Antioxidants in Tea and Their Potential Health Benefits - Assignment Example

Antioxidants in Tea and Their Potential Health Benefits Name University Professor Course Date Antioxidants in Tea and Their Potential Health Benefits Introduction Tea is considered as one of the largest consumed beverages in the world. There is a very high consumption rate of tea and it is therefore crucial to understand the potential health benefits that are associated with this beverage. There are various types of tea categorized according to the way they are processed (Langley 2004, p. 185). These categories are black, green, white, and oolong teas. Green tea is made from the freshly unfermented tea leaves which are just steamed or pan fried. The minimal processing of this tea preserves most of the antioxidants making it to be the richer in the antioxidant contents than black and oolong teas. White tea, which is made from the young leaves of the Camellia sinesis plant, undergoes minimum processing and hence it has the highest amount of antioxidants and nutritional value. Herbal teas are however not true teas as they are made from the dried leaves of such plants as mint and chamomile. Tea contains many compounds that are beneficial to the human body. Some of these compounds include theaflavins and catechins, and have antioxidant properties. The many health benefits associated with tea consumption are due to the antioxidant capabilities. The antioxidants interact with the free radicals such as nitrogen dioxide and nitric oxides. If the free radicals are let uninterrupted they damage the DNA and cell membranes (Kraunig 2003, p.252). The radials that are already present in human body are destroyed by the tea antioxidants through a process called electron delocalization.Even though vegetables such as spinach and broccoli are known to have high levels of antioxidants, the antioxidants in tea are believed to be in higher contents than in vegetables. After consuming tea, the antioxidants in the plasma increase within the first thirty minutes of tea consumption and reach the peak two hours after drinking tea. Studies have shown that regular consumption of tea assists in the reduction of lipid peroxidation and also contributes in damaging the free radicals that might be present in the body. Evidence also continues to indicate the role played by antioxidants in protecting the body against some health conditions such as heart diseases, cancer, and stroke. The systems that lead to these diseases or conditions are promoted by the presence of free radicals in the body and hence antioxidants come in handy in opposing these radicals (Nicoletta 2010, p. 36). In addition to some common antioxidants such as vitamin C and E, it has been demonstrated through research, that polypherols or plant derived antioxidants, have a lot of health benefits in human beings. Free radicals occur in the body due to some chemical reactions that happen during the normal cellular processes. Free radicals may also be formed as a result of a body’s mechanism of responding to excess pollution that may be caused by UV sunlight or consumption of cigarettes or exposure to their smoke. In an effort to be stable, free radicals attack other molecules in the body causing cell damage and influencing the formation of more free radicals. Some scientists suggest that this kind of action is common in chronic diseases such as cancer, stroke, and Alzheimer disease among others. The mechanisms of action of the antioxidants include targeting the reactive oxygen and nitrogen free radicals. Antioxidants also reduce the concentration of localized oxygen and by so also reduce the oxidation potential of the molecules (Lakenbrink 2004, p. 853). Antioxidants also metabolize lipid peroxides into non-radical products. In addition, antioxidants contribute in chelating metal ions to prevent the existence of free radicals. The antioxidants in tea regulate the free radical from damaging the cell’s DNA which might eventually lead to cancer. Antioxidants also inhibit the free radicals from triggering inflammation in the body cells or impairing the immune system. There are some antioxidants that are synthesized within the body cells (endogenous) while others need to be provided through diet. The quantity of flavonoids that are present in tea depends on the variety of leaf, the environment where the tea is grown, and the process of manufacturing. Green teas contain simple flavonoids known as catechins. During the oxidation process to make black tea, simple flavonoids are converted to more complex types such as theaflavins and thearubigins.In the today’s world human beings are exposed to stress and free radicals as they undertake their daily activities. Free radicals may destroy the body cells and DNA molecules. One of the main benefits of tea is that it is a great source of antioxidants which contribute in reducing the harmful effects of the free radicals (Paquay 2003, p. 92). Theaflavins are part of the oxidants that are present in black tea and engage in fighting any abnormal cells that are introduced to the body and destroy them before they cause any harem to the body cells.A research that was done by John Weinberger who was a senior