Many people wonder why cancer develops and whether it can be prevented. While some cancers are linked to lifestyle habits, others seem to happen even when people live healthy lives.
A recent study from Yale University helps explain why this happens by looking closely at changes in our DNA.
DNA carries the instructions that tell our cells how to grow and work. Over time, DNA can develop small changes called mutations. Some mutations happen naturally as we get older, while others are caused by things in our environment, such as cigarette smoke, harmful chemicals, or too much sunlight.
When enough harmful mutations build up, normal cells can become cancer cells. Scientists have known for many years that both aging and environmental exposures play a role, but it has not always been clear how much each factor contributes to different cancers.
In the new study, researchers examined 24 different types of cancer to better understand where the DNA mutations came from. They wanted to estimate how much of each cancer was linked to avoidable causes and how much was mainly due to the natural aging process.
The results showed that several common cancers are strongly connected to lifestyle and environmental factors. Skin cancers, including melanoma, basal cell carcinoma, and squamous cell carcinoma, were found to be largely linked to too much exposure to ultraviolet light from the sun or tanning beds.
Lung cancer was closely tied to tobacco smoking, and bladder cancer was also strongly linked to harmful chemicals found in cigarette smoke.
These findings suggest that many cases of these cancers could be prevented by reducing exposure to known risks. Avoiding smoking, staying away from secondhand smoke, using sunscreen, wearing protective clothing, and limiting time in strong sunlight may all help lower the chance of developing these diseases.
Not every cancer appears to be highly preventable, however. The researchers found that prostate cancer and some brain cancers known as gliomas seem to result mainly from natural DNA changes that occur as people age. This means healthy habits are still important, but they may not completely prevent these cancers.
The study may also help identify people who face higher risks because of their jobs or surroundings, especially those exposed to harmful chemicals. By learning more about how different mutations develop, scientists hope to discover additional cancer causes and create better ways to prevent, detect, and treat the disease.
The researchers noted that their work does not include every possible type of genetic change. More complex DNA changes still need further investigation, so future studies will continue to build on these findings.
The research was led by Jeffrey Townsend at Yale University and published in the journal Molecular Biology and Evolution. The study highlights that while no one can control every cancer risk, healthy choices can make a real difference for many common cancers. As research continues, scientists hope to provide even better guidance on how people can protect their health.
If you care about cancer, please read studies that a low-carb diet could increase overall cancer risk, and vitamin D supplements could strongly reduce cancer death.
For more health information, please see recent studies about how drinking milk affects the risks of heart disease and cancer and results showing higher intake of dairy foods linked to higher prostate cancer risk.
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