The health advice that keeps you from getting sick might actually harm you once you're already ill. This counterintuitive medical reality has a new name: "Cuomo's paradox" , coined by Professor Raphael Cuomo at UC San Diego School of Medicine after analysing findings across numerous studies.
Author
- Justin Stebbing
Professor of Biomedical Sciences, Anglia Ruskin University
The paradox describes how behaviour long considered unhealthy - carrying extra weight, drinking moderate amounts of alcohol, having elevated cholesterol - sometimes correlates with better survival in people who already have cancer or heart disease. It's a phenomenon that challenges the one-size-fits-all approach to medical advice.
This doesn't mean throwing prevention guidelines out the window. Rather, it suggests nutrition should be treated as stage-specific medicine. Before diagnosis, the goal is clear: reduce your risk of getting sick. After diagnosis, the priorities shift dramatically to preserving strength, tolerating harsh treatments and avoiding dangerous complications.
The distinction matters enormously for the millions living with advanced cancer or heart disease. Too often, doctors apply prevention-focused advice - lose weight, eliminate alcohol, slash cholesterol levels - to patients whose immediate battle is surviving chemotherapy or managing frailty. These competing goals can point to entirely different dietary strategies.
Cuomo argues for personalised nutrition after diagnosis rather than copying prevention guidance. What keeps a healthy 40-year-old disease-free may not help a 70-year-old cancer patient get through treatment.
The pattern isn't entirely new. Researchers have long documented the obesity paradox in cardiovascular and cancer care, where heavier patients sometimes survive longer once they're ill. These observations have sparked years of debate, with critics pointing to measurement timing, unintentional weight loss from illness, and statistical quirks that might explain the findings.
Although careful study design can reduce some paradoxical signals, they don't always disappear. Cuomo's contribution is connecting these recurring reversals across multiple factors - weight, alcohol, cholesterol - and multiple diseases, creating a unified framework for stage-specific nutrition .
The findings don't negate established science. Obesity and alcohol clearly increase cancer risk and worsen heart health. But once illness strikes, the survival equations change, and rigid prevention targets may not suit every patient undergoing treatment.
The paradox in practice
Why might extra weight help cancer survival? The answer lies in the brutal reality of cancer treatment. Chemotherapy, radiation and surgery are physically punishing , breaking down muscle and tissue. Patients with greater reserves - both fat and crucially, muscle mass - may be able to weather these assaults better and resist the rapid weight loss that signals declining health.
When a person was last weighed matters too. A person who is underweight now - at diagnosis - may have been overweight before they became ill, but is at a higher risk of death compared with an overweight person for the reasons stated above.
Similar patterns appear with alcohol. Although drinking clearly increases cancer risk in proportion to consumption and duration , some studies suggest light-to-moderate drinkers show better or equivalent post-diagnosis outcomes compared to non-drinkers. The interpretation remains murky - light drinkers may have different social or health behaviour, while some may quit alcohol due to illness, skewing comparisons.
Cholesterol presents another puzzle. In advanced heart disease, extremely low cholesterol sometimes signals broader health problems: inflammation, malnutrition and liver dysfunction. In these cases, low cholesterol is more likely to reflect underlying illness rather than directly cause poor outcomes, meaning that sicker patients often show low levels. This creates a U-shaped pattern where both very high and very low cholesterol are linked to an increased risk of death.
Cuomo's message isn't that "high cholesterol is good" but that aggressively pursuing prevention targets in frail patients might not improve survival and could conflict with maintaining strength and quality of life. Treatment decisions require individualisation and careful monitoring.
For doctors, this means separating prevention from survival goals. Before diagnosis, standard guidance applies: maintain healthy weight, limit alcohol, manage cholesterol. After diagnosis, targets should reflect disease stage, treatment plans, body composition and other health conditions. The focus shifts to avoiding unintentional weight loss while maintaining muscle and energy during active treatment.
Cuomo's paradox doesn't upend health advice. It emphasises context. The behaviour that prevents disease isn't always that which best supports survival once serious illness arrives. That's not permission for unhealthy habits - it's a call for individualised care that balances survival, strength and quality of life through careful medical oversight.
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.
