Does Green Tea Really Aid Weight Loss?

Recently there has been increased interest in “tea diets”. Sometimes referred to as Green Tea Diets, but more recently marketed as Wuyi Tea Diets, these so called “diets” use effective advertising tricks to sell tea to vulnerable people on the premise that it can help them to lose weight. Much of the publicity surrounding the tea was caused when it was discussed by Dr. Nicholas Perricone on the Oprah Winfrey show. More recently celebrities such as Johnny Depp, Justin Bieber and Victoria Beckham have all claimed that green tea forms a part of their daily diet.

Although these Wuyi teas do have some health benefits that other drinks do not provide, they are not a cure for obesity, and their ability to help a person lose weight is debatable. Usually it is advised that a healthy diet and exercise is also taken while on the “tea diet”, which makes the effectiveness of the tea itself seem all the more unlikely.

According to one aggressive sales pitch, Wuyi tea has the following properties: “zero carbohydrates, zero calories, zero fats, Wu-Yi Tea extremely powerful“. Being free of carbs and calories is in itself debatable, but advertising a tea to be fat free is just taking the sales pitch a little too far. It is like marketing “fat free beer” and “low carb vodka” as the latest health drinks!

So, what is Wuyi Tea?

Wuyi Tea is simply tea from the Wuyi Mountains in China. The Wuyi mountains are situated in between Wuyishan City, in Fujian province and Wuyishan Town, in Jiangxi province. The mountains cover an area of 60 km². It is now a biodiversity conservation zone. Several varieties of tea are grown around Mount Wuyi, including Da Hong Pao tea and Lapsang souchong. “Wuyi tea” as sold on the internet is often a blend of various teas from this region, and is not always the best tea available from the area.

The most popular Wuyi teas sold for weight loss are Oolong and the generic Green tea. These teas are possibly the healthiest teas in the world, as they contain various properties which have allowed them to be classes as “superfoods”. Research has shown that drinking green tea increases bone density due to the presence of flavonoids and phytoestrogen. It also contains antioxidants which research has shown may help to prevent various forms of cancer, reduce Alzheimers, protect the heart and even fight HIV.

Research (published in the journal Chemical Research in Toxicology) has also suggested that green tea may help to reduce the risk of rheumatoid arthritis and to lower cholesterol levels.

Can Green Tea Help You Lose Weight?

This is still unclear. Green tea contains an antioxidant called epigallocatechin gallate, which is claimed to have a calorie-burning (fat burning) effect. However, biologists are quick to point out that these properties are quickly lost after the leaves are picked, so therefore dried tea leaves are unlikely to hold any useful amounts of epigallocatechin gallate.

It is thought that the tea reduces weight by stopping fat cells from releasing inflammatory chemicals that attract more fat causing them to grow in size. Many green teas sold for weight loss purposes also contain olive and grape components, which have a similar effect. Spearmint is often added to improve the flavour. Is it important to note that if the tea sold was good quality tea from Wuyi, there would be no need to add spearmint to improve flavour.

Health Risks of Green Tea

The websites that are selling Green teas from the Wuyi region never mention the known health risks associated with drinking copious amounts of the tea. In 2005 studies revealed that green tea can increase the risk of birth defects such as spina bifida (published in Cancer Research). Furthermore, in 2007 research published in Chemical Research in Toxicology, showed that consuming large amounts of polyphenol can cause liver malfunction.

A word of caution: there are a lot of differences between various types of green tea. It is possible that if you chose to buy a product online for a specific purpose, you may actually be receiving an inferior product.

So, Green tea from the mountains of Wuyi may contain some properties to help you lose weight. They certainly contain other properties that will provide health benefits. However, not all green teas are equal, and drinking too much may cause other health problems.

