Researchers say quitting cigarettes is much safer than merely cutting back to one per day.
According to the research published in the British Medical Journal, one cigarette per day still poses a 50 percent chance of developing heart disease and a 30 percent chance of suffering a stroke.
The research is an analysis of 141 studies.
According to the study, a 20 cigarette per day lifestyle can cause seven heart attacks or stroke in a group of 100 people while one cigarette a day would reduce it to three.
On a gender basis, the research said men who smoke one cigarette a day have 48 percent risk of developing heart disease and 25 percent more likely to have a stroke than those who have never smoked.
For women, the chances are higher at 57 percent and 31 percent for heart disease and stroke respectively.
“There’s been a trend in quite a few countries for heavy smokers to cut down, thinking that’s perfectly fine, which is the case for things like cancer,” Allan Hackshaw, professor at the UCL Cancer Institute at University College London, who led the study, told BBC.
“But for these two common disorders, which they’re probably more likely to get than cancer, it’s not the case. They’ve got to stop completely.”
Hackshaw said those who quit smoking early can reduce their risk of cardiovascular diseases.