Another fat browner: curcumin
We recently wrote about a Japanese human study in which green tea causes white fat cells [see example on the right] to change into brown fat cells. Because brown fat cells can burn stored fat, green tea is potentially interesting for people who want to reduce their body fat percentage. Now we've found a Chinese animal study in which curcumin, the most important bioactive substance in turmeric, has the same effect.
Molecular biologists at the Fourth Military Medical University in China gave mice 0, 50 or 100 mg curcumin orally every day for a period of 50 days. The human equivalent of these doses, for someone weighing 80 kg, would be about 0, 400 or 800 mg curcumin per day.
The mice that had been given curcumin did not eat less - but nevertheless became less heavy than the mice that had not had curcumin.
At the end of the 50 days, the curcumin mice had less body fat than the mice in the control group. The curcumin supplementation had probably boosted the mice's calorie burning. One sign of this was that the body temperature of the mice in the curcumin groups was higher.
The curcumin supplementation also increased the number of mitochondria in the mice's lower abdominal cavity. That's a sign that curcumin changes white fat cells into brown fat cells. You can read about the difference between brown and white fat cells here.
Supplementation boosted the synthesis of UCP1, a molecule that makes cells burn more energy, and PGC-1-alpha, a molecule that makes cells synthesise more mitochondria.
"These findings establish an important role for curcumin in browning white fat, and we propose that curcumin may be used for therapy in obese patients," the researchers wrote.
About fifteen years ago pharmaceutical companies were feverishly studying beta-3 agonists in the hope that these would be the way to put an end to the obesity epidemic. [Curr Pharm Des. 2001 Sep;7(14):1433-49.] [Diabetes Metab. 1999 Mar;25(1):11-21.] [Int J Obes Relat Metab Disord. 1996 Mar;20(3):191-9.]
They weren't successful. Beta-3 agonists work in rats and mice, but not in humans. If the Chinese are right in their assumptions about the way in which curcumin works, it's doubtful whether curcumin will be an effective slimming supplement for humans.
Biochem Biophys Res Commun. 2015 Oct 16;466(2):247-53.
Two cups of green tea daily results in more brown fat 25.04.2017
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