NEW YORK – New research from Stanford University suggests the molecular processes at play during aging proceed in fits and starts, dynamically shifting once as individuals go through middle age and again as they become more elderly.
"Understanding the molecular changes underlying aging and identifying therapeutic targets for aging-related diseases is crucial for increasing health span," senior and corresponding author Michael Snyder, chair of genetics at Stanford University School of Medicine and director of the Stanford Center for Genomics and Personalized Medicine, and his colleagues wrote in a paper published in Nature Aging on Wednesday.
For their study, the researchers analyzed clinical lab test data in blood samples collected over time from 108 individuals between the ages of 25 and 75 — from transcriptomic, proteomic, and metabolomic patterns to blood cytokines and lipid profiles. They also used 16S rRNA gene sequencing to profile the bacteria, viruses, and fungi found in the skin, oral, nasal, and fecal microbiome of the participants.
"This comprehensive multiomics data and approach allow for a more nuanced understanding of the complexities involved in the aging process, which we believe adds value to the existing body of research," the authors wrote.
Based on data spanning more than 135,000 microbial representatives and molecular measurements over time, the team discovered that pronounced molecular and microbial community changes occurred at roughly 44 years of age, on average, affecting not only women who may be going through perimenopause or menopause but male participants, as well.
In particular, the researchers highlighted molecular shifts related to everything from skin, muscle, and extracellular matrix functions to cardiovascular disease risk and metabolism of alcohol, caffeine, and lipids.
"I think this information is important because it puts individuals as well as physicians on the alert," Snyder said in an email, though he cautioned that "we do not always know the underlying causes for these shifts."
Another set of molecular and biochemical changes occurred at an average age of 60, the researchers reported, leading to altered skin, muscle, kidney function, and metabolism of caffeine and carbohydrates, as well as changes in the immune system's ability to ward off disease.
"The changes at the 60s is well known, as many age-related diseases occur then and the immune system is less effective," Snyder said, noting that the biochemical changes arising during this period, including those in kidney function and carbohydrate metabolism, "were not known or at least not well documented."
The latest results line up with prior studies that have described spikes in age-related disease rather than disease risk that ratchets up consistently with age.
"By considering the nonlinear dynamics of aging-related changes, we can gain insights into specific periods of significant changes (around age 40 and age 60) and the molecular mechanisms underlying age-related diseases," the authors wrote, "which could lead to the development of early diagnosis and prevention strategies."
Even so, they noted that "further research is needed to validate and expand upon these findings, potentially incorporating larger cohorts to capture the full complexity of aging."