A new study carried out by a team lead by Salim Yusuf and Koon Teo at the University of Hamilton, Canada found that all forms of tobacco use increases the risk of heart attack.
The study published in the Lancet Medical journal found that Tobacco use in all forms, whether smoked or chewed first hand or second hand, increases the risk of heart attack. The study was conducted among 27,000 people in 52 countries to calculate the risk of heart attack from various forms of tobacco use.
The study found that compared to people who had never smoked, people who smoked had triple the risk of heart attack and the risk increased by 5.6 per cent for every daily cigarette smoked. Even light smokers and people who chewed tobacco had doubled risk.
Passive smokers exposed to 21 hours a week of second hand smoke had a heart attack risk of 62%, while people exposed to 1-7 hours of second hand smoke per week had a risk of 24 percent.
The study also found that the risk of heart attack diminished over time after an individual had stopped smoking with the rate of reduction dependent on the heaviness of the habit.
In light smokers who smoked less than 10 cigarettes a day, there was no increased risk five years after quitting; however, heavy smokers who quit see a decrease in heart attack risk, but still had an excess risk of around 22 percent 20 years after quitting.