Supplement Godfather

Raspberry Ketone has become  an extremely popular fat-burning ingredient in recent years because the infamous Dr. Oz has repeatedly mentioned its bene ts on his TV show. Before Dr. Oz had probably ever even heard of raspberry ketone, cutting-edge sports supplement formulators were well aware of this ingredient and its ability to support fat loss through its unique mechanisms of action. So, how does raspberry ketone really work to help shed fat?

Mechanism #1
After dietary fat is consumed, it’s digested by pancreatic lipase and absorbed from the small intestine. So, one way to prevent fat gain is to inhibit the digestion and absorption of dietary fat. Raspberry ketone (RK) has been shown to reduce the elevation of plasma triglycerides when taken before meals containing fat. When fat is consumed, RK inhibits pancreatic lipase activity. But, if dietary fat isn’t consumed, RK doesn’t have a significant effect on inhibiting pancreatic lipase activity. This leads researchers to believe that the site of the inhibitory action of RK on fat digestion and absorption is the fat itself and not the enzyme. Bottom line: RK can help inhibit fat absorption, but this definitely isn’t the primary fat-loss mechanism behind this ingredient.

Mechanism #2
Researchers have examined RK’s e ect on lipolysis of white fat cells. Because the catecholamines norepinephrine and epinephrine are known to stimulate lipolysis via beta-adrenergic receptor, researchers examined RK’s e ect on lipolysis in fat cells and its ability to bind various subtypes of beta-adrenergic receptors. Although RK failed to stimulate lipolysis in the absence of norepinephrine and failed to bind to beta-adrenergic receptors, it was e ective in increasing norepinephrineinduced lipolysis. Researchers then examined RK’s e ects on the rate-limiting step of lipolysis in fat cells (the hydrolysis of triacylglycerol), which is catalyzed by hormone-sensitive lipase (HSL). Study results suggest that RK enhances norepinephrine- induced lipolysis not via HSL activation, but via an increase in the translocation of HSL from the cytosol to the lipid droplets in the fat cells. This is truly a unique mechanism of fat burning that only RK can support!

Mechanism #3:
Various compounds can boost fat loss by enhancing metabolism via an increase of thermogenesis in brown adipose tissues (BAT). RK also stimulates energy metabolism via a similar mechanism. RK supplementation increases oxygen consumption and reduces the respiratory quotient. Another study examined RK’s effect on energy metabolism by measuring cytochrome c oxidase activity in BAT. RK significantly increased both the specific activity and total activity of cytochrome c oxidase. These results indicate that RK activates BAT thermogenesis and enhances energy expenditure.

The Bottom Line on the Science Behind Raspberry Ketone and Fat Loss
RK causes fat loss through multiple mechanisms. RK stimulates the metabolism of white and brown adipose tissues and inhibits small intestinal absorption of dietary fat by suppressing pancreatic lipase activity. RK also exerts its fat-loss effect via an increase of norepinephrine-induced lipolysis in white adipocytes and an enhancement of thermogenesis (energy expenditure) in BAT.

References:
Park KS. Raspberry ketone increases both lipolysis and fatty acid oxidation in 3 T3-L1 adipocytes. Planta Med. 2010 Oct;76(15):1654-8.
Morimoto C, Satoh Y, Hara M, Inoue S, Tsujita T, Okuda H. Anti-obese action of raspberry ketone. Life Sci. 2005 May 27;77(2):194-204.

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