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.

Spicy peppers may hold a key to weight loss

How would you like to burn calories from the comfort of your dining room? Of course you would. Researchers at the UCLA Center for Human Nutrition are a step ahead of you.

Some food scientists believe that jalapenos and other hot peppers not only “burn” the tongue when eaten but also increase the diner’s body temperature. They hypothesize that the energy required to do this burns calories just as surely as traditional forms of exercise.

One potential problem is that not everyone appreciates the flavor of spicy peppers. That kick comes courtesy of capsaicin, a chemical developed by plants to defend themselves against animals who’d want to eat them. Thankfully for timid eaters, some peppers produce a version of capsaicin called dihydrocapsiate (a.k.a. DCT) that has a mild taste.

So the UCLA researchers recruited 34 volunteers who were trying to lose weight. Some got pills containing DCT to take with their meals; others got dummy pills. The researchers measured each volunteer's energy expenditure after he or she ate and found it was highest in those volunteers who got the biggest doses of DCT – almost twice as high as in those who took the placebo. Not only that, the DCT prompted those who took it to burn more fat.

The findings are promising, but it’s not time to start swallowing DCT pills on your own, the researchers warn. The volunteers in their study were on a low-calorie liquid diet, and the results might not translate to people eating regular food. Also, it might work for people with fat to spare but not for those who are already lean.

At this point, the only advice the researchers offer is this: If you’re inclined to eat jalapenos and other hot peppers, feel free to pile them high.

The study results are being presented Tuesday evening at the Experimental Biology 2010 meeting in Anaheim.

Capsaicin plus green tea combo aids weight loss

A combination of capsaicin and green tea could promote the feeling of fullness and sustain satiety, indicating it could be successful for weight management, says a new study.

Researchers from Denmark and the Netherlands report sweet pepper may also reduce energy intake during positive energy balance, according to findings of their 27-person study published in Clinical Nutrition.


“We conclude that thermogenic food ingredients have energy intake reducing effects when used in combinations, and in positive energy balance,” wrote the researchers, led by Professor Margriet Westerterp-Plantenga from Maastricht University.


“These results suggest that bioactive ingredients (capsaicin, green tea, CH-19) may be helpful in reducing energy intake to prevent body weight gain and may support body weight loss by relatively sustaining satiety and suppressing hunger,” they added.


The research taps into the burgeoning weight loss and management market, estimated to already be worth $7bn (€5.2bn) globally. It also has implications for diabetes.


With 50 per cent of Europeans and 62 per cent of Americans classed as overweight, the food industry is waking up to the potential of products for weight loss and management.


The slimming ingredients market can be divided into five groups based on the mechanisms of action - boosting fat burning/ thermogenesis, inhibiting protein breakdown, suppressing appetite/ boosting satiety (feeling of fullness), blocking fat absorption, and regulating mood (linked to food consumption).

Study details


Westerterp-Plantenga and her co-workers recruited 27 people with an average age of 27 and an average BMI of 22.2 kg/m2, and randomised them to three weeks of negative (less calories consumed than used) and three weeks of positive energy balance (more calories consumed than used). During these periods ten separate test days were used to test the effects of capsaicin, green tea, CH-19 sweet pepper, capsaicin plus green tea, or placebo on appetite, energy intake, body weight and heart rate.


Only the CH-19 and the capsaicin plus green tea combinations produced a reduction in energy intake during the positive energy balance period. Moreover, the combined supplement produced suppressed hunger and increased satiety, and this was greater during negative than positive energy balance, wrote the researchers. This indicated that energy balance did not affect energy intake but did affect appetite.


Active components


Commenting on the mechanism, the researchers note that both catechins and caffeine in green tea may be behind the effects, with epigallocatechin gallate (EGCG) previously noted to reduced food intake and body weight in rats.


On the use of capsaicin the researchers note that long-term intervention is “hardly possible and results in bad compliance”, and that CH-19 sweet pepper, which is non-pungent, could be “an attractive alternative to capsaicin”.


“Since CH-19 sweet pepper was an efficient suppressor of energy intake it would be of interest to investigate if a combination of CH-19 sweet pepper and green tea leads to a similar synergistic effect on energy intake,” wrote Westerterp-Plantenga
and her co-workers.


“Capsaicin only increases liking of the food when used at lower concentrations, and one can only comply with a relatively small dosage of capsaicin over the longer term.


“Therefore we suggest that a lower dosage of capsaicin should be combined with other bioactive ingredients (e.g. CH-19 sweet pepper) in order to reach optimal effects,” they concluded.

Source: Clinical Nutrition
Published online ahead of print, doi: 10.1016/j.clnu.2009.01.010
“Effects of capsaicin, green tea and CH-19 sweet pepper on appetite and energy intake in humans in negative and positive energy balance”
Authors: H.C. Reinbach, A. Smeets, T. Martinussen, P. Møller, M.S. Westerterp-Plantenga
Abstract available here

Paprika

PAPRIKA - A bold red that is slightly lighter and brighter than chili powder, paprika (Capsicum annuum species) is a ground pepper harvested from an annual shrub of the nightshade family. The flavor can range from sweet to bitter to red hot. Although the spice is a favorite of Eastern Europeans and the Balkans, as it is a central ingredient in goulash, it originated in the Western Hemisphere. Columbus brought the spice to Spain where it spread to Turkey and then "Turkish pepper", as it became known, was introduced in Hungary in 1604.

Paprika peppers contain seven times as much Vitamin C as oranges and taking capsicum is thought to improve the immune system's defenses against infection and cancer. In 1937 the Hungarian scientist Dr. Szent Gyorgyi won a Nobel Prize for his work with paprika pepper pods and Vitamin C research.

Capsaicin in capsicum
The fruit of most species of Capsicum contains capsaicin (methyl vanillyl nonenamide), a lipophilic chemical that can produce a strong burning sensation in the mouth of the unaccustomed eater.