The study carried out at Canada's McGill University in Montreal examined more than 2,600 patients at high risk of a heart attack, including some with diabetes or pre-existing heart problems.
It found that existing anti-cholesterol treatments were more successful when doctors regularly talked to their patients about how to reduce their heart risks by leading a healthier lifestyle, such as by taking exercise.
A 43-year-old man who was overweight and a smoker, with high cholesterol and blood pressure, for example, was calculated to have a heart-health level equivalent to that of a 51-year-old, it said.
But if he followed all the guidelines he gets for his treatment, he could reduce this age index to the equivalent of a healthy 42-year-old man.
The study was published in the US medical journal Archives of Internal Medicine.