Famous for the precision of their clocks, the Swiss have now come up with another method for calculating time, and for some the new timepiece may be much too accurate. Based on a new study, scientists at the University of Zurich have developed an easy-to-read chart that spells out in exact percentages the likelihood you will live another decade. Though it only applies to people at the ages of 65 and 75, the message is loud and clear to one and all: Eat your fruits and veggies, stay active, limit your cocktails, and quit smoking. “The effect of each individual factor on life expectancy is relatively high,” said Dr. Eva Martin-Diener, who led the research team.
The inspiration for the chart was simple: The research team wanted to quantify and also illustrate the combined effects of four behavioral risk factors for non-communicable diseases, such as cancer or cardiovascular disease, on mortality. The team began by analyzing two Swiss population studies conducted between 1977 and 1993. Altogether they assessed data from 16,721 participants; the researchers recorded each person’s smoking status, alcohol consumption, physical activity, and diet. Then, by linking across public health records, the team was able to "follow" participants for 31years, recording 3,533 total deaths in that time.
What did they discover after estimating 10-year survival probabilities for 65- and 75-year-olds based on the data they’d gathered?
“A healthy lifestyle can help you stay ten years’ younger,” said Martin-Diener. In real numbers, you are two-and-a-half times more likely to die (compared to those who look after their health) if you smoke, drink a lot, eat an unhealthy diet, and don’t exercise. For 65-year-olds, the probability of surviving the next decade was 86 percent for men with no behavioral risk factors and 67 percent for men with all four risk factors. In women, the numbers were 90 percent and 77 percent, respectively. Among 75-year-olds, probabilities were 67 percent and 35 percent for men, and 74 percent and 47 percent for women.
“We were very surprised by the 2.5 fold higher risk when all four risk factors are combined,” said Dr. Brian Martin, another author of the study. When calculated separately, the impact of an unhealthy diet, not enough exercise, or too much alcohol resulted in an elevated mortality risk of around 15 percent for each factor. Smoking, even when it is a solo risk factor, causes the most harm. Compared with a group of non-smokers, smokers have a 57 percent higher risk of dying prematurely.
Source: Martin-Diener E, Meyer J, Braun J, Tarnutzer S, Fäh D, Rohrmann S, Martin BW. The combined effect on survival of four main behavioural risk factors for non-communicable diseases. Preventive Medicine. 2014.