The following are risk factors for colorectal carcinoma:
- animal fat intake:
- the relative risk for the highest intake quintile versus the lowest intake quintile is 1.89 (95% confidence 1.13 to 3.15)
- women eating beef, pork or lamb daily have a relative risk of colorectal cancer of 2.49 vs women who eat these meats less than once per month
- dietary fibre intake:
- trials suggest that vegetable fibre and not cereal fibre are effective in reducing colorectal cancer
- migrant studies indicate that when populations move from a low-risk area (e.g. Japan) to a high-risk area (e.g. the USA), the incidence increases rapidly within the first generation of migrants
- diet is definitely the most important exogenous factor identified up to now in the aetiology of colorectal cancer
- association between consumption of ultra-processed foods and risk of colorectal cancer:
- a study found that high consumption of total ultra-processed foods in men and certain subgroups of ultra-processed foods in men and women was associated with an increased risk of colorectal cancer (2):
- compared with those in the lowest fifth of ultra-processed food consumption, men in the highest fifth of consumption had a 29% higher risk of developing colorectal cancer and the positive association was limited to distal colon cancer (72% increased risk)
- associations remained significant after further adjustment for body mass index or indicators of nutritional quality of the diet (that is, western dietary pattern or dietary quality score).
- no association was observed between overall ultra-processed food consumption and risk of colorectal cancer among women
- among subgroups of ultra-processed foods, higher consumption of meat/poultry/seafood based ready-to-eat products among men and ready-to-eat/heat mixed dishes among women was associated with increased risk of colorectal cancer
- yogurt and dairy based desserts were negatively associated with the risk of colorectal cancer among women
Calcium intake as a protective factor in colorectal cancer:
A prospective study of more than half a million UK women conducted over almost 17 years showed (3):
- research team, led by the University of Oxford, tracked the intake of 97 dietary factors in 542,778 women from 2001 for an average of 16.6 years
- during this period 12,251 participants developed colorectal cancer
- calcium intake showed the strongest protective effect, with each additional 300 mg per day – equivalent to a large glass of milk – associated with a 17% reduced RR (relative risk)
- six dairy-related factors associated with calcium – dairy milk, yogurt, riboflavin, magnesium, phosphorus, and potassium intakes – also demonstrated inverse associations with colorectal cancer risk
- alcohol showed the reverse association, with each additional 20 g daily – equivalent to one large glass of wine – associated with a 15% RR increase
- weaker associations were seen for the combined category of red and processed meat, with each additional 30 g/per day associated with an 8% increased RR for colorectal cancer
- study authors concluded that dairy products help protect against colorectal cancer, and that this is driven largely or wholly by calcium
Reference:
- (1) Labianca R et al. Primary colon cancer: ESMO Clinical Practice Guidelines for diagnosis, adjuvant treatment and follow-up. Ann Oncol. 2010;21 Suppl 5:v70-7.
- (2) Wang L, Du M, Wang K, Khandpur N, Rossato S L, Drouin-Chartier J et al. Association of ultra-processed food consumption with colorectal cancer risk among men and women: results from three prospective US cohort studies BMJ 2022; 378 :e068921 doi:10.1136/bmj-2021-068921
- (3) Papier, K., Bradbury, K.E., Balkwill, A. et al. Diet-wide analyses for risk of colorectal cancer: prospective study of 12,251 incident cases among 542,778 women in the UK. Nat Commun16, 375 (2025)