Cancer is largely preventable, but most people don’t know it

Thanks to COVID-19, an estimated 10 million cancer screenings were skipped or canceled during the pandemic.

Because routine screening detects cancer in its earlier stages — when treatments are more effective — the head of the National Cancer Institute has warned of as many as 10,000 excess deaths in years to come due to later detection of colon and breast cancer.

This was the headline cancer story of the COVID-19 pandemic. But early detection and treatment are not the only — or even best — ways to fight cancer. An even more effective strategy is simply preventing cancer in the first place. And most cancers are preventable.

If you didn’t know that, don’t blame yourself. The medical and public health communities have not done a great job explaining what we know about cancer risks and how to reduce them.

Getting out the message about the relationship between smoking and lung cancer was one of the most effective public health strategies in history.

Yet beyond that, many people mistakenly believe that the determining factor in getting cancer is genetics or simply bad luck — influences entirely out of their control.

While it’s true that some cancers come from inherited mutations or other genetic predispositions, most experts agree that about 70 percent of cancers can be prevented. This could be among the least-known medical facts of our time.  

A 2019 study by the American Institute for Cancer Research found that more than half of Americans don’t realize that the type of food they eat, as well as the amount of alcohol they drink, play an important role in developing certain cancers. We tell patients about the increased risk of diabetes and heart disease from being overweight or obese — but we rarely tell them that obesity also increases their cancer risk. As a nation, we have a lot of work to do to educate people on the specific steps they can take to prevent cancer in their own lives.

For example, a diet without enough fruits and vegetables can significantly increase your risk of certain cancers. To add them, use any means possible — fresh, canned, or frozen. Most of us aren’t getting enough. It’s also time to cut out — or at least way back on — processed and fatty meats and salty snacks. Instead, try fish twice a week and use different herbs and spices. If you have a choice, select coffee or tea for their anti-inflammatory properties instead of sugary juice.

People also need to know about the relationship between physical inactivity and cancer cell growth — because the science on the subject speaks volumes. Getting in your daily 10,000 steps isn’t a bad thing, but it’s not enough for cancer prevention. That requires working up a sweat for 20 minutes to half an hour about five days a week. What activity you do — from jogging to biking to vacuuming the house — is less important than ensuring you get to at least a moderate level of intensity. How do you know you’re there? Though you may still be able to talk while doing it, you shouldn’t have enough extra breath to sing.
It’s also time to explain how chronic stress, and the hormones it creates, may decrease immune function — and how to relieve that stress. Meditation is very effective, as are breathing exercises, and plenty of online resources are available for free. If you are experiencing anxiety and stress that won’t quit, don’t be afraid to acknowledge it, and ask for help from a support group, counselor, or mental health professional.

And don’t forget the importance of quality sleep as well as the quantity. Sleep is a time for your body to clear out toxins. To maximize sleep, make your bedroom a spa — cool, quiet, and dark. And no, you can’t catch up on sleep on weekends. For more effective cancer prevention, make it a lifestyle priority to get a good night’s sleep every night. 

If you’re flossing your teeth every day for good dental hygiene, good for you. You’re also decreasing your cancer risk, because gum disease has links to cancer.

Overall, we need to empower people with the knowledge they need to take control of their cancer risk. In biomedical research, prevention has always taken a back seat. Yet studies consistently underscore that our underinvestment in prevention keeps cancer rates and deaths at unnecessarily high levels. High-profile fundraisers and cancer awareness months that promote screenings are important, and we should continue to support them. But we need public health campaigns that connect our daily health choices to cancer risk. It may not be glitzy to show the relationship between lack of physical activity and growth of cancer cells, or how chronic stress can contribute to cancer risk, but that’s what the science tells us. That’s the kind of information that people need and deserve.  

Better information leads to better health. Learning the pivotal role that lifestyle plays in cancer risk will complement screening and treatment in such a way that we can finally win the war on cancer, declared more than half a century ago.

John Whyte, M.D., board-certified internist and chief medical officer of WebMD, is the author of “Take Control of Your Cancer Risk.”