Why do health stories about food and cancer grab so much attention? Because they offer an enticing promise: that a single item on your plate, or even a sudden change in what you crave, might hold the key to spotting disease early.
Author
- Justin Stebbing
Professor of Biomedical Sciences, Anglia Ruskin University
It's a compelling idea , but in reality the science of appetite, taste, and cancer is far messier than the headlines suggest .
This eye-catching idea oversimplifies reality. While cancer can change appetite and taste, there's no solid evidence that a sudden craving, such as an abrupt fixation on sweets, serves as a dependable early warning signal for undiagnosed cancer.
This is a classic case where interesting clinical anecdotes and stories have been stretched into a sweeping rule that doesn't work as a screening tool.
The grain of truth behind these headlines comes from clinical observations. Some cancer patients do report altered taste and appetite . In older case studies , patients described dramatic changes - tea suddenly tasting awful, or favourite foods becoming repulsive - sometimes before diagnosis, sometimes after treatment began.
These accounts seem compelling, but they were never designed to prove that a particular craving reliably predicts cancer. They show that cancer can affect how we taste and eat, not that a single symptom can replace proper diagnosis.
Modern research paints a more complex picture. Studies examining "altered food behaviour" around cancer cover a wide range of changes: cravings, aversions, emotional eating and treatment-related appetite shifts.
These studies look at different cancers, stages, and time points - before, during and after treatment. The overall message is that eating behaviour can change in the context of cancer , influenced by biology (inflammation and metabolism), physiology (changes to taste and smell) and psychology (stress and mood).
What we don't see is a specific craving pattern that reliably warns of cancer in healthy people. Appetite changes can be part of the cancer story, but they're not a diagnostic shortcut .
It's worth bearing in mind how common appetite changes are in everyday life. Many ordinary factors affect what tastes good and what the body wants, including medications, pregnancy, stress, quitting smoking and anaemia.
A sudden enthusiasm for a particular food might be interesting , but it rarely points to a single cause. That's why doctors look for clusters of symptoms and lasting patterns rather than drawing conclusions from one change.
Chewing ice
There is one area where cravings connect meaningfully to health: ice chewing. Constantly chewing ice (called pagophagia) can signal iron deficiency, which has treatable causes that should be found and addressed. This is completely different from claims that tumours program sugar cravings.
Ice chewing represents a well-established link between unusual eating behaviour and a specific, testable condition. Iron deficiency itself is both common and often missed .
Iron is essential for making haemoglobin, which carries oxygen in red blood cells, and plays broader roles in energy and immune function. When levels drop, symptoms are often vague: persistent fatigue despite adequate sleep, exercise intolerance, shortness of breath and headaches, to name a few.
These overlap with many other conditions, which is why testing matters rather than guessing. Iron comes from red meat, poultry, seafood, beans, lentils, leafy greens, and fortified cereals and breads. However, a "good" diet doesn't always guarantee adequate iron if losses are high, needs are elevated, or absorption is poor - another reason to confirm and treat the problem with proper testing.
No magic clues
Returning to the headlines, it's easy to see why supposed tell-tale cravings capture attention. They promise a simple signal in a confusing health landscape. But medicine rarely offers magic clues.
The sensible approach is twofold . First, treat new, persistent, and unexplained changes in taste or appetite as worth noting - not panicking about. Consider the full picture: other symptoms, recent illnesses, medications, stress and overall health. If behaviour like ice chewing appears or fatigue becomes stubborn, checking for iron deficiency makes sense.
Second, for cancer risk concerns, rely on established warning signs and screening tests. Unexplained weight loss, unusual bleeding, changes in bowel habits, swallowing difficulties, new or changing lumps and age-appropriate screening catch far more cancers than chasing a single craving ever will.
The craving narrative carries another danger: it can fuel harmful behaviour, like trying to "starve" a tumour by cutting out major nutrients.
Severe restriction can cause dangerous weight loss, malnutrition and, worse, treatment tolerance, undermining recovery rather than helping. Tumours don't outsmart sensible nutrition. What helps most is maintaining strength with a balanced diet, staying active when possible, following evidence-based screening and treatment , and using targeted tests - like iron studies - when symptoms suggest they might be helpful .
Appetite and taste are sensitive measures of health and their changes deserve attention. They're part of the medical conversation, not a crystal ball.
If something feels wrong and stays wrong - whether that's a new aversion to familiar foods, an odd fixation that won't go away, or constant ice chewing - the next step isn't to search Google for hidden meanings. Instead, talk with a doctor.
Simple tests can quickly rule out common problems, and if something more serious is happening, acting on established warning signs and screening guidelines offers the best chance of catching it early.
Justin Stebbing does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
