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HomeLatest newsHealth & wellnessWant to try and prevent cancer? Then don’t fall for these 7 common myths about the disease
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Want to try and prevent cancer? Then don’t fall for these 7 common myths about the disease

For National Cancer Prevention Month, we talked to a pair of top experts about common falsehoods about the disease—and what the latest science says about cancer prevention truths.

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One of the last things you want to hear your doctor say is, “You have cancer.”

Last year, over 1.6 million people in the U.S. unfortunately heard those very words when they were given a cancer diagnosis, according to the American Cancer Society (ACS).

And while there’s no magic bullet for avoiding cancer entirely, there are steps you can take to help lower your risk of developing the disease over the course of your lifetime.

In fact, “it’s thought that almost half of all common cancers can be prevented through healthy lifestyle changes and getting needed screenings,” says Therese Bevers, M.D., medical director of the Cancer Prevention Center at the University of Texas MD Anderson Cancer Center.

And there’s no better time than National Cancer Prevention Month to get started, which is why we’ve compiled some of the top myths about the dreaded C word—and the latest truths on what you really need to know about the disease.

TEST inset - cancer myth/truth - family history

Myth #1: If there’s no family history, you don’t have to worry about getting cancer.

Truth: Wrong! Genetics only accounts for 5 to 10% of all cancers, according to the National Cancer Institute.

“Only a small portion of cancers are inherited,” stresses Dr. Bevers.

In fact, your risk of developing any type of cancer—regardless of family history—is one in three, per the ACS.

If you do have a family history of cancer, be sure to tell your doctor because that knowledge can be power: It can help inform what kind of tests your M.D. may choose to run, which could lead to an earlier diagnosis and more effective treatment should you develop cancer. Your primary care physician can also refer you to a genetic counselor, who can help you decide whether you should undergo testing for any mutations you may have inherited.

TEST INSET - cancer myths - sunscreen

Tymonko Galyna/Shutterstock / Tymonko Galyna

Myth #2: There’s nothing you can do to prevent cancer.

Truth: While many cases of cancer have no obvious cause, about 42% of cancer diagnoses and 45% of cancer deaths in the United States are linked to modifiable risk factors, according to a 2017 ACS study. This means nearly half of all cancer cases could potentially have been prevented through lifestyle changes.

“Personally, I suspect that more than half of all cancer cases could be avoided if people took simple steps, like eating a plant-based diet, limiting alcohol and doing 150 minutes of moderate activity (such as swift walking), or 75 minutes of brisk activity, a week,” says Dr. Bevers.

The top cancer culprits, per the study? Cigarette smoking (responsible for 19% of all cancer cases), being overweight (nearly 8%), drinking too much (almost 6%), getting too much sun (5%) and being a couch potato (3%).

And the truth is that even small lifestyle tweaks can help make a difference when it comes to decreasing your risk factor of developing cancer.
Case in point: Shedding just 5% of your body weight can help lower your cancer risk if you’re overweight, according to a 2016 study done at the Fred Hutchinson Cancer Research Center in Seattle. And the more you exercise, the lower your risk is of developing 13 different types of cancer, including lung, liver and breast, based on a 2016 study published in JAMA Internal Medicine.

Dr. Bevers notes that many cases of melanoma—the deadliest of all the skin cancers, which has been on the rise in the United States over the last 30 years—could be prevented if people better shielded themselves from UV rays, like by wearing a broad-spectrum, water-resistant sunscreen whenever they’re outdoors.

Plant foods are rich in fiber and phytochemicals, which have cancer-fighting properties. This doesn’t mean you should avoid meat entirely, but it should play more of a side role.
Therese Bevers, M.D.

TEST inset - cancer myth/truth - mediterranean diet

Igor Dutina/Shutterstock / Igor Dutina

Myth #3: Diet has nothing to do with preventing cancer.

Truth: While it’s true there are no specific “superfoods” that can single-handedly keep you healthy, a growing body of research has shown that one style of eating could reduce overall cancer risk by as much as 10 to 12%: a plant-based diet.

One 2015 study published in The American Journal of Clinical Nutrition, for instance, found that women who followed a plant-based diet, consisting primarily of fruits, vegetables, whole grains, beans, nuts and seeds, had a 15% lower risk of developing breast cancer, compared to those who relied more on meat-and-potatoes fare.

“Plant foods are rich in fiber and phytochemicals, which have cancer-fighting properties,” notes Dr. Bevers. “This doesn’t mean you should avoid meat entirely, but it should play more of a side role.”

And when you do have a craving for meat, limit red meat and avoid processed varieties, focusing instead on chicken, fish and other white meats. People who do so have about a 25% lowered risk of death from various conditions, including cancer, according to a study published last year in the British Medical Journal.

Can’t bear to give up barbecue? Just make sure your steak or chicken isn’t grilled to a crisp. Cooking meat at high temperatures releases chemicals called heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs)—both of which have been linked to an increased cancer risk.

