From Ergo Log
A hefty dose of Hibiscus sabdariffa extract in a supplement causes modest weight loss. Researchers at Chung-Shan Medical University in Taiwan announced this in Food & Function.
Lose weight with Hibiscus sabdariffa
Health fanatics the world over drink tea made from the flowers of Hibiscus sabdariffa. Hibiscus tea is said to be good for the heart and blood vessels. And indeed, animal studies and a few human studies have shown that supplementation with Hibiscus sabdariffa extracts improves cholesterol levels.
In animal studies supplementation with Hibiscus sabdariffa extract has also caused weight loss. [J Biomed Biotechnol. 2009; 2009: 394592.] The researchers wondered whether supplementation with Hibiscus sabdariffa might also induce weight loss in humans.
The researchers made their own extract from Hibiscus sabdariffa flowers. They dried flowers from the plant, left them floating around in water at 95 degrees for two hours, and then filtered and freeze-dried the liquid. The Taiwanese then put the powder they’d obtained into capsules, 450 mg in each.
The researchers used 36 people aged 18-65 with a BMI of 27 or higher for their experiment. They gave half of the subjects 6 capsules containing Hibiscus sabdariffa every day for 12 weeks: 2 after breakfast, 2 after lunch and 2 after dinner. So the subjects took a total of 2700 mg extract per day.
The other subjects took capsules that contained no active ingredients.
The supplementation resulted in modest weight loss of just over one kilogram.
The Taiwanese suspect that the slimming effect is due to the flavonoids, anthocyanins and phenolic acids in the extract. For all the substances listed below, which the Taiwanese found in their extract, the researchers found indications in the literature of their anti-obesogenic effect.
The Taiwanese’ extract of Hibiscus sabdariffa consisted however of only 1.4 percent flavonoids, 2.5 percent anthocyanins and 1.7 percent phenolic acids. But an important component of Hibiscus sabdariffa that the Taiwanese neglect to mention is hydroxycitric acid. Hydroxycitric acid is also the most important active ingredient in Garcinia cambogia. [Appl Microbiol Biotechnol. 2007 Jul;75(5):977-82.] It may be the case that hydroxycitric acid is the primary active substance in the extract the researchers made.
Hydroxycitric acid inhibits the enzymes ATP-citrate lyase (involved in the synthesis of fat) and alpha-amylase and alpha-glucosidase (both necessary for the conversion of carbohydrates in food into absorbable glucose) in the human body.
Food Funct. 2014 Apr;5(4):734-9.