Fat burners are abound in the supplement world, and for good reason. I will be real, if you could give me a pill that instantly gave me abs ten years ago I probably would have taken it.
One of the more popular ones on the market today is Garcinia Cambogia. It is heavily advertised as a fat burner and is recommended by our “favorite” Dr., Good Ol’ Dr. Mehmet Oz.
Now if his endorsement isn’t enough to make you question it, maybe the science behind it will convince that taking them is a waste of your money.
What is Garcinia Cambogia?
Garcinia Cambogia is a fruit that is relatively high in hydroxycitric acid, which has a similar culinary experience to citric acid (it gives a sour flavor like eating a lemon). One of the forms of hydroxycitric acid, is believe to prevent production of fat (de novo lipogenesis) by inhibiting a key enzyme (Citrate Lyase) in the fatty acid biosynthesis pathway.
Essentially, the idea is that inhibiting Citrate Lyase with garcinia cambogia can reduce the production of fat from non-fat dietary sources (i.e. carbs and protein). Without getting to far into the biochemistry weeds, here is the theory behind garcinia cambogia as a “fat burner”
Here it is again: Garcinia Cambogia is a source of hydroxycitric acid, which inhibits an enzyme, citrate lyase, which can reduce the production of fatty acids from non-fat dietary sources.
Even before we dive into the science, the marketing claims of garcinia cambogia are DOA. If anything it is a preventer of “fat creation” not a direct fat burner.
Scoreboard update: Science=1, Marketing Hype=0
Does it Actually Work?
Now let’s move onto some of the actual intervention studies done where scientists looked to see whether or not garcinia cambogia supplementation actual reduces fat in vivo.
Starting with the positive results. Two studies have shown that garcinia cambogia does indeed reduce fat production (de novo lipogenesis), reduced weight regain after fat loss, and for some reason also suppressed food intake (1,2).
There is one catch to these studies though, they were done on rats. This presents a serious limitation as de novo lipogenesis, the main target of garcinia cambogia, is way higher in rats than humans (3,4,5).
Onto the most important species: humans. Surprisingly, several studies have tested Dr. Oz’s miracle fat burner (I mean de novo lipogenesis suppressor). In a study where participants were given 2 grams of garcinia cambogia per day for 10 weeks, there was no effect of garcinia cambogia on weight loss or body fat (6). Strike 1
Image is data reconstruction from a table in reference 6. While the body fat looks like it might be lower in the GC group, it is not statistically different
Another study published in the Journal of the American Medical Association also found that 1.5 g/day of garcinia cambogia supplementation for 12 weeks had absolutely no effect body weight or fat loss (7).
In fact, the data in this study indicates it might even have a negative effect (Yes, I know there is no statistical significance, but the fact the data shows what might be an opposite effect is interesting in and of itself). Strike 2
Image from reference 7
Appetite Suppressant? Probably Not
The appetite suppressing effect found in the rats was also tested directly in humans. Not surprisingly, the appetite suppressing effect of garcinia cambogia was not found in humans consuming 2.4 grams of garcinia cambogia per day for 12 weeks (8). I believe that would be Strike 3.
The Wrap Up
Garcinia Cambogia has theoretical implications for suppression de novo lipogenesis that show promise in rats. In humans, it has no evidence to support its use. So save your money and put it towards something useful, like taking yourself out to a nice dinner or to pay for your next two months of Netflix (Yes, I support your binge watching of House of Cards).