There are many conflicting opinions on the health benefits of drinking green tea, but which ones are right?
We reported earlier that a 16-year-old girl in England contracted hepatitis from some green tea that she bought online. While it is certainly a tragic and bizarre case, it doesn’t mean green tea is unsafe to drink or poses serious health risks as a whole. In fact, there are a wide range of reasons why green tea is actually really good for you.
Green tea is brewed from the leaves of the Camellia sinensis plant, and has undergone a minimal level of oxidation as it’s processed. It first gained popularity in China, but has become popular in many cultures in Asia and beyond. Western countries have adopted green tea alongside traditionally brewed black tea.
In addition to brewing green tea into a normal hot cup of tea, it can be used for other beverages, dietary supplements, and even cosmetics. There are many different strains of green tea, which can vary widely across growing environments and methods, production, and harvesting methods.
While there are many claims on some of the health benefits about green tea, there is an extensive body of research that confirms drinking green tea is probably not such a bad idea every now and then.
The easiest way of drinking green tea is to simply brew the leaves in hot water. A typical serving consists of two grams of dried leaves per 100 milliliters of water. It is steeped at a maximum temperature of 87 degrees and should only brew for about three minutes.
Chinese green tea consists of over 600 different strains of the Camellia sinensis plant, which translates to an incredible variety in flavors and health benefits. Tea leaves are dried over fire in a pan, in an oven, or under the sun in traditional Chinese methods, and have an earthy flavor. Japanese green tea, on the other hand, is steamed which gives them a leafier flavor.
Green tea offers a wide range of enzymes, amino acids, carbohydrates, sterols, lipids, dietary minerals, and phytochemicals like polyphenols, flavinols, and caffeine. That’s a lot to keep track of, but in varying concentrations these chemicals help regulate a number of body functions and protect against disease and degradation of all types.
The polyphenols found in green tea include epigallocatechin gallate, epigallocatechin, epicatechin gallate, and epicatechin. The flavinols in green tea are primarily kaempferol, quercetin and myricitin. Research outlining the health benefits of these specific compoings is thin, but more general studies on the overall health benefits of green tea have proven to follow a positive trend.
A panel of scientists submitted a report about the health effects of green tea to the European Commission in 2011, and found that many of the claims made about the benefits of drinking great tea were not supported by solid scientific evidence. Even though the average concentration of many of these compounds is higher in green tea than most other food or beverage products, there is little peer reviewed research to support claims that they provide specific health benefits.
Among the claims that green tea can improve health are that it can help prevent or treat cancer. There is little clear evidence that proves this, but few studies have examined the question on a large scale. Interestingly, black tea has been shown to be linked to a significant reduction in cancer deaths across the board.
Even though it has not been linked to preventing cancer, green tea has been shown to have some serious health benefits. Research has shown that green tea can improve blood flow and decrease levels of cholesterol. A study in 2013 showed that green tea helped ward off a wide range of cardiovascular issues from hypertension to congestive heart failure. The brain benefits from a healthy heart as well – MRIs in a Swiss study showed that people who drank green tea had improved working-memories and decreased levels of the plaques that buildup in the synapses suspected of causing Alzheimer’s disease.
Green tea can also help people who suffer from diabetes. It has been shown to keep blood sugar lower through regulated cholesterol and blood pressure. This can help protect against the damages caused by a diet high in fat.
Green tea won’t specifically help you lose weight, but it’s a great substitute for sugary juices and sodas. One of the key ingredients in green tea, EGCG can help keep your appetite mildly suppressed so you don’t feel as hungry, but there are no proven weight loss properties of green tea.
Overall, green tea is correlated to a lower risk of death from just about any cause. People who drink at least one cup of green tea each day are four percent less likely to die for any reason.
Despite the wonderful health benefits that can be achieved by incorporating green tea into your diet, there is still a risk of toxicity from drinking too much. Reports of liver toxicity from drinking high doses, nearing 30 mg/kg/day have been reported in people taking green tea dietary supplements. The culprit is epigallocatechin gallate, EGCG, one of the catechins commonly found in green tea. It may have had something to do with the young British girl contracting hepatitis in the recent case, but fear not – green tea is safe, healthy, and even delicious!