ANN ARBOR, Mich. — Stress is hardly ever considered a good thing, but a surprising new study finds that experiencing a little bit of stress and adversity early on in life may just extend one’s lifespan.
By studying a type of roundworm called C. elegans, researchers at the University of Michigan have discovered that oxidative stress early in life increases stress resistance later on in adulthood.
Oxidative stress is a naturally occurring form of stress at the cellular level, or part of the aging process. However, it can also be caused from other stressful situations such as exercise, calorie restriction, and pollution exposure. Essentially, this form of stress occurs when cells produce too many oxidants and free radicals than they really need.
While analyzing a group of C. elegans roundworms, the research team noted that the worms which produced more oxidants during their developmental phase lived longer than worms producing fewer oxidants.
The elements that determine longevity have been a prominent focus of researchers for centuries, and the scientific community is in agreement that both genetic and environmental factors play a large role in lifespan. That being said, there are other factors at play when it comes to the duration of one’s life, and researchers are still working to understand these more stochastic, or seemingly random, elements.
In pursuit of these discoveries, C. elegans roundworms have proven particularly useful in research circles due to the fact that every hermaphroditic, roundworm mother gives birth to hundreds of genetically identical offspring. But, despite the fact that all of these “children” are genetically identical, their lifespans vary a great deal. This makes them the perfect research subjects for scientists investigating lifespan fluctuations and their causes.
“If lifespan was determined solely by genes and environment, we would expect that genetically identical worms grown on the same petri dish would all drop dead at about the same time, but this is not at all what happens. Some worms live only three days while others are still happily moving around after 20 days,” comments study author and scientist Ursula Jakob in a release. “The question then is, what is it, apart from genetics and environment, that is causing this big difference in lifespan?”
While observing a group of young C. elegans worms, researchers noticed that certain worms were producing more reactive oxygen species (ROS) than others. ROS are oxidants produced by every single air-breathing being. ROS is also linked to the aging process, for example, many anti-aging creams available today are intended to combat the oxidative damage caused by ROS. Interestingly, in this case, the study’s authors actually found that the worms producing more ROS during development were living longer.
“Experiencing stress at this early point in life may make you better able to fight stress you might encounter later in life,” says study author and scientist Daphne Bazopoulou.
So, in order to validate their findings, the researchers exposed the entire group of developing worms to more ROS. Sure enough, the average lifespan of the entire population went up.
While the study’s authors weren’t able to figure out what is causing certain worms to experience more oxidative stress, they were able to successfully uncover what is extending the worms’ lifespans at a genetic level. First, they sorted through thousands of C. elegans larvae depending on their oxidative stress levels, and separated worms that produced high levels of ROS from worms producing smaller amounts.
This separation illustrated that the two groups had one major difference: a fluctuation in a certain type of protein responsible for packaging and ordering DNA. Now, how this difference actually manifests itself in the worms and ultimately influences their lifespan is still unknown, but, the research team were able to determine that the same protein appears to be sensitive to oxidative stress in mammalian cells.
“The general idea that early life events have such profound, positive effects later in life is truly fascinating. Given the strong connection between stress, aging and age-related diseases, it is possible that early events in life might also affect the predisposition for age-associated diseases, such as dementia and Alzheimer’s disease,” Jakob concludes.
The study is published in the scientific journal Nature.