Is raspberry ketone effective for weight loss?

Posted 19 December 2012

The use of raspberry ketone for weight loss has produced a lot of talk following an endorsement by television host Dr. Oz as a “fat-burner in a bottle.” [1] The Dr. Oz Show Website recommends raspberry ketones “paired with regular exercise and a well-balanced diet,” but sales of “the number one miracle in a bottle to burn your fat” have soared, unlike sales of fruits and vegetables.

But is there evidence that it works or is this another scam? 

The response to this question is posted on the Medscape website. In the event that the website is not available, I have posted the article below.

Update: There is also an excellent article published on the Huffington Post website: “What They Don’t Want You to Know About Raspberry Ketones
Link will open in a new window.

Question

Is raspberry ketone effective for weight loss?

Response from Gayle Nicholas Scott, PharmD

Assistant Professor, Eastern Virginia Medical School, Norfolk, Virginia; Clinical Pharmacist, Chesapeake Regional Medical Center, Chesapeake, Virginia

The use of raspberry ketone for weight loss has produced a lot of talk following an endorsement by television host Dr. Oz as a “fat-burner in a bottle.” [1] The Dr. Oz Show Website recommends raspberry ketones “paired with regular exercise and a well-balanced diet,” but sales of “the number one miracle in a bottle to burn your fat” have soared, unlike sales of fruits and vegetables.

Raspberry ketone, also known as rheosmin, and chemically as 4-(4′-hydroxyphenyl)-2-butanone, has been known as a flavoring agent since the 1920s and is used for its fragrance in cosmetics and as an insect attractant. [2] Raspberry ketone is one of the most expensive flavoring agents in the food industry ($20,000/kg). Of note, natural raspberry ketone is not extracted from raspberries, which have very low raspberry ketone content. Natural sources include peaches, grapes, apples, rhubarb, and the bark of trees such as yew, maple, and pine. Raspberry ketone can also be synthesized chemically, but this product cannot be labeled as a natural flavor. Additionally, “natural” raspberry ketone is produced via microbial synthesis. [3,4]

Raspberry ketone is structurally similar to synephrine and capsaicin. [5] Synephrine, a sympathomimetic, is used in dietary supplements for weight loss to replace ephedrine, which was banned by the US Food and Drug Administration because of cardiovascular toxicity. [6] Capsaicin is a component of cayenne pepper and is used topically for myalgia and sold under a number of names. Capsaicin also has sympathomimetic activity and has generated sporadic reports of cardiovascular toxicity. [7-9]

Research on raspberry ketone is scant. A MEDLINE search generated 3 studies of raspberry ketone for weight loss: 2 in rodents and 1 in vitro with no human studies. A study in mice fed a high-fat diet and raspberry ketone (2% of total diet) showed that raspberry ketone prevented weight gain and elevation of liver and adipose tissue weight, which the authors attributed to increased norepinephrine-induced lipolysis in white adipocytes. [5] A study conducted decades earlier reported no effects on the body weight of rats given raspberry ketone 100 mg/kg, a dose up to 200 times greater than the estimated dietary intake in humans. [10] In vitro research suggests that raspberry ketone might increase secretion of adiponectin, which is involved in lipid and glucose metabolism and in body weight. [11]

Other animal and in vitro research suggests that raspberry ketone may protect against nonalcoholic steatohepatitis, increase skin insulin-like growth factor-1 (which is involved in promoting hair growth and increasing skin elasticity), and possess antiandrogenic, anti-inflammatory, antimelanogenic (skin lightening) activity. [12-16] Very preliminary research in humans (< 15 subjects) suggests that topical application of raspberry ketone might increase hair growth in patients with alopecia and increase skin elasticity. [13]

The safety of oral raspberry ketone in humans is unknown. Given the chemical similarity of raspberry ketone to synephrine and capsaicin, patients with conditions that increase the risk for cardiovascular adverse events, such as hypertension, should avoid raspberry ketone. Without research in humans on the efficacy and safety of raspberry ketone for weight loss, raspberry ketone should not be recommended. Advise patients to instead heed the other 2 parts of Dr. Oz’s recommendation — regular exercise and a well-balanced diet.

