Ageing occurs in dramatic bursts at 44 and 60 years
The human body does not age steadily throughout middle age and, instead, goes through bursts of rapid aging typically at around age 44 and again at 60 years; according to a new study published yesterday in the journal Nature Aging: ‘Nonlinear dynamics of multi-omics profiles during human aging’ (Shen, 2024).
In other words, many molecules and microbes do not change steadily over time; but rather, there are two major waves of aging occurring at about these ages.
The authors performed comprehensive multi-omics profiling on a longitudinal human cohort of 108 participants – aged between 25 years and 75 years.
The participants resided in California, United States, and were tracked for a median period of 1.7 years, with a maximum follow-up duration of 6.8 years.
135 different molecules (RNA, proteins and metabolites) and microbiomes (bacteria, viruses and fungi living in the participants’ guts and skin) were measured.
At each visit, the researchers collected blood, stool, skin swab, oral swab and nasal swab samples. In total, 5,405 biological samples (including 1,440 blood samples, 926 stool samples, 1,116 skin swab samples, 1,001 oral swab samples and 922 nasal swab samples) were collected.
The analysis revealed consistent nonlinear patterns in molecular markers of aging, with substantial dysregulation occurring at two major periods occurring at approximately 44 years and 60 years of chronological age.
Distinct molecules and functional pathways associated with these periods were also identified, e.g. cardiovascular disease, and changes in lipid and alcohol metabolism at the 44-year transition; and immune regulation and carbohydrate metabolism changes at the 60-year transition.
Study lead author Professor Michael Snyder, at Stanford University, said:
“We don’t change gradually with time. There are some really dramatic changes. It seems that dramatic changes occur at age 44 and then at age 60, regardless of what class of molecules you look at”
The findings could explain why diseases such as cardiovascular disease (e.g. IHD) and neurodegenerative disease (e.g. strokes, Parkinsons and dementia) commonly occur at certain ages – starting at around age 45 and 60, respectively.
Skin and muscle molecules underwent changes in both waves.
It is possible that some of the observations are caused by lifestyle changes at certain ages as well.