The study – published in the American Journal of Clinical Nutrition – analyses data from almost half a million people, finding that drinking several cups of coffee a day could help protect against colon cancer by between 15% and 25%.
Led by Rashmi Sinha from the US National Cancer Research Institute in Rockville, the team evaluated coffee and tea intakes of participants from the NIH-AARP Diet and Health Study included – taking into account both caffeinated and decaffeinated consumption – in relation to colon (proximal and distal) and rectal cancers.
“In this large US cohort, coffee was inversely associated with colon cancer, particularly proximal tumors,” said Sinha and her team. “Additional investigations of coffee intake and its components in the prevention of colorectal cancer by sub-sites are warranted.”
Commenting on the research, the UK’s NHS Choices service noted that the study was ‘well conducted’ and “does suggest a link between coffee consumption and reduced bowel cancer risk.”
“However, the researchers did recommend that further investigation into the link is needed, including study of the specific chemicals in coffee that could be having an effect.”
Using the participant data from 489,706 men and women taking part in the NIH-AARP Diet and Health Study, Sinha and her team analysed information from self-administered questionnaires of demographics diet and lifestyle.
The team then followed the participants for an average of 10.5 years. In this time 2863 proximal colon cancers, 1993 distal colon, and 1874 rectal cancers, were identified in the group.
Approximately 16% of participants drank four or more cups of coffee per day, said the researchers.
Compared with non-drinkers, drinkers of four to five cups of coffee per day and six or more cups coffee per day had a lower risk of colon cancer – particularly of proximal tumours.
The team revealed that among those drinking between four and six cups per day cancer over the decade of follow up was 15% lower than non-drinkers of coffee. Among those who drank at least six cups a day, the incidence was 24% lower.
Sinha and her team noted that drinking decaffeinated coffee appeared to have some beneficial effect, although it was not as strong, while drinking tea had no observable effect.
“Additional investigations of coffee intake and its components in the prevention of colorectal cancer … are warranted,” they conclude.
Source: American Journal of Clinical Nutrition
Volume 96, Number 2. Pages 374-381, doi: 10.3945/ajcn.111.031328
“Caffeinated and decaffeinated coffee and tea intakes and risk of colorectal cancer in a large prospective study”
Authors: Rashmi Sinha, Amanda J Cross, Carrie R Daniel, Barry I Graubard, et al