Pu-Erh tea really works: extracts from this Chinese tea promote weight loss. Japanese researchers at Fukuoka University have demonstrated the slimming effects of Pu-Erh tea in a human study, published recently in Nutrition.
Pu-Erh tea comes from the Yunnan highlands of China. It is black tea that is created by drying green tea leaves at a high temperature and then fermenting them in a humid environment using Aspergillus niger. Pu-Erh tea contains relatively high amounts of gallic acid [structural formula shown below].
Water-based Pu-Erh extracts consist for about three percents of this phenol, and researchers suspect that gallic acid is the most active ingredient in Pu-Erh tea. The compound reduces the production of the enzyme lipase by the pancreas, and as a result Pu-Erh tea inhibits the absorption of fat, in animal studies. [Phytother Res. 2008 Oct;22(10):1275-81.] Another possible mechanism is that Pu-Erh extracts block the enzyme that converts nutrients into fat in the liver. [Oncol Res. 2005;16 (3):119-28.]
Previously published human studies have shown that Pu-Erh reduces the concentration of 'bad cholesterol' LDL, triglycerides and that it also reduces weight. [Nutr Res. 2008 Jul;28(7):450-6.] [Ann Nutr Metab. 2008;53(1):33-42.]
The Japanese gave 18 slightly overweight subjects, with a BMI of 26, one gram a day of Pu-Erh extract for a period of 12 weeks. The extracts were packed in sachets and produced by Nippon Supplement, the sponsor of the study. Three times a day the subjects dissolved the contents of a sachet in a glass of warm water and drank it at the mealtime. Eighteen subjects in the control group were given a product that contained no Pu-Erh tea.
The subjects were in their early fifties, and both men and women took part. Their average weight was 74 kg. They were all put on a similar diet, which provided 30 calories per kg bodyweight.
After 12 weeks the subjects in the Pu-Erh group had lost slightly more weight. The subjects in the control group had lost about a kilogram. In the four weeks after the Pu-Erh course the kilograms lost stayed off.