A free radical is an unstable molecule with an unpaired electron. To become stable, it may take an electron from a nearby lipid, protein or strand of DNA. That newly altered molecule may then react with another, creating a chain reaction.
What can happen when the load is high?
The lesson follows the chain from cellular and DNA damage to inflammatory signalling, breakdown of structural proteins such as collagen, and disruption of mitochondrial energy production. The body has repair and antioxidant systems for this; harm becomes more likely when production repeatedly outruns those defences.
Everyday sources: from lower to higher exposure
Food and cooking: repeated deep-frying, charred food and overheated oils can increase oxidised compounds. Home and work: tobacco smoke, solvents, some cleaning chemicals and poor indoor air add exposure. Environment: traffic pollution, industrial emissions, heavy metals and strong UV exposure can raise the burden further. Exercise also produces ROS, but sensible training supports adaptation; the concern is extreme effort without enough recovery.
Free radicals are part of a bigger story
Multiple exposures do not prove that a symptom has one cause. They help explain why Velta’s lessons connect free radicals to oxidative stress and inflammation: the concepts overlap, but they are not interchangeable. The practical aim is to reduce avoidable exposure and support the body’s normal defences.
From the lesson
Common questions
Does cooking create free radicals?+
High temperatures and repeatedly heated oils can create oxidised products. Steaming, boiling and gentler cooking reduce that exposure.
Does exercise create oxidative stress?+
Exercise temporarily raises ROS, but regular, well-recovered training strengthens antioxidant adaptation. Excessive training without recovery is different.
What should I read next?+
Start with the oxidative-stress and inflammation lessons to see how the body normally manages reactive molecules.