Chapter 41
Lifestyle+ — 32
Another study, of more than seven hundred thousand US veterans, showed there was even more to gain in life expectancy. The cumulative effect of all eight factors tallied in these vets—never smoking, physical activity, no excessive alcohol consumption, restorative sleep, nutrition, stress management, social connections, and no opioid disorder—was associated with twenty-four years of added life expectancy at age forty for males and 20.5 years for females. A lifestyle score based on those same factors was associated with increased likelihood of becoming a centenarian. A prospective study of healthy lifestyle, consisting of never smoking, BMI less than 25 kg/m2, high-quality diet score, regular exercise, and no more than moderate alcohol intake, was associated with marked improvement in healthy aging, of about eight to ten years without cancer, cardiovascular disease, or type 2 diabetes, as seen in figure 3.12 for people at age fifty. A favorable lifestyle was linked to lower risk of dementia across the range of low to high genetic risk. The capacity for lifestyle to mitigate genetic predisposition, calculated by polygenic risk score, was highlighted in a UK Biobank study with a thirteen-year follow-up that showed its favorable impact for over forty diseases.
This has been a survey of the lifestyle factors that are critical to healthy aging. The broad, body-wide, marked impact of these factors is also a function of their interdependence. It’s not just diet, just exercise, just sleep, or just social isolation. Our environmental exposures are far more important than have been generally acknowledged. All of them come together to create a healthy lifestyle+ package. They may be considered “low tech” since much has been known about some, particularly diet and exercise, for thousands of years, but they have been refined and our knowledge has grown tremendously. My overall sense is that it will be hard for any new drug or intervention to match overwhelming consequences of a well-guided healthy lifestyle, but that doesn’t mean it isn’t worth reaping the advantages of the combination.
Figure 3.12. Relationship of life expectancy (LE) and number of lifestyle risk factors (never smoking, no obesity, diet quality score, physical activity, and level of alcohol intake). Adapted from Yanping Li et al., “Healthy lifestyle and life expectancy free of cancer, cardiovascular disease, and type 2 diabetes: Prospective cohort study,” British Medical Journal 368 (January 2020): 16669, https://doi.org/10.1136/bmj.16669.
We’re ready to go high tech and see why rebooting our approach to dreaded diseases, and diagnosing them earlier, make them eminently more treatable. And even better, with the medical forecasting of high risk of a specific condition in an individual, we can prevent it from occurring. Once determining such risks, our ability to prevent or substantially delay age-related diseases will always substantially depend on attention to lifestyle+ factors.