A supplement containing the transition metal tungsten encourages weight loss. Endocrinologists at the University of Barcelona stumbled across the weight-loss effect of tungsten when doing an animal study, which was published in 2005 in Endocrinology.
Tungsten is extracted from the earth as an ore. The pure metal was used for the filament in traditional light bulbs; now it is found mainly in electronic equipment. Minute quantities are found in nuts, beans and seeds.
The Spanish research group discovered in the mid-nineties that tungsten imitates the effect of insulin in rats. [J Biol Chem. 1994 Aug 5; 269(31): 20047-53.] It then became clear from a series of animal studies that tungsten also made rats thinner. In the 2005 study the Spanish researchers re-examined this effect.
The researchers fattened male rats using feed that was enriched with bacon, liver sausage and cookies [UO]. Some of the fattened rats were given drinking water in which tungsten had been dissolved. To be precise: the researchers used Na2WO4, the sodium salt of tungsten [UO, tungstate]. One ml of drinking water contained 0.3, 0.7 or 2 mg of the salt. The rats consumed an average of 33, 77 or 227 mg tungsten per kg bodyweight per day. Don't try this at home, folks.
The rats in the tungsten group put on less weight than the animals that were fattened but not given the supplement. The rats in the group that got the highest tungsten dose became thinner even than the animals in the control group, despite the fatty diet they were on.
The oxygen uptake of the rats that got tungsten increased, so they were expending more energy. At the same time, their respiratory exchange ratio [RER] went down, so they were burning more fatty acids.
When the researchers measured the rats' body composition, they noticed that tungsten supplementation had reduced the amount of fat reserves. Cells in the fat tissue had even died.
Cells in both muscle tissue [gM] and fat tissue [eWAT] had both started to make more of the proteins UCP2 and UCP3. UCPs, or uncoupling proteins, which boost cells' caloric expenditure.
"These findings strongly support tungstate as an attractive therapeutic approach for the treatment of obesity", the researchers conclude. Sounds promising, but experimenting with tungsten may not be a good idea. Although itís not very toxic, tungsten doesnít belong in your body. Doses as high as those the Spaniards used will cause problems in the long run.
Endocrinology. 2005 Oct;146(10):4362-9.