researcher at a Cancer Prevention Institute in New York, concluded that both black and green teas contained the same amounts of polyphenols. His study also found out that the antioxidants found in tea were able to block any cell damage associated with smoking tobacco or other toxic chemicals. He also suggested that decaffeinated tea was also alright since the removal of caffeine does not affected the flavanoids present in tea. According to some performed at Rutgers University, antioxidants present in black tea may assist in the prevention of prostate, stomach, and breast cancers (Russo & Russo, 2004, p. 139). A chemical compound, TF-2, that is found in black tea is known to cause death of cancer cells without affecting the normal cells.Another research that was conducted in Pace University recommended that drinking tea could help in deactivating some viruses like herpes that are essential in preventing pneumonia, diarrhea, cystitis, and other forms of skin infections. Studies have shown that tea flavonoids are water-soluble. One study indicated that a cup of UK tea that was allowed to brew for around 60 seconds contained approximately 140mg of flavonoids (Karakaya 2005, p. 23). It seems the concentration of flavonoids in tea increase with the increase in the brewing time. Some of the tea flavonoids are absorbed by human body. There are some researches that indicate an enhanced plasma levels in the body following a continued consumption of tea. In the same studies it was noted that the plasma antioxidant leached high levels after around thirty minutes of tea consumption. The catechins levels were higher after the consumption of green tea in comparison to the black tea but their antioxidant effects were similar. This finding led to the conclusion that the thearubigens and theaflavins that are found in black tea also have potential as antioxidants. The addition of milk into tea does not in any way affect the performance of the tea flavonoids as antioxidants. Green tea antioxidants are known to have numerous health benefits in human beings. It is believed that green tea oxidants assist in fighting the free radicals that are harmful to our bodies. Free radicals are found in the sunlight, food, and in the air. Whenever the body absorbs oxygen and converts it into energy through oxidation, free radicals are released in this process. Antioxidants mop up the free radicals before they can cause any harm in the body. The free radicals are highly reactive and harmful molecules that move around the body. They damage the body cells and DNA causing aging, heart diseases, cancers and strokes. Quite often the wrinkles that are formed in the skin during aging are caused by free radicals. Antioxidants slow down the aging process by reducing the impact of the free radicals. The healing is done at the cellular level culminating into more benefits. According to a research done by the US Department of Agriculture (USDA) in 2007, green tea has a flavonoid called catechins (flavan-3-ols). Dried green tea can contain up to 40% of catechins. In reality, green tea has more catechins than dark chocolate (Serafin 2006, p. 30). This research also found out that a cup of green tea has more than 200 milligrams of catechins which is equivalent to what is contained in eight apples. There are four polyphenol catechins that are found in green tea that include gallocatechin (GC), epigallochatechin (EGC), epicatechin (EC), and epigallocatechin gallate (EGCG). Catechins are antioxidants in nature and are believed to have the ability to prevent cancer and heart diseases. Green tea ahs more catechins than black tea and oolong tea. Researchers attribute this to the way green tea is processed. Catechins have antioxidant power that prevents peroxidation in the cell membranes and the artery walls and hence reducing the formation of atherosclerotic plaque. The EGCG is particularly responsible fro suppressing growth tumors and also inhibits the enzymes that cause the spread of cancer in the body. The EGCG, unlike other catechins, has a unique ability to combat cancer. Research has shown that EGCG has more antioxidant power than ascorbic acid, and vitamin C. catechins also inhibit the growth of bacteria such as E.coli. Green tea contains gallic acid which is an antioxidant with many health benefits in the body. Gallic acid occurs as a free molecule and possesses anti-fungal and anti-viral properties. This acid acts as an antioxidant and protects the body cells against oxidative damage. It is particularly known to damage cancer cells without causing harm to the healthy body cells. During internal haemorrhage, gallic acid is used to reduce the magnitude of the bleeding. Gallic acid is also used in the treatment of albuminuria and diabetes (Du Toit 2004, 65). Albuminuria is a health condition where the urine contains an abnormal level of the albumin protein. If not controlled this condition leads to a kidney failure. In addition, some ointments that are used in the treatment of psoriasis and haemorrhoids contain gallic acid. Psoriasis is a skin disorder that leads to the growth of the skin cells at a very high rate causing the extra cells to pile up on the skin. Through research it has