All forms of tobacco consumption -- smoking, chewing and second hand smoke -- raise the risk of heart attack by up to three times, according to the results of a new study in Friday's edition of the Lancet medical journal.

The study, covering a total of 27,000 people in 52 countries, found that tobacco use in any form -- including sheesha, popular in the Middle East, and beedie, common in South Asia -- were bad for health.

Compared to people who had never smoked, heavy smokers had a tripled risk of heart attack while even light smokers and people who chewed tobacco had a doubled risk.

The INTERHEART study was carried out by a team lead by Salim Yusuf and Koon Teo of McMaster University, Ontario, Canada.

It also found that the risk of heart attack diminished over time after an individual had stopped smoking -- with the rate of diminution dependent on the heaviness of the habit.

In light smokers -- less than 10 a day -- there was no increased risk five years after quitting, but in people who had smoked more that 20 a day there was still a 22 percent increased risk of heart attack two decades later.

"Since the risks of heart attack associated with smoking dissipate substantially after smoking cessation, public health efforts to prevent people from starting the habit and promote quitting ... will have a large impact in prevention of heart attack worldwide," Yusuf said.