Raspberry ketones (RK) are the chemical compounds that give raspberries their enticing aroma. And when ketones are taken from raspberries, they can be used to add fragrance and flavor to things such as colas, ice cream, and cosmetics.
But the buzz that has put raspberry ketones in the spotlight is the claim that raspberry ketone supplements can melt away fat and prevent weight gain -- even in the face of a high-fat diet. But can they really do that?
The answer is no one knows. Experts say that investing anywhere from $12 to $20 in a bottle of raspberry ketone supplements amounts to little more than wishful thinking. And doing so may or may not be harmful.
What the Science Says
There have been no human studies so far on the weight loss effects of raspberry ketones.
The only studies on the effect of raspberry ketones on fat are a handful of animal studies. The studies were done over the last 10 to 15 years. Researchers looked at the effect of raspberry ketones on rats, mice, and rabbits.
There are also a few studies on the effect of raspberry ketones on isolated cells in test tubes. But there is no way to know whether the same results would be produced in people.
The excitement over the potential benefit is understandable. In the animal studies, raspberry ketones appear to alter the animals' metabolism. As a result, the animals had a:
- Speed-up in the processing of fat
- Reduction of fatty tissue, especially in the liver
In the animal studies, raspberry ketones also seemed to affect the production of certain hormones that increase the body's ability to burn fat.
But whether raspberry ketones would have the same effect on metabolism and hormone production in humans hasn't been studied.
Until it has, experts say you're better off holding onto your money. Instead, concentrate on a healthy, balanced diet and regular exercise. Both of those have been shown to be effective ways to manage weight.
The Unknown Potential for Harm
Raspberry ketones in food and cosmetics are generally considered safe. But no one knows what short- or long-term effect raspberry ketone supplements could have on your overall health. That's because there has been no study to document potential side effects. There are also no studies that look at potential drug or food interactions.
The fact that raspberry ketones chemically resemble other stimulants suggests the potential for certain side effects. And there are anecdotal reports of jitteriness, increased blood pressure, and rapid heartbeat among people taking raspberry ketone supplements. But without the evidence, no one can say what dosage of raspberry ketone supplements, if any, might be safe to take.
The best advice is to discuss your concerns about weight and weight management with your doctor before trying any unproven method for weight control.