Introductions
Phytochemicals are “compounds found in plant-derived foods that have biological activity in the body” (Whitney and Rofles 469). They are classified as non-nutrients. They are found in fruits and vegetables, whole grain and nuts. Phytochemicals are responsible for the taste, Aroma and color of plant food. Thousands of phytochemicals have been discovered and research is still ongoing on a lot more. These phytochemicals have been grouped according to source and possible health benefits. These groupings include: Flavanoids, Carotenoids, Isothiocynates, Indoles, Organosulphurs, Phenolic acids, and Phytic acids, Saponins, Tannins, Phtyoestrogens, Curcumin, Monoterpenes, Alkylresorcinols, Capsaicin, Resveratrol, Lignans and Protease Inhibitors (Whitney and Rofles 471). Phytochemicals have been discovered to produce profound physiological effects in the body. Numerous researches have found out they act as antioxidants and aid in suppressing a number of diseases. People are encouraged to consume phytochemicals in organic foods rather than synthetic ones. This paper discusses garlic, one of the common vegetables. Researchers have shown contains a lot of phytochemicals with promises of many health benefits.
Garlic
Cultivated Garlic (scientifically Allium Sativum, common names, Stinking Rose or Poor Man’s Treale) belongs to the lily family or bulb-shaped plants that also include Onion, Chives, Leeks and Shallots. Mature garlic is tough with white leaves enclosing internal cloves. For many generations, garlic has been used for flavoring food and medicinal purposes. In recent times, it has gained scientists’ attention due to the many potential health benefits it exhibits.
Active compounds
A good number of phytochemicals can be derived from raw garlic. Many of these phytochemicals are only formed when the garlic is chopped, chewed or crushed. Once it is cut, chemical reactions take place resulting in many new compounds accompanied with intense odor (“Garlic 6”). Sulphur containing phytochemicals of garlic include: allicin, alliin and ajoene, dithiin, S-Allylcysteine, Diallylsulphides, methiin and Allyl Methyl Sulphides (Bao and Fenwick 152). Alliin is converted to allicin by the enzyme alliinase when intact garlic is cut.Allicin is thermally unstable and decomposes to yield other phytochemicals such ajoene and various derivatives of dithiin. This phytochemicals may inturn react with the enzyme and form other compounds (Bao and Fenwick 152). Allicin is responsible for the strong odor of garlic. Other important phytochemicals in garlic include flavonoids, citral, geraniol, linalool, A-phellandrene and B-phellandrene. The amount of phytochemical present in a garlic extract has been cited to depend on the processing method, the type of species, geographic location and storage (Lachance 82).
Garlic also contains vitamins and important minerals such as B-Vitamins especially B-1, vitamin C, vitamin A, ascorbic acid, phosphorous, potassium, sulphur, selenium, calcium, magnesium, germanium, sodium, iron, manganese and trace iodine (“Garlic 6”).
Types of preparations
There are four major types of garlic preparations: garlic powder, aged garlic extract (AGE), garlic oil and garlic oil macerate (Amagase et al. n.pag). Garlic powder is made by slicing or crushing garlic cloves then drying and grinding them into powder (“Garlic and Cancer” 2). Aged garlic extract is made from whole or sliced garlic cloves that are soaked in alcohol solution or a suitable solvent for varying amount of time (“Garlic and Cancer 2”). This process is believed to substantially reduce allicin and increase the amount highly bioactive compounds such as S-allylcysteine (SAC), S-allylmercaptocysteine and allixins.It is commonly used in laboratory experiments and some consider it a superior form of garlic. Garlic oil macerate is made from encapsulated mixture of whole grain cloves ground into vegetable oil (“Garlic and Cancer 2”). Garlic essential oil is obtained by passing steam through garlic (“Garlic and Cancer 2”). Since cooking can denature alliinase, the enzyme in cut garlic, it is recommended letting garlic stand for at least quarter an hour before cooking it. This is to allow enough time for other phytochemicals to form.