References

  1. The Dr. Oz Show. Raspberry ketone: fat-burner in a bottle. http://www.doctoroz.com/videos/miracle-fat-burner-bottle Accessed November 11, 2012.
  2. Smith LR. Rheosmin (“raspberry ketone”) and zingerone, and their preparation by crossed aldol-catalytic hydrogenation sequences. Chem Edu. 1996;1:1-18.
  3. Beekwilder J, van der Meer IM, Sibbesen O, et al. Microbial production of natural raspberry ketone. Biotechnol J. 2007;2:1270-1279.
  4. Feron G, Mauvais G, Martin F, Semon E, Blin-Perrin C. Microbial production of 4-hydroxybenzylidene acetone, the direct precursor of raspberry ketone. Lett Appl Microbiol. 2007;45:29-35.
  5. Morimoto C, Satoh Y, Hara M, Inoue S, Tsujita T, Okuda H. Anti-obese action of raspberry ketone. Life Sci. 2005;77:194-204.
  6. Inchiosa MA. Experience (mostly negative) with the use of sympathomimetic agents for weight loss. J Obes. 2011;2011. [Epub 2010 Aug 12]
  7. Sogut O, Kaya H, Gokdemir MT, Sezen Y. Acute myocardial infarction and coronary vasospasm associated with the ingestion of cayenne pepper pills in a 25-year-old male. Int J Emerg Med. 2012;5:5.
  8. Sayin MR, Karabag T, Dogan SM, Akpinar I, Aydin M. A case of acute myocardial infarction due to the use of cayenne pepper pills. Wien Klin Wochenschr. 2012;124:285-287.
  9. Akçay AB, Ozcan T, Seyis S, Acele A. Coronary vasospasm and acute myocardial infarction induced by a topical capsaicin patch. Turk Kardiyol Dern Ars. 2009;37:497-500.
  10. Gaunt IF, Sharratt M, Colley J, Lansdown AB, Grasso P. Acute and short-term toxicity of p-hydroxybenzyl acetone in rats. Food Cosmet Toxicol.1970;8:349-358.
  11. Park KS. Raspberry ketone increases both lipolysis and fatty acid oxidation in 3T3-L1 adipocytes. Planta Med. 2010;76:1654-1658.
  12. Wang L, Meng X, Zhang F. Raspberry ketone protects rats fed high-fat diets against nonalcoholic steatohepatitis. J Med Food. 2012;15:495-503.
  13. Harada N, Okajima K, Narimatsu N, Kurihara H, Nakagata N. Effect of topical application of raspberry ketone on dermal production of insulin-like growth factor-I in mice and on hair growth and skin elasticity in humans. Growth Horm IGFRes. 2008;18:335-344.
  14. Ogawa Y, Akamatsu M, Hotta Y, Hosoda A, Tamura H. Effect of essential oils, such as raspberry ketone and its derivatives, on antiandrogenic activity based on in vitro reporter gene assay. Bioorg Med Chem Lett. 2010;20:2111-2114.
  15. Jeong JB, Jeong HJ. Rheosmin, a naturally occurring phenolic compound inhibits LPS-induced iNOS and COX-2 expression in RAW264.7 cells by blocking NF-kappaB activation pathway. Food Chem Toxicol. 2010;48:2148-2153.
  16. Lin CV, Ding H, Kuo S, Chin L, Wu J, Chang T. Evaluation of in vitro and in vivo depigmenting activity of raspberry ketone from Rheum officinale. Int J Mol Sci. 2011;12:4819-4835.

One Response to Is raspberry ketone effective for weight loss?

  1. shun 1 June, 2015 at 8:22 pm #

    I lost 26kg in 5 months just exercising and diet.im going to put raspberry ketone to test soon.i need to get rid of the belly fat and hip.

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