If you think you’re less likely to develop cancer from smokeless tobacco than from cigarettes, think again.

A national study suggests smokeless tobacco users have high levels of known carcinogens, like nicotine, in their bodies and “in some cases these levels are higher than those observed among cigarette smokers.”

That’s no surprise to Dr. Muhammad Moid, a Marshfield Clinic Health System oncologist/hematologist who has seen numerous cancer patients with tell-tale signs of chewing tobacco usage.

Hard-to-treat cancers

“Up until now, most research has focused on just smoking but it should include chewing tobacco,” Moid said. “We see people who chew tobacco and have really bad cancers. Some people don’t seek help right away and just let the cancer get worse.

These include cancers of the larynx and esophagus, which if allowed to grow can become very aggressive and hard to treat.

Cause and effect for other health problems

“The more you look at it, the more it’s becoming clear that chewing tobacco can lead to cancer and other health problems from increased heart rate and blood pressure, such as heart attacks,” Moid said.

The Food and Drug Administration and Centers for Disease Control and Prevention participated in the federal study. Unlike some previous studies, this involved taking blood and urine samples from a large cross-section of the population, rather than relying on people to answer questionnaires truthfully.

This study also found smokeless tobacco is used most commonly by 9.6 percent of young males and by 3.2 percent of the general public. Those numbers may seem small until you apply them to the U.S. population of about 340 million people.

Study authors said findings highlight the need for further study of ingredients found in smokeless tobacco, especially since tobacco manufacturers are pushing back against regulations for stricter warnings on their products.

These products have warning labels claiming they can cause mouth cancer, gum disease and tooth loss but manufacturers argue there is insufficient evidence to support those claims.

If you use smokeless tobacco products, talk with your doctor about how it may be affecting your health.