Garlic is reputed to be one of the most beneficial spices/condiments, man has known because of its ability to reduce serum cholesterol, when consumed regularly. As many do not like the intense smell native to garlic, there is considerable resistance in adopting it as a regular component of the diet consumed every day. The lingering strong body odor that refuses to fade away from the body quickly makes the situation worse. Garlic derives its characteristic aroma from the break down products of the chemical Allicin which is considered to be beneficial for reducing cholesterol build up in the arteries and lessen the chances of risk of stroke and heart attack.
Now it turns out that garlic also happens to be one of the significant food components possessing powerful anti oxidant activity, though it does not boast of levels of traditionally well established anti oxidants like flavonoids that are known to be present in green tea, grapes and many other plant sources in abundance. Anti oxidant organic compounds when ingested are able to neutralize the damaging effects of free radicals generated at the tissue level and prevent cell damage. If some of the recent reports are to be believed, Allicin, derived from Alliin aminoacid by the action of Allinase enzyme during crushing of the garlic cloves is the active principle responsible for the anti oxidant activity, though the precise mechanism is not yet known. As Allicin is not very stable, it is presumed that some of the metabolic products of Allicin could be the real substances that trap the oxy radicals. On the other hand Allixin, a non-sulfur containing compound has been suggested as the active principle with significant anti-oxidant activity and therefore the ability of garlic to fight against cancer is attributed to this substance at least by some experts.
In spite of the divergence of opinion, Allicin has been shown to be active against stomach cancer by several studies. Use of pure Alliin and allicinase enzyme in conjunction with Rituxymab antibody has been demonstrated to be able to kill cancer cells confirming that Allicin can also be effective against some cancer forms. Sulfenic acids, break down products of Allicin have been found to be effective in trapping free radicals. Besides its anti cancer property, Allicin is also known to have other beneficial effects like reducing atherosclerosis, decreasing fat deposition in the body, normalizing lipoprotein balance, decreasing blood pressure and is anti thrombotic and anti inflammatory.
Allistatin I and II are bioflavonoids, present in garlic with antibiotic properties against many viral and bacterial infections. Their effectiveness against Sstaphylococcus and E.coli are well established and the activity exhibited by them is more powerfull than many antibiotic drugs used to fight infections in allopathy. In some countries garlic is an accepted remedy for whooping cough and influenza infections. Besides garlic also contains other bioflavonoids like quercitin and cyanidins with health promoting properties which cannot be ignored. The established credentials of garlic as a health protecting food adjunct have helped food technologists to evolve technologies for preparing biologically active products from this source. Tendency of Allicin to decompose in concentrated form has been overcome by suitable dilution and drying to get active powder preparations with its activity stabilized. Unless the tissue structure is disrupted Alliin and Allinase cannot react to gether to form Allicin and such a preprocessing step is a prerequisite for obtaining effective end products. While Allicin is responsible for the pungency in garlic, di allyl sulfide, a break down product from Allicin contributes to the strong aroma.
Hundreds of garlic based products being marketed with tall claims are not subjected to any statutory control and consumers are at their wits end to decide about their choice. One of the most prevalent types of misleading information is to use the term 'Allicin equivalent' on the label. Allicin is not readily present in garlic and not only it is unstable, its formation is dependent on enzyme Allinase which must be present in such products. The USP standards require garlic powder preparations to contain Alliin not less than 0.3% in dry weight basis. Expressing Allicin value in terms of 'Allicin releasing' potential is considered more useful and reliable for consumer guidance. Probably it is time now to evolve enforceable standards in India for different garlic products based on the levels of some of the active principles which may be easy to measure in analytical laboratories and to insist on mandatory labeling to make the products transparent in terms of the health attributes.