Diet, Exercise & Lifestyle

Alcohol causes at least seven cancers and there is no safe threshold. Price, availability and cancer warning labels are the tools that work; most people still do not know alcohol causes cancer.

Daily low-dose aspirin lowers bowel cancer risk in people with Lynch syndrome and appears to cut recurrence in bowel cancers with a particular mutation. In healthy older people it caused more harm than good.

People with severe obesity who have weight-loss surgery develop about a third fewer cancers over the following decade, especially womb and other hormone-related cancers, than similar people who do not.

Cachexia pharmacotherapy covers three drug approaches to cancer wasting: a new antibody that blocks the hormone suppressing appetite, an appetite hormone mimic approved only in Japan, and a very cheap old tablet. None is yet standard everywhere; all beat what came before.

Treating the wasting that kills many cancer patients, by blocking the hormone that suppresses appetite.

Giving the same drug at a different time of day, because the body clock changes how much damage it does and how well the immune system responds.

Coffee does not cause cancer and is probably protective against liver and womb cancer. Very hot drinks of any kind may raise oesophageal cancer risk.

Patients who eat plenty of fibre and avoid probiotic pills seem to respond better to immunotherapy for melanoma, probably because fibre feeds the right gut bacteria. A proper trial is under way.

Most people on cancer treatment take supplements, often without telling their team. Antioxidants, St John's wort, high-dose vitamins and some herbs can blunt chemotherapy or radiotherapy or interact with targeted drugs.

Being overweight after breast cancer is linked with more recurrence, so a 3,000-woman trial tested a two-year telephone weight-loss programme. Women lost weight, but the trial did not clearly show fewer recurrences.

Instead of starving patients before and after an operation, modern surgical pathways feed them early, give carbohydrate drinks the night before, and get them walking the next day. Complications and hospital stays fall.

Nutrition support means tube feeding into the gut, or nutrition into a vein when the gut cannot be used. It is life-saving in the right patient, harmful or futile in the wrong one.

Structured exercise during and after treatment, which the CHALLENGE trial showed improves survival in colon cancer.

Moderate exercise while on chemotherapy is safe and reduces fatigue, helps people finish their planned doses, and may protect the heart and nerves.

Transplanting gut bacteria from patients who responded to immunotherapy into those who did not. In small studies a minority of resistant melanomas started responding. Randomised trials are running.

Eating very little for a few days around each chemotherapy dose might protect normal cells and sensitise the tumour. Early trials are intriguing but small, and it is not something to try without a dietitian.

GLP-1 agonists, the new weight-loss injections, lower weight by 15-20%. Early observational data suggest fewer obesity-related cancers in people who take them, but no trial has yet tested cancer as an outcome.

Drinks enriched with arginine, omega-3 fats and nucleotides for a week before a big operation seem to reduce infections afterwards, though the trials are old and mostly industry-funded.

A ketogenic diet is a very-low-carbohydrate, high-fat diet that makes the body run on ketones. The idea is to starve brain tumours of glucose. It is safe and feasible for a few months, but no trial has shown it makes people live longer.

Diets built around vegetables, wholegrains, legumes, nuts, fish and olive oil, with little red or processed meat, are linked with lower cancer risk and better survival after diagnosis. The evidence is strong for the pattern, weak for any single food.

Removing an amino acid or nutrient that certain tumours cannot make for themselves, while normal cells can.

Changing the gut bacteria of a patient whose immunotherapy stopped working, in the hope of restarting the response.

Screening for malnutrition, dietitian-led counselling, supplements and tube or intravenous feeding where indicated, plus treatment of cancer cachexia, the muscle-wasting syndrome that affects up to 80% of advanced patients.

Nutrition screening means weighing every patient, asking a few screening questions, and referring those at risk to a dietitian. It is simple, guideline-endorsed, and still not done routinely.

Prehabilitation is a few weeks of structured exercise, nutrition and psychological preparation between diagnosis and surgery to make patients fitter for the operation and speed recovery.

Antibiotics in the weeks before immunotherapy are linked with worse outcomes, and shop-bought probiotics may not help and might hurt. Avoiding both where possible is a low-cost precaution.

Processed meat (bacon, ham, sausages) definitely causes bowel cancer; red meat probably does. The risk per person is modest, but because so many people eat it, the population impact is large.

Lifting weights and eating enough protein is the only treatment shown to build muscle in people with cancer wasting, but most are too unwell to do it alone and the trials are small.

Half of people with cancer sleep badly, so sleep and body-clock interventions matter. Talking therapy for insomnia works well and is under-used; whether fixing sleep or body-clock disruption changes the cancer itself is unproven.

Stopping smoking after a cancer diagnosis improves survival, reduces treatment complications and second cancers, and is the single most effective supportive intervention that oncology services still routinely fail to deliver.

For years women with breast cancer were told to avoid soy because it contains plant oestrogens. Large studies show moderate soy food intake is safe and may slightly reduce recurrence, including on tamoxifen.

A supervised, coached exercise programme for three years after bowel cancer treatment cut recurrence and death in a large randomised trial. It is the first lifestyle intervention proven to work like an adjuvant drug.

Time-restricted eating means eating within a window of 8-12 hours a day and fasting overnight. It improves blood sugar and weight a little; whether it changes cancer risk or recurrence is unknown.

Diets high in industrially processed foods and sugary drinks are linked with more cancer, mainly through obesity but perhaps also through additives and packaging chemicals. Sugar itself does not 'feed' a tumour in the way social media claims.

The largest trial of vitamin D and fish-oil pills found they did not prevent cancer. A possible reduction in cancer deaths, and hints of benefit after a digestive cancer diagnosis, keep the question alive.