OWNING a car and TV increases the risk of having a heart attack by more than a quarter, a study has found.
But the dangers of a sedentary lifestyle can easily be cancelled out by exercise, say researchers.
Mild leisure time activity reduces the chances of a heart attack by 13pc, while moderate to strenuous exercise cuts the risk by 24pc.
The findings, published in the European Heart Journal, come from the Interheart study which looked at more than 24,000 people from 52 countries around the world.
Scientists compared the work and leisure exercise habits of around 10,000 people who had suffered a first heart attack with 14,217 healthy individuals.
Participants were asked about their ownership of goods such as cars, motorcycles, stereos, TVs and computers, as well as land and livestock.
Researchers took account of factors such as age, sex, country, income, smoking, alcohol consumption, education and diet.
After making these adjustments, the team found light and moderate work activity reduced heart attack risk, but not heavy physical labour.
All levels of exercise during leisure time lowered the risk compared with sedentary pursuits such as reading and watching TV.
People who owned a car and TV – both indicators of sedentary lifestyle – were 27% more likely to have suffered a heart attack than whose who did not.
Study leader Professor Claes Held, from Uppsala University Hospital in Sweden, said: “Until now, few studies have looked at the different aspects of physical activity both at work and during leisure time in relation to the risk of heart attacks.
“Much is already known about the association between physical activity and cardiovascular risk, but what this study adds, among many other things, is a global perspective. The study shows that mild to moderate physical activity at work, and any level of physical activity during leisure time, reduces the risk of heart attack, independent of other traditional risk factors in men and women of all ages, in most regions of the world and in countries with low, middle or high income levels.
“Interestingly, heavy physical labour at work did not protect against heart attacks.
“These data extend the importance of physical activity and confirm a consistent protective effect of physical activity across all country income levels in addition to the known benefits of modifying traditional risk factors such as smoking.
“Furthermore, ownership of a car and TV, which promotes sedentary behaviour, was found to be independently associated with the risk of heart attacks.”
A greater proportion of people in low-income countries had sedentary jobs and did less exercise in their leisure time than in middle and high-income countries, the study found.
“This may partly be explained by differences in education and other socio-economic factors,” the authors wrote. “In addition, this may also reflect differences in culture and in climate. The likelihood of a subject performing leisure time PA (physical exercise) in tropical or hot climate zones is less than in more temperate areas of the world.”
Leisure time physical activity was divided into four categories: mainly sedentary (sitting reading, watching TV), mild exercise (yoga, fishing, easy walking), moderate exercise (walking, cycling, light gardening) and strenuous exercise (running, football, vigorous swimming).
One highlighted finding was the fact that heart attack risk was reduced even in people who exercised well below current guideline levels.
In an accompanying editorial, doctors Emeline Van Craenenbroeck and Viviane Conraads, from Antwerp University Hospital in Belgium, wrote: “If we want to support healthy longevity, we should put a stop to the pandemic of sedentarism.
“Staying physically fit throughout life may well be one of the easiest, cheapest and most effective ways to avoid the coronary care unit.”
Natasha Stewart, senior cardiac nurse at the British Heart Foundation (BHF), said: “This study reminds us that we all need to be regularly active to keep our hearts healthy.
“The link between keeping active and lowering your risk of developing coronary heart disease and having a heart attack is well-established.
“We recommend at least 30 minutes of moderate-intensity physical activity each day, on at least five days a week. Making small changes to your lifestyle can help make a big difference to your heart health.
“Walking to the local shop rather than driving, or playing sport rather than watching it on TV, will help to work towards long-term benefits for your health.”