That smoking or being obese is associated with poor health outcomes is not exactly breaking news. But last week, Health Affairs featured a study that for the first time looks at the extent to which risky behaviors (smoking, having a poor diet, being physically inactive, and drinking excessive amounts of alcohol) collectively impact the health and life expectancy of the US population, and what improvements in health might be gained through healthy behaviors.
Researchers used data from the Health and Retirement Study to look at the overall health of people age 50 and older who had healthy behaviors – they never smoked, were not obese, and consumed alcohol moderately (defined as 14 or fewer drinks a week for men and seven or fewer drinks a week for women). Compared to the US population as a whole, these “healthy” adults had a life expectancy at age 50 that was seven years longer than the rest of the population. They also experienced more years of disability-free living – up to six years.
The sample consisted of 14,804 respondents who were between the ages of 50 and 74 in 1998. Deaths and transitions across disability states were modeled during the period from 2000 to 2012.
Findings: Remaining life expectancy at age 50 was 27.7 years for all men and 31.4 years for all women – or a life expectancy of 77.7 years for men and 81.4 years for women. The study showed that women spent 5.8 years of life disabled, compared to 4.0 years for men. For both men and women, obesity had a small effect on overall life expectancy and a more substantial effect on disability-free life expectancy. Being obese shortened disability-free life expectancy by 2.3 years for men and 4.8 years for women. People who were not obese also spent less time disabled compared to obese people. Men and women who had never smoked had a substantially longer overall and disability-free life expectancy and lived longer with a disability, compared to people who had smoked. Compared to heavy drinkers and people who didn’t drink, or drank less than the moderate definition from above, moderate drinkers had longer overall and disability-free life expectancies.
Compared to all men and women, respectively, non-obese men and women who never smoked, as well as non-obese men and women who never smoked and who were moderate drinkers, live longer. They also live more years free of disability. By contrast, obese men and women who had ever smoked and were not moderate drinkers had significantly shorter life expectancies – both overall and disability-free – compared to all men and women.
As described in the chart, the differences are even greater between the populations with the best and the worst profiles. The example the researchers used to illustrate this is of a 50-year-old woman who has never smoked, is not obese, and drinks moderately – she is expected to live until she’s almost eighty-nine, roughly twelve years longer than a 50-year-old obese woman who never smoked and does not drink moderately. For men, the difference in life expectancy between these two categories is slightly more than eleven years.
Analysis: The population with healthy behaviors the researchers examined in this study are considered a vanguard population – a group that exhibit exceptionally favorable health. The authors state that to their knowledge such a population with multiple healthy behaviors has not been studied. They also note that the population is socioeconomically diverse and draws broadly from diverse racial/ethnic groups.
Compared to the 1970s, our daily lives look very different today thanks to the internet, smartphones, social media, and other technological innovations. However, we have not improved health behaviors very much. By ages 50–59, nearly 80 percent of US adults have either smoked, been obese, or both – a level that has remained surprisingly stable since the 1970s (as smoking rates have fallen in some populations, obesity has greatly increased). This study has the potential to inform policymakers and health researchers about the impact a combination of healthy behaviors can have on mortality and disability.
An important step moving forward will be to find more effective ways to reduce obesity, poor diet, and excessive drinking using the same types of strategies that worked to reduce smoking rates.
(Source: Neil Mehta and Mikko Myrskyla, “The population health benefits of a healthy lifestyle: Life expectancy increased and onset of disability delayed,” Health Affairs, July 2017)
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