🔍 Common myths about nutrition and cancer

This is probably the most widespread nutrition myth in cancer care. The truth is that all cells — both normal and cancerous — use glucose as a source of energy. There is no evidence that cutting sugar from your diet "starves" tumors. The Canadian Cancer Society and Memorial Sloan Kettering are explicit: a sugar-free diet does not treat or prevent cancer. Excessively restricting sugars can lead to a calorie deficit and weight loss — genuine adverse effects during treatment.

The alkaline diet, the ketogenic diet and other special regimens are often promoted online as cancer "treatments". Clinical evidence does not support these claims. ESPEN emphasises that no special diet has enough evidence to be recommended outside a clinical trial. Some restrictive regimens may even interfere with treatment or increase the risk of malnutrition.

Antioxidants in high doses (IV vitamin C, vitamin E, beta-carotene) can interfere with chemotherapy and radiotherapy, which work partly by producing free radicals. Memorial Sloan Kettering recommends avoiding high-dose supplements alongside treatment without your oncologist's approval. Fruit and vegetables are safe sources of antioxidants — pharmacological supplements are not equivalent.

• ✓There is no evidence that sugar feeds cancer preferentially over healthy cells
• ✓Special restrictive diets are not clinically recommended outside trials
• ✓High-dose antioxidant supplements can interfere with chemotherapy
• ✓Varied, balanced eating remains the best guide