Table 5.

Summary of major epidemiological studies examining the association of fiber intake with CRC.

Author, Year	Study Design	Country/Center	Result
Peters U, 2003 [34]	Observational	USA	Dietary fiber, particularly from grains, cereals and fruits, was associated with decreased risk of distal colon adenoma
Bingham, 2003 [32]	Observational	Europe	Inverse relationship; In populations with low average intake of dietary fiber, an approximate doubling of total fiber intake from foods could reduce the risk of colorectal cancer by 40%.
Larsson SC, 2005 [33]	Observational	Sweden	Inverse relationship-high consumption of whole grains may decrease the risk of colon cancer in women
Dahm CC, 2010 [47]	Case-Control	UK	Inverse relationship
Fuchs CS, 1999 [36]	Observational	USA	No protective effect of fiber
Beresford SA, 2006 [12]	Randomized Controlled Trial	USA	No protective effect
Park Y, 2005 [40]	Pooled Analysis	USA, Europe	After accounting for other dietary risk factors, high dietary fiber intake was not associated with a reduced risk of colorectal cancer.
MacLennan R, 1995 [37]	Randomized Controlled Trial	Australia	No significant prevention of new adenomas
Schatzkin A, 2000 [38]	Randomized Controlled Trial	USA	Low fat and high fiber diet including fruits and vegetables did not influence the risk of recurrence of colorectal adenomas.
Alberts DS, 2000 [39]	Randomized Controlled Trial	USA	Wheat bran fiber did not protect against colorectal adenomas.
Asano T, 2002 [48]	Meta-analysis	USA, Canada	No evidence from RCTs to suggest that increased dietary fiber intake will reduce the incidence or recurrence of adenomatous polyps within a two to four year period.
Mehta RS, 2017 [42]	Prospective Cohort Study	USA	Prudent diets rich in whole grains and dietary fiber were associated with a lower risk for F. nucleatum-positive colorectal cancer but not F. nucleatum- negative cancer