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.

In a randomised placebo-controlled trial of 364 people, eight weeks of Wisconsin American ginseng modestly improved cancer-related fatigue, mainly in those still on treatment. The 2024 fatigue guideline says it may be offered during treatment; quality of the product matters.

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: ponsegromab, an antibody that blocks the appetite-suppressing hormone GDF-15 and is in phase 3; anamorelin, a ghrelin mimic approved only in Japan; and low-dose olanzapine, a generic tablet available everywhere that ASCO added to guidance in 2024. None has yet been shown to improve physical function.

Cachexia-directed therapy treats cancer wasting by blocking GDF-15, a hormone that rises in advanced cancer and acts on the brainstem to suppress appetite. Pfizer's antibody ponsegromab improved weight in a phase 2 trial and is in phase 2/3 in pancreatic cancer cachexia; whether weight gain translates into function is the open question.

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: IARC downgraded it in 2016, and cohort studies link two to three cups a day with lower rates of liver and womb cancer. Drinks of any kind served above 65 C are classed as a probable cause of oesophageal cancer, so the temperature, not the coffee, is the risk.

The staging CT scan every cancer patient already has can be measured for muscle and fat at the level of the third lumbar vertebra; low muscle predicts chemotherapy toxicity and shorter survival across cancers, and software now does the measuring automatically.

Curcumin, the yellow pigment in turmeric, kills cancer cells in a dish and is one of the most studied supplements, but it is barely absorbed from the gut and no randomised trial has shown it treats cancer in people. Cooking with turmeric is fine; high-dose capsules can interact with chemotherapy and blood thinners.

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.

Fasting-mimicking diets cut food intake for three days around each chemotherapy dose to lower glucose, insulin and IGF-1, which may shield normal cells and sensitise the tumour. The DIRECT trial in early breast cancer improved radiological response but fewer than 20% of patients kept to the diet, and it is unsafe in cachexia or without a dietitian.

Fatigue is the commonest thing left behind by cancer treatment and the least treated: about a third of women in two large breast cancer cohorts still had severe fatigue years after diagnosis. What works is exercise, cognitive behavioural therapy and mindfulness programmes. What does not is the stimulant tablet people most often ask for, and the 2024 guideline says so.

Fish oil rich in EPA was expected to slow cancer-related muscle wasting by damping inflammation. Randomised trials and a Cochrane review found no convincing effect on weight or survival, though fish oil is safe and sits comfortably inside general nutritional support.

The Gerson regimen prescribes hourly juices, a strict low-salt vegetarian diet, supplements and several coffee enemas a day, and is sold at clinics in Mexico. It has never shown benefit in any controlled study, and coffee enemas have caused fatal electrolyte disturbances and infections.

Ginger capsules taken alongside standard anti-sickness drugs reduced nausea in the largest randomised trial, but other trials found no effect and the doses and products vary. It is safe for most people, with a caution about bleeding for anyone on anticoagulants.

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.

These are the two questions people ask most often after an operation and the two with the least evidence behind the answers. No trial establishes when it is safe to drive after cancer surgery, and in the United Kingdom the licence holder must notify the DVLA of an illness affecting safe driving. For exercise the dose is published.

Drinking green tea is safe and pleasant, but a Cochrane review found no consistent evidence that it prevents cancer, and concentrated green tea extract capsules have caused liver injury and can interfere with some drugs.

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 restricts carbohydrate so the body runs on ketones, on the theory that glioblastoma cells depend on glucose while neurons can burn ketones. Small trials show it is safe and achievable for three to six months with supervision, but none has shown a benefit against the tumour, and adherence beyond three months is poor.

Reishi, turkey tail, shiitake, maitake and cordyceps extracts are rich in beta-glucans that stimulate natural killer cells in the laboratory and are sold as supplements to people with cancer. A 2016 Cochrane review found five small, poor-quality reishi trials and no evidence it treats cancer; the other species lack randomised efficacy trials, and rare liver toxicity is reported.

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.

Melatonin helps some people sleep and is safe at usual doses, but the claim that high-dose melatonin improves survival rests on a series of small unblinded trials from one group that has never been reproduced elsewhere. It is not a cancer treatment.

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.

Muscle lost during treatment is usually regained with resistance training and enough protein, over months rather than weeks. Muscle lost to cancer cachexia is different: while the cancer is active, training and food slow the loss but rarely reverse it, and the consensus definition says so plainly.

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) is classed by IARC as a definite cause of bowel cancer and red meat as a probable one, with about 18% higher risk per 50 g of processed meat a day. One person's extra lifetime risk is a few percentage points, but 5 to 10% of bowel cancers in high-income countries are attributed to it.

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.

In 962 people interviewed six times over 18 months after surgery for a first non-metastatic cancer, 59 per cent had insomnia symptoms at the start, 28 per cent met criteria for an insomnia syndrome, and 36 per cent still had symptoms at 18 months. A short course of talking therapy for insomnia improved sleep efficiency by 15.5 per cent against 6.1 per cent in controls.

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.

Biotin, marine-protein and multi-ingredient capsules are advertised directly to people whose hair has thinned after treatment. No randomised trial of any of them has been run in chemotherapy or endocrine-therapy hair loss. High-dose biotin also distorts hospital blood tests, including the one used to diagnose a heart attack.

Slow, low-impact movement practices from Chinese tradition improve fatigue, sleep and balance in people with cancer. Randomised trials are moderately sized and positive, and the 2024 fatigue guideline recommends them during treatment.

Exercise is the best-evidenced thing a person can do for their own recovery, and the guidelines put a number on it: moderate aerobic exercise at least three times a week for at least thirty minutes, for eight to twelve weeks, plus resistance training twice a week, two sets of eight to fifteen repetitions at sixty per cent or more of the heaviest weight you can lift once.

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.

The programme behind the best colorectal result was four weeks long, supervised in hospital, and had four parts: high-intensity exercise three times a week, a nutritional intervention, psychological support, and smoking cessation where it applied. Supervision is the ingredient the trials keep separating out, and the window is what the pathway leaves.

Yoga combining postures, breathing and relaxation reduces fatigue, anxiety and low mood and improves sleep and quality of life, on the evidence of a Cochrane review of 24 randomised trials in women with breast cancer. SIO-ASCO guidelines recommend it for fatigue and anxiety during treatment; it does not replace aerobic and resistance exercise.