Facts about the latest diet craze
Raspberry ketone is being touted as a "miracle fat burner," but experts don't yet know if it's effective -- or safe.
Here's what we know about raspberry ketone, thanks to some smart investigation by dietitian intern Marian Crockett:
Claim: "Raspberry ketone is the primary aroma compound of red raspberries."
Fact: True. Raspberry ketone (also referred to as RK) is a chemical compound that gives raspberries their fruity fragrance. Food and cosmetic manufacturers add it to their products for this purpose.
Claim: "Research has shown that raspberry ketone can help with weight-loss efforts, especially when paired with regular exercise and a well-balanced diet of healthy and whole foods."
Fact: Regular exercise and a well-balanced diet do indeed help with weight loss efforts. Raspberry ketone has not been scientifically studied in humans, so it's anyone's guess whether it aids weight loss.
Claim: "Raspberry ketone causes the fat within your cells to get broken up more effectively, helping your body burn fat faster."
Fact: Perhaps if you are a rat. One study tested RK on six obese male rats and compared it to six other rats. The rats fed RK were more likely to lose weight. Another study exposed RK to fat cells in a test tube and found that RK stimulated the breakdown of these cells.
Claim: "The recommended dose of raspberry ketone for weight loss is 100 milligrams per day."
Fact: Who knows? No human studies have yet been done. (I think I already said this.) And if we extrapolate the dosage given in the six-obese-male-rat study, it would translate to several thousand milligrams in humans.
Claim: "Raspberry ketone product is made from ingredients that are 100 percent natural, ensuring that there are no negative side effects."
Fact: Rattlesnakes are 100 percent natural and can still bite you. Some concern has been expressed that RK is chemically similar to a stimulant called "synephrine" which can increase heart rate and blood pressure . not a good idea for anyone with a heart condition.
Claim: RK "slices up fat molecules so it burns easier ."
Fact:RK's chemical structure is also similar to capsaicin -- the heat-generating substance in hot peppers. In a test tube, RK appears to stimulate a protein that breaks down fat.
Claim: "Raspberry ketone is a miracle fat burner in a bottle."
Fact: Raspberry ketone is a "miracle money maker" in a bottle. Unless you are an obese male rat, it is way too early to draw any conclusions about the effectiveness or safety of RK as a weight loss aid.
A recent review article in the International Journal of Sports Nutrition concluded: "There is no strong research evidence indicating that a specific supplement will produce significant weight loss, especially in the long term. Weight-loss supplements containing metabolic stimulants (such as caffeine, ephedra, or synephrine) are most likely to produce adverse side effects and should be avoided."
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