Even a heart attack or stroke won't force people to eat right, exercise and stop smoking, a new study suggests.

"It's a whole societal issue in attitude," said Dr. Koon Teo, the chief of cardiology service at McMaster University Medical Centre in Hamilton, Ont., and one of the study's authors.

The study was published Wednesday in the Journal of the American Medical Association, and examines health habits after a heart attack or stroke, as well as how economic factors in different countries influence those habits.

Teo is part of a team of researchers carrying out an ongoing survey of 153,966 adults from 628 cities and towns in 17 different countries as part of the Prospective Urban Rural Epidemiology Study — a global study examining the environmental, societal and biological effects of obesity and chronic health problems.

From that study, 7,519 people reported having a heart attack or stroke. Teo and his team used eating healthy, quitting smoking and regular exercise as measuring sticks to see how much people changed their lifestyles after a traumatic life event.

According to the results, 14.3 per cent didn't adopt any of these healthy behaviours, and only 4.3 per cent adopted all three.

Teo said the study is important in that it measured people's behaviour five years after a stroke or heart attack.

"In the beginning, people get scared and do things," he said, adding that the positive behaviour can quickly change, and people return to old habits.

Of those surveyed for the study:

  • 18.5 per cent continued to smoke after a heart attack or stroke.
  • 35.1 per cent were highly physically active after a heart attack or stroke.
  • 39 per cent adopted better eating habits after a heart attack or stroke.

Teo said the study is one of the biggest cross-border projects of its kind used to illustrate how income levels can affect health, when considering economic development, societal and lifestyle changes associated with urbanization.

"It was a big undertaking," he said. "It was a lot of hard work on everybody's parts because people are very concerned in all these countries."

Of those who took part in the study, more people in high-income countries reportedly quit smoking after a heart attack or stroke — 74.9 per cent — while low income countries had fewer people (38.1 per cent) quit smoking after health problems.

Those surveyed in low-income countries also scored the lowest for healthy eating and physical activity levels after a stroke or cardiac event.

People with heart and stroke issues should be concerned with these results and do what they can to change them, Teo told CBC News. People who have had a heart attack or stroke are more likely to have another, he said.

But studies have shown that exercise, healthy eating and quitting smoking can reduce that risk 20 to 25 per cent, Teo said. Couple that with medication, and that number doubles to 50 per cent, he added.

"And that is substantial."

Several of the authors of the study have disclosed financial ties to pharmaceutical companies, like Novartis, King Pharma, and GlaxoSmithKline.