Free radicals cause four main types of damage to the body:
Damage to cell membranes
Damage to the arteries of the circulatory system
Damage to the double bonds in DNA
Free radicals can steal an electron and break down another biomolecule such as loose proteins, sugars, fatty acids, etc. that are NOT part of a larger chemical structure. In these cases the free radical does little damage. If a free radical steals an electron from one of the proteins that is contained in a strand of collagen (rather than a loose protein), it causes a change in the chemical structure of the collagen at that point and causes a break in the collagen strand. This is damage. Once a bundle of collagen has multiple points of damage which occurs over years, the strand of collagen becomes dysfunctional and loses its elastic quality. The skin begins to sag. Over time free radical damage happens to the various components of the body and this damage is progressive.
Free radicals chip away at cell walls, molecule by molecule, making holes. The cells leak and lose their chemical balances. Subsequent free radicals are able to chip away at DNA, making cells dysfunctional. If this damage affects cellular DNA, the cell may malfunction and this is what happens cell by cell over the lifetime of a human being, ultimately causing entire organs to malfunction, because their cells malfunction. If the DNA of basal keratinocytes, for example, are damaged the cells may become dysfunctional and the basal cells will reproduce cells that are equally as damaged and dysfunctional, resulting in the aging and dysfunction of the skin and its various components. Damage to the cell wall ordinarily causes wrinkles, hardening of the skin, therefore premature aging.
In recent years it has come into focus that free radicals such as smoking and inflammatory toxins or foods produce the degenerative diseases of aging. It is well established that inflammation is the key destructive force ultimately causing coronary artery disease. Free radicals can unquestionably cause oxidative damage to DNA. Increasing oxidative DNA damage is typically accompanied by an increase in cancer risk.
Free radicals damage the artery walls, and this is of course the first stage of a heart attack, along with the thickening of the arteries caused by cholesterol, and build up of calcium.
The most common inflammation is arthritis. The joint lubricant known as synovial fluid loses its lubricating quality due to infection by free radicals. Without lubrication, swelling occurs.
How do we avoid all this? improve our diet to ensure we do not take in too many polyunsaturated fats, along with anti oxidant nutrient supplements.