Pu-erh Tea an Alternative Chinese Tea

Although green, oolong and wuyi teas are the most well known in the west, they are not the only types of Chinese tea that are thought to aid weight loss. A lesser known tea called Pu-er tea (Pu-erh, Pu’er tea, Puer tea or Bolay tea) is also very popular in China. I learned about it direct from a Chinese friend who told me that it is in fact better than oolong in her opinion. All the women she knows drink it to manage their weight (and they are all very slim).

In China it is often just called black tea and it is very different from other teas. It does not have to be drunk immediately, in fact some people brew the tea and then keep it like wine to age in a bottle before drinking.

Pu’er tea can generally be bought as a loose leaf tea of as a cake of compacted tea leaves. The tea is traditionally made form wild tea leaves and is known as a broad leaf tea. As it is naturally a dark tea many people mistake it for being a black tea, and many Chinese people refer to it as the black tea, but it is really a green tea.

Pu’er is classified as a black tea as it is post-fermented, but this is something many people feel is unjust and that it should have its own classification due to its unique flavor.

Although pu-erh teas are often called black teas,  pu-erh teas can actually be one of three types of tea, depending on the processing methods: green tea, fermented tea, and secondary-oxidation/fermentation tea.

Types of Pu’er Tea

• Maocha Tea: Green pu-erh leaves that are sold in loose leaf form.
• Green/raw pu’er Tea: Pressed maocha that has not undergone additional processing.
• Ripened/cooked pu’er Tea: Pressed maocha that has undergone fermentation in the ripening process for up to a year.
• Aged raw pu’er Tea: A tea that has undergone a slow secondary oxidation and a certain degree of microbial fermentation.

The type that you are most likely to find is the maocha tea.

Health Benefits of Pu’er Tea

Pu’er is claimed to have several health benefits of which weight loss is just one. It can also help to:

• Reduce blood cholesterol
• Antimicrobial properties
• According to TCM is invigorates the spleen

Is it better than oolong tea for weight loss? Well, many Chinese believe that it is the best. But it is also more valuable and there could be commercial interests at play. At the moment there is not any concrete scientific reasoning for its weight loss effect, although theories do exist, including increasing metabolism and reducing nutrient absorption (it contains polyphenols which block fat absorption).

Where to Buy Pu’er Tea

Pu’er tea can be purchased at specialized tea stores. Often it is sold in tea bag form, which generally indicated a lower quality tea.

Conclusion

Although there has been a lot of research in recent years investigating the effects of green tea on fatty tissue metabolism, there is still no clear evidence that it is really effective. It is used in some thermogenic pills to increase metabolism, but it is always combined with caffeine. Although there is some evidence to suggest that it helps block the absorption of fat during the digestive process, it really seems at present that green tea is just a stimulant which encourages you to be more active.

Green tea does appear to have several health benefits though, such as improved bone density. However, the recommendations of following a healthy and balanced diet remain. Green tea is certainly not a magic weight loss cure and no substitute for healthy eating a regular exercise.

Tea Research

There have been several studies into the weight loss effect of pu’er tea:

“Mechanisms of hypolipidemic and anti-obesity effects of tea and tea polyphenols“. Jen-Kun Lin, Shoei-Yn Lin-Shiau. Molecular Nutrition & Food Research Vol. 50, Issue 2, pages 211–217, February 2006

“Pu-erh tea supplementation suppresses fatty acid synthase expression in the rat liver through downregulating Akt and JNK signalings as demonstrated in human hepatoma HepG2 cells“. by Chiang CT, Weng MS, Lin-Shiau SY, Kuo KL, Tsai YJ, Lin JK. Oncology Research. 2005;16(3):119-28.

Web References:

• Green tea ‘may protect the heart’ – BBC News, Monday, 28 February, 2005
• Green tea may increase birth defect risk – New Scientist, 26 March 2005
  
• Green tea compound Alzheimer hope – BBC News, 20 September 2005
  
• Green tea can be harmful in large quantities – New Scientist, 05 May 2007
• Green tea could cut arthritis risk – BBC News, 15 February, 2003
  

Photo by Wikimol