Is tea a royal drink? People often thing of tea as a drink exclusively consumed by the Queen of England as she sits around with her ladies-in-waiting, sipping delicately with their pinky fingers raised gracefully. World-wide statistics show otherwise. In fact, these studies show that tea is the second most consumed beverage in the world, water being the first. Hundreds of millions of people drink tea, and studies suggest that green tea, in particular, has many health benefits.
Camellia sinensis is the plant that tea that derives from. The various kinds of tea arise from the different types harvesting and processing done to each type of tea. For example, green tea is made from unfermented leaves and contains the highest concentration of polyphenols which are powerful antioxidants. Antioxidants fight free radicals, which damage compounds in the body that change cells, damage DNA and even cause cell death. Many scientists even believe that free radicals contribute to the aging process, as well as health problems like cancer and heart disease. The polyphenols in green tea are classified as catechins, which are known for having beneficial anti-inflammatory and anti-carcinogenic properties. They can neutralize damaging free radicals and may reduce or even help prevent some of the damage free radicals incur.
Green tea contains six primary catechins compounds, with EGCG being the most active component and most studied. The polyphenols provide green tea’s stimulatory effects. The amino acid L-theanine, found in green tea, is also being studied for its calming effects on the nervous system. Studies show that this zero calorie beverage is kind of a miracle drink. A typical cup of tea usually contains 250-350 mg tea solids, of which 30-42% are catechins and 3-6% caffeine.
University life is not a walk in the royal gardens, and stress levels can go through the roof at times. Drinking tea may just be all the help we need to handle the stress we deal with constantly, as consumption of green tea immensely lowers stress levels. Studies show that ingestion of green tea inhibits the increase of salivary CgA concentration levels, which typically increase after mentally stressful tasks. In addition, drinking tea has been associated with lower risks of depression. A 2015 meta-analysis of eleven studies found that for every three cups of tea consumed per day, the relative risk of depression decreased by 37%.
As a student, drinking tea can help us in more ways than just alleviating stress. It can also aid in acing the many exams we are bombarded with as green tea enhances cognitive functions, particularly the working memory. Various research results provide evidence for the putative beneficial effect of green tea on cognitive functioning. This is true specifically with working memory processing at the neural system level by suggesting changes in short-term plasticity of parieto-frontal brain connections. This knowledge may help assess the efficacy of green tea for treatment of cognitive impairments in psychiatric disorders such as dementia. Researchers found that treatment with EGCG (a green tea extract) significantly increased the number of cells associated with neurogenesis (brain cell growth). Green tea also prevents the formation of potentially dangerous amyloid aggregates, and also actually breaks down existing aggregates in proteins that contained metals associated with Alzheimer’s disease.
For all of you who want to lose those “freshman fifteen”, green tea may be a helpful addition to your diet. Green tea boosts metabolism and helps burn fat. The catechins in green tea effect lipid metabolism by helping them metabolize through different pathways and thus prevent the appearance of atherosclerotic plaque. Its intake decreases the absorption of triglycerides and cholesterol. These findings confirmed by the fact that it green tea increases excretion of fat. One can burn seventy to eighty additional calories a day just by drinking green tea.
Green tea also helps prevent against the development of type 1 diabetes and slows down its progression once it has developed, by helping to regulate glucose in the body. In fact, research does show that polyphenols help regular blood sugar. As glucose levels rise, polyphenols assist in making the cells more sensitive to insulin’s effects. Studies also show that green tea even helps decrease the risk of developing type 2 diabetes. It also reduces the risk of heart disease by lowering cholesterol and triglyceride levels.
Green tea is like the gift that never stops giving, by even helping to protect against cancer. EGCG has been shown to be most effective at eliminating free radicals. The National Cancer Institute has said that the polyphenols in tea have decreased tumor growth in the lab and animal studies and may protect against damage caused by UVB radiation. Tea polyphenols have been shown to inhibit tumor cell proliferation and induce apoptosis. They inhibit angiogenesis and tumor cell invasiveness.
Green tea has positive impacts on breast, bladder, colon, ovarian, colorectal, esophageal, lung, pancreatic, prostate, skin and stomach cancer. EGCG changes the metabolism of pancreatic cancer by suppressing the expression of LDHA, a critical enzyme in cancer metabolism. Studies have shown these positive correlations between drinking green tea and cancer, although the precise mechanisms have not yet been established. Since green tea helps prevent colon cancer, it may also help reduce inflammation associated with Crohn’s disease and ulcerative colitis, because these irritable bowel diseases increase risk for colon cancer. Fueling the belief that green tea works wonders, in countries where green tea consumptions are high, such as in Japan, cancer rates tend to be lower. However, that may be due to other lifestyle factors and not just the green tea.
Allergy season is in its all-time prime, with the changing of seasons, so you may want to stock up on the green tea for another reason: its anti-allergenic properties. Tea polyphenol can reduce pollen allergies. A methylated form of EGCG can block the IgF receptor, which is the key receptor involved in an allergic reaction. It also helps the body’s immune system fight off infection by increasing immune system activity in the blood.
As if those aren’t enough reasons to convince you to add a cup of tea to your breakfast, lunch, dinner and snack, tea also protects bones, contains fluoride and tannins that may prevent tooth plaque from forming, positively affects tissues of the eyes – especially tissue relating to the retina, and in general, according to studies, reduces risk of dying from any cause.
If you’re thinking green tea sounds just too good to be true, think again. It is true! Tea itself appears to have little to no harmful effects, except the usual case of jitters that comes along with too much caffeine, as I’m sure many of you have experienced. Tea is generally recognized as safe by the FDA, although tea has been found to decrease the bioavailability of iron when taken with meals, so those with a history of iron-deficiency should take care not to consume tea along with iron supplements. Furthermore, don’t drink it scalding hot because extremely hot beverages increase the risk of esophageal cancer, and obviously you also don’t want to burn your tongue!
The US Food and Drug Administration is not yet fully convinced though, stating in 2005 that “there is no credible evidence to support qualified health claims for green tea consumption and a reduced risk of gastric, lung, colon/rectal, esophageal, pancreatic, ovarian and combined cancers.” And again in 2006, the FDA rejected a petition to allow tea labels to state that green tea reduces the risk of heart disease due to lack of credible evidence. More research is being done constantly, and the evidence is piling up. Soon, even the skeptical FDA will be promoting tea drinking.
In answer to the question, to tea or not to tea? Definitely, “to tea”! It can only do you good. So, sit down with your ladies (and gentlemen), lift your pinky fingers proudly to the air and let green tea do its magic!
Sources:
http://www.cancer.gov/about-cancer/causes-prevention/risk/diet/tea-fact-sheet
http://www.health.harvard.edu/staying-healthy/tea-a-cup-of-good-health
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