By Amanda Gardner
Everyone knows by now that eating right, exercising, and shunning smoking and other bad habits increases our chances of having a long and healthy life.
If you're hitting some -- but only some -- of these goals, it's better than nothing. But according to a new study, you're likely missing out on the full benefits that come with living a healthy lifestyle across the board.
In the study, which included 5,100 middle-aged British civil servants, those who engaged in four key behaviors -- not smoking, moderate drinking, exercising regularly, and eating fruits and vegetables daily -- had triple the odds of avoiding disability, chronic disease, or mental health problems over a 16-year period, when compared with people who practiced none of these behaviors.
Each of the four behaviors, practiced on their own, increased the odds of what the researchers termed "successful aging" by 30 percent to 50 percent. When practiced together, however, the behaviors seemed to produce a compound benefit greater than the sum of its parts.
"Individual healthy behaviors are moderately associated with successful aging, but their combined impact is quite substantial," says lead author Séverine Sabia, Ph.D., an epidemiology and public health researcher at University College London, in the UK. "Multiple healthy behaviors appear to increase the chance of reaching old age disease-free and fully functional."
The findings suggest that following a healthy lifestyle is a lot like collecting compound interest on a loan or investment, says Richard Birkel, Ph.D., senior vice president of health at the National Council on Aging, in Washington, D.C.
"By treating our bodies with care and avoiding harmful substances over a long period of time, the health effects are compounded," Birkel says. "Over time, because we are free of disability and illness and have more energy, we are able to live more fully and take on more challenges. ... There seems to be a virtuous chain reaction in which small positives lead to a critical mass of health and well-being."
The idea that healthy behaviors can amplify each other might seem like common sense. (If you exercise daily but eat only fast food, for instance, you're probably not getting maximal results.) But the new research is noteworthy for its scope and its attempt to quantify the benefits of a healthy lifestyle.
The study is among the first of its kind to examine the outcomes associated with combinations of behaviors in midlife, rather than specific health measures (such as body mass index) that reflect those behaviors, says S. Jay Olshansky, Ph.D., a professor of public health at the Center on Aging at the University of Illinois at Chicago.
What's more, the outcomes used in the study were unusually comprehensive. Sabia and her colleagues defined successful aging using five separate dimensions of health: cognitive, mental, physical, respiratory, and cardiovascular. This is a "real strength," Birkel says.
A holistic measure like successful aging "defines a state of being, rather than a set of isolated health outcomes," Birkel adds. "This is, of course, the status we all aspire to as we age -- not just absence of disease or chronic conditions, but having good mental health and being independent and active."
The study, which was published today in the Canadian Medical Association Journal, did have some important limitations. For one, it was an observational study, meaning it shows an association and does not establish a cause-and-effect relationship between the various health behaviors and outcomes.
And given that some of the participants were only 60 years old at the conclusion of the study, it's hard to know whether the findings -- especially those regarding mental functioning -- will remain steady with time, says Clinton Wright, M.D., a neurologist at the University of Miami Miller School of Medicine.
Still, says Birkel, the findings are "very good and reassuring news," and make a strong argument for adopting healthy lifestyle behaviors no matter how old you are.