A Follow-up Study of Physical Activity and Incidence of Colorectal Polyps in African-American Women

Abstract

Background: Physical activity is associated with a reduced risk of colon cancer, but the effect of activity on colorectal adenomas, which are precursors to colon cancer, is uncertain. The influence of physical activity on colorectal adenomas among African-American women is of particular interest because African-American women have an increased risk of colon cancer relative to other U.S. women. Methods: We prospectively assessed the relation of physical activity to the incidence of colorectal polyps among AfricanAmerican women. We followed 45,400 women in the Black Women's Health Study from 1997 to 2003. Data were obtained by biennial mailed questionnaires. During 287,029 person-years of follow-up, 1,390 women reported having been diagnosed with colorectal polyps. A review of medical records of 58 women who reported colorectal polyps indicated that 59% had adenomas and 41% had hyperplastic

Is adherence to diet, physical activity, and body weight cancer prevention recommendations associated with colorectal cancer incidence in African American women?

“…Conversely, among African American cases and controls, higher fiber intake was inversely associated, while high fruit and added sugar intake were positively and diets high in legumes and dairy were inversely associated with rectal cancer risk. Increased risk of colorectal adenomas and polyps, potential precursors to colorectal cancer were associated with unhealthy diet patterns, higher body weight and physical activity levels in the BWHS [31,36,37]. …”

Colon Cancer: A Civilization Disorder

“…The incidence rate ratio for the finding of colonic adenomas amongst African-American women was 0.94 and 0.72 for groups with low physical activity (<5 metabolic equivalent-hours/week) and high physical activity (≥40 metabolic equivalent-hours/week), respectively (P trend = 0.01) [24]. …”

Lifestyle factors, obesity and the risk of colorectal adenomas in EPIC-Heidelberg

“…There was also no association with vigorous physical activity (data not shown). A protective relationship between physical activity and large adenoma was found in prospective [22,24,26] and casecontrol studies [7,23,24,[42][43][44], although some other studies could not confirm this [7,9,21]. In some studies, the effect was gender specific, the association being statistically significant for males only [45][46][47].…”

“…Results appear to be most consistent for smoking and use of NSAIDs with an increased adenoma risk among former and current smokers [3] and a decreased risk among subjects with regular use of NSAIDs [4][5][6][7]. In contrast, results for alcohol consumption [7][8][9][10][11][12][13][14][15][16][17][18][19][20], obesity [7,9,16,[21][22][23][24][25], and physical activity [7,9,21,22,24,26] are sometimes conflicting. Such diverse results may be due to several factors including study design (cohort vs. case-control studies), study population and possibly inherent genetic variation, or differences in the percentage of adenoma of different sites or morphology.…”