TL;DR
Get health and wellness essentials delivered free — and shop member deals
- Fast, free delivery on millions of items
- Access to Prime Big Deal Days deals on October 6–7
- Prime Video, Amazon Music and more included
Researchers found that cellular autophagy did not follow one pattern of decline with age: results varied across skin cells and induced neurons and differed by sex. A five-person pilot suggested exercise may change autophagy in older adults’ blood cells, but larger studies are needed to test the finding.
Autophagy, the process cells use to break down and recycle damaged material, does not simply decline with age, according to a study published September 27 in Aging Cell. Researchers at Sanford Burnham Prebys Medical Discovery Institute found that measured activity varied by cell type and sex, challenging a common assumption about aging and cellular recycling; a separate pilot involving five older adults suggested exercise may also affect it.
The team analyzed skin and blood samples from volunteers aged 23 to 72 who reported having no chronic diseases. Researchers also converted skin cells into induced neurons, allowing them to examine three cell types. They sequenced RNA transcripts to assess the expression of autophagy-related genes and used a separate technique to measure autophagy activity directly.
In the study’s results, autophagy declined with age in tests of male skin cells, stayed stable in female skin cells and increased in female induced neurons. The researchers also found that gene-expression levels did not correspond to direct measures of how quickly cellular recycling was occurring. That difference cautions against treating gene transcripts alone as a reliable measure of autophagy activity, the authors said.
The team also examined links between autophagy and physical function among adults aged 70 and older. Higher measured activity was associated with poorer physical-function indicators across the cell types studied, including lower aerobic fitness in relation to blood-cell activity and lower grip strength in relation to activity in induced neurons. These are reported associations, not evidence that autophagy caused the differences.
Why Cell-Specific Results Matter
The findings complicate efforts to treat autophagy as a single process that uniformly weakens with age. If activity differs among tissues and between sexes, a result from one cell type may not describe what is happening elsewhere in the body. The study’s comparison of gene expression with direct activity measurements also points to a measurement problem: a change in autophagy-related transcripts does not necessarily show that cellular recycling itself has changed.
This matters to research into healthy aging because scientists are exploring whether autophagy could be targeted by future interventions. The reported associations with physical function also suggest that more autophagy is not automatically a sign of better health in every age group. The study does not establish whether changing autophagy improves health, nor does it provide a basis for individual treatment decisions.
As an affiliate, we earn on qualifying purchases.
How Researchers Measured Recycling
Autophagy helps cells break down and reuse proteins and other material. A decline in the process is often discussed as one feature of aging and has been associated with age-related conditions. The study’s authors said the evidence for a simple age-related decline in humans is limited, motivating their examination of healthy volunteers across different cell types.
The research combined RNA sequencing with a direct assay of autophagy activity. It also included an initial exercise test: five participants aged 77 to 88 provided blood samples before and after a 12-week mild exercise program focused on fall prevention. The report said blood-cell autophagy activity appeared to move toward levels seen in younger people as physical performance improved. The small pilot cannot establish that exercise caused either change.
“We commonly see people cite this idea that autophagy declines with age, but the actual evidence for this in humans is very thin.”
— Caroline Kumsta, senior and corresponding author
Limits of the Early Evidence
The source report does not provide the full sample size for the main volunteer study, and the participants’ self-reported absence of chronic disease does not establish that the results apply to people with age-related conditions. The findings describe particular cells and measured associations; they do not show why autophagy differed or whether those patterns occur broadly in the population.
The exercise result is especially preliminary: it involved only five participants, focused on blood cells and used a mild fall-prevention program. The report does not establish that the activity changes caused improved physical performance, or that the same result would occur with other forms of exercise, in other tissues or in a larger group.
Larger Exercise Studies Ahead
The researchers said larger studies with more participants and improved testing protocols are underway with UC San Diego’s Exercise and Physical Activity Resource Center. A pilot grant from the Altman Clinical and Translational Research Institute at UC San Diego will support expanded research on exercise, autophagy and physical function in aging. Those studies may help test whether the initial blood-cell findings are repeatable and how they relate to changes in physical performance.
Further work will also be needed to clarify how age and sex shape activity across different cell types, and whether autophagy measurements can predict meaningful health outcomes. Until then, the study supports a more qualified account of cellular recycling in aging, rather than a single pattern of decline.
Key Questions
What is autophagy?
Autophagy is a cellular process that breaks down and recycles material such as damaged proteins.
Did the study find that autophagy always declines with age?
No. The results varied by cell type and sex: activity declined in male skin cells, remained stable in female skin cells and increased in female induced neurons.
Does the study show that exercise improves autophagy?
Not conclusively. A pilot with five adults aged 77 to 88 suggested blood-cell activity changed after a 12-week program, but the small study cannot establish cause and effect.
Does higher autophagy mean better health?
The study does not support a simple answer. Among older adults, higher activity was associated with some poorer physical-function indicators, but these associations do not prove that autophagy caused them.
What research is planned next?
The team says larger studies with more participants and improved testing protocols are underway to investigate exercise, autophagy and physical function.
Source: rss
Cold & flu season Picks
humidifiers
As an affiliate, we earn on qualifying purchases.
