Centenarian is the word for people who live to be at least 100 years old. Centenarians should not be confused with Centurions, who are Roman soldiers commanded by Caesars; they often did not live very long at all. Supercentenarians are people who have lived to at least age 110. What can they teach us?
There are between 50 and 100 known supercentenarians, with good documentation as to their age. Each year some die while other people reach 110. Few ever live beyond 115. There are also dozens of fakers, who claim to be the world's oldest living person, usually for the attention. They are in their 90s but may have the world's most wrinkled skin.
You may think that you would never want to live that long. Many young people say they want to be gone by 80 (although not too many 79-year-olds say that). Few want to linger and suffer. But it turns out that the people who live the longest generally suffer the least disease; they are much less likely to have heart disease and cancer in mid-life. So, long life starts to look more appealing.
Genes are important to long life but not nearly as important as you might think. Only about a quarter to a third of the variation in longevity is accounted for by genes, and even that is likely an overestimate of direct biological effects. These estimates come from studies of twins, and if you think about it, you know many cases in which one sibling lived long but another did not, even though both share the same parents.
Many long-lived individuals have way outlived their parents' or siblings' lifespan. But it does seem to be the case that if you have lived to be 100, then you probably also have some long-lived relatives. So it makes sense to look for the genes that may be relevant to a very long, healthy life.
A clever study has just been published about the genetics of supercentenarians. The researchers collected blood samples from 17 supercentenarians. Then, complex analyses of their DNA were conducted, looking for the gene or genes that may be the secret to long life. If such genes were discovered and their functions understood, it might be possible to manufacture new drugs to promote good health. And such genes might help us predict longevity.
One of the supercentenarians was still driving a car at age 107. This is reminiscent of my own study, The Longevity Project, in which some of the participants are now centenarians and are still active and vigorous (and sometimes driving). In The Longevity Project, we have studied over 1500 individuals since they were children in the 1920s. We have found again and again that people who face life’s challenges with persistence, prudence, and a planful relishing of the experience will often tend to thrive. These thrivers and survivors were well-integrated into their communities and led active daily lives. For men especially, a long, happy marriage was a great predictor of thriving, and there is no gene that codes for happy-marriage proteins. But would the new supercentenarian study reveal the genetic basis of long life?
Alas, no super-gene or variant popped out. The new study contributed to the emerging research field of genes and health, but did not discover the secret to longevity.
Surprising the researchers, one of the supercentenarians carried a known harmful (pathogenic) variation of a gene. This genetic variation is associated with a form of heart disease in which the muscle wall deteriorates and your risk of sudden death rises significantly (technically termed arrhythmogenic right ventricular cardiomyopathy). This genetic variation, and others like it, is not that uncommon, and so you may well be warned that you have this risk. But here it appears in someone who lived in good health beyond age 110!
There is no gene that will make you live to 110, just as there is no magic pill and no enchanted diet. Some individuals surely face worse biological odds of great health, and some people are simply unlucky. But for most of us, how we live our lives deeply determines whether we thrive and live long, or suffer and succumb. Men at some time are masters of their fates. The fault, dear Brutus, is not in our stars but in ourselves.
If you are interested, The Longevity Project, which explains the long-term pathways to thriving, was published in paperback edition by Plume (see http://www.howardsfriedman.com/longevityproject/ and is also available on Kindle and Nook. The book also contains self-assessment quizzes to help you figure your current trajectory. There is also a Facebook page for The Longevity Project.
Copyright © 2014 Howard S. Friedman, all rights reserved. The supercentenarian study was published November 12, 2014 in PLoS One DOI: 10.1371/journal.pone.0112430
Photo: Betty White at the Time 100 gala in 2010 By David Shankbone, via Wikimedia Commons, creative commons license.