Chewing tobacco is harmful to the heart and blood vessels.
Chewing tobacco is a known risk factor for oral cancers, but in contrast to the case with smoking, the cardiovascular effects of the habit have been unclear. Smokeless tobacco has immediate effects on blood pressure, heart rate and adrenaline release that may lead to problems in cardiovascular system.
Researchers from the Mayo Clinic in Rochester, Minnesota, did a study and looked at various measures of cardiovascular and nervous system activity among 16 young men before and after the volunteers used chewing tobacco and found that tobacco consumption not only increased blood pressure, but also dampened the body's normal stabilising response to blood pressure spikes. Over the time, chewing tobacco could lead to chronic high blood pressure or other ill effects on the heart and blood vessels.
Normally, when a healthy person's blood pressure shoots up, nervous system activity shifts in order to bring the pressure back down slowing the heart rate and decreasing resistance in blood vessels throughout the body.
After the study participants used chewing tobacco, their heart rates increased strikingly, despite an increase in their blood pressure, and their levels of the hormone adrenaline shot up roughly 50 per cent. Resistance in the body's peripheral blood vessels, which should have decreased in response to the blood pressure elevation, held steady instead.
The findings suggest that chewing tobacco triggers a marked increase in activity of the sympathetic nervous system the part of the nervous system that constricts blood vessels and boosts blood pressure and heart rate in response to stress, danger or other stimuli.
Nicotine is the likely culprit, since the same effects were not seen when the researchers made the study participants use a nicotine and tobacco free placebo chew. Besides the potential for long-term damage to the cardiovascular system, chewing tobacco may pose a more-immediate risk to people who already have heart disease.
Adrenaline, can promote blood clotting, so the surge in the hormone caused by smokeless tobacco could potentially contribute to a heart attack in susceptible people.