Since Feb. 6th, Doctor Oz’s show, Raspberry Ketone has become a highly sought after supplement for weight loss. Much has been said and written about RK (Raspberry Ketone) since. However, little can be found about RK from a scientific perspective. In this blog, we will take a brief side-road detour into the science of RK. Care to join me?
Warning – Please accept my advance apology for some of the terms and data presented can be boring to some readers. But if you stay on, you will better understand the reason why it is so popular for weight management and our overall health. I welcome your input and comment as well.
Raspberry Ketone, is an aromatic compound of red raspberry (Rubus idaeus) used in the food industry in its chemical form (4-(4-hydroxyphenyl) butan-2-one). As shown below, the chemical structure of RK is similar to the structure of synephrine and others, compounds known to exert anti-obese actions and alter the lipid metabolism.
Raspberry Ketones are found naturally in red raspberries. They are responsible for the aroma of red raspberries. Don’t be fooled that all RK’s are natural and good for us. RKs can be either naturally extracted from the fruit itself or made synthetically. Much of the processed food industry use the synthetic version for flavor and aroma. Though we do not fully scientifically understand why natural form has a much better efficacy, all I can offer here is that the natural phytochemical form is complex and not in isolated form which makes it somehow more effective and less prone to side-effects than its synthetic counterpart.
Much has already been established, like many other berries, that Raspberry is also a potent antioxidant. Among several significant phytochemicals, red raspberries contain ellagic acid, a phenolic compound that exhibits anti-carcinogenic effects against a wide range of carcinogens in several tissues. Past in-vitro and in-vivo studies, have demonstrated ellagic acid contributes to significant inhibition of colon, esophageal, liver, lung, tongue, and skin cancers in rats and mice. Anthocyanins are also in red raspberries providing potent antioxidants that protect against heart disease and anti-aging effects.
Other Nutraceutical Values of Red Rapsberries
|Anthocyanins||20-65 mg/100 g|
|Ellagic Acid||3.39 mg/g dry wt|
|ORAC||24 umole TE/g|
|Salicylic Acid||5 mg/100g|
As far as my research take me, so far I could only find 2 studies done on Raspberry Ketone. Both of which are animal based studies. One of them, conducted by a Japanese University and another by the Korean FDA.
Life Sci. 2005 May 27;77(2):194-204. Epub 2005 Feb 25. “Anti-obese action of raspberry ketone,” by: Morimoto C, Satoh Y, Hara M, Inoue S, Tsujita T, Okuda H. – Department of Medical Biochemistry, Ehime University School of Medicine, Shigenobu-cho, Onsen-gun, Ehime 791-0295, Japan. email@example.com
The purpose of this study is to clarify whether RK helps prevent obesity and activate lipid metabolism in lab rodents. Following in-vivo experiments were set up – 1. mice were fed a high-fat diet including 0.5%, 1% (approximately 100mg/day in human), or 2% (approximately 300mg/day in human) of RK for 10 weeks; 2. mice were given a high-fat diet for 6 weeks and subsequently fed the same high-fat diet containing 1% RK for the next 5 weeks.
To spare you from pouring over the detailed technical jargon and graphics, I made 5 personal observations from this landmark study:
First, RK made a clear difference in reducing the overall body weight and individual organ weight in the high-fat diet population.
Second, RK showed evidence that it supresses fat absorption by inhibiting the glycerol hydrolysis effect. That is, RK is effective in calorie burn while we are in a resting state.
Thirdly, RK increased norepinephine-induced lipolysis. That is, it increased the fat breakdown rate in the presence of norepinephine compound, which is produced when we are in an active kinetic state.
Fourthly, The researchers showed that, a greater amount of hormone-sensitive lipase goes to the vesicles in which the fat cells store their fatty acids. Hormone-sensitive lipase gets fat cells to mobilize and excrete fatty acids.
Fifthly, RK was found to increase brown adipose tissue thermogenesis – the burning of calories through heat.
In layman’s terms, in more than one manner, the Raspberry Ketone increases thermogenesis and oxidation (burning) of body fat during resting as well as active states. Unlike many of other weight loss supplements, RK does all of that effectively and efficiently without any stimulant or stimulation to our cardiovascular system.
Planta Med. 2010 Oct;76(15):1654-8. Epub 2010 Apr 27. “Raspberry Ketone increases both lipolysis and fatty acid oxidation in 3T3-L1 adipocytes,” Park K.S., Nutrition & Functional Food Research Team, Korea Food & Drug Administration, Seoul, Korea. firstname.lastname@example.org
This is a more recent publication which further confirms independently the previous cited work and further asserts that raspberry ketone increased both the expression and secretion of adiponectin. Adiponectin is a protein hormone which modulates a number of metabolic processes, including glucose regulation and fatty acid catabolism.
Past research into adiponectin has shown that human levels of adiponectin are inversely correlated with our body fat percentage. That is, higher adiponectin equates to lower levels of body fat.
This theory was re-affirmed as the fat lab mice in this study, melted off their body-fat easily in the presence of RK. A higher levels of adiponection have been shown, in other studies, to potentially positively impact the type 2 diabetes, obesity, atherosclerosis, non-alcoholic fatty liver disease and metabolic syndrome.
The researchers of this study concluded that Raspberry Ketone “holds great promise as an herbal medicine since its biological activities alter the lipid metabolism in 3T3-L1 adipocytes.”