Colon Polyps (Colonic Adenoma): Prevention

To prevent colon adenomas/colon polyps (colonic polyps), attention must be paid to reducing individual risk factors. Behavioral risk factors

  • Diet
    • Diet too rich in fats (high intake of saturated fatty acids of animal origin and of the polyunsaturated fatty acid linoleic acid (omega-6 fatty acid), contained in safflower, sunflower and corn oil) and low in complex carbohydrates and fiber
    • high consumption of red meat, i.e. muscle meat of pork, beef, lamb, veal, mutton, horse, sheep, goat
      • Red meat is classified by the World Health Organization (WHO) as “probably carcinogenic to humans”, that is, carcinogenic.Meat and sausage products are classified as so-called “definite group 1 carcinogen” and are thus comparable (qualitatively, but not quantitatively) to the carcinogenic (cancer-causing) effect of tobacco smoking. Meat products include products whose meat component has been preserved or improved in flavor by processing methods such as salting, curing, smoking, or fermenting: Sausages, cold cuts, ham, corned beef, jerky, air-dried beef, canned meat. Daily consumption of 50 g of processed meats (equivalent to two slices of sausage) increases the risk of colon cancer by 18%, and daily consumption of 100 g of red meat by 17%.
      • Other studies suggest that iron ingested with meat may contribute to the increase in risk, as iron can promote the formation of harmful nitroso compounds in the body. Red meat or processed meat has a higher average iron content than poultry, so its consumption may not have affected colorectal cancer risk in this study. Studies in rats with chemically-induced colon carcinoma (chemically-induced colon cancer) uniformly showed that dietary hemoglobin (red blood pigment) and red meat promote lesions (tissue damage) in the intestine as a precursor to carcinoma (tumor). The mechanism is still unknown, but heme iron has a catalytic (accelerating) effect on the endogenous (endogenous) formation of carcinogenic (cancer-promoting) nitroso compounds and on the formation of cytotoxic (cell-damaging) and genotoxic (genetic-damaging) aldehydes by means of lipid peroxidation (conversion of fatty acids, creating free radicals).
      • Other studies describe animal protein as an independent risk factor. In high-protein diets, increased proteins, peptides and urea pass into the colon. As an end product of bacterial metabolism ammonium ions are formed, which have a cytotoxic effect.
    • Too little fruit and vegetable consumption
    • Heterocyclic aromatic amines (HAA) – these are formed exclusively when food (especially meat and fish) is heated (> 150 °C) and are considered carcinogenic. HAA develop mainly in the crust. The more browned the meat, the more HAA are formed. Individuals who have a high intake of HAAs have a 50 percent higher risk of developing polyps (adenomas) of the colon (large intestine), which are often precancerous lesions (precursors) for colon carcinoma (colon cancer).
    • Micronutrient deficiency (vital substances) – insufficient supply of vitamin D and calcium (calcium binds promoters such as bile acids); see Prevention with micronutrients.
  • Consumption of stimulants
    • Alcohol (woman: > 20 g/day; man: > 30 g/day) – especially with reduced folic acid intake!
    • Tobacco (smoking) (An association between cigarette smoking and colorectal adenomatous polyps has already been demonstrated in numerous studies. A meta-analysis shows that such precursors of colorectal cancer are also more aggressive in smokers).
  • Physical activity
    • Physical inactivity
  • Overweight (BMI ≥ 25; obesity).
    • Severe weight gain (mean 17.4 kg) versus stable overweight: summed OR for colorectal adenoma occurrence was 1.39 (95% CI 1.17-1.65)
    • Each 5 kg weight gain increased the risk of adenomas by 7% (2-11%; n = 7 studies)
  • Android body fat distribution, i.e., abdominal/visceral truncal central body fat (apple type) – there is a high waist circumference or an increased waist-to-hip ratio (THQ; waist-to-hip ratio (WHR)); Each 25 cm2 increase in visceral fat volume is associated with a 13% increase in adenoma riskWhen waist circumference is measured according to the International Diabetes Federation guideline (IDF, 2005), the following standard values apply:
    • Men <94 cm
    • Women < 80 cm

    The German Obesity Society published somewhat more moderate figures for waist circumference in 2006: < 102 cm for men and < 88 cm for women.

Prevention factors (protective factors)

  • 25-OH vitamin D (calcifediol) – patients with the highest serum 25-OH vitamin D levels had a 30% lower risk of colorectal adenomas than those with the lowest 25-OH vitamin D levels.

Secondary prevention

  • Secondary prevention of advanced colorectal neoplasia (neoplasms of the colon and rectum): the median risk of developing metachronous neoplasia was reduced by just over 60% with non-ASS-type NSAIDs, 30% with low-dose acetylsalicylic acid (ASA; ≤ 160 mg/day), and 10% with calcium.