It is almost impossible to have never heard of green tea and its many benefits. It has been a staple of Chinese medicine for thousands of years, believed to be able to treat every ailment known to man. Supposedly, the leaves of the tea have far higher concentrations of antioxidants, which is what makes them the ‘elixir of life’. We know that this is true, and that the tea contains folate, B vitamins, potassium, manganese, caffeine and magnesium, as well as catechins.
Every type of tea, from green to oolong to black, is made from Camellia sinensis, which is the tea plant. The difference is the method of production. Green tea is made by steaming fresh leaves, whereas oolong and black use fermented leaves. Allegedly, green tea reduces cholesterol, boost weight loss, prevents cancer, fights cardiovascular disease and halts Alzheimer’s. But are these true?
The Evidence on Green Tea and Cancer
While many people believe that the antioxidants in green tea can protect people from cancer, there is actually not much evidence to prove this. Some 1.6 million participants took part in 51 different studies and the results of these studies were reviewed in 2009.
There is insufficient and conflicting evidence to give any firm recommendations regarding green tea consumption for cancer prevention.
A similar study was conducted in 2015. This looked at whether one of the compounds in green tea could magnify the effects of Herceptin, which is used on breast and stomach cancer patients. Human trials are currently taking place to see whether or not this is actually the case.
The Evidence on Green Tea and Weight Loss
Catechin and caffeine are believed to help the body burn more calories. Supposedly, they do so by speeding up metabolism. There are a lot of products available on the market today that have higher concentrations of catechin and caffeine, which are sold as weight loss products. However, a review was conducted in 2012, looking at 18 studies with a total of 1,945 people and these could not prove that this actually works.
Green tea preparations appear to induce a small, statistically non-significant weight loss in overweight or obese adults. Because the amount of weight loss is small, it is not likely to be clinically important. Green tea had no significant effect on the maintenance of weight loss.
The Evidence on Green Tea and Cholesterol
Two separate studies were conducted to determine the effect of green tea on cholesterol. A study in 2013 showed that consuming black or green tea could help to lower blood pressure. However, it only looked at short term trials. Another study, conducted in 2011, had the same results. However, scientists are still trying to determine just how much green or black tea needs to be consumed in order to achieve measurable results. Additionally, there is no information on long term effects of consuming green tea.
The Evidence on Green Tea and Alzheimer’s
There is some evidence to suggest that there is a link between green tea and Alzheimer’s prevention, but it is weak. A study conducted in the UK in 2010 found that there was some evidence of protection in the brains of lab animals.
The researchers say their results show that green tea metabolites (the contents of the green tea extract) can reduce cell death caused by hydrogen peroxide and beta-amyloid protein in the laboratory. They say this provides the basis for further study of flavanols as a potential way of alleviating some of the effects of Alzheimer’s disease.
The Evidence on Green Tea and Blood Pressure
There has been quite a few scientific studies that looked at the link between green tea and blood pressure. Some evidence suggests that blood pressure is indeed reduced in people who drink green tea. However, it is not clear whether this reduction is enough to actually prevent heart disease.
The Evidence on Green Tea and Tooth Decay
Finally, there is a belief that green tea can help prevent tooth decay. A study found that there is indeed some truth in this. In fact, it was as effective as chlorhexidine, an antibacterial mouth wash. Most people would agree that it is a lot more convenient to simply use mouth wash. However, those people who prefer natural products, or those with dietary choices such as vegans, will find that green tea is the better option.
Is Green Tea the Elixir of Life?
It is certainly true that green tea will not damage the body. It is also filled with antioxidants and other components vital to good health. However, the claims around its exact health benefits are inconclusive at best. At the same time, experts still have not reached an agreement on this, which is proven by the fact that many further studies into the different possible benefits of green tea are still continuing today.
Historically, green tea has been used to treat a huge variety of conditions, including obesity, depression, arthritis and much more. Furthermore, Chinese medicine is by and large a preventative type of medicine, which means prescriptions are given to help people avoid diseases, rather than treating them when they happen. Green tea has been used as a preventative for cancer and other illnesses for thousands of years. However, the reality is also that cancer is highly prevalent in China, albeit with concentrations in different types of cancer than in this country.
Significant differences in cancer incidence sites were found between the two countries. Cancer may be prevented through public education and awareness. Programs to promote cancer prevention in China, especially those of the lung, breast, and gastrointestinal region, must also be implemented.
Some, however, suggest that the soaring rates of cancer in China are indicative of the fact that people are moving away from their traditional ways of life. Few statistics exist on the rates of cancer in China throughout history, because the country is so closed off. As such, it may be true that cancer has only just started to become so common since people are using chemical and pharmaceutical remedies nowadays.