that coffee consumption is linked to skin cancer. Caffeine, however, may protect skin cells against the harmful effects of UVB radiation92-94, with some research suggesting a reduced risk of malignant melanoma associated with caffeinated coffee consumption.
- A 2015 meta-analysis suggested that cutaneous melanoma risk decreased by 3% and 4% for a 1 cup increment of total coffee and caffeinated coffee, respectively92
- A 2016 systematic review and meta-analysis concluded that there is a possible association between regular coffee consumption and a reduced risk of melanoma, although the authors suggested that further research is required93
- A 2016 meta-analysis concluded that a linear dose response effect was observed between a reduced risk of malignant melanoma and caffeinated coffee consumption, but not decaffeinated coffee94
Coffee and lung cancer
Although a high consumption of coffee (more than 5 cups per day) has been associated with an increased risk of lung cancer, residual confounding effects of smoking or other factors have been identified95.
Indeed, IARC’s 2016 review stated that although a positive association is observed in some studies, this is most likely to be explained by confounding factors such as smoking. The report concluded that there was inadequate evidence to suggest any association between lung cancer and coffee consumption1.
- A 2016 meta-analysis of 12,276 cases of lung cancer and 102,516 controls suggested a significant association between intake of 3 or more cups of coffee per day and increased risk of lung cancer in men but not in women, in American and Asian populations but not in European populations, and in smokers but not non-smokers95
Coffee and brain tumours
Coffee consumption may be linked to a reduced risk of brain tumours but given that the number of studies is limited, more research is required to confirm this inverse association96. Similarly, IARC has not reviewed coffee consumption in relation to brain tumours1.
- A 2019 meta-analysis of 11 articles suggested that there was a protective effect of coffee consumption on brain cancer risk, especially in Asian populations96
Maternal coffee consumption and childhood leukemia
There are limited studies in this area with some variable results97-99. IARC’s review concluded that a lack of consistency amongst studies led to inconclusive and inadequate evidence of any association between coffee consumption and childhood leukaemia1. Pregnant and breastfeeding women are advised by EFSA to drink no more than 200mg of caffeine per day from all sources, which is equivalent to 2-3 cups of coffee2.
- A 2015 meta-analysis comprising a total of 3,649 cases and 5,705 controls conclude that their findings “confirm the detrimental association between maternal coffee consumption and childhood leukemia risk, and provide indications for a similar role for maternal cola consumption”97
- A further 2015 study examining parental smoking, maternal alcohol, coffee and tea consumption during pregnancy, and childhood acute leukemia concluded that childhood acute leukemia was not associated with coffee consumption during pregnancy, but an association was seen between coffee consumption and acute lymphoblastic leukemia98
- A 2018 pooled analysis from the Childhood Leukaemia International Consortium suggested that whilst there was no association seen with any maternal coffee consumption, there was some evidence of a positive exposure response. This led the authors to conclude that, despite some limitations, their findings suggest coffee may be associated with an increased risk of acute lymphoblastic leukaemia and they supported the advice to limit caffeine intake during pregnancy99