TEST inset - cancer myth/truth - sleep

all asleep while reading book in bed at night

kaipong/Getty Images/iStockphoto

Myth #4: Sleep doesn’t play a part in cancer prevention.

Truth: On the contrary—men under the age of 65 who only get three to five hours of sleep per night have a 55% greater risk of dying of prostate cancer than men who clock seven hours, according to one study presented last year at the American Association for Cancer Research.

Another study, published in the journal Cancer, found that people who slept less than six hours a night had a 50% greater chance of developing colorectal adenomas (a precursor to colon cancer) than those who got at least seven hours.

“We’re still trying to understand the mechanism, but one thought is sleep deprivation can lead to inflammation that may make you more susceptible to cancer,” explains Dr. Bevers.

TEST inset - cancer myth/truth - dentist

David Tadevosian/Shutterstock / David Tadevosian

Myth #5: There’s no connection between oral health and cancer.

Truth: People with severe gum disease have a 24% higher overall risk of developing cancer compared to those with mild or no gum disease, according to a Tufts University study published last month in the Journal of the National Cancer Institute.

There are two theories as to why: one is that gum disease causes inflammation in your mouth that can spread to other parts of the body; another is that certain bacteria in your mouth can contribute to cancer. So make it a point to brush and floss regularly, and see your dentist every six months for a cleaning.

One fact remains clear: Mammography is still the best tool available to screen for breast cancer, with research showing it has lowered the number of breast cancer deaths by 40% since 1990.

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Female Patient Having Mammogram In Hospital Radiology Department

Myth #6: Mammograms don’t reduce deaths from breast cancer.

Truth: Different health organizations give different recommendations for when women should get their first mammogram—the ACS recommends women get them annually starting at age 45 and switch to every two years after 55, for instance, while the American College of Radiology recommends getting an annual mammogram once you hit the big 4-0.

But one fact remains clear: Mammography is still the best tool available to screen for breast cancer, with research showing it has lowered the number of breast cancer deaths by 40% since 1990.

“No one’s recommending women not get mammograms,” Dr. Bevers explains. It’s just that these organizations base their advice on factors ranging from the risks of overtesting (since the vast majority of women who get breast cancer are over 50) to the security of beginning testing earlier.

Bottom line: When to get your first mammogram, and how often to retest, is a personal decision between you and your doctor, and may be influenced by whether you have a family history of breast cancer.

And if you do decide to get screened less frequently, make sure you stay up to date.

“It’s human nature to have some slippage in the interval between mammograms, so if a woman is told to get a mammogram every year, it’ll end up being closer to every 14 or 15 months,” says Dr. Bevers. “You don’t want to let it slip to 2 1/2 years. A deadly cancer could be missed in the meantime.”

TEST INSET - cancer myth/truth - man at doctor

Amble Design/Shutterstock / Amble Design

Myth #7: Get the right screenings, and you can detect any cancer early.

Truth: Cancer is a complicated disease, which sometimes makes it tricky to spot. While such regular screenings as Pap smears, mammograms and colonoscopies have been shown to decrease deaths from certain cancers, other tests, like those for prostate cancer, have not always proved to be as effective.

“The current test to screen for prostate cancer is the PSA blood test, which measures a protein made by the prostate gland. While the test can be very useful in signaling a problem in men already diagnosed with prostate cancer, as a screening tool, the PSA test has shown to have a high rate of false positives, meaning further testing may be needed before a diagnosis can be made,” says Marco Gottardis, Ph.D., Vice President and Prostate Cancer Disease Area Stronghold Leader for the Oncology Therapeutic Area at Janssen Research & Development, part of the Johnson & Johnson family of companies. “Not all increases in PSA levels are due to prostate cancer—PSA can be elevated for many other reasons.”

And even if prostate cancer is diagnosed, it can be hard to tell which types require prompt intervention and which can simply be monitored carefully. Since many types of prostate cancer grow very slowly and may never cause symptoms, it can make treatment, and its potential side effects, inadvisable.

That’s why Gottardis and his team are working to develop two tests that have the potential to provide more accurate diagnosis and treatment. The first one is geared toward examining certain biomarkers that could help determine which patients are more likely to develop the disease. “We hope to eventually be able to tell people which therapy they’ll need to be on, or if they can just take a watch-and-wait approach,” he says.

The second test is focused on looking for a potential early-stage marker for prostate cancer.

“Dying cancer cells release tiny pieces of their DNA into the bloodstream, which we can pick up when a patient has advanced prostate cancer,” Gottardis explains. “So we’re attempting to see if we can detect this DNA even earlier.”

If their trials are successful, these tests could eventually replace PSA testing—good news, since, as with any cancer, the next best thing to preventing it in the first place is catching and treating it early.

Grappling with a cancer diagnosis?

At, you’ll find expert articles and videos, leads for support services and more to help you cope with the disease.

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