been reported that green tea contains carotenoids. Carotenoids are important nutrients in the body as they help in improving the eye sight (Russo & Russo, 2004, p. 142). Evidence has also shown that women who eat diets rich in carotenoid have significant low chances of getting breast cancer which has claimed many lives in the world and continues to be a life threatening health problem. Another natural antioxidant that is present in tea is the tocopherol. The nutritive value of foods is reduced when the fats and oils in them are oxidized. During the oxidation of these fats and oils, the lipid peroxides are generated and cause harm to the human body. Tocopheral is known to prevent this oxidation making oily foods to remain fresh as in their initial state. Green tea also contains ascorbic acid or vitamin C which is a vital mineral in the body. Vitamin C is required for the repair of tissues in the human body. It assists the body in making collagen, a protein that is used in making skin, ligaments, and blood vessels. Ascorbic acid also plays a vital role in the healing of wounds, and in the repair and maintenance of teeth and bones. Vitamin C is an antioxidant that also assists in preventing some of the damages caused by free radicals that are formed when the body transforms food into energy. Chromium, a nutrient that is present in tea, works with the insulin to assist cells in the intake of glucose in the blood cells. It therefore improves the effectiveness of insulin in the body. This nutrient is required by the body in small amounts and its deficiency reduces the effectiveness of insulin and hence impairing the glucose tolerance (Cao & Sofie 2003, p. 29). Researchers have not yet come up with the Recommended Dietary Allowances (RDA) for chromium but its presence in human body is measured in hair or blood. Manganese nutrient is found in tea in trace amounts. This mineral is responsible for the activation of enzymes in order to be able to absorb key nutrients such as thiamin, ascorbic acid, and biotin. It acts as a catalyst during the synthesis of cholesterol and fatty acids and also facilitates in the metabolism of carbohydrates and proteins (Panglossi, 2006, p. 47). At times manganese also takes part in the production of sex hormones that are responsible for the maintenance of reproductive health. Manganese also activates other enzymes such as glycolsyltranserferases that is significant in the formation of bones. Deficiency of this nutrient may cause impaired growth, defects in fat and carbohydrate metabolism, and skeletal disorders. Although a deficiency of this nutrient in human body is rare, acute deficiencies in children may cause blindness and paralysis. Another antioxidant that is present in tea, though in little amounts, is selenium. Selenium protects the body cells from the damage that may be caused by free radicals. It is also known to assist in the production of the thyroid hormone by the thyroid glands. Further researches have shown that selenium also helps in lowering the risk of joint inflammation in human beings. Deficiency of this nutrient may cause hair discoloration and weakness in the body muscles. Zinc is an essential trace element that is present in green tea. It is significant in human nutrition and public health. Zinc deficiency is associated with dwarfism in human beings making a vital nutritional element in human life. Most of the cellular metabolism processes in the body depend on zinc. Zinc plays a vital role in the reproduction and immune systems. It influences hormone release in the body and regulates the cells in the process off growth and development. The structures of proteins and cell membranes are also formed with the assistance from zinc. Lack of zinc in the body makes the cell membranes to be susceptible to the oxidative damage. Studies carried out in various parts of the world indicate that green tea ahs the capability to fight the excess body fat and hence contributing to weight loss. The catechins present in tea trigger the weight loss by enhancing the burning of calories in the body. They also control the cholesterol levels in the body (Rosen, 2008, p. 37). Green tea, unlike the black and the oolong teas does not undergo fermentation before drying. Potassium is a mineral component that is present in tea. It is necessary for the proper functioning of all cells and tissues in the body. It is required for the normal heart function and in the digestive and muscular activities. Hyperkalemia is a condition where the blood has more potassium than the body requires. Hypokalemia on the other hand is having too little potassium in the body. Some studies have indicated that potassium contributes in the lowering the blood pressure. People who consume a lot of diet that have high levels of potassium also have decreased chances of getting stroke. Another element that is present in tea is vitamin K. this vitamin plays a vital role in blood clotting and bone metabolism. It also prevents calcification of blood arteries. Scientists also say that vitamin K assists in the regulation of blood sugar. Vitamin K regulates blood clotting by assisting in the transportation of calcium. Vitamin K also plays a significant role in