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Raspberry Ketone for Weight Loss: A Review


Posted on February 17th, 2012 by Matt Schoeneberger

Dr. Oz recently gave some air time to a supplement called Raspberry Ketone (RK), promoting it as an effective agent for aiding weight loss. The segment of the show was titled “Miracle Fat-Burner in a Bottle“. Search around the internet and you’ll find plenty of sites hyping the product. Let’s find out what the scientific evidence says about RK.

First, let me point out that fat loss expert Lisa Lynn says, when asked how she found out about raspberry ketone, “Research, research, research.” Not so fast, Lisa! I can find only 3 papers specific to raspberry ketone: 1 study performed on mice (Morimoto), 1 paper regarding RK’s effects on lipolysis through modulation of adiponectin (Park), and 1 abstract from a presentation given regarding RK’s effects on rats (Wang). Human studies? Not one. Proof that raspberry ketone is a safe, effective fat burner? Not a chance!

Now, since I pride myself on being impartial and giving fair reviews of weight loss products, I will say that the evidence so far is intriguing. This compound should definitely be put through rigorous scientific testing to assure its safety and efficacy. Then, and only then, should it be recommended by the likes of Dr. Oz and Miss Lynn.

The Evidence

Morimoto

First, let’s discuss the Morimoto study. They fed mice a diet high in fat (beef tallow) in an effort to induce obesity. It worked – the mice gained weight. They also gave groups of mice varying amounts of RK. The group given the highest level of RK gained less weight than mice given the fat-inducing diet only. This isn’t exactly a weight loss study – it’s more like a weight gain study. The researchers also determined that RK reduced absorption of dietary fat in the small intestine through a blunted pancreatic lipase activity. This could mean the wonderful fat-blocker side effect: loose stool (what aisle are the adult diapers in).

One more thing about the Morimoto study: they never, ever say how much RK they gave the mice, except as a percentage of food weight. The mice were fed RK as .5, 1 or 2% gram weight of the diet and we’re never told how many grams of food/day the mice eat, so we don’t know how much RK they consumed. We might be able to figure it out, though. The weight-inducing food breaks down like this:

beef tallow 40%, casein 34–36%, corn starch 10%, sugar 9%, vitamin mixture (AIN-93G) 1% and mineral mixture (AIN-93G) 4% (w/w per 100 g diet)

In other words, for the ingredients that will yield energy content: 40 grams beef tallow (360 calories), 35 grams casein (140), 10 grams corn starch (40 calorie), 9 grams sugar (36 calories). This totals 576 calories for every 100 grams. Stay with me, this math gets fun in a second.

The researchers tell us the mice fed the high-fat diet ate about 800 KJ per week, or about 191 calories. This is about 1/3 of the 100 gram mixture we saw up above, which means the 2% RK group ate about .6 grams of RK/week, or 86 mg/day. The 1% group consumed about half that, or .3 grams/week or 42 mg/day. This is for a 35 gram animal. This means for a human who weighs about 155 lbs (70 kg), a dose of 17.2 grams/day for the 2% group or 8.5 grams/day for the 1% group. On Dr. Oz, Lisa recommends a couple hundred milligrams/day. Not even close to the effective dose used on mice in the Morimoto study. Apparently, neither Dr. Oz or Lisa Lynn can do simple math.

At a typical dose of 150 mg per capsule, you’d be consuming 57 capsules/day to reach the smaller effective dose of the Morimoto mice . Do you think this sounds like fun? Me neither. And at $15/bottle with 180 capsules in each bottle, you’re talking about spending  $142.50 every 30 days. You’ve been meaning to cancel your cable and cell phone service anyway, right?

Wang

The Wang presentation is unavailable to me in full text, but they also used .5, 1 and 2% dosages, this time in rats. The same argument applies.

Park

The Park paper gives us insight into the possible mechanisms by which RK might elicit its fat-burning effect. This means nothing until it’s shown to be effective in humans at a tolerable, safe dose.

How is it that a health professional like Dr Oz, along with his staff and probably a few bucks, end up giving such high praise to this supplement? “Miracle Fat Burner” Really!? At this time it is clear, from the evidence, that RK is NOT a useful weight loss supplement.

 

References

Morimoto, C., Satoh, Y., Hara, M., Inoue, S., Tsujita, T., & Okuda, H. (2005). Anti-obese action of raspberry ketone. Life sciences, 77(2), 194-204. doi:10.1016/j.lfs.2004.12.029

Park KS. Raspberry ketone increases both lipolysis and fatty acid oxidation in 3T3-L1 adipocytes. Planta Med. 2010 Oct:76(15):1654-8. Epub 2010 Apr 27

Schoeneberger MS, Thiboutot JR. Nobody ever reads references: If you see this, email us to receive 10 SPEED bonus points. Int J of SPEED. 89(2) 101-1001. 

