Raspberry ketone is an aromatic compound found in red raspberries. It's extracted and used in perfumes and cosmetics, and it's also used as a flavoring agent in some fruit-flavored foods. Apparently it's being touted as a semi-magical weight loss aid. But does it work? Who knows -- there's very little research evidence that shows if it works on humans or not.
There are some studies on mice. They were given raspberry ketone, and it appeared to prevent weight gain when the little rodents were fed high-fat diets. Apparently the anti-obesity effects were due to stimulation of lipolysis (which is how the body breaks down fat in fat cells called adipocytes) in both regular fat tissue and brown fat tissue. It also suppressed release of pancreatic lipase -- a digestive enzyme needed to break down dietary fats so they can be absorbed through the small intestinal wall.
But this research was done on mice. We're humans, not rodents. We have different physiology and different emotional reasons for eating (or not eating) fats and other foods. So just because mice didn't get fat doesn't mean raspberry ketone will work the same way in humans. We need clinical research to know that, and I can't find any research on people.
So will it hurt you to take raspberry ketone supplements? Probably not. Will it help you lose weight? I don't know, but I doubt it. More than likely it will just make your wallet a little lighter.
What Do I Need To Know Before I Try Raspberry Ketone?
Natural raspberry ketone is expensive, so it isn't easy for manufacturers to buy enough of it at a reasonable price. Most of the raspberry ketone products are artificially created from other ingredients. Don't be fooled by the label -- it may have words like "natural" and "high quality" even if the product contains only artificial raspberry ketone.
Since there's no solid evidence that backs up the claims that it will help you lose weight (whether your find natural or artificial raspberry ketone), you'll still have to cut back on calories or exercise more if you want to lose weight.
Can't I Just Eat Lots of Raspberries?
I doubt if you could eat enough raspberries every day to get enough of the raspberry ketone, but raspberries (like all berries) are low in calories and a good source of vitamins and fiber. Eating raspberries may help you lose weight if choose them over higher-calorie desserts and treats. According to the Academy of Nutrition and Dietetics, most people don't eat enough fruits and vegetables every day, so eating raspberries can help you increase your intake.
Our Alternative Medicine Guide at About.com, Dr. Cathy Wong has written in depth about raspberry ketones.
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.
Natural Standard, Professional Monograph. "Raspberry Ketone." Accessed February 2, 2013. http://naturalstandard.com.