Almost 40% of cancers are avoidable, of which 16 to 20% are linked to alimentary factors. If food itself does not allow to avoid the risk of cancer or cannot cure the illness, there are good hygiene and diet-related habits to adopt to prevent primarily (to avoid the appearance of a cancer) and to prevent secondarily (in case of cancer during treatment or remission).
Drinking alcohol is the first purveyor of cancer with a hygiene/diet-related origin (around 8%) after tobacco. Alcohol, if it is not formally contraindicated in case of cancer, remains not recommended and drinking it must remain strictly occasional. You must not exceed 2 glasses a day and must not drink every day. In any case, you must make sure that alcohol is compatible with thetreatment you are receiving on an anti-tumoral level (in particular, in the scope of a therapeutic trial), but also support care treatments (possible interaction with painkillers, in particular morphine).
Food must be balanced, without any specific rule. No diet has been proven in terms of preventing and treating cancer. The keto diet, or fasting (even intermittently) are not recommended. If it is true that tumour cells consume more sugar than healthy cells, it has never been proven in humans that a carbohydrate-free diet or fasting reduce the risk of cancer or increases the effectiveness of the treatment. On the contrary, with the risk of malnutrition being greater in case of cancer, any restrictive diet is not to be prescribed under current knowledge. An exception is made if a prolonged corticosteroid therapy is indicated, in this case, rapid intake of salt and sugar must be limited.
No food by itself is capable of acting as an anti-cancer remedy, but the role of certain foods is now well-known. Red meats and cold meats increase the risk of cancers, in particular digestive cancers.
They must not be consumed daily. Food rich in fibres and vegetables must be favoured.
When the diet is balanced, no supplement, in particular with vitamins, is necessary. On the contrary, taking supplements excessively, like beta-Carotene, can induce an excess risk of cancer. In addition, supplements, including those of a natural origin, have a risk of interaction with a certain number of cancer treatments. Generally speaking, do not take any supplements with or without a medical prescription (vitamins, phytotherapy, homeopathy) before having discussed this with your oncologist.
Being overweight and obesity induce an excess risk of cancer and increase cardiovascular risk.
Being overweight can appear or be aggravated by cancer treatments carried out through prolonged hormone therapies and corticosteroid therapy.
It is therefore important to maintain your body weight during and after treatments. Key elements are a balanced diet, rich in fish and food of a plant origin (vegetable fats, rather than animal fats, fibres, etc.). Regular physical activity (30 minutes a day minimum, at moderate intensity, brisk walking, for example).
At the start of the illness and during chemotherapy, weight-loss often occurs.
It will be necessary first to identify the reasons for this weight-loss:
Your doctor will find, with you, the best solution for treating factors favouring weight-loss.
Most frequently, this is a loss of appetite. To improve the situation, it is recommended to split your food, i.e. make consequential meals, but more frequently during the day, favour food that you like and enrich your usual food (by adding eggs, cream, cheese, for example).
It can also be necessary to supplement your food with ONS (Oral Nutritional Supplements). These supplements are issued at the chemist upon medical prescription. They are available in different forms: milk drinks, fruit juices, biscuit, etc. They are to be taken in addition to meals and must not be substituted for them. Rich in protein, they allow sufficient nutritional intake to be maintained and to correct malnutrition. In extreme cases of malnutrition or in case of a blocking tumour, you can resort to artificial feeding using a tube (tube which goes from the nose directly into the stomach) or by perfusions.
In any case, in case of difficulty balancing your weight, you can call upon the establishment’s nutrition team who looks after you: at first, the dietician and nutritionist doctor. Any weight-loss of >2kg requires dietary management.