But first, what exactly is a free radical? Not a fiery Berkeley politico but rather a lonely unpaired electron lost and spinning around an atomic nucleus. Electrons are compelled to travel in pairs; an unpaired electron therefore will greedily grab the next electron it meets, regardless of pedigree or station. DNA, RNA, mitochondria—it's open season. Sometimes the miscegenation does serious damage to the cell, resulting (the theory goes) in a gradual and irreversible deterioration. For us this means wrinkles and sagging and creaking joints.
The role of antioxidants in this schema is simple: They are brought onboard to hook up with the vagrant electrons and prevent damage. Harman's observation was supported by then-novel insights into management of radiation exposure, a large concern in the 1950s. One known effect of radiation was tissue damage that looked to us like aging. Among the treatments that seemed to blunt this effect were antioxidants such as melatonin, Acetylcysteine, and pentoxiphylline. Presto: A star was born. Never mind how meager the slings and arrows of everyday life are compared with radiation from an atom bomb. If it (might) work for gamma rays, imagine what it can do for my tennis elbow.
If only reality would play along. As noted by Anthes, and Michael Specter in his book Denialism, the first clear crack in the façade was the 2007 revelation in JAMA that antioxidant vitamins were not merely useless but harmful. Building on this clinical observation, a German group has developed a plausible scientific explanation of the increased risk. The title of the group's most recent publication, "Extending life span by increasing oxidative stress," pretty much sums up their view: The human cell should toughen up. It can benefit from enduring something harsh like the insult caused by free radicals. This way, the organism is more prepared to fend off the inevitable Big One, be it cancer or a toxic fume or perhaps a bout of cholera. Practice makes perfect.
Linkback:
https://tubagbohol.mikeligalig.com/index.php?topic=42772.0