Caffeinated and decaffeinated coffee and tea intakes and risk of colorectal cancer in a large prospective study.
BACKGROUND
Coffee and tea are widely consumed globally and are rich sources of potential chemopreventive compounds. Epidemiologic data for coffee and tea intakes in relation to colorectal cancer remain unclear. Despite differences in gut physiology, few studies have conducted investigations by anatomic subsites.


OBJECTIVE
We evaluated coffee and tea intakes (caffeinated and decaffeinated) in relation to colon (proximal and distal) and rectal cancers.


METHODS
The NIH-AARP Diet and Health Study included 489,706 men and women who completed a baseline (1995-1996) self-administered questionnaire of demographics, diet, and lifestyle. Over a median of 10.5 y of follow-up, we identified 2863 proximal colon, 1993 distal colon, and 1874 rectal cancers. Multivariable HRs and 95% CIs were estimated by using Cox regression.


RESULTS
Approximately 16% of participants drank ≥4 cups coffee/d. Compared with nondrinkers, drinkers of 4-5 cups coffee/d (HR: 0.85; 95% CI: 0.75, 0.96) and ≥6 cups coffee/d (HR: 0.74; 95% CI: 0.61, 0.89; P-trend < 0.001) had a lower risk of colon cancer, particularly of proximal tumors (HR for ≥6 cups/d: 0.62; 95% CI: 0.49, 0.81; P-trend < 0.0001). Results were similar to those overall for drinkers of predominantly caffeinated coffee. Although individual HRs were not significant, there was a significant P-trend for both colon and rectal cancers for people who drank predominantly decaffeinated coffee. No associations were observed for tea.


CONCLUSIONS
In this large US cohort, coffee was inversely associated with colon cancer, particularly proximal tumors. Additional investigations of coffee intake and its components in the prevention of colorectal cancer by subsites are warranted. The NIH-AARP Diet and Health Study was registered at clinicaltrials.gov as NCT00340015.
Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Department of Health and Human Services, Rockville, MD, USA. sinhar@nih.gov
Rashmi
R
Sinha
Amanda J
AJ
Cross
Carrie R
CR
Daniel
Barry I
BI
Graubard
Jennifer W
JW
Wu
Albert R
AR
Hollenbeck
Marc J
MJ
Gunter
Yikyung
Y
Park
Neal D
ND
Freedman
D001628:Beverages / Q000032:analysis*; D002110:Caffeine / Q000008:administration & dosage*; D003069:Coffee / Q000737:chemistry*; D015179:Colorectal Neoplasms / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D004032:Diet; D005247:Feeding Behavior; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D011795:Surveys and Questionnaires; D013662:Tea / Q000737:chemistry*
D003069:Coffee; D013662:Tea; D002110:Caffeine