reducing bone fractures especially in women at postmenopausal who are mainly at the risk of osteoporosis (Shahidi, 2007, p. 227). Vitamin K also assists in reducing bleeding during liver diseases. In the cases of heavy menstrual bleeding, Vitamin K can be used in reducing the bleeding Tea has an antibiotic effect that helps in oral and bone health. There are some elements in tea that assist in increasing iron absorption in the body as well as acting as a relief to stomach discomforts. Flavanols are antioxidants that are also present in tea. Studies have shown that a high intake of flavanols is a factor in the reduction of risks that are associated with vascular disease. Various clinical studies have proved that flavanols also help in the platelet reactivity and reduced oxidative stress. Foods that are rich in flavanols, including tea, give some protection against thrombosis. According to a research done in Hawaii, it was found out that flavanols reduce the chances of getting pancreatic cancer. During the research 530 of the people involved in the study developed pancreatic cancer and those people who had the highest consumption of flavanols had a risk of getting pancreatic cancer 23% lower than those who had low levels of getting pancreatic cancer. Tea contains fluoride mineral in large amounts but this mineral is quite important in the body if it is taken in small amounts. Fluoride is helpful in maintaining strong and cavity free teeth. Green tea contains higher amount of fluoride than black tea but most of the fluoride taken into the body is deposited in the teeth and bones while the extra is excreted to control it from reaching toxic levels. Aspalathin is a component that is found in rooibos tea which is the flavonoid that is found in largest amounts in the rooibos tea. It is known as herbal tea in many regions and contains antioxidants effects in the human body. Aspalathin is really helpful in the control of blood sugar. As an antioxidant it is considered to be an effective scavenger for the free radicals that are bound to damage the body cells (Cao & Sofie 2003, p. 32). The effect of aspalathin is almost equal to the effect brought by catechins. Aspalathin has health benefits as it helps in glucose homeostasis in the type 2 diabetes. It does so by stimulating the uptake of glucose n the muscle tissues and the secretion of insulin from the beta-cells in the pancreas. A study done in Cheng Kung University found out that drinking tea contributed in strengthening bones and tea due to the presence of fluoride and flavanoids. The study involved more than 1030 people who were interviewed. Health benefits were more common in people who drank tea daily for more than six years. The highest bone mineral density was noticed in people who had consumed tea for more than ten years. In another study done in Indiana University it was found out that green tea was beneficial in reducing the oxidative stress that occurs as a result of cigarette smoking. Oxidative stress is known to participate in the development of some diseases such as cancer. The research found out that smokers reduced their oxidative stress by more than 50% when they consumed at least six cups of tea daily. This eventually lowers their risk of cancer, heart disease, and other ailments that are associated with smoking. In a study done in the Chinese Academy of Preventive Medicine, it was found out that drinking tea assisted in improving the pre-cancerous conditions of oral leukoplakia in patients and this proved that tea had some antioxidants that were responsible for the prevention of oral cancer. Antioxidants in tea are known to contribute in the prevention of rheumatoid arthritis. This prevention as caused by the presence of anti inflammatory properties (Langley 2004, p. 187). Arthritis is an inflammatory disease that causes swelling and pain in the joints. The antioxidant in tea reduces the severity of the symptoms that are associated with arthritis. A study that was carried out in UK, aimed to find out whether green tea could be used in the treatment of the Alzheimer’s disease. The study found out that once the green tea is digested in the stomach, it results in chemicals that are capable of protecting the body against the Alzheimer’s disease. Digested green tea was also found to have anti-cancer properties that were able to slow down the growth of tumor cells. The anti cancer compound in the green tea is Epigallocatechin gallate which prevents cancer cells from growing by attaching to the enzyme dihydrofolate reductase. EGCG that is found in green tea inhibits the enzyme DHFR which is used as a target for the anti cancer drugs. The researchers however still have no idea on the amount of green tea that one is supposed to take in order to experience the expected health benefits. Studies have indicated that compounds known as theaflavins that are found in tea are able to lower the bad cholesterol in the human body and also promote the level of the good cholesterol. Theaflavins are formed through the polymerization of the green tea polyphenols or flavanoids, a process that takes place during fermentation of green tea (Erba 2005, p. 145). Theaflavins are produced when the green tea