Healthspan Happenings: The Genetics of Longevity, Exceptional Aging, and a New Leader in Human Lifespan

aging time

 

Welcome back to Healthspan Happenings, our weekly rundown of what’s going on in the world of longevity research and the science of aging. This week, we’re talking about the heritability of longevity, the longest running research project on human aging, and the increasing lifespans of people in Spain.

 

If you think that long life runs in the family…

 

Stop and ask yourself why. Traditionally, longevity researchers have suggested that genetics play about a 30 percent role in determining how long we will live. Think of it like this: if your parents, grandparents, and great-grandparents lived a longer-than-average amount of time, then your chances of living longer would increase by about 30 percent when compared to people whose families lived shorter lives. Therefore, human longevity has been significantly connected to winning the genetic lottery.

However, genetics might not play as large of a role in determining lifespan, according to a recent study by Calico Life Sciences. Drawing on the recorded lifespans of 400 million people (via Ancestry.com), the research team noticed a strange web of relations. They found that people related socially (families, friends, lovers, etc.) shared similar lifespans to those who were biologically related—sometimes even more so. The researchers attributed this finding to something they called ‘assortative mating,’ or the human mating practices that encourage similar people to reproduce.

Simply stated, like often attracts like. Wealthy people tend to mate with other wealthy people. Tall people tend to date other tall people. This throws a wrench into the heritability of longevity because people inherit social, economic, and material conditions just like they inherit genetic material. For example, economically disadvantaged folks have a higher likelihood of producing offspring together because they run in similar social circles. Their lack of money could contribute to a shorter lifespan—a lack of wealth that would also be felt by their children. This isn’t to say that there is no genetic connection to longer lifespan. But rather, these findings suggest that heritability has only about a 7 percent effect on determining human longevity.

 

If the idea of aging makes you think about wrinkled faces and diseased bodies…

 

You’ve fallen for a stereotype. As the longest running study on human longevity suggests, we only definitively know two things about aging: 1) aging is not synonymous with disease and 2) aging is different for everyone.

The Baltimore Longitudinal Study of Aging (BLSA) has worked with nearly 3200 individuals over the course of 60 years and these are the two things that they know for sure. Consequently, older adults are just as (if not more) diverse than younger populations. Genetics, lifestyle decisions, and various diseases all impact how our bodies age. Conflating aging with a disease has its pros and cons, but one of those cons is the misconception—and fear—that aging is a disastrous and painstaking process.

As researchers at BLSA note, some individuals live well into their eighties with little or no major health problems. These instances of “exceptional aging” provide evidence that a unique cocktail of lifestyle activities, genetics, and medical interventions could eventually be the new standard of aging—rather than the exception.

 

If you love Spain for its cuisine and high-tempo dances…

 

You might have a new reason to visit. Spain is currently on its way to having the longest life expectancy in the world, according to a report from the Institute for Health Metrics and Evaluation. The report claims that the average life expectancy of Spaniards will increase to 85.8 years by 2040, thereby surpassing Japan whose current life expectancy sits at 84 years.

But why is Spain’s life expectancy increasing? For starters, Spanish cuisine strictly adheres to what has become known as the Mediterranean diet. This diet (which emphasizes plant-based foods and minimizes the consumption of red meat, butter, and salts) frequently enters discussions on human longevity and has ushered some support for validating its usefulness.

Furthermore, Spain’s healthcare system ranks as one of the best in the world. This is due in part to the accessibility of its healthcare services, which (unlike in the US) is guaranteed as a constitutional right. In addition to the diet and healthcare system, Spain also has a strong sense of family ties—which goes a long way for healthy aging. Culture then, just as much as diet and exercise, plays a major role in facilitating how we age.