The study, published in the British Medical Journal, included data for more than 110,000 people and looked specifically at cardiovascular disease, cancer and type 2 diabetes.
Researchers, including from the Harvard School of Public Health in Boston and the Amsterdam University of Applied Sciences, looked at five “low-risk” healthy habits – never smoking, a healthy body mass index (BMI) of 18 to 25, moderate to vigorous physical activity for at least 30 minutes per day (including brisk walking), moderate alcohol intake and a healthy diet.
Moderate alcohol intake was regarded as 5g to 15g of pure alcohol per day for women (one unit of alcohol has 8g of pure alcohol, so 15g is about one 175ml glass of wine), and 5g to 30g per day of alcohol for men (30g is about 1.5 pints of beer).
The team then looked at life expectancy free of diabetes, cardiovascular diseases and cancer, and how many more disease-free years people could expect from the age of 50.
The results showed that women leading a healthy lifestyle (adopting four or five healthy living factors) had a disease-free life expectancy at 50 of 34.4 more years, taking them to the age of 84 without diabetes, cancer or heart disease.
This compared with just 23.7 more years of disease-free life expectancy from 50 for women who had not adopted any of the elements of a healthy lifestyle.
For men aged 50, those who adopted four or five healthy living factors could expect a further 31.1 years free from disease, compared with just 23.5 years for men who had no healthy lifestyle behaviours.
Men who smoked more than 15 cigarettes a day, and obese men and women (with a BMI over 30) had the worst chances of living a life free from disease.
The researchers concluded: “We observed that adherence to a low-risk lifestyle was associated with a longer life expectancy at age 50 free of major chronic diseases of approximately 7.6 years in men and 10 years in women compared with participants with no low-risk lifestyle factors.
“Public policies for improving food and the physical environment conducive to adopting a healthy diet and lifestyle, as well as relevant policies and regulations (for example, smoking bans in public places or trans fat restrictions) are critical to improving life expectancy, especially life expectancy free of major chronic diseases.”
Dr Kate Allen, executive director of science and public affairs at the World Cancer Research Fund, said: “This new, large study further confirms our own research that having a healthy lifestyle lowers your risk of cancer and other diseases.
“We hope the government will be persuaded by the mounting evidence, and take bold, positive steps to protect the nation’s health by making our environments healthier, so that it is easier for people to make healthy choices.
“This includes a 9pm watershed on junk food advertising, subsidies on healthy food to make them more affordable, and better urban design that encourages walking and cycling over driving.”
Prof Jonathan Valabhji, clinical director for diabetes and obesity for the NHS, said: “Expanding waistlines are damaging for both the health of the nation and the NHS – leading to a string of dangerous diseases with a heavy cost for taxpayers.
“The NHS long term plan is playing its part through a range of ambitious actions – including piloting low-calorie diets which have been shown can put type 2 diabetes into remission – but people can take simple common sense steps to lead longer and healthier lives.”