ferments to form oolong or black tea. The color and the flavor of the tea occur as a result of the theaflavins. The medicinal benefits that are associated with theaflavins include improvement in cardiovascular health, immune system, cancer, metabolism, diabetes, and others. Teas are easy to be processed in the body and are therefore recommended for the people with digestive problems. It has no calories until sugar or milk is added and this could be used as strategy to reduce the calories intake. Due to this characteristic, tea can be used as an aid for losing weight. White tea consists of some amounts of antioxidants that are related in reducing the risks of the coronary heart disease (Cao & Sofie 2003, p. 33). Actually antioxidants in the white tea help in reducing the impacts of poisonous substances in the body. When one has low moods, tea is known to increase performance and concentration and hence improves personal mood. Antioxidants present in Puerh tea is produces antioxidants that are responsible in the reduction of the levels of the blood lipids and by so doing reduces the chances of fat build up in the arteries. It is also rumored that tea antioxidants are also useful in reducing the effects of hangover when it is taken before or after the consumption of alcohol. Oolong tea has antioxidants that assist in reducing pollutants in the atmosphere that could be made up of free radicals in the environment. The polyphenols present in tea assist in the digestive system and in some cases it is reported to relieve headaches in human beings. A study that was conducted by Cao in 1996 found out that green tea has more antioxidants capable of fighting free radicals in the body than even vegetables such as kale and garlic. Epigallocatechin (EGCG) is said to be twice as powerful as the antioxidant found in red wine. Green tea is water soluble and when one takes too much of it is excreted by the body through the excretory system. This is of advantage than in vitamin E that too much of it is retained in the body fats if it’s taken in excess (Erba 2005, p. 146). EGCG is believed to be a better antioxidant by performance than other antioxidants like butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). The polyphenols that are present in green tea play a role in the prevention of Parkinson’s disease. The antioxidants help in the flow of dopamine in the human brain (Carmen 2006, p. 81). The main cause of Parkinson’s is the lack of dopamine in some part of the brain and the tea polyphenols prevents the depletion of dopamine. This disease affects movement and balance and affects more than one million Americans every year. A research conducted in Singapore reported that consuming 23 cups of black tea in a month may reduce the chances of getting Parkinson’s disease by around 71%. An eye cataract is one of the major causes of blindness in the world. More than half of all the Americans who are aged more than 65 years have cataracts (Nicoletta 2010, p. 36). Although other conditions such as diabetes and smoking can also contribute to the development of cataracts, age is the main factor. For the last one decade, researchers have been working hard to identify the effects of black tea, green tea, and EGCG from green tea extracts on the prevention of the eye cataracts. The clouding of the eye lens is related to oxidative stress. The damaged cells in the retina and the lens of the eye are caused by the free radicals of oxygen molecules. More cataract research has paid more attention to the effects of antioxidants like vitamin E and EGCG, in the prevention of free radical damage. An animal study realized a cataract reduction when the green tea extracts were used after the start of cataracts (Nicoletta 2010, p. 37). When both the green and black tea extracts were given to rats, the development of the cataracts reduced significantly due to the antioxidant properties of the extracts. The studies found out that the antioxidant capabilities of the tea oxidants (EGCG) portrayed some protective effects to eye cataracts. The UV light is also known to form free radicals in the eye lens. A study showed that caffeine inhibited some chemical reactions to UV light that were responsible for the eye damage. This could form an explanation why the green tea and EGCG, and black tea with high levels of caffeine, showed protective effects to cataracts. Diabetes is another disease that is known to contribute to the progression of the eye cataract. Green teas inhibit diabetic eye cataracts and also reduce the high blood sugar. Rooibos is another name of red tea that is found in South Africa. This type of tea has less content of tannin and it therefore tastes sweeter other types of teas (Erba 2005, p. 148). Red tea produces many antioxidants that include aspalathin, rutin, nothofagin, quercetin, isoquercitrin, orientin, isoorientin, luteolin, vitexin, isovitexi, and chrysoeriol. Rooibos tea continues to be used in many parts of Africa to assist in health problems such as lack of sleep, hypertension, headaches, and irritability. Some allergies such as asthma and eczema can be treated by use of the red tea. The antioxidants that are found in the read tea can even be applied practically