Why do some people live and stay healthier for much longer than others?
Throughout history individuals have been recorded who have reached an exceptional age; Jeanne Calment, an exceptionally long-lived French woman born in 1875, became the world’s oldest person in 1997 at 122 years old.
This longevity can be attributed in part to environmental and behavioral factors, such as better nutrition, medical care, hygiene, and luck. But as average life expectancy continues to rise around the world due to general improvements in these and other factors, it’s clear that exceptional longevity and healthy aging tend to run in families.
This suggests that genetic differences play a role in ensuring longer life and good health throughout life.
A recent study has shown that children of exceptionally long-lived parents have a similarly reduced risk of developing type II diabetes compared to the general population. Surprisingly, this benefit extends to their spouses as well.
Among the children and their spouses, 3.7% and 3.8% developed type II diabetes during the course of the study, respectively. This corresponds to a rate of 4.6 to 4.7 new cases of type II diabetes per 1,000 person-years, which is about 53% lower than the rate of 9.9 among people ages 45 to 64 in the general US population
“While this latest finding may not be intuitive, previous studies have also reported marked survival and health advantages among spouses and children in long-lived families,” says first author Iva Miljkovic, a professor in the University’s School of Public Health. from Pittsburgh. US.
The study was part of the Long Life Family Study (LLFS) which focuses on families in the US and Denmark with multiple exceptionally long-lived members. The purpose was to identify over two generations which biological processes are associated with long life and healthy ageing.
The health of 4,559 long-lived (over 90 years of age at enrollment) focal women and men, 1,445 of their siblings (themselves over 80 years of age), 2,329 children (between 32 and 88 years of age) of the focal person or of his brother, and 785 of the spouses of those children, from 2006 to 2017.
By taking blood samples, the researchers studied the levels of biomarkers that affect the risk of type II diabetes among children and their spouses, and found that there appear to be different underlying factors that promote this lower risk of type II diabetes.
“We found that growth factor signaling and proinflammatory biomarkers appear to have stronger positive and negative effects on diabetes risk in spouses of children of exceptional survivors than in the children themselves,” says Miljkovic.
“This suggests that different biological risk factors affect this risk in the two groups.”
Does this mean that spouses come to resemble each other in their blood levels of biomarkers simply by sharing a home and lifestyle, regardless of their genetic background in early life?
“It is possible that people unconsciously tend to choose their partners through so-called ‘assortative mating,’ that is, they tend to match their underlying phenotypes and genotypes, including those that affect diabetes risk and longevity,” he explains. .
“Further LLFS studies are required to identify the mechanisms and pathways (genetic, epigenetic, molecular, health trajectories and behaviors, and lifestyle patterns) to understand why being married to a long-term family member also leads to poorer health. metabolism and survival. advantage, similar to that of your spouse,” she adds.
The research was published in the journal Frontiers in clinical diabetes and medical care.
Cellular aging and senescence
The short film of the International Scientific Film Festival SCINEMA 2021 cellular senescence explores the biological phenomenon of cellular senescence, a hallmark of aging.
This is a process in which cells irreversibly stop dividing by mitosis and their growth stops permanently, without undergoing cell death.
The process was discovered in 1961 by Leonard Hayflick and Paul Moorhead, when they found that human fetal fibroblast cells in culture could only reach a maximum of 40-60 cell population doublings (via mitotic cell division) before becoming senescent. .
Called the Hayflick limit, this is the number of times a normal somatic cell can undergo cell division before senescence is triggered.
Every time a cell undergoes mitosis, the telomeres at the ends of each chromosome, which work to protect DNA from degradation, shorten slightly, and once they shorten to a critical length, cell division ceases altogether.
This fundamental process is a double-edged sword for the body: it is beneficial as an antitumor mechanism because it can also be triggered by other cellular stress signals and prevent the proliferation of cancer cells, but it also promotes ageing.
As we age, more and more of our cells go into senescence, and the buildup of these cells can compromise tissue repair and regeneration and is ultimately detrimental.
You can watch the movie here.