There’s no question that chronic stress caused by things like an unsustainable workload, poor relationships, lack of sleep, or financial hardships can wreak havoc on your health.
Hormetic stressors, on the other hand, are controlled, acute stressors that trigger healthy adaptive responses. Hormesis has a dose-response relationship and represents how “high doses of certain substances or exposures can have a toxic effect, while low doses can be beneficial,” says integrative physician Robert Rountree, M.D. “It’s the periodic nature of the stressor that defines hormesis—short-lived doses of stress activate positive response patterns.”
What does this look like in real life? Researchers have found that hormesis is a common thread underlying many of the health benefits associated with intermittent fasting, cold exposure, heat exposure, high-intensity interval training (HIIT), intermittent hypoxia, and even certain phytonutrients found in plant food, like the glucosinolates in cruciferous vegetables.
High or prolonged doses of any of these behaviors or substances aren’t sustainable or healthy (spend too much time in cold water, and you’re gonna get hypothermia). But in short bursts, the little bit of irritation that these stressors cause is just enough to knock you out of comfortable homeostasis and activate a variety of cellular mechanisms and signaling pathways that promote stress resilience, repair cellular damage (via processes like autophagy), repair DNA, combat oxidative stress, produce new mitochondria, reduce inflammation, support elimination of toxins, improve blood sugar regulation, reduce risk of cancer, and more, explains Rountree.
In fact, some experts believe that if you don’t expose yourself to enough hormetic stress, it’s hard to achieve optimal health and well-being. In a 2020 research review, Elissa Epel, Ph.D., director of the University of California–San Francisco Aging, Metabolism and Emotion Center, writes that “biologically, the lack of acute stressors prevents the intermittent episodes of cellular ‘housecleaning’ activities that slow aging.”
There’s also increasing evidence that the stress resilience we obtain from one hormetic stressor may help the body adapt to other stressors—even to psychological stressors like depression and anxiety—which is called “cross-adaptation,” according to Jenna Macciochi, Ph.D., author of Immunity: The Science of Staying Well.