to wounds and irritated skins to assist in the healing process. This is made possible by the fact that antioxidants are anti-fungal, anti-viral, and anti bacterial in nature. In addition, there are some antioxidants in red tea that are said to clear psoriasis and acne on human skin. This has made several companies to use rooibos tea in making soaps and facial creams. Rutin antioxidant inhibits the activity of the enzyme histidine decarboxylase that is involved in the creation of histamine in the gastric mucosa. Rutin is made up of quercetin and disaccharide rutinose. Rutin contains some anti-inflammatory properties that are used in the prevention of mucosal ulceration through restraining stress (Nicoletta 2010, p. 38). Researchers report that rutin is a scavenger of hydroxyl and superoxide radicals and also prevent lipid perodixation. Quercetin is an antioxidant that is common in red tea and can be used to fight cancer, cataracts, gouts and ulcers. It has the ability to slow down the growth of cancer cells and also plays a vital role in apoptosis, which is a process that gets rid of defective cells from the human body. In a study that was done in 2001, quercetin was found to inhibit the growth of cancerous cells in a study that aimed to find its effect in prostate cancer. More reports from various studies proposed that quercetin may be used in fighting sarcoidosis, which is an inflammatory disease. It is also quite helpful in the treatment of asthma and diabetes. In diabetes it was reported to lower the glucose levels in the blood. Quercetin also reduces metastasis in pancreatic cancer. It also helps in the prevention of the colon cancer cells by the proliferation of colon29 cancer cells. Antioxidants in tea also contribute in reducing the impact of the cancer cells in the human blood. When human cells are exposed to radiation, orientin protects lipid perodixation in the liver, bone marrow, and in the gastrointestinal tract. Ellagic acid is an antioxidant that is found in tea and other fruits. It is known to strengthen the connective tissue in the body which controls the spread of the cancer cells in the body. This antioxidant is capable of inhibiting the cell mutations that occur in the DNA of the cancer cells. Studies have also shown that this acid can cause apoptosis or the death of the cancer cells. Once the body cells die, the body replaces them with healthy cells (Carmen 2006, p. 85). Radiotherapy, chemotherapy, and other forms of cancer treatment end up causing the death of healthy cells in the process of killing the cancer cells and even at times destroy the immune system. It is therefore quite clear that ellagic acid offers a better treatment for the cancer cells. Through vitro research, ellagic acid was found to inhibit the growth of tumor and also reduced the chances of getting the colon cancer (Shahidi, 2007, p. 237). In a study conducted in the University of South Carolina where a group of 500 cervical cancer patients were examined, the ellagic acid was reported to cause a G- arrest by stopping the mitosis of cancer cells and caused normal death cell to the breast, pancreas, skin, colon, esophageal, and prostate cancer cells. The European medical studies also demonstrated that Ellagic Acid was capable of lowering the occurrences of birth defects, promote the faster healing of wounds, and reduce the chemically induced liver fibrosis. Another health benefit of the ellagic acid is that it is anti-bacterial in nature and is able to eliminate the H. pylori bacteria that causes stomach ulcers and also inactivate the cancer causing cells in the human body (Du Toit 2004, 68). Since the cancer cells require more glucose than the normal cells, ellagic acid is combined with glucose to assist in the inhibition of the cancer cells. Scientists from Scotland were the first to identify that some antioxidants in tea could be used to combat diabetes. They said that antioxidants such as thearubigins and theaflavins acted in similar way as insulin. Conclusion In general, it is a known fact that tea is a great source of many antioxidants that are vital in human beings since antioxidants are one of the key elements required for human nutrition. The main types of antioxidants present in tea are flavonoids and help in reducing the risk of cardiovascular diseases, cancers, eye cataracts, cognitive impairment, osteoporosis, Alzheimer’s, Parkinson’s, and liver diseases. Antioxidants in tea also contribute in the treatment of diabetes, skin diseases, asthma, arthritis, skin inflammation, and gout among others. In addition, tea also acts as a source of many vitamins and minerals that are crucial for the normal functioning of the human body. It is therefore important for us to include tea in our daily diets so as to enjoy the health benefits that are associated with the antioxidants use in order to maintain the overall health and well being. References Carmen, C. (2006). Beneficial effects of Green tea- A Review. Journal of the American College of Nutrition. Vol 25 No.2, 79-99. Erba, D. (2005). Effectiveness of moderate green tea consumption on antioxidative status and plasma lipid profile in humans. 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