23.5 The Centenarians

There is one more source of knowledge about longevity: people who live a long time. Do they do something that others do not?

Far from Modern Life and Times

In the 1970s, three remote places—one in the Republic of Georgia, one in Pakistan, and one in Ecuador—were in the news because many vigorous old people lived there. Some were over 100 years old. One researcher wrote:

Guess Their Age Someone who has not read this chapter would be surprised to learn that Bessie Cooper (left) was 114 and Jiroemon Kimura (right) was 112 when these photos were taken. The pictures are not the most current, however: She was the oldest woman alive until her death at age 116 in 2012, and he turned 115 the same year—the oldest man to have lived so long. Some of the reasons for longevity are visible: genes (note their smooth skin), caregivers (note her carefully coiffed hair and his pristine white shirt), technology (glasses and hearing aid), and attitude (proud smiles). Not visible is their independence (she lived alone on a Georgia farm from ages 67 to 105) or many descendants (over 60 for Jiroemon, including that infant great-great-grandchild on the right).

© DAVID GOLDMAN/AP/CORBIS
THE ASAHI SHIMBUN/GETTY IMAGES

More comprehensive studies (Pitskhelauri, 1982; Buettner, 2008) found that lifestyles in all three of these regions were similar in four ways:

1. Diet. People ate mostly fresh vegetables and herbs, with little meat or fat. They thought it better to be a little bit hungry than too full.
2. Work. Even the very old did farm work, household tasks, and child care.
3. Family and community. The elderly were well integrated into families of several generations and interacted frequently with friends and neighbors.
4. Exercise and relaxation. Most took a walk every morning and evening (often up and down mountains), napped midday, and socialized in the evening.

Perhaps these factors—diet, work, social interaction, and exercise—lengthen life.

The theory that the social context promotes longevity is buttressed by evidence from bumblebees. Genetically, worker bees and queen bees are the same, but worker bees live about three months while queen bees, fed special food and treated with deference, live about five years. When a queen dies, a worker bee is chosen to become a queen, thereby living 20 times longer than that bee otherwise would have.

Maximum Life Expectancy

To the Max Fred Hale, here with three of his 11 great-great grandchildren on his 113th birthday, was the oldest living man for nine months until he died in his sleep a few days shy of his 114th birthday. Until a few years earlier, he lived independently in his home in Maine, shoveling snow off his roof at age 103.

©CHRIS RANK/CORBIS

Surely your suspicions were raised by the preceding paragraphs. Humans have almost nothing in common with bumblebees, and the information about those long-lived people was published decades ago.

Indeed, the three regions famous for long-lived humans lack verifiable birth or marriage records. Everyone who claimed to be a centenarian was probably exaggerating, and every researcher who believed them was too eager to accept the idea that life would be long and wonderful if only the ills of modern civilization were absent (Thorson, 1995). Some people still move to those remote places in order to live longer (e.g., Volkwein-Caplan, 2012), but most scientists consider that foolish.

As for preventing the ills of old age, it does seem that exercise, diet, and social integration add a few years to the average life—but not decades. It is important to distinguish the average life span from the maximum.

Genes seem to bestow on every species an inherent maximum life span, defined as the oldest possible age that members of that species can attain (Wolf, 2010). Under ideal circumstances, the maximum that rats live seems to be 4 years; rabbits, 13; tigers, 26; house cats, 30; brown bats, 34; brown bears, 37; chimpanzees, 55; Indian elephants, 70; finback whales, 80; humans, 122; lake sturgeon, 150; giant tortoises, 180.

Maximum life span is quite different from average life expectancy, which is the average life span of individuals in a particular group. In human groups, average life expectancy varies a great deal, depending on historical, cultural, and socioeconomic factors as well as on genes (Sierra et al., 2009).

In the United States the average has doubled in the past century and continues to rise. In 2012, average life expectancy at birth was about 76 years for men and 81 years for women. That is four years longer than it was 30 years ago, and it is projected to be another five years longer in 2050 (United Nations, 2012).

In most of the twentieth century, dramatic increases in average life expectancy in every nation occurred because public health measures (clean water, immunization, and so on) prevented the deaths of many infants and children. Recent increases in life expectancy are attributed to the reduction in deaths in middle age from adult diseases (heart attack, pneumonia, cancer, etc.). The average has increased; the maximum probably has not.

Now the challenge is to increase the life span of the very old. Gerontologists are engaged in a “fiery debate” as to whether the average life span will keep rising, and whether the maximum is genetically fixed (Couzin-Frankel, 2011b, p. 549). It is known that the oldest well-documented life ended at age 122, when Jeanne Calment died in southern France in 1997. No one has yet been proven to have outlived her, despite documented birth dates for a billion people who have died since then. That suggests that the maximum is set at 122, although some disagree.

Everyone agrees, however, that the last years of life can be good ones. Those who study centenarians find many quite happy (Jopp & Rott, 2006; Paúl et al., 2013). Jeanne Calment enjoyed a glass of red wine and some olive oil each day. “I will die laughing,” she said.

Disease, disability, depression, and dementia may eventually set in; studies disagree about how common these problems are past age 100. Some studies find fewer physical and mental health problems after age 100 than before. For example, in Sweden, where medical care is free, centenarians were less likely to take antide-pressants, but more likely to use pain medication, than those who were aged 80 or so (Wastesson et al., 2012).

Could centenarians be happier than octogenarians, as these Swedish data suggest? That is not known. However, it is true that more and more people live past 100, and many of them are energetic, alert, and optimistic (Perls, 2008; Poon, 2008). Social relationships in particular correlate with robust mental health (Margrett et al., 2011). Centenarians tend to be upbeat about life.

That could be considered the theme of this chapter: Attitude is crucial as senescence continues. As noted in the beginning of the chapter, ageism shortens life and makes the final years less satisfying. Don’t let it. As thousands of centenarians demonstrate, a long life can be a happy one.