Can a healthy lifestyle really add years to your life? Yes, says a study by public health physicians at the University of Zuirich who documented for the first time the impact of behavioral factors on life expectancy in numbers. They conclude that you can live longer thanks to fruit, an active lifestyle, limited alcohol and no cigarettes.
The reason for the study was to integrate the results into prevention and health counseling in primary care. The Federal Office of Public Health is currently developing a national prevention strategy with the goal of improving the populations health competence and encouraging healthy behavior. They are focusing on the main risk factors for diseases - cancer, diabetes, cardiovascular disease and chronic respiratory disorders that are linked to personal behavior including tobacco smoking, an unhealthy diet, physical inactivity and harmful alcohol consumption. These four factors were examined for their individual and combined effects on life expectancy. They are using the information to depict the dependency of life expectancy and four risk behaviors for the groups in what they refer to as survival charts. The impact of individual risk factors and their combined effect on mortality are visible at a glance on the survival charts. In the future, doctors can refer to the charts when giving health counseling to their patents in primary care.
The researchers used data from the Swiss National Cohort and focused on cardiovascular diseases and cancer because they account for the most deaths in Switzerland. The researchers correlated data on tobacco consumption from 16,721 people between the ages of 16 and 90 from 1977 to 1993 with the corresponding deaths up to 2008. When biological risk factors such as weight and blood pressure were taken into account the impact of the four forms of behavior was still visible.
The unhealthy lifestyle results displayed a long-lasting impact. Whereas high wine consumption, cigarettes, an unhealthy diet and physical inactivity hardly had any effect on mortality among the 45 to 55 year olds, it did have a visible effect on the 65 to 75 year olds. So the probability of a 75-year-old man with none of the four risk factors surviving the next 10 years was 67 percent exactly the same as the risk for a smoker who is 10 years younger, does not exercise, does not eat healthy and drinks a lot.
An individual who smokes, drinks a lot, is physically inactive and has an unhealthy diet has 2.5 fold higher mortality risk in epidemiological terms than an individual who looks after his health, says lead author Eva Martin-Diener. Or to put it positively, a healthy lifestyle can help you stay 10 years younger. The effect of reach individual factor on life expectancy is relatively high, but smoking seems to be the most harmful. Compared with a group of non-smokers, smokers have a 57 percent higher risk of dying prematurely. The impact of a unhealthy diet, not enough sport, and alcohol abuse results in an elevated mortality risk of around 15 percent for each factor.
We were surprised by the 2.5 fold higher risk when all four risk factors are combined, said Brian Martin, Private Docent from the Institute of Social and Preventive Medicine at the University of Zurich. Hence, the probability of a 75-year-old man with all risk factors surviving the next 10 years is, for instance, 35 percent, without risk factors 67 percent for a woman 47 and 74 percent respectively.