Primary Prevention of Colorectal Cancer

Abstract

Colorectal cancer has been strongly associated with a Western lifestyle. In the past several decades, much has been learned about the dietary, lifestyle, and medication risk factors for this malignancy. Although there is controversy about the role of specific nutritional factors, consideration of the dietary pattern as a whole appears useful for formulating recommendations. For example, several studies have shown that high intake of red and processed meats, highly refined grains and starches, and sugars is related to increased risk of colorectal cancer. Replacing these factors with poultry, fish, and plant sources as the primary source of protein; unsaturated fats as the primary source of fat; and unrefined grains, legumes and fruits as the primary source of carbohydrates is likely to lower risk of colorectal cancer. Although a role for supplements, including vitamin D, folate, and vitamin B6, remains uncertain, calcium supplementation is likely to be at least modestly beneficial. With respect to lifestyle, compelling evidence indicates that avoidance of smoking and heavy alcohol use, prevention of weight gain, and the maintenance of a reasonable level of physical activity are associated with markedly lower risks of colorectal cancer. Medications such as aspirin and nonsteroidal anti-inflammatory drugs and post-menopausal hormones for women are associated with significant reductions in colorectal cancer risk, though their utility is affected by associated risks. Taken together, modifications in diet and lifestyle should substantially reduce the risk of colorectal cancer and could complement screening in reducing colorectal cancer incidence.

Vitamins, minerals, essential fatty acids and colorectal cancer risk in the United Kingdom Dietary Cohort Consortium

“…9 There has been more research on B vitamins, particularly folic acid. 2 We observed no associations of thiamin, riboflavin, vitamin B6, folate or vitamin B12 with risk for colorectal cancer. There was a significant increase in risk of rectal cancer in association with the highest category of folate intake, but the test for trend was not significant and this observation may be due to chance because we examined many associations (45).…”

“…1 Unknown for some participants; percentages are calculated after excluding these participants and may not add to 100 due to rounding. 2 Total retinol equivalent (not available for UKWCS). 3 Not available for the NSHD or UKWCS.…”

“…[10][11][12] The other B vitamins have been little studied. 2,13 Calcium and vitamin D have been extensively studied in relation to the risk for colorectal cancer. 2 Several previous prospective studies have observed inverse associations of dietary calcium and of serum and dietary vitamin D with risk for colorectal cancer, 2,14 but the Women's Health Initiative randomized controlled trial did not find evidence of benefit with supplemental calcium and vitamin D, 15 and neither dietary calcium nor dietary vitamin D was associated with risk in our analysis.…”

“…There is substantial evidence that high intakes of red and processed meat increase risk, and that high intakes of dietary fibre decrease risk. 1,2 Previous studies have also investigated the possibility that various vitamins, minerals and essential fatty acids may influence risk, but the results have not been consistent. 1,2 In this study, we analysed dietary data from food diaries collected in the United Kingdom (UK) Dietary Cohort Consortium.…”

“…1,2 Previous studies have also investigated the possibility that various vitamins, minerals and essential fatty acids may influence risk, but the results have not been consistent. 1,2 In this study, we analysed dietary data from food diaries collected in the United Kingdom (UK) Dietary Cohort Consortium. 3 Previous analyses of food diary data from this consortium have shown that the risk for colorectal cancer is inversely associated with the intake of fiber, but not associated with intakes of fat or moderately high intakes of meat or fish.…”