A recent study from Yale University has helped answer a question many people ask: how much of cancer is within our control, and how much just happens with age?
By looking at DNA mutations that lead to cancer, the researchers found that some cancers are clearly linked to lifestyle choices, while others are more likely caused by natural changes in the body over time. The findings help us understand which cancers we might be able to prevent—and how.
Cancer happens when the DNA inside our cells gets damaged. This damage causes cells to grow and divide in abnormal ways, sometimes forming tumors. While some of this damage happens naturally as we age, many mutations are caused by things outside the body, like tobacco smoke or sunlight.
The Yale researchers studied 24 different types of cancer and compared the DNA changes in each to figure out how much came from external factors versus internal, age-related ones.
Their findings show that several common cancers are strongly linked to preventable causes. For example, skin cancers like melanoma, basal cell carcinoma, and squamous cell carcinoma are largely caused by ultraviolet (UV) radiation from the sun or tanning beds. Lung cancer is another major example—it is mostly caused by smoking tobacco.
In fact, lung cancer is considered one of the most preventable cancers simply because smoking is such a strong and avoidable risk factor. Bladder cancer can also be influenced by chemicals found in tobacco smoke and other environmental toxins.
These results underline the power of personal choices in protecting our health. By quitting smoking, avoiding secondhand smoke, and using sunscreen or protective clothing to avoid sunburns, people can significantly reduce their chances of developing these types of cancer.
On the other hand, the study also identified some cancers that seem to develop mostly due to age and natural DNA changes, rather than from environmental exposure.
Prostate cancer and gliomas (a type of brain tumor), for example, were found to be less influenced by outside factors. These cancers tend to develop as people grow older, and even people who live very healthy lifestyles may still get them.
This distinction between preventable and less-preventable cancers is important. It means that while we can take steps to reduce our risk, we also need to accept that not all cancers can be avoided. Still, knowing which ones are linked to lifestyle gives individuals and healthcare systems better guidance on where to focus prevention efforts.
Beyond helping individuals, this research can also inform public health decisions. It could help identify workers in industries where exposure to harmful substances is high, or guide future studies that look for unknown causes of cancer.
The researchers also noted that their study didn’t include every possible genetic change—some complex changes, like having extra copies of certain genes or whole chromosomes, were not part of this research and need more study in the future.
Led by Professor Jeffrey Townsend, the study was published in Molecular Biology and Evolution. It adds to the growing body of research showing that we can make meaningful choices to reduce cancer risk. For example, other recent studies have found that low-carb diets might raise cancer risk, while vitamin D supplements may lower the risk of dying from cancer.
In summary, while some types of cancer are out of our hands, many can be influenced by our daily habits. The key message is clear: healthy choices like not smoking, avoiding too much sun, and staying aware of new health research can truly make a difference in lowering the risk of certain cancers. As science continues to evolve, so does our ability to protect ourselves.
If you care about cancer risk, please read studies that exercise may stop cancer in its tracks, and vitamin D can cut cancer death risk.
For more health information, please see recent studies that yogurt and high-fiber diet may cut lung cancer risk, and results showing that new cancer treatment may reawaken the immune system.
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