Benarkah Teh Hijau Bermanfaat Bagi Kesehatan…?

Di tengah-tengah meningkatnya kesadaran masyarakat akan kesehatan dan makanan yang menyehatkan,teh hijau telah dikenal memberikan manfaat tersendiri bagi kesehatan, terutama jantung dan kanker, terutama di asia.Teh hijau selama ini juga dikenal sebagai antioksidan melawan oksidasi lipid, radikal bebas dan mengurangi tekanan oksidatif dan LDL (Low Density Lipoprotein

Apakah benar…?

ABSTRACT: One of the core competencies in the IFT Education standards is for students to achieve competency in communications skills (that is, oral and written communication, listening, interviewing, and so on). According to the IFT guidelines, by the time students graduate, they should not only be able to search for and condense information but also be able to “communicate technical information to a non-technical audience.” The Education Division of IFT sponsors an annual writing competition for undergraduate students to bring attention to and promote the development of communication skills. The short essays can be on any technical subject or latest development in the food science and technology field that may be important to the consumer. The article must be written in nontechnical language such that someone reading a local newspaper could understand it. Due date for submissions is typically the first week in June. More information on eligibility, rules, submission, and judging criteria will be posted on IFT’s Education Division website. Monetary prizes are awarded to the authors of the top 3 papers, and the winning entry is published in the Journal of Food Science Education (JFSE) each year. JFSE is pleased to publish this year’s winning entry submitted by Stephanie Chiu from the Univ. of British Columbia.
Drinking green tea has always been associated with good health. Asian countries have known about the medicinal and nutritional benefits of tea for centuries. Because of an increasingly health conscious society concerned about cancer and heart disease, many have sought other ways of improving their health. It is believed that drinking green tea every day can offer many health benefits. But is green tea really that good for you? The U.S. Food and Drug Administration (FDA) announced that they could not find solid evidence to support the claim that green tea significantly reduces the risk of heart disease or certain cancers (US FDA 2005, 2006). Huh? What is going on here? There seems to be conflicting information on the health benefits of green tea! But before you stop drinking green tea, you should know all the facts.

Green tea, one of the most popular beverages in the world, is known for its natural antioxidant properties (Pokorný and others 2001). Antioxidants are substances which offer protection against lipid oxidation, react and interfere with free radicals, reduce oxidative stress, and stop low-density lipoproteins (LDLs) or “bad cholesterol” from being oxidized because they can lead to atherosclerosis (Baskin and Salem 1997; Pokorný and others 2001). Antioxidants also help the body protect itself against damage caused by reactive oxygen species (ROS) which are associated with degenerative diseases (Shahidi and Naczk 2004). Both oxidation and oxidative stress are bad because they produce substances called free radicals and ROS which can have damaging effects on DNA, protein and lipids of cells (Pokorný and others 2001). In addition, antioxidants have shown anticarcinogenic activity (Baskin and Salem 1997). There are many different types of antioxidants out there which fall under many categories because of their unique chemical structures. In green tea, antioxidants such as flavonoids are present where the most abundant flavonoids are catechins (Peterson and others 2005).

Extensive research suggests that green tea may play an important role in reducing the risk of a number of illnesses, including cancer and coronary heart disease (Meskin and others 2004; Oak and others 2005). In Japanese populations, green tea consumption has been associated with a lower incidence of coronary heart disease which may be due to the catechins’ ability to prevent LDL from being oxidized (Sutherland and others 2006; Zaveri 2006). Catechins also have anticlotting, antiplatelet, and anti-inflammatory properties against atherosclerosis (Son and others 2004; Cheng 2006). Studies on hamsters have shown that green tea effectively inhibits atherosclerosis (Vinson and others 2004). It is also suggested that green tea has preventive effects on chronic inflammatory diseases and neurological disorders (Cheng 2006).

Other health benefits include significant protection against Parkinson’s disease, Alzheimer’s disease, stroke, neurodegenerative diseases, and other agerelated diseases (Zaveri 2006). There have been other studies showing antidiabetic effects from green tea consumption (Cheng 2006). Even though animals were used as models, catechins can play a role in treating humans with type 2 diabetes (Cheng 2006; Zaveri 2006).

Drinking green tea may also reduce the risk of cancer, but studies done on humans have shown inconsistent results (Zaveri 2006). Studies in certain countries have observed either a positive, a negative, or no significant association between tea consumption and cancer incidence (Meskin and others 2004).

A number of studies have shown conflicting results on the effectiveness of green tea (Sutherland and others 2006). One study could not find a link between catechins and a reduced risk of coronary heart disease, but in another study, Japanese men who drank 4 or more cups of green tea a day exhibited a lower risk of atherosclerosis (Sutherland and others 2006). There have also been conflicting reports on tea and stroke incidence (Sutherland and others 2006). Nonetheless, more research needs to be done given that a number of studies have been done on animals and it may be difficult to draw conclusions for humans based on animal models (Vinson and others 2004).

Despite the conflicting reports on the effectiveness of green tea, there is sufficient evidence to suggest that catechins may be useful because they are powerful antioxidants capable of preventing lipid oxidation, inhibiting oxidative stress, and interfering with free radical formation, and hence it is suggested that they could play an important role in cardiovascular disease, cancer, and neurodegenerative diseases (Sutherland and others 2006).

Even though the FDA says that there is not enough evidence to show that green tea reduces the risk of heart disease or cancer, keep in mind that green tea contains many powerful antioxidants, and that drinking several cups of green tea a day may improve your health. Remember that studies on green tea are still ongoing and, in time, researchers may finally prove the beneficial health effects of drinking green tea.

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  • Journal Of Food Science
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