“Mortality is plastic.”

Last night I went to hear Dr. Rudi Westendorp, the head of gerontology at the Leiden University Medical Center in the Netherlands, speak at Mount Sinai about good health after 85.  A slight and smiling man in a red bowtie, Westendorp was introduced by International Longevity Center director Robert Butler and opened with a zinger: “There is no biological limit to human age. Mortality is plastic, as the biologists say.” (This 2004 paper of Westendorp’s is packed with demographic data supporting his contention that “the limit of our biological design has not yet been reached.”)

Growing old isn’t new. What’s new is how many of us now routinely do. Over the last 150 years, lifespans have doubled (roughly from 40 to 80). From an evolutionary point of view, these additional years serve no purpose. As no more than “the temporary hosts of our genome,” in Westendorp’s poetic phrase, Darwin’s done with us once our kids have reached puberty. Here’s the intriguing corollary:  because evolutionary evidence does not apply to these additional years of life, they take place in what Nobelist P. B. Medawar termed “the evolutionary shadow.” We have no construct for them. Gray hair and reading glasses remind us that the machine will fail “like a cheap car” — Westendorp’s cheerful analogy. “But because this process is not programmed," he explained, "you can do something about it.”   

We know the drill: don’t smoke; control weight and blood pressure; eat healthily, exercise, yadda yadda. Also that it’s never too early to start; aging probably begins in childhood. Arguably most important of all is to support research into the basic biology of aging. One thing doctors are starting to realize is that older patients shouldn’t necessarily be put on the same medical regimes as middle-aged patients.  For example, it turns out that high cholesterol is beneficial (!), and that people over 75 with high blood pressure live longer. We don’t know why, at least not yet.