Secrets of a Long Life
Long livers share predictable behavior and psychology.
Posted Jan 16, 2019
Centenarians may have genetic advantages but there are several behavioral and psychological traits that most share. These promote healthy aging and long life. How important is genetics? It is surprisingly unimportant, accounting for less than 10 percent of differences in longevity according to the most sophisticated research.
The Wealth Effect
If biology is not destiny, then what accounts for differences in lifespan? One factor receiving a lot of recent attention was income level, with the richest segment of the population living longer than the poorest fifth.
Of course, these differences are not just about money. The haves experience lower levels of obesity than the have-nots because they have more opportunities to be physically active and consume a healthier, more varied diet. They also have greater access to medical care. Much of the wealth differential is conflated with behavioral differences and long livers benefit from numerous behavioral and psychological advantages.
To begin with, they are more physically active and more mentally engaged.
As I pointed out in a recent post, the benefits of physical activity are intimately related to the benefits of mental activity as the ancient Romans, and others, recognized in the concept of a healthy mind in a healthy body.
This connection becomes all important for older people because the brain is arguably the organ that is most challenged by old age.
Physical activity has three kinds of benefits for the elderly:
The first is that people who are highly physically active do not lose either muscle mass, or muscle strength that used to be considered normal consequences of aging. In other words, aging of the muscular system is dramatically slowed permitting high levels of physical activity into old age.
The second effect is that physically active older people have a more robust immune system, indicating that senescence of the immune system also slows giving them a better capacity to fight diseases and infections.
The third effect is on the physiology of the brain. This is reflected in greater proliferation of stem cells in the hippocampus that plays a key role in memory. This implies that the brains of exercisers likely have a greater capacity for counteracting age-related deterioration of brain function and cognitive capacity. Their circulatory systems are also likely to be in good shape so that age-related deterioration of brain circulation that is a factor in senile dementia is less of an issue. Of course, senile dementia often strikes close to the end of life.
Physical activity probably protects neural function because the brain happens to be active when the body is moving. With this in mind, it is not a surprise to learn that long livers are mentally very active.
A highly active mind is the key to how well the brain ages. It doesn't very much matter what the brain is doing so long as it is challenging or exposes the thinker to new information. Whether a person spends their time playing bridge, doing crosswords, solving math puzzles, or feeding a passionate interest in TV sports, what matters is not how sophisticated the pursuit so much as the extent to which the individual is mentally engaged.
One clue to the importance of an active mind is the fact that people who are well educated live substantially longer than those who are not (1). Presumably, the fact that their mental capacity is trained by years of third-level education means that they are more open to a wide range of topics and interests. So their brains are likely to be more active throughout life.
If the brain is constantly being challenged by having to process a wealth of new information, it is going to be metabolically active and to use up energy that is provided by the brain's circulatory system. This means that the circulatory system is likely to be better maintained.
One explanation of the longevity advantage of education is that those with college degrees have better circulation down to the level of the capillaries. Inadequate blood flow in capillaries is associated with cognitive decline in old age. If educated people have a better functioning circulation, they are better able to resist senile dementia.
Another critical feature of longevity may be the degree with which we are involved in the lives of other people whether it is relatives, friends, or the local community.
People who are married generally live longer than those who are single and those who lose a spouse incur a cost to health and length of life given that they are more vulnerable to depression and heart disease.
Having a partner gives a person a greater sense of purpose as they plan for their future. Any kind of social commitment appears to improve health and well being, whether it is dedication to a career, to scientific research, to political activism, to a sports team, to charitable causes, or to relatives.
This connection was brought home by early experiments where residents of retirement communities who were simply asked to care for a house plant saw a significant reduction in mortality rates. More substantial reductions in mortality rates were found for the elderly in assisted living facilities when they were provided with pets (dogs and birds) to care for and given the opportunity to work in a garden. (2). They were also much happier.
It follows that anyone with strong lifetime social or personal commitments can enjoy life longer as well as more. People with commitments tend to be both more energetic and more optimistic.
Whereas depression, and pessimism are predictive of a variety of bodily illnesses, including cardiovascular disease, optimists enjoy a health advantage that contributes to their length of life (3). Of course, this is a complex relationship because chronic illnesses are also a cause of depression.
Optimism is affected by genetics but people can also learn to be more optimistic by challenging persistent patterns of unduly negative thinking. So our actions, and thought patterns may have a substantial impact on our health and length of life.
1 Molla, M. T., Madans, J. H., and Wagener, D. K. ( 2004). Differentials in adult mortality and activity limitation by years of education in the united states at the end of the 1990s. Population and Development Review. 30, 625-646.
2 Gawande, A. (2014). Being mortal. New York: Metropolitan Books.
3 Seligman, M. E. P. (2012). Flourish. New York: Atria books.