Source: www.mayoclinic.org Authors: Robert Wolk et al. Use of smokeless tobacco raises short-term adrenaline levels in the bloodstream by more than 50 percent and also causes the heart rate and blood pressure to surge, according to findings of a Mayo Clinic study published this week in Journal of the American College of Cardiology. The results suggest that snuff tobacco has a powerful stimulant effect but that it also dampens the body's normal protective responses to blood pressure elevation. The study of 16 young men who were habitual spit tobacco users measured their responses 30 minutes after dipping snuff. These readings were compared with measurements from another session involving the same participants after they had used a placebo product that was similar in taste, color and texture but did not contain tobacco or nicotine. The study was randomized and double-blinded; neither the researchers nor the subjects were told when they were taking the placebo and when they were using the tobacco product. After snuff use, heart rate increased by about 15 beats per minute (25 percent), systolic blood pressure went up by 12 mmHg (10 percent), and measurements of adrenalin in the bloodstream increased by more than 50 percent. "These results suggest a very significant excitatory effect of substances contained in spit tobacco on the part of the nervous system regulating the heart and blood vessels," says Virend Somers, M.D., Ph.D., the Mayo Clinic cardiologist who led the study. "Although we did anticipate some increase in blood pressure, we were surprised [...]