Potential Health benefits
A lot of researches on garlic extracts continue to yield promises of many health benefits. The health benefits of garlic extracts are attributed to its numerous phytochemicals. Cultivated garlic has shown the ability to prevent blood clotting that result from platelets aggregation. This has been linked to two of its active compounds, Ajoene and Dithiins (Lachance 83). Laboratory studies indicate allicin possesses strong antibacterial, antiviral and antifugal properties (Lechance 83) that may be effective in treating diseases such as pneumonia and urinary tract infection. Researches on effects of garlic on blood glucose have yielded promising hypoglycemic and hyperglycemic activities, suggesting possible use in treating diabetics. S-allylcysteine, found in aged garlic preparations has demonstrated ability to lower the dangerous cholesterol (LDL) in the blood and elevate the good cholesterol (HDL). This has been cited as potentially decreasing the risk of developing dangerous chronic diseases associated with high serum cholesterol such as atherosclerosis, hypercholesterolemia and cardiovascular diseases such as heart failure and cardiopathy. Garlic also contributes in boosting the immune system to fight off pathogens and maintain health owing to the many vitamins and minerals it contains. Flavonoid, one of garlic’s phytochemicals said to be an effective anti-oxidant serving to protect cell against destructive free radicals (Whitney & Rofles 471). Current research suggests that garlic may help prevent or slow development of certain forms of cancer such as those of the pancreas, colon, esophagus and breast. DiallylSulphide, a phytochemical found in garlic oil has been found to be an antioxidant with antitumor properties. Sulphur containing compounds in garlic afford the body with protection by speeding up production of carcinogenic destroying enzymes and slowing production of carcinogen-activating enzymes (Whitney and Rofles 470). On going researches also continue to show that certain peptides in garlic have a potential to lower blood pressure. These peptides “inhibited the enzyme that converts Angiotensin I to angiotension II. Angiotensin II can raise the blood pressure” (“Garlic 15”). Garlic has also been used to prevent and treat diseases such as Scurvy and Beriberi, owing to the fact that it contains vitamin C and Thiamine (Goebel 208).Garlic also contain a high proportion of oligosaccharides, a carbohydrate considered good for intestinal microflora.
Side effects
Excessive consumption of garlic can result in strong breath and body odor. This is because the metabolites from garlic’s sulphur compounds are indigestible and can only be excreted via lungs and skin. To avoid bad breath, deodorized forms are available. Parsley can also be used. Garlic contact with skin or its pungent smell may cause allergies that range from mild to life-threatening in certain individuals. This may include asthmatic reaction and contact dermatitis. Garlic has also been shown to produce significant side effect when used with several prescription drugs, especially HIV drugs such as saquinavir, indinavir and ritinavir owing to a reduction in protease inhibitors attributed to garlic. Pregnant women using garlic may experience some stomach upset (“Garlic” 7). Garlic has blood thinning properties and should not be used with blood-thinning medication prior to surgery as it may increase the risk of bleeding. Other rare effects reported on using garlic supplements include headache, fatigue, muscle aches and dizziness (Ehrlich n.pag).
Conclusion
The popularity and long history of garlic has continued to generate interest in many scientists. Scientific researches and cultural myths point to its many possible health benefits. However, current results in many areas of these researches remain inconclusive. Therefore, further researches are needed. Garlic may turn out to be a very good for our health.
Works Cited
Amagase H, Petesch BL, Matsuura H, Kasuga S and Itakura Y. “Intake of Garlic and its Bioactive Components.”. Journal of Nutrition, 131(3s) (2001):955S-62S. Web.
Bao, Yongping and Roger Fenwick. Phytochemicals in Health and Diseases. Baco Raton:CRS Press, 2004. Print.
Ehrlich, Steven D. “Garlic”. U of Maryland Medical Center. U of Maryland. 2008. Web.
“Garlic”. nutraceutical.com. Woodland Publishing, 1995.Web.
“Garlic and Cancer Prevention”. Cancer.gov.National Institute of Health. 2008.Web.
Goebel, R.J, R and W Jones. “Garlic and Health” Vegetable Fruits, Herbs in Health Promotion. Ed. R.R Watson. Boca Raton: CRC Press, 2001. 205-216. Print.
Lachance, Paul A. Nutraceuticals: Designer foods III Garlic, Soy and Licorice. Hoboken: Wiley-Blackwell, 1997. Print.
Whitney, Eleanor and Sharon R. Rofles. Understanding Nutrition. Belmont: Cengage, 2008. Print.