Forty per cent of cancers are attributable to avoidable factors, and diet, weight and physical activity represent the largest share after tobacco. This is not an opinion: it is the result of the Continuous Update Project (CUP), the most comprehensive systematic analysis of world literature, run by the World Cancer Research Fund (WCRF) and the American Institute for Cancer Research (AICR). Their recommendations, translated to the plate, form the foundation of nutritional cancer prevention.
Carcinogenesis: three phases, thirty years, nutritional targets
Cancer is not an event: it is a process unfolding over 10 to 30 years in three phases.
Initiation: a mutation settles in a cell (carcinogen, replication error, chronic inflammation). Diet modulates this phase through exposure to dietary carcinogens (alcohol → acetaldehyde, processed meats → nitrites, grilling → HCA/PAH) and through protections (antioxidants, folates, DNA repair).
Promotion: the mutated cell multiplies under the effect of favouring signals. This is where diet plays the most: insulin and IGF-1 (the hyperinsulinaemia of overweight), chronic inflammation, hormones, the microbiome and its metabolites.
Progression: the tumour becomes invasive. At this stage diet no longer acts on the tumour but on the terrain (immunity, malnutrition, tolerance of treatments).
The lesson of carcinogenesis: cancer is not the doing of a single ‘carcinogenic’ food, but of a terrain that promotes for decades. Prevention is a durable architecture, not a cure.
The 10 WCRF/AICR recommendations translated to the plate
The WCRF expert report (3rd edition, updated by the CUP) sets out ten recommendations, translated here:
- A healthy weight: overweight is linked to 13 cancers (post-menopausal breast, colon, pancreas, liver, oesophagus…). Inflammatory obesity is a terrain of promotion.
- Physical activity: protects independently of weight, via insulin, inflammation, transit.
- Whole grains, legumes, vegetables, fruit: the base of the plate.
- Limit fast food and ultra-processed products: caloric density, low satiety, and growing data on packaging contaminants.
- Limit red meat (under 350-500 g cooked per week) and avoid processed meats: nitrites, haem iron, high-temperature cooking.
- Limit sugary drinks: promotion via insulin and overweight.
- Limit alcohol: group 1 IARC carcinogen, with no protective threshold for cancer.
- Do not use supplements to prevent cancer: high-dose beta-carotene trials paradoxically increased lung cancer in smokers.
- Breastfeed if possible: protects the mother (breast) and the child (overweight).
- After a cancer, follow the same recommendations in the absence of contraindication.
Protective foods: fibre, crucifers, polyphenols
Fibre: the strongest level of evidence, especially for colorectal cancer. Every 10 g/day of fibre reduces risk by about 10 per cent. Mechanism: faster transit, dilution of carcinogens, butyrate production by the gut microbiome which feeds and protects colonocytes.
Crucifers (broccoli, cabbage, cauliflower, rocket): glucosinolates convert to sulforaphane and indole-3-carbinol, which modulate hepatic detoxification and oestrogen metabolism. Encouraging data, mostly hormonal.
Polyphenols (green tea, berries, turmeric, pomegranate): anti-inflammatory, microbiome modulators, documented antiangiogenic effects in vitro. As whole food, in diversity, never as a substitute for the architecture.
Alliums (garlic, onion, leek): sulphur compounds, encouraging data on digestive cancers.
Foods to limit: ultra-processed, alcohol, processed meats
Ultra-processed foods: the NutriNet-Santé cohort showed a dose-dependent association between the share of ultra-processed foods and the risk of overall and breast cancer. Mechanisms: caloric density, additives (emulsifiers that impair the intestinal mucus), packaging contaminants, fibre loss.
Alcohol: no protective threshold for cancer (the ‘protective glass of wine’ concerns the cardiovascular system at very low doses and is increasingly contested). Acetaldehyde is a direct carcinogen.
Processed meats: IARC group 1 (established carcinogen), mostly colorectal. Nitrite and cooking (smoking salts, grilling) produce nitrosamines and HCAs.
Red meat: group 2A (probable), dose-responsible; the recommended limit is about 350-500 g cooked per week.
| Recommendation | Documented mechanism | TCM reading |
|---|---|---|
The TCM reading: terrain, Phlegm, Stagnation
TCM reads cancer in the classics under the name of zheng jia (癥瘕), abdominal masses, and liu (瘤), tumours. Three terrains predispose:
Phlegm: the viscous accumulation that the Spleen has not transformed. Tumours are literally read as condensed Phlegm: the Damp-Phlegm terrain (overweight, sedentary life, sugars) is the terrain where masses form.
Qi Stagnation and Blood: prolonged Liver stagnation produces Blood Stasis, and fixed painful masses belong to congealed Blood. Managing emotions and stress is part of the terrain.
Toxicity: prolonged Damp-Heat that has become corrupted. The classics describe ulcerated, infected tumours as a Heat Toxicity that has broken through.
The TCM prevention strategy joins the WCRF: do not let the terrain produce the mass (dry the Dampness, mobilise the Blood, clarify the Heat, support the Spleen that transforms). The article on the four terrains of inflammation situates this framework.
What requires medical advice
Any suspicion of cancer belongs to the doctor; nutritional prevention is no substitute for organised screening (breast, colorectal, cervix) or oncology treatment. ‘Anticancer’ supplements sold online (high-dose curcumin, artemisinin, ‘miracle’ foods) have shown paradoxical effects in some cases and can interfere with treatments.
FAQ: diet and cancer
Can a food cause cancer?
Not in isolation: cancer results from a 10-30 year process on a terrain. No single food ‘gives’ cancer; it is the lasting dietary pattern that modulates risk.
Do antioxidant supplements prevent cancer?
The data run the other way: high-dose beta-carotene and vitamin E trials showed neutral or harmful effects. The WCRF recommendation is explicit: prevention goes through food, not supplements.
Does fasting prevent cancer?
Human data are insufficient. Intermittent fasting has mechanistic arguments (lower insulin, autophagy) but is not an established recommendation in cancer prevention; it can be harmful during treatment.
Should sugar ‘that feeds cancer’ be cut out?
Sugar does not feed cancer more than other cells; but excess sugars produce the hyperinsulinaemia and overweight that promote carcinogenesis. The recommendation is to limit added sugars, not to eliminate all carbohydrates.
Cancer prevention: an architecture of terrain
The WCRF recommendations are not a list of forbidden foods: they describe an architecture (healthy weight, activity, fibre, plants, moderation) that removes the ground on which cancer promotes itself. TCM reads the same landscape: no mass without Dampness that stagnates and Blood that congeals. To situate your terrain: the Yin Shi energy test identifies the profile in a few minutes.
To go further
Yin Shi ecosystem resources directly related to this article.