8 Proven Lifestyle Shifts That Could Lower Cancer Risk
Cancer continues to rank among the top causes of death worldwide. Rates are also climbing in adults under 50, raising urgent questions about prevention. A major study published in Nature Medicine offers a clear message: a significant share of cancer cases may be avoidable.
After reviewing 30 preventable causes of cancer, researchers estimated that 37% of the 18.7 million new cancer cases diagnosed in 2022 were linked to risk factors that can be changed. That equals nearly four in 10 cases worldwide.
The data also revealed notable differences by sex. Around 30% of cancer cases in women were considered preventable, compared with 45% in men.
Amar Rewari, M.D., chief of radiation oncology for Luminis Health and host of the Value Health Voices Podcast, explains that these findings reshape how cancer risk should be viewed.
“They reinforce a powerful and often underappreciated message that a large share of cancer risk is not inevitable. Nearly 40% of cancers globally are linked to factors we already understand and, at least in theory, can change. This shifts the conversation from cancer being driven mainly by genetics or bad luck to one where prevention plays a central role,” he says.
The Leading Preventable Causes of Cancer
Freepik | Research shows tobacco and alcohol are the leading contributors to the global cancer burden.
The researchers identified behavioral, environmental, and occupational exposures that significantly increase cancer risk. A small group of factors accounts for a large portion of the global burden.
The most common preventable causes include:
1. Tobacco smoking
2. Alcohol consumption
3. Obesity
4. Insufficient physical activity
5. Smokeless tobacco use
6. Air pollution
7. Ultraviolet radiation
8. Infections
Dr. Rewari notes a striking pattern: “Tobacco remains the single largest contributor worldwide, followed by infections such as HPV, H. pylori, and hepatitis viruses, and then alcohol, obesity, and physical inactivity.”
Geography also plays a major role. In higher-income countries, smoking, obesity, and alcohol use drive many cancer cases. In lower-resource regions, infection-related cancers remain a dominant cause.
“In higher-income countries, lifestyle factors like smoking, obesity, and alcohol play a larger role, while in lower-resource settings, infection-related cancers remain a major driver,” Dr. Rewari explains.
Infection-Related Cancers
Certain infections strongly increase cancer risk, especially in areas with limited healthcare access. Early-life chronic infections often go untreated due to overcrowding, poor sanitation, unsafe water, and limited vaccine availability.
For example:
Stomach cancer linked to H. pylori infection has been especially common in parts of Japan and Korea. Liver cancer tied to hepatitis B and C infections has been heavily represented in parts of Africa.
Expanded access to vaccines and screening programs has already reduced cases in several regions. However, disparities remain.
“This highlights the need for prevention strategies that are tailored to where people live and the risks they face, rather than a one-size-fits-all approach,” Dr. Rewari says.
Why These Findings Matter
Cancer often gets framed as a result of genetics or chance. This research challenges that assumption.
According to Dr. Rewari, the data “shift the conversation” toward prevention. Many of the biggest public health gains against cancer over the past few decades have come from reducing exposure to known risks — especially tobacco and certain infections — rather than relying solely on treatment advances.
The consistency of the findings stands out. A limited set of modifiable exposures continues to drive a significant portion of the global cancer burden. That pattern appears across regions and populations.
What This Means for Everyday Life
Freepik | Minimize cancer risk by ditching tobacco, limiting alcohol, and staying physical active.
The research underscores that daily choices and environmental conditions directly affect long-term cancer risk. While no strategy eliminates risk entirely, targeted actions can make a measurable difference over time.
Dr. Rewari emphasizes several key steps:
1. Avoid all forms of tobacco.
2. Limit alcohol intake.
3. Stay physically active.
4. Maintain a healthy weight.
5. Stay current on recommended vaccines, including hepatitis B and HPV.
Immunizations serve as more than infection control tools. As Dr. Rewari explains, vaccines such as hepatitis B and HPV are “powerful cancer-prevention tools, not just infection-prevention tools.”
At the same time, prevention does not rest solely on individuals. Clean air policies, safe workplaces, and improved access to preventive care all shape cancer outcomes at the population level.
“Individual actions are important, but so are broader policies that support clean air, safer workplaces, and access to preventative care,” Dr. Rewari says. “Cancer prevention works best when people are supported by healthier environments and policies, not left to do it all on their own.”
Understanding the Word “Preventable”
The term “preventable” can be misunderstood. Avoiding one habit does not guarantee protection. Many cancers develop over decades, and risk factors often overlap.
“These numbers are based on large-population studies, so they’re meant to show big-picture patterns rather than explain why any one individual developed cancer,” Dr. Rewari explains.
Even so, the broader implication remains clear. Reducing well-established risk factors at scale could prevent millions of cancer cases over time.
Scientific evidence shows that many cancer cases worldwide link to modifiable risk factors, including tobacco use, alcohol intake, infections, obesity, physical inactivity, air pollution, and ultraviolet exposure. These factors account for a substantial portion of annual diagnoses.
Cancer cannot be completely prevented. Still, focused prevention efforts matter. Strong public health policies, wider vaccine access, safer environments, and informed lifestyle choices can significantly reduce overall risk.