Does Garcinia Cambogia Help with Weight Loss?

What's the evidence to support the claims behind this popular weight loss supplement?

Monica Reinagel, MS, LD/N, CNS,
August 28, 2013
Episode #249

Losing weight isn't easy. Keeping it off can be just as challenging. So, when we hear about a pill that supposedly subdues your appetite or revs up your fat-burning metabolism, we want so badly to believe that the claims are true! My friend Carly, for example, is a fit and youthful-looking 62. She's worked hard over the years to get and stay slim and for the last couple of years has been taking garcinia cambogia. She's convinced that the supplement takes the edge off her appetite and keeps her on track. Could she be onto something or has she simply fallen prey to good marketing or wishful thinking? 

See also: How to Lose Weight Without Dieting;

What's in Garcinia Cambogia?

The fact that HCