Can you take action to prevent cancer? The answer is yes. While not all cancers are preventable, you can significantly reduce your risk of getting cancer.
4 in every 10 cancer cases are preventable (AACR).
According to AACR, tobacco smoking (19%), excess body fat (7.5%), alcohol (6%), UV radiation (5%), poor diet (4.5%), infections (4%), and sedentary lifestyles (3.5%) are the main risk factors for cancer*.
The following sections explain the risk factors in more detail. I didn't feel that a section dedicated to the risk factor of abdominal obesity is necessary because it's largely a result of poor diet, physical inactivity, and excess alcohol consumption.
* Numbers in parentheses indicate % of US cases in adults age >30 attributable to the indicated risk factors.
Tobacco Smoking--Leading Preventable Cause of Cancer
Process and Psychology of Quitting Smoking This video (by Dr. Mike Evans, a staff physician at St. Michael's Hospital and an Associate Professor of Family Medicine) sheds some light on the journey of quitting smoking and the psychology that goes into this, without getting too preachy or critical. If you're trying to quit, see smokefree.gov for more resources and tools. Some additional helpful resources include American Lung Association's Freedom From Smoking, CDC's Quit Smoking Resources, and Quitline Services (national quitline number is 1-800-QUIT-NOW (1-800-784-8669)).
In the US, alcohol use causes ≈ 1 in every 15 cancer cases.
Alcohol use causes at least 6 different types of cancer, including bowel cancer, breast cancer, and esophageal cancer.
Alcohol breaks down and metabolizes into carcinogens, which directly damage cellular DNA. Alcohol also affects breast cancer-related hormones like estrogen.
Although excessive drinking is most dangerous, moderate drinking* may also increase cancer risk.
* Moderate drinking is defined as ≤ 1 drink per day for women and ≤ 2 drinks per day for men (AACR).
How Alcohol Causes Cancer
Alcohol is broken down by the liver into acetaldehyde, a carcinogen. If we drink too much alcohol, the acetaldehyde can't be processed quickly enough and it builds up, leading to irreversible DNA damage (Cancer Council Victoria).
Alcohol consumption increases estrogen levels in the bloodstream. This increases breast cancer risk in women by causing breast tissue to develop abnormally and stimulating cell growth/division, which increases DNA damage (Cancer Council Victoria).
Alcohol consumption directly damages tissues in the throat and mouth; this makes it easier for other carcinogens like tobacco to enter the tissues and cause DNA damage (Cancer Council Victoria).
Rethinking Alcohol Consumption Alcohol is a big part of American culture and is associated with many positive life events (e.g., graduation, marriage). But, alcohol (especially excessive alcohol consumption) has its flipsides and leads to many preventable accidents and diseases like cancer. Just because someone isn't an alcoholic (i.e., he/she is still functional at home and work and doesn't have severe problems) doesn't mean that he/she is not suffering from excessive alcohol consumption. The following video by Dr. Mike Evans—a staff physician at St. Michael's Hospital and an Associate Professor of Family Medicine—sheds further light on this topic.
SAMHSA's National Helpline serves as a confidential resource for individuals and families who are navigating mental health or substance use issues. The helpline is accessible 24 hours a day, seven days a week, throughout the entire year, and is available in both English and Spanish languages. By contacting the helpline, individuals can receive information, guidance, and referrals to appropriate treatment services, all in a supportive and non-judgmental manner.
Helpline: 1-800-662-HELP (1-800-662-4357)
Alcoholics Anonymous (AA): While AA is commonly associated with individuals who identify as "alcoholics," it also welcomes individuals who wish to address problematic drinking behavior. AA offers peer support through meetings and a 12-step program.
SMART Recovery: Self-Management and Recovery Training (SMART) is a global community that offers support for individuals seeking to manage addictive behaviors, including alcohol use. SMART Recovery emphasizes self-empowerment and provides online and in-person meetings.
Moderation Management: Moderation Management is a support program for individuals seeking to reduce or moderate their alcohol consumption. The program emphasizes self-management and provides online and in-person meetings.
Unhealthy eating can lead to excess visceral fat, which is the second leading preventable cause of cancer deaths.
Unhealthy items like processed foods, sugar-sweetened drinks, refined grains increase the risk for cancer.
Healthy foods like whole grains, fruits, vegetables, and beans lower the risk.
Making Positive Changes in Your Diet There's no such thing like the best diet. A healthy diet that you can maintain in the long run is the best diet for you. Weight loss is only one reason to have a healthy diet; there are other health benefits, too. Maintaining a healthy diet is not about constant willpower; rather, it's about understanding what triggers us to overeat or eat unhealthy, making our home environment more conducive to healthy eating (e.g., keeping sliced fruit out on the counter rather than a bag of cookies), and having social support and support from your family to make these changes. The following video explains this more completely.
Publisher: Dr. Mike Evans Duration: 15:13
Helpful Resources:
American Heart Association's Healthy Eating - The American Heart Association provides guidance on heart-healthy eating, including tips for grocery shopping, cooking, and reducing added sugars, sodium, and unhealthy fats.
Academy of Nutrition and Dietetics - The Academy of Nutrition and Dietetics is a trusted source for practical and evidence-based nutrition guidance. On their website, you'll find many easy-to-follow recipes and nutrition resources for diverse health needs/conditions. Accessible to all, the Academy's expert advice can help you make informed, healthy choices for you and your family.
ChooseMyPlate - The U.S. Department of Agriculture (USDA) offers ChooseMyPlate, a resource with information and tools to help individuals build balanced meals, make healthier food choices, and manage portion sizes.
Nutrition.gov - Nutrition.gov offers a variety of nutrition resources, including information on healthy eating, dietary supplements, and meal planning. The website is managed by the USDA's Food and Nutrition Information Center.
Sufficient physical activity (≥ 150 min of moderate activity per week for adults, 60 min daily for adolescents) benefits physical and mental health in several other ways, too (Preventing Cancer | AACR Cancer Progress Report 2022).
Physical exercise can be as low-tech as doing 30 minutes of walking (or another form of moderate activity) five times a week and mixing in some simple strength-building exercises (e.g., sit-ups, push-ups).
The video below shows (using strong peer-reviewed evidence) that exercise improves overall health in several ways, hence helping cancer patients and caregivers. Exercise doesn't help too much in weight loss, but being physically active is just as important as maintaining a healthy weight. In many cases, skinny but sedentary people fare worse than obese but active people. If walking outside in your neighborhood isn't safe, you can try walking in your home (or stair climbing); this may not be as effective as brisk walking outside but is far better than being sedentary.
Additional Resources from the American Heart Association The American Heart Association provides tips and resources for getting active, including suggestions for exercises that require no equipment and can be done in small spaces.
According to the AACR, 1 in every 20 US cancer cases are caused by UV (ultraviolet) radiation.
According to the Skin Cancer Foundation, UV exposure causes over 85% of all skin cancers. To reduce UV exposure,
Seek shade (especially from 10 AM to 4 PM).
Avoid indoor tanning.
Wear clothes that cover your arms and legs. Wearing wide-brimmed hat and wrap-around sunglasses also helps cover your body.
Apply adequate sunscreen, with an SPF ≥ 15 (ideally ≥ 30), at least 30 min before going outside (even if it's cloudy). Reapply every 2 hours. Also, reapply after swimming or heavy sweating.
The video below (published by Doc Unlock) shows how UV exposure damages the skin and causes skin cancer.
Video Publisher: Doc Unlock (click on text for more details) Duration: 3:43
Infections
According to the AACR, 1 in every 25 US cancer cases are caused by infections.
Here are some specific strategies to prevent infections that can lead to cancer, according to the National Cancer Institute and the Center for Disease Control:
Vaccinations are available for certain cancer-causing viruses:
Human Papillomavirus (HPV) Vaccine: HPV is associated with cervical, anal, oropharyngeal, and other cancers. The HPV vaccine is recommended for both boys and girls, typically starting at age 11 or 12, but can be given as early as age 9 and up to age 26 (or even later in certain cases).
Hepatitis B Vaccine: Hepatitis B virus (HBV) can cause liver cancer. The vaccine is typically given as a series of three shots, starting at birth, and is part of the routine childhood vaccination schedule. It is also recommended for adults at risk of HBV infection.
Safe Sexual Practices: Monogamy and fidelity (i.e., having only one sexual partner) are clearly effective in reducing STI risk. Barrier protection (e.g., condems) can also help.
Safe Injection Practices: Avoiding shared needles and ensuring the use of sterile needles for injections can reduce the risk of transmission of viruses like hepatitis B and C, which can cause liver cancer. Also, intravenous drug use increases the risk of infections that increase cancer risk.
Early Detection and Treatment of Infections: Regular medical check-ups and screenings can help detect infections, such as hepatitis B and C, early. Early treatment of these infections can reduce the risk of cancer.
Helicobacter pylori (H. pylori) Infection: H. pylori is a bacterial infection associated with stomach cancer. Individuals diagnosed with H. pylori infection should receive appropriate antibiotic treatment to eradicate the bacteria.
Spread Awareness
Share this information with your family and friends: most people don't know how to prevent cancer.
Over 3 in every 5 people don't know that obesity, alcohol use, unhealthy eating, and physical inactivity are linked to cancer; 22% of people still don't know that smoking causes cancer even though it is the number one preventable cause of cancer deaths (American Cancer Society).
Even more people are unaware of how these risk factors cause cancer and how to reduce them.
Contribute to the fight against cancer by sharing this information with your family and friends.