Raspberry ketones are a natural substance often touted as a weight loss aid. Raspberry ketones are the compounds that give red raspberries (Rubus idaeus) their sweet aroma, and are extracted from the fruit and sold in dietary supplement form.
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Raspberry ketones are said to be similar in structure to capsaicin (a natural chemical found to alter fat metabolism in several preliminary studies). Proponents claim that the compounds help trigger the breakdown of fat cells. However, there is currently a lack of scientific evidence to support the claim that raspberry ketones can promote weight loss.
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Benefits of Raspberry Ketones for Weight Loss
So far, research on the health effects of raspberry ketones is extremely limited. While a small number of animal-based studies have tested raspberry ketones for their potential anti-obesity benefits, there are no clinical trials showing that taking raspberry ketone supplements can support weight loss efforts.
The available research on raspberry ketones includes a 2005 study published in the journal Life Sciences. For the study, scientists conducted several experiments that involved feeding raspberry ketones to mice. In one study, mice were fed a high-fat diet for six weeks. Then, for the next five weeks, the mice were fed the same high-fat diet enriched with raspberry ketones. Results revealed that the addition of raspberry ketones help reverse the weight gain induced by the high-fat diet. The study's authors also found that raspberry ketones appeared to protect against the buildup of fat in the liver.
In a more recent study, researchers tested the effects of raspberry ketones on fat cells. Published in Planta Medica in 2010, the study found that raspberry ketones helped activate adiponectin (a hormone that regulates fat breakdown).
Are Raspberry Ketones Safe?
Due to a lack of scientific research, little is known about the safety of consuming raspberry ketone supplements in the long term.
However, since raspberry ketones are thought to stimulate the release of norepinephrine, there's some concern that use of raspberry ketone supplements could be harmful to people with certain chronic conditions (including high blood pressure, asthma, and chronic obstructive pulmonary disease). Norepinephrine is a type of nervous system chemical that is known to increase blood pressure.
Where to Find Raspberry Ketones
Widely available for purchase online, supplements containing raspberry ketones are sold in many natural-food stores and in stores specializing in dietary supplements.
Should You Use Raspberry Ketones for Weight Loss?
Due to a lack of supporting research, raspberry ketones cannot currently be recommended for weight loss. If you're looking to lose weight, the National Institutes of Health recommend following a weight-management plan that pairs healthy eating with regular exercise. Keeping a food diary, getting eight hours of sleep each night, and managing your stress may also help you reach and maintain a healthy weight. In addition, there's some evidence that certain alternative therapies (including yoga, meditation, and tai chi) may support weight-loss efforts.
If you're considering the use of raspberry ketones for weight loss (or any other health-related purpose), make sure to consult your physician before starting your supplement regimen.
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.
National Institutes of Health. "Weight-Control Information Network - Weight Loss for Life." NIH Publication No. 04–3700. January 2009.
Park KS. "Raspberry ketone increases both lipolysis and fatty acid oxidation in 3T3-L1 adipocytes." Planta Med. 2010 Oct;76(15):1654-8.