Glossary · Biology
Hormesis
In short
Hormesis means that a short, moderate stress prompts the body to adapt in ways that make it more resilient, while more of it does harm. Exercise is the best-known example.
Behind the term is a dose-response curve that turns: a little helps, a lot harms. During exercise, oxygen radicals and small injuries arise, to which muscles and mitochondria respond by building up. Heat, cold, fasting and some plant compounds are linked to similar adaptation programmes.
The concept is plausible and well supported for exercise. For many other stimuli it is more an explanation than a proof: that a stimulus triggers stress signals in cells does not yet show that people become healthier as a result.
One consequence is often overlooked: dampening the stress signal, for example with large amounts of antioxidants, may also dampen the adaptation.
The amount makes the stimulus — too little does nothing, too much does harm.
Where this comes up in the fact checks
- Sauna & cold – Sauna and cold baths are considered hormetic stimuli; where randomized testing was done, the added benefit did not appear.
- Resveratrol – Combined with exercise, it cancelled out the training effect in a randomized trial.
- Metformin – Two exercise studies came out against metformin.
Sources
Related terms: Mitochondria · Autophagy
Information only, not medical advice. The BK-Score is a subjective assessment according to disclosed rules – not a scientific evaluation. Scoring rules