What did scientists conclude?
They concluded that raspberry ketone prevents and improves obesity and fatty liver in certain animal models. While the exact mechanism has not been thoroughly understood, these effects appear to stem from the action of raspberry ketone in altering the lipid metabolism, or more specifically, in increasing norepinephrine-induced lipolysis in white adipocytes (fat cells).
Scientists speculate that raspberry ketone stimulates the energy metabolism via a mechanism similar to that of capsaicin. Capsaicin, a compound found in chili peppers, has been looked at in humans for weight loss.
In another study, the effect of raspberry ketone on energy metabolism was examined by measuring metabolic markers in brown fat tissue, a special kind of fat that generates heat in a process called thermogenesis. These results reportedly indicate that raspberry ketone activates the brown fat thermogenesis and enhances energy metabolism. In any case, more detailed studies are called for to determine a mechanism for raspberry ketone.
What do the animal data on raspberry ketone mean for humans?
Mice and rats are the most widely used animal models in biomedical research. It is important to note that besides being non-human mammals, these animals are housed under standard laboratory conditions, and the use of overweight and unstimulated animals as standard controls may bias the measured experimental outcomes.
Animal models and test tube experiments are important parts of scientific discovery and innovation, especially at early stages. Positive early results in the lab can be promising, but these do not always mean the same outcomes will occur in humans.