Life to years, not years to life

Last thoughts on subjective ageing. Modern medicine should be adding life to years; not just more years to life.  According to Stats Canada, there were over 861,000 people aged 85 and older counted in the 2021 Census, more than twice the number observed in the 2001 Census. The population aged 85 and older is one of the fastest-growing age groups, with a 12% increase from 2016. Currently, 2.3% of the population is aged 85 and older.

The lifespan of an 85-year­old man in Canada is 6.7 years and the lifespan of an 85-year-old woman in Canada is 8 years. The good news is that these surviving octogenarians are more likely to be active. For example, by the end of his life, the average 85-year-old man will have spent only 0.56 years in an institution, and the average 85-year-old woman will have spent 1.5 years.

Between ages 75 and 84, 73% of elderly people report no disability; and after age 85, 40% of the population remains fully functional. Over the last century, the number of years an individual spends in active retirement has increased 10-fold.

In order that successful aging not to seem like an oxymoron, the concept of aging must be viewed from three dimensions: decline, change, and development. The term "ageing" can connote decline, and decline is not successful. After age 20 our senses slowly fail us. By age 70 we can identify only 50% of the smells that we could recognize at 40. Our vision in dim light declines steadily, until by age 80, few of us can drive at night; by age 90, 50% of us can no longer use public transportation.

But the term "ageing" also conveys change, a relatively neutral meaning. Analogous to the transformation of trees from spring to winter, our hair changes from chestnut to white, our waistline becomes bigger, our eyes acquire crow's feet, and our frequency of making love shifts from three times a week to twice a month. At the beach, we pick up grandkids instead of sweethearts, but our capacity for joy is undiminished.

Finally, the term "ageing" also conveys development and maturation. Analogous to a grand vineyard wine evolving from bitterness to perfection, at 70 we are often more patient, more tolerant, and more accepting of the effect on ourselves and others. We are more likely to tolerate paradoxes, to appreciate relativity, and to understand that every present has both a past and a future. Finally, like age itself, experience can only increase with time.

When examiners used a global definition of successful aging at age 75, 80% of the Berlin Aging Study cohort were still considered in "good health" (cognitively fit, active, and involved in life) or in "average health" (relatively healthy, still independent, and satisfied with life). At age 95, this level of health was still maintained by 30% of the subjects. These figures would have been significantly better had those with "terminal decline" been excluded. For example, the average centenarian lives without major disability until age 97! 

The stats in this blog are from Stats Canada, and an article written in a 1998 article on Successful Ageing by George E. Vaillant, M.D. Kenneth Mukamal, M.D. published by Harvard Second Generation Studies.