Dietary Patterns and Colorectal Cancer Risk: a Review of 17 Years of Evidence (2000–2016)

Abstract

Purpose of review Colorectal cancer (CRC) is a global public health problem, with an estimated 1.4 million cases diagnosed worldwide in 2012. Evidence suggests that diet may be important for primary prevention. Recent findings The 2017 WCRF/AICR Continuous Update Project on colorectal cancer concluded that there is convincing evidence linking several individual dietary factors with CRC risk but the evidence for dietary patterns was limited and inconclusive. Also, previous reviews and meta-analyses have not critically synthesized various dietary patterns. This review synthesized data from dietary patterns studies over a 17-year period from 2000 to 2016. Summary We included 49 studies (28 cohort and 21 case-control) that examined the association of index-based and empirically-derived dietary patterns and CRC risk. A synthesis of food group components comprising the different index-based and empirically-derived patterns revealed two distinct dietary patterns associated with CRC risk. A “healthy” pattern, generally characterized by high intake of fruits and vegetables, wholegrains, nuts and legumes, fish and other seafood, milk and other dairy products, was associated with lower CRC risk. In contrast, the “unhealthy” pattern, characterized by high intakes of red meat, processed meat, sugar-sweetened beverages, refined grains, desserts and potatoes was associated with higher CRC risk. It is notable that the number of food groups, the intake quantity, the exact types of foods in each food group, differed between populations, yet the two dietary patterns remained consistent across regions, especially in empirically-derived patterns, an indication of the high reproducibility of these patterns. However, findings for CRC risk in both index-based and empirically-derived patterns, differed by sex, with stronger associations among men than women; study design, a higher proportion of case-control studies reported significant findings compared to prospective studies. Consuming a dietary pattern high in fruits and vegetables and low in meats and sweets is protective against CRC risk. However, important questions remain about mechanisms underlying differences by sex; life-course timing of exposure to dietary patterns; interaction of dietary patterns with the microbiome or with lifestyle factors including physical activity; and elucidation of subsite differences.

The Role of Probiotics in Colorectal Cancer Management

“…Colorectal cancer (CRC) is one of the most common (∼1.4 million cases of CRC in 2012) cancerous disease worldwide and cause leading cancer-associated deaths (∼700 thousands of mortality) [1]. Several factors are associated with the incidence of CRC such as unhealthy diet and lifestyle, heredity, metabolic disorders, and genetic factors [2][3][4][5].…”

The role of plant-based nutrition in cancer prevention

“…Responsible for the protective effect of vegan and vegetarian diets are plant-based foods including vegetables, fruits, whole grains, legumes, nuts and seeds [121][122][123][124] . Intake of fruits and vegetables and high fiber intake, particularly from vegetables and whole grains, has been associated with reduced risk of CRC in systematic meta-analyses and epidemiologic studies [125][126][127][128][129][130] . Fiber may help protect against CRC by reducing fecal bile acid concentrations and by being paired with micronutrients and minerals such as magnesium.…”

Predictors of the Healthy Eating Index and Glycemic Index in Multi-Ethnic Colorectal Cancer Families

“…Colorectal cancer (CRC) is recognized as the most preventable cancer worldwide [ 1 ]. Unhealthy dietary habits with excess caloric intake and weight gain, smoking, and over-consuming alcohol can increase the risk of developing CRC [ 2 , 3 , 4 , 5 , 6 ] through inflammatory oxidative stress pathways [ 7 , 8 , 9 , 10 , 11 , 12 ]. Furthermore, based on the strong evidence defined by The American Institute for Cancer Research (AICR), plant-based foods and healthy weight, reducing red meat and alcohol intake [ 1 , 13 ] can prevent CRC.…”

“…A healthy diet has been associated with decreased CRC risk, examined by using the healthy eating index (HEI) [ 14 , 15 , 16 , 17 , 18 ]. Elements of a healthy diet include adequate intakes of vegetables and dark green vegetables, fruits and whole fruits, grains and whole grains, nuts and legumes, proteins including fish and other seafood, milk or alternative dairy products for lactose intolerance; and limiting salt, saturated fat, and empty calories from sugar and alcohol [ 2 , 3 , 4 , 5 , 7 , 8 ]. Higher HEI scores are associated with decreased CRC risk [ 19 , 20 , 21 ].…”