All organs seem to be equally unimportant for longevity
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In the quest for a long life, it appears that not all organs hold equal significance. Research indicates that maintaining a youthful brain and immune system is crucial, overshadowing even the aging of the heart or lungs.
We already know that different organs age at varying rates, but the factors that most significantly affect lifespan remain elusive. Hamilton Sehawee from the Icahn School of Medicine at Mount Sinai, New York, leads this inquiry.
To explore this, his team assessed the levels of around 3,000 proteins in blood samples from over 44,000 participants aged between 40 and 70 years, all part of the UK Biobank Study.
Leveraging genetic data from earlier studies, the researchers mapped the locations of these proteins in the body, identifying several that were notably concentrated in 11 regions, including the immune system, brain, heart, liver, lungs, muscles, pancreas, kidneys, intestines, and adipose tissue. Elevated levels of these proteins suggest vital roles in the proper functioning of these organs and systems.
The team then employed machine learning models to estimate the ages of participants based on half of the data, developing distinct models for each of the 11 body areas. Generally, these predictions were consistent with the actual ages of the participants, although some models did occasionally overestimate or underestimate, supporting the notion that organs indeed age differently, according to Oh.
Using their trained model, the researchers predicted the organ and immune system ages of the other half of participants who were monitored for an average of 11 years after blood samples were taken.
They discovered that having even one organ showing signs of premature aging or an aging immune system correlated with a 1.5 to 3 times higher risk of death during follow-up, with the stakes increasing alongside the number of aging organs.
Interestingly, exceptions arose in cases where the heart and lungs appeared considerably younger than anticipated, which did not correlate with a lower mortality risk during the study period. However, possessing a youthful brain or immune system was associated with a roughly 40% reduction in death risk. These areas also intensified the overall risk reduction to 56%, particularly when both were young.
“The brain and immune system influence numerous other bodily functions, so it’s expected that their deterioration could significantly impact life expectancy,” remarked Alan Cohen from Columbia University in New York.
Nonetheless, Cohen cautions that protein markers may not entirely encapsulate the aging process. “There may be gaps in our understanding of the exact origins of these proteins. Certain organs may release their proteins into the bloodstream more readily than others, skewing perceptions of their importance,” he notes.
Moreover, further research involving a broader demographic that includes more ethnic and economically varied populations is necessary, as the current study participants were predominantly affluent individuals with European ancestry, according to Richard Shiou of King’s College London. Oh and his team are planning additional studies to explore this further.
Even if these findings hold true, concrete methods for curbing the aging processes in the brain and immune system remain elusive. Oh mentions that pinpointing aging markers in these areas could pave the way for medication targeting.
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Source: www.newscientist.com
