Keep Kelly Busy
Free radicals are unstable molecules that include the hydrogen atom, nitric oxide (NO) and reactive oxygen species. These naturally occur in the body as a result of chemical reactions during normal cellular processes. They can also be formed in response to excess pollution, too much UV sunlight and exposure to cigarette smoke. In an attempt to stabilise, they attack other molecules in the body potentially leading to cell damage and triggering the formation of another free radical resulting in a chain reaction. Some scientists believe that this type of free radical action has been implicated in certain chronic and ageing diseases such as cancer, heart disease, stroke, rheumatoid arthritis, cataracts and Alzheimer’s disease.
Protective mechanisms of antioxidants
Antioxidants are compounds that help to inhibit the many oxidation reactions caused by free radicals thereby preventing or delaying damage to the cells and tissues. Their mechanisms of action include:-
· Scavenging reactive oxygen and nitrogen free radical species
· Decreasing the localised oxygen concentration thereby reducing molecular oxygen’s oxidation potential
· Metabolising lipid peroxides to non-radical products
· Chelating metal ions to prevent the generation of free radicals
In this way antioxidants limit the free radical damage from:-
· Oxidising Low Density Lipoprotein (LDL) cholesterol, which may increase the risk of athersclerosis
· Promoting platelet adhesion, which can lead to thrombosis thereby increasing the risk of heart disease or stroke
· Damaging the cell’s DNA, which may lead to cancer
· Blocking the normal endothelial cell function and vasodilatation in response to nitric oxide, a potential mechanism for heart disease and cancer
· Triggering inflammation
· Impairing immune function
The writers would've been better off going with polyphenols:
Furthermore, because of the accumulating evidence to suggest that oxidative stress plays a pivotal role in neurodegenerative diseases, the effect of tea’s polyphenols are now being considered as possible neuroprotective agents in progressive neurodegenerative disorders ... As well as antioxidant properties, animal and in-vitro studies suggest that certain polyphenols found in tea may have a protective role through their action on cell signalling pathways as well as their influence on the mortality of neuronal cells. [iii] However, well controlled, in vivo studies are required to further understand the action of tea polyphenols in the brain.
And while I'm on the subject, neutrons have neither a polarity nor a "flow" - discuss.