In recent years it has been marketed more aggressively online by companies that sell both green or oolong tea and pills containing extract of oolong tea.
The big question is, is oolong really effective at helping you to lose weight, or is it a case of old Chinese wives getting it wrong?
Fortunately to help answer this question there has been a lot of scientific research into oolong tea and green tea over the past decade. Most of the research has been carried out in Japan where oolong tea is very popular.
Polyphenol-enriched oolong tea increases fecal lipid excretion
A paper was written by researchers at The University of Tokushima, Tokushima, Japan in 2006 which examined the role of polyphenol in oolong tea.
It was found previously that the chemical in oolong tea that seems to aid the breakdown of fat is polyphenol. So researchers decided to see if creating high strength oolong tea would lead to increased fat loss.
In their study they examined 12 young adults. They were all placed on the same high fat diet and then some were given a placebo (no polyphenols) and others an enriched source of polyphenols in a high strength oolong tea.
It was found that lipid excretion in the feces was significantly higher in the high strength oolong tea that had been enriched with polyphenols. On average around twice as much fat was excreted from the body. Also, cholesterol excretion was increased by about 50%.
The results of the study concluded that when people are on a high fat diet polyphenol-enriched oolong tea increased the excretion of dietary fat. However, it is not clear if oolong tea would effective be for people using a low fat diet or calorie restrictive to lose weight.
Polyphenol-enriched oolong tea increases fecal lipid excretion. By Hsu TF, Kusumoto A, Abe K, Hosoda K, Kiso Y, Wang MF, Yamamoto S. Published in Eur J Clin Nutr. 2006 Nov;60(11):1330-6. Epub 2006 Jun 28. Web source: http://www.ncbi.nlm.nih.gov/pubmed/16804556