Smokeless tobacco (search) boosts heart rate, blood pressure, and adrenalin.

The results have “potential implications” for heart risk, the study notes. The study was small and short, so it’s not the final word on smokeless tobacco. But the findings indicate cigarettes may not be the only tobacco product that affects the heart.

Smokeless tobacco, also called snuff or “spit” tobacco, is used by more than 5 million adults and more than 750,000 adolescents, say researchers. With more young men — especially athletes — using smokeless tobacco, the researchers were curious about its impact.

Experts have already tied smokeless tobacco to oral cancer (search) and dental problems such as receding gums, bone loss, and bad breath. In 1986, the U.S. Surgeon General concluded that smokeless tobacco isn’t a safe alternative for cigarettes or cigars, according to the American Cancer Society (ACS). Smokeless tobacco may also lead to nicotine addiction, says the ACS.

Not as much is known about how smokeless tobacco affects the heart. But doctors do know that cigarettes are a heart hazard. Quitting smoking is widely regarded as one of the best things a smoker can do for his heart.

Studying Smokeless Tobacco

Participants were 16 healthy young men who habitually used smokeless tobacco. They were about 22 years old, on average.

The men were asked not to use smokeless tobacco or smoke for 12 hours before each of two study sessions. They were randomly given either 1.5 grams of smokeless tobacco or a placebo to chew for 15 minutes, followed immediately by the other substance.

No one knew which product the men received. The smokeless tobacco used was Copenhagen moist tobacco snuff. The placebo was Smokey Mountain snuff, which does not contain tobacco or nicotine.

Hearts Rev Up

When the men chewed smokeless tobacco, their hearts beat faster, increasing by an average of 16 beats per minute. Their blood pressure also rose by 10 mmHg, and their adrenaline — also called epinephrine — went up by 50 percent.

“Although we did anticipate some increase in blood pressure, we were surprised at the magnitude of the increase, as well as the very striking increases in heart rate,” says researcher Virend Somers, MD, PhD, FACC, in a news release.

“Also surprising was the substantial increase in [adrenalin],” continues Somers, who works at the Mayo Clinic in Rochester, Minn. Since the participants were young and healthy, the researchers expected that “any responses we measured would in fact be blunted. Therefore, the degree of increase in the measurements we took was of great interest,” says Somers.

The study was very brief, so it doesn’t show the heart effects of long-term smokeless tobacco use. It’s also possible that some of the effects could come from high sodium content in smokeless tobacco products (which differs by brands), as well as other ingredients besides nicotine, such as licorice, says the study, which didn’t measure those items.

The study appears in the Journal of the American College of Cardiology’s March 15 edition.

By Miranda Hitti, reviewed by Michael W. Smith, MD

SOURCES: Wolk, R. Journal of the American College of Cardiology, March 15, 2005; vol 45: pp 910-914. American Cancer Society, “Smokeless Tobacco.” WebMD Medical Feature Archive: “Addicted to Dipping.” News release, American College of Cardiology.