|Image 1: According to Wood et al. (1988) black pepper contains between 3-8% piperine. A teaspoon of black pepper would thus deliver have 60-160mg piperine, which would mean that you would have to swallow roughly 4 of those to get the fat loss effect (if it does translate to humans)|
Note: It always amazes me how scientists design their experimental diets. Usually we have those "high fat diets" that then turn out to be high fat + high carb (like 40% carb, 50% fat, 10% protein). So I was curious what a "high carbohydrate, high fat" diet (HCHF) would look like. Well, let me put it like that. I am not sure, whether the control diet that consisted of a meat-free rat and mouse feed (Specialty Feeds, Australia) that was mixed with cornstarch (yes, the devil! ;-) and water was so much "healthier" than the fattening HCHF diet where part of the cornstarch and the water was replaced with condensed milk, fructose and beef tallow... I mean, condensed milk and beef tallow do sound pretty good, and let's be honest even "normal" corn starch is probably not much better than pure fructose... what do you say? "Scientific Idiocy?" Well, I didn't say that ;-)So far for the bad news. Now for the good one: A recent study from the University of Southern Queensland found that the addition of ~30mg piperine per kg body weight to the chow of 8-9 week old male Wistar rats, who were fed a high carbohydrate + high fat diet for 16 weeks (cf. red box above), ...
[...] reduced blood pressure, improved cardiac and liver structure and function, reduced oxidative stress, and attenuated inﬂammatory and metabolic changes induced by HCHF diet as compared to CS diet.Moreover, the addition of 30mg/kg piperine (=4.86mg/kg for humans) kept the rats on the "typical Western diet" (high carbs + high fat) healthy, it also kept them reasonably lean and, more importantly, it also reduced the weight of the abdominal fat pads by -16% in the "control" (=high carb) group (cf. figure 1).
|Figure 1: Changes in dietary intake and body composition of male Wistar rats receiving 30mg/kg piperine in their cornstarch (control) or high carbohydrate + high fat (HCHF); values relative to unsupplemented control (data calculated based on Diwan. 2011)|
|Figure 2: Changes in inflammatory markers and anti-oxidant status of male Wistar rats receiving 30mg/kg piperine in their cornstarch (control) or high carbohydrate + high fat (HCHF); values relative to unsupplemented control (data calculated based on Diwan. 2011)|
A potential fat-burner with a bitter after taste
Although Kim et al. observed similar effects in another recent study on mice, who were fed the classic high-fat diet for 3 weeks (the study compared piperine to pipernonaline, and dehydropipernonaline, Kim. 2011), these positive results do yet still have a peppery, ahh... I mean bitter after-taste. Yes, piperine exerted beneficial effects on body composition in both groups and had ameliorated the negative effects of the high carbohydrate + high fat diet on inflammatory markers (most importantly C-reactive protein) and anti-oxidant status and thusly prevented fibrosis, inflammation, and the accumulation of mast cells in the heart and liver of the animal, BUT in view of the colorful poly-pharmacological OTC self-doctoring approaches of many of the self-proclaimed "health conscious" consumers, I am kind of worried that the addition of 400mg of piperine per day (that would be the HED for an 80kg human being) could have unpredictable consequences. That being said, I am not even convinced that we would see similarly profound effects in human studies. After all, it would not be the first "proven" fat burner that turns out to be a non-starter in human trials... if you insist on trying it, do me a favor and not mix it with a lot of other supplements or even medical drugs!