Wang Lili, Meng Xianjun, Zhang Yan, Zhao Wei. Experimental study on the mechanism of raspberry ketone on simple obesity and insulin resistance relevant to obesity. http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=6027896

 

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25 Responses to “Raspberry Ketone for Weight Loss: A Review”

  1. Chris says:

    I have found that at any point in time that a supplement or prescription or any kind of treatment is touted as “miracle” it not only isn’t it usually is not useful at all. Especially where weight loss is concerned. But it must sell the stuff or they wouldn’t use it in the advertising.

    p.s. what can I use 10 SPEED bonus points for?

  2. Matt Schoeneberger says:

    *SPEED Bonus Points are not real, are purely fictional, and are redeemable for nothing except a heightened sense of self-worth from knowing you’ve earned SPEED Bonus Points
    :)

    I forgot our lawyers wanted us to put that in there.

  3. TonyMar says:

    On the 2/20/12 edition of Dr. Oz, he recommended 7KETO, Forskolin, Caraway Seeds and Saffron extract. Putting 7 keto and “double blind” into Google and came up with a long article that had many mice and one paragraph about humans, same thing with Forskolin and Relora. The caraway seeds were for “bloating” or intestinal gas. Saffron was told as an appetite suppressant for emotional eating. 7Keto: http://www.lef.org/magazine/mag2005/may2005_cover_keto_01.htm Forskolin: http://content.nhiondemand.com/shp/monoVMN.asp?objID=100819&ctype=ds Relora: http://www.nutraceuticalsworld.com/issues/2004-06/view_supplier-research/-36137/ and Saffron Extract: http://www.lef.org/magazine/mag2010/aug2010_Curb-Compulsive-Eating-Naturally_02.htm
    That’s a lot of supplements and a lot of money. Last week is was CLA and I see you’ve an article on CLA. I don’t think he’s announced Licorice Flavonoids and Garcina Combogia, although I have read “double blind” studies about both of those as visceral fat burning supplements. My particular interest in this is “what works for those over 60 yrs of age.”
    Thanks for your website, very informative and highly authoritative. Scientific studies and double blind are always interesting to read about. You’re doing a great job. TM

  4. Matt Schoeneberger says:

    TonyMar, Thanks for the kind words and the links. I’ve thought a lot about whether or not to write many more articles in response to Dr. Oz’s recommendations. One part of me doesn’t want to become a Dr. Oz watchdog, but it seems almost necessary with the increased frequency of his evidence-lacking recommendations.

    Recently on Dr.Ozfans.com, Shannon shared her thoughts on his pushing of products: http://www.drozfans.com/dr-ozs-advice/dr-oz-white-kidney-bean-extract-block-carbs-from-being-absorbed/comment-page-3/#comment-96085

    “I agree that i am now very leery of Dr. Oz because lately it seems that all he is doing is selling products….he used to teach us things and show body parts when he’d put his purple gloves on. Now it just seems to be about weight loss and pushing products. I’m really turned off by that….and not even sure if the white kidney bean extract would even work!”

    It’s a shame, really. He’s got a huge audience that would benefit greatly from his ability to get complicated topics across to the layperson. My guess is he (and the producers) are simply responding to demand.

    -Matt

    • Charels Abboud MD says:

      I have looked at your program and it looks pretty good , nothing groundbreaking but a good plan , although its the same as many out there it is common sense that it will work just like all the other good exercise and diet programs out there., nothing fancy but good. I dont think people should look for the miricle pill to solve thier wieghtloss issues , thiere is reachrch in Germaany that shows raspberry K make work by helping to increase body temperature safley thus burning calories , there muight be some merit to that but the thing that works best is a good exercise and diet like yours and the otherones out there. just like thiere is no miricle pill out there ther is no miricle program either all parograms with an exellent diet and excersiae program will work , that is common sense

      • Matt Schoeneberger says:

        Charles,

        I tend to agree. We’re definitely not against supplements, so if more quality research shows a real-world significant effect of RK (per cost, of course) I’d be all for supporting its use. But, as you said, supps are not the magic bullet people are looking for.

        To your comments about our program, I agree mostly :) The diet and exercise portions are nothing ground-breaking – mostly because there is no such thing. The same things that have worked decades continue to work. However, I think our program differs slightly from many, not all, programs in that we make a larger emphasis on the sleep, psychology and environment aspects of the weight struggle. Is there anything ground-breaking in those aspects? Not really. Sleep is still important just like your Grandmother told you – but to get people to understand how these aspects apply to weight loss is vital to their success. Not many programs are making this focus a priority.

        Thanks for your comments!

        -Matt

      • Matt Schoeneberger says:

        Interesting also that you have the same IP as a former visitor. Hi Greg!

  5. Jessica says:

    I, like many other countless others, have fallen for the Raspberry Ketone gimmick that was sold by Dr.Oz but now I am feeling extremely gassy. Have you read any articles or reseached some of the extra side effects. I have been taking them for a wekk now and dont feel my best due to the gas and bloating. Please help and let me know what you find. I have found a few articles and blogs and comments abt Konja

  6. Jessica says:

    Diregard previous msg (not complete)…I, like many other countless others, have fallen for the Raspberry Ketone gimmick that was sold by Dr.Oz but now I am feeling extremely gassy. Have you read any articles or reseached some of the extra side effects. I have been taking them for a week now and dont feel my best due to the gas and bloating. Please help and let me know what you find. I have found a few articles and blogs and comments abt Konjic roots (???) causes bloating and gasiness but nothing abt the famous “raspberry ketones”. Please Help!
    Thanks :)

    • Matt Schoeneberger says:

      Jessica,

      I briefly mentioned above that one aspect of RK may be to block absorption of fat. The researchers (Morimoto) found the dose of RK needed to be pretty high to achieve this effect in rats. But, you may be experiencing some side effects due to this aspect of the product. Any time a nutrient is blocked from being absorbed in the small intestine, we run the risk of gas and bloating like symptoms as it gets passed through into the colon.

      I don’t know that these side effects will do much harm other than the symptoms you’ve presented, but your experience already doesn’t sound like much fun to me.

      -Matt

  7. Jay says:

    Thank you for this, I was also wondering why dr Oz advocates this product while there is no research in humans backing it up at all. Sometimes Dr Oz gives really good tips, but other times he (or the staff thinking up the items?) gets way off track.
    I have bookmarked your website!

  8. I am so grateful to you for the clarity and logic (not to mention the math skills) that you apply to all the media hype to which we are subjected. Each time something is mentioned on Dr. Oz I immediately consult your site. Maybe I should just remove my name from his TV show e-mail list. How he can risk his reputation and credibility as a practicing physician at a prestigious New York hospital is beyond me!

  9. [...] justify its cost? Maybe. Raspberry Ketone – we’ve reviewed this supplement previously here. 7-Keto – This one has some research to discuss, so excuse the length of this section. [...]

  10. [...] on the show? Dr Oz has repeatedly misrepresented the facts on supplements, see Matts posts HERE,  HERE and HERE. What’s the deal Dr.Oz? I though you were all about giving your audience [...]

  11. virginia rosemond says:

    I, like many others, rushed out to buy Rasberry Keytones for the reduction of belly fat. The results of taking one capsule a day (500 mg) for one week has been bloating and gas. In addition, I have experienced heightened anxiety and general hyperactivity during the day and disturbing dreams at night. At this point, I am discontinuing taking these and am extremely disappointed in Dr. Oz for recommending this poorly researched product.

    • Matt Schoeneberger says:

      Thanks for sharing. I’m surprised you had those symptoms with RK, but it sounds like discontinuing is the right move. The situation with Dr. Oz is unfortunate, since he could get a great message out to a lot of people.

      Now that I think of it, he could do best by starting his show with “Instead of sitting on your coach watching me for the next hour, how about you get up and get some exercise. Then do that every time I’m on.”

    • Ronda says:

      I also have experienced horrible gas after taking the RK, been horribly tired with crazy dreams.

  12. Evelyne says:

    I too have been experiencing alot of gas and bloating, to the point of being extremely uncomfortable and nauseous. This is the second time I’ve tried to take them but I get the same results. I would like to try Calcium Pyruvate, also suggested by Dr Oz. Any thoughts?

    • Matt Schoeneberger says:

      Evelyne,

      Pyruvate is back on the scene, huh? I used to be forced to sell pyruvate supplements at a gym where I trained when I was just getting started. I never did hit my quotas… I just couldn’t tell people to waste their money.

      I haven’t seen much evidence lately on calcium pyruvate. One study comes to mind and it did not show a significant effect on body composition in female athletes: http://www.nutritionjrnl.com/article/S0899-9007(04)00291-6/abstract

      I would advise you NOT to waste your money on calcium pyruvate.

      At this point, I would also recommend you to stop watching Dr. Oz for weight loss supplement advice. He may recommend a few good supplements, but how is the average person supposed to be able to weed them out from all the other crap he talks about? Better to just stick to the basics that bring results: get good sleep, journal and track progress, control diet, get activity every day, etc.

      Good Luck!

    • Matt Schoeneberger says:

      One more thing about pyruvate – the studies that show positive on insulin status in rats/mice use ridiculous amounts of pyruvate, like this one that uses pyruvate as 6% of the diet: http://www.ajcn.org/content/59/2/331.short

      In other words, if you were eating 1000 calories/day, you’d be taking 60 grams of pyruvate per day. This product is sold in 500mg capsules, so you’d need to take 120 pills/day – you can see how that’s impossible both physically and financially.

      Update – I realized I had the math wrong. This should be 6 grams/day or 12 pills/day. Much less ridiculous, but still wicked expensive.

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