Even light or occasional smoking can cause serious heart problems, a new study warns.Researchers say just two to five cigarettes per day can significantly increase the risk of heart failure and death.They reviewed 22 long-term investigations that included more than 300,000 adults who were followed for up to 20 years.The results showed people who smoked two to five cigarettes per day had a 50% higher risk of heart failure and a 60% higher risk of death from any cause, compared to people who never smoked.The risk dropped substantially in the first decade after quitting, but even up to 30 years later, former smokers still faced a greater risk than never smokers.The study authors say, “It is remarkable how harmful smoking is – even low doses of smoking confer large cardiovascular risks.”The researchers say these findings highlight the importance of smoking prevention and cessation programs.Source: PLOS Medicine .Sign up for our weekly HealthDay newsletter