Table 2. 87 Risk factors (excluding genes and SNPs) considered across all included studies.

Personal characteristics Age BMI Gender Consanguinuity Family history of colorectal cancer Height Race / ethnicity Marital status Education level Employment status Knowledge of high-fibre diet Years of education Urban or rural living Personal medical history Gastric operation history Gallbladder operation history Appendix operations Hypertension Diabetes or history of diabetes Inflammatory bowel disease History of coronary heart disease History of cardiovascular disease Polyp history History of cancer Defaecation frequency Non-specific abdominal pain Female hormonal factors HRT (ever, current or past) Oestrogen use Menopausal status Age at menarche Age at first childbirth Age at menopause Lifestyle Smoking (tobacco or Sheesha) Alcohol Physical activity Sleep Drug and vitamin supplementation NSAID use Aspirin use Multivitamin use Calcium supplementation Vitamin D supplementation Vitamin C supplementation Vitamin E supplementation

Diet Fibre intake Meat Red meat Processed meat Servings of beef, pork or lamb White meat Frozen meat/chicken Preference for well-done meat Vegetables Fresh vegetables Green vegetables Green salad Fruit Fast food Processed food Pickled food Fried food Smoked food Eggs Milk Fat Saturated fat Bakery products Refined grain Tea Olive oil Soft drinks Bamboo root intake Cold cereal Glycaemic index of intake Western diet Prudent dietary pattern Calorific intake Mutagen index* Calcium intake Folic acid intake Lutein intake Biomarkers Fasting glucose Hyperlipidaemia Cholesterol Triglycerides Haemoglobin Other tests Faecal immunochemical test Faecal occult blood test Prior sigmoidoscopy or colonoscopy