Scientists have found that people age at the molecular level in two accelerated stages - first at 44 years of age, and then again at the age of 60, NOVA reported.
In the study, published in the journal Nature Aging, scientists from Stanford University and the University of Technology in Singapore followed 108 participants over several years to observe changes in the participants' molecules - RNA, proteins and their microbiomes.
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Scientists have found that human aging does not proceed in a gradual, linear fashion. Most of the molecules they studied showed accelerated, non-linear changes between the ages of 44 and 60.
Associate professor of microbiome medicine at the University of Technology and study author Xiaotao Shen told CNN that the results show that “we are not aging gradually”. “Certain moments in time are particularly important for our aging and health,”, he added.
For example, the ability to metabolize caffeine noticeably declines - first around age 40 and again around age 60. “Components involved in metabolizing alcohol also decline, especially around age 40,” Michael Snyder, head of Stanford's Department of Genetics and author of the study, told CNN, referring to the two waves of aging.
Snyder added that anecdotal evidence “people often experience muscle injuries and see that fat accumulation occurs in their 40s (related to lipid metabolism), and definitely sarcopenia (muscle loss) affects people in Their 60s. This is a very big problem“.
„In both age groups, there were changes in the proteins that hold tissues together, which probably helps explain changes in the skin, muscles and cardiovascular system,” he adds. Disease risks also increase more rapidly, especially after age 60.
The study found that people aged 60 and over were more susceptible to cardiovascular disease, kidney problems and type 2 diabetes.
Discovering such patterns could help diagnose and prevent disease, says the study, which said it also identified “clinically applicable markers” that could be used to improve health care management and the well-being of an aging population.
The study focused on participants between the ages of 25 and 75 for almost two years. All participants lived in California, were healthy, and were of diverse ethnic backgrounds. Every three to six months, samples of blood, feces, skin, and nasal and oral swabs were taken from them.