Capsaicin's weight loss mechanism

Researchers in Korea have published new evidence that suggests the mechanisms behind why capsaicin may aid weight loss.Capsaicin is found in the white pulp of chili peppers and is the compound that gives them their ‘heat’, causing a burning sensation in any tissue it comes into contact with. However studies have investigated the compounds potential health benefits, including helping weight loss, having anti-inflammatory properties, antioxidant activity, and inhibiting a number of cancer cells.

Previous laboratory studies have hinted that capsaicin may help to fight obesity by reducing the amount of calories absorbed in the gut, reducing fat tissue, speeding up metabolism, and lowering lipid levels in the blood. However the mechanisms behind how it might have such a dramatic effect on weight loss have until now remained a mystery.

Research led by Professor Jong Won Yun at the Daegu University in South Korea, suggests that capsaicin may cause weight loss and stop fat build up by stimulating the expression of certain fat degrading proteins, and down-regulating other proteins that work to synthesize fat.

The study involved feeding rats a high fat diet, with one group also being given a treatment of capsaicin. The capsaicin-stimulated rats lost 8 percent body weight compared to the non capsaicin fed rats fed on the same diet. Importantly the new research also showed that capsaicin fed rats showed changes in expression of over 20 key lipid processing proteins.

Prof. Yun claims that the changes in body fat observed “provide valuable new molecular insights into the mechanism of the anti-obesity effects of capsaicin".

The Korean research team also found that glycerol-3-phosphate dehydrogenase (GPDH) and malate dehydrogenase (MDH) were significantly down-regulated by capsaicin, resulting in a reduction in glycolytic activity and less overall fat synthesis.

The capsaicin also seemed to have a dramatic effect on levels of tumor necrosis factor-alpha (TNF-a), a gene that is commonly over expressed in many fat cells. “In this study, the TNF-a gene was significantly up-regulated in high fatty diet rats, and their levels were markedly decreased again with capsaicin treatment.”

The research also found an up regulation of the enzyme NQO1, leading to the conclusion that capsaicin may stimulate the enzyme and that it may have a potential use as a therapeutic target for obesity. Prof. Yun told NutraIngredients.com that the next steps in finding a way to use capsaicin as a safe anti-obesity therapy would be to perform functional study to fully identify the proteins stimulated by capsaicin, in gene knockout mice.

Obesity is a global public health problem, and is an important risk factor in many diseases, including cardiovascular and metabolic diseases such as hypertension and diabetes. Tackling obesity is a priority for many countries, and the use of functional foods as an aid to increase weight loss is a growing market, estimated to be worth over $43 billion in the U.S by 2013. The potential for the use of capsaicin as a component of functional weight loss foods is growing as the mechanisms behind its effects are better understood.