Swedish researchers who two years ago reported no association of heart attacks with snus use (abstract here) now conclude there is no association with stroke (here). The new study, appearing in the Journal of Internal Medicine, is once again the product of a collaboration of scientists from the Karolinska Institute; Sweden’s Umeå, Uppsala and Lund Universities; and the University of Milano-Bicocca in Italy.
Compared with never users of tobacco, the hazard ratio (HR, similar to relative risk, adjusted for age and body mass index, BMI) for stroke among current snus users was 1.04 (95% Confidence Interval = 0.92 – 1.17). HRs were not elevated with higher levels of snus consumption (1 can per day) or longer duration (20+ years).
Claims that snus causes heart attacks and strokes were first raised in 1994 by the Karolinska Institute’s Gunilla Bolinder. (details here). I challenged the Institute’s specious claims in the medical literature in 1995 (here) and later with Carl Phillips and Karyn Heavner (here and here), as well as in this blog (here, here and here).
It is well known that nicotine does not cause cancer, but its role in cardiovascular diseases has been difficult to determine. Studying users of Swedish snus, who consume large quantities of smoke-free nicotine over decades, the Swedish researchers concluded that nicotine was unlikely to be a contributor to heart attacks or strokes.
Smokeless tobacco and nicotine have been demonized for no valid scientific reasons. The Swedish findings are vitally important to all consumers of nicotine and tobacco products, including e-cigarettes.