Autophagy: mild cellular stress makes you live longer and healthier

Moderate stress to get tougher

It has been long known that body stress can be beneficial for the organism. In fact, going to the gym, the sauna or for a jog is not only good for your health but also for your mental state and longevity. Led by Caroline Kumsta, PhD, researchers at Sanford Burnham Prebys Medical Discovery Institute (SBP) identified the cellular recycling process responsible for the beneficial effects of enduring mild stress: autophagy.

They strongly believe that this mechanism and its benefits could be the key for extending lifespan. Published in Nature Communications, the research team hopes that the study on autophagy would lead to treatments for neurodegenerative diseases such as Huntington’s, Alzheimer’s and Parkinson’s.

Autophagy, a natural defense mechanism against stress

Our organism uses autophagy as a means to recycle old, non-functioning and useless cell parts so that their components can be re-used to make new molecules. These compounds can also serve as energy sources when there is no substrate available to power the cell. Thus, autophagy is a mechanism that helps coping with stress and sets off whenever the organism faces harsh conditions.

Stress could be beneficial in a certain extent since short periods of mild stress can make simple organisms and human cells more resistant and equipped to survive additional stress later in life. That is why long life and stress resistance are linked, and the SBP research team tested the importance of autophagy in becoming stress resistant.

Mild heat shock stress, a “hot” topic?

Kumsta and her team used C. elegans, a transparent worm that only lives a couple of weeks, and presents genetic similarities with humans. After incubating a batch of worms for one hour at 36 °C (stress inducing temperature improving the organism’s survival), the researchers exposed the same batch to another longer mild heat stress session a few days later.

They noted higher survival rates in worms with no autophagy deficiency, suggesting that this mechanism is the key to their resistance to mild stress and survival. They also noted that worms presenting an accumulation of aggregated proteins in some tissues saw the number of these abnormal aggregates significantly reduced due to autophagy after the mild heat shock. This feature is often observed in some neurodegenerative diseases appearing with age where abnormal protein aggregates are formed in neurons.

As this research raises many exciting questions, Kumsta suggested that “going to the sauna or doing hot yoga may not be a bad idea” to toughen up and live longer but they still have to prove that it could definitely be beneficial for humans.