Many people move through daily life without questioning long-standing habits. Small routines often feel harmless because they are familiar and widely accepted.
Over time, however, these choices can quietly influence health in ways that only become visible years later.
Cancer is frequently linked to genetics or bad luck, but growing research suggests that everyday behaviour plays a far greater role than many realise.
A global wake-up call
A large international study led by the World Health Organization analysed cancer data from 185 countries across 36 cancer types.
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The findings indicate that a substantial proportion of cancers diagnosed in 2022 were connected to causes that could, in theory, be avoided.
In total, more than one third of new cases worldwide were associated with preventable factors, underlining the impact of lifestyle and environmental exposure.
The main driver
Among all the risks examined, tobacco use emerged as the most significant contributor.
Smoking alone accounted for around 15 percent of all new cancer cases globally. Other major factors included infections known to cause cancer, alcohol consumption, excess body weight, physical inactivity, air pollution and ultraviolet radiation exposure.
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The most important preventable contributors identified were:
- Tobacco use
- Cancer-related infections
- Alcohol consumption
- High body mass index
- Physical inactivity
- Air pollution and UV exposure
Unequal impact
The study also highlighted differences between men and women. A larger share of cancer cases among men were linked to preventable causes, largely driven by smoking.
Among women, infections represented a greater proportion of cases, though tobacco remained a key factor.
Researchers note that understanding these differences could help improve future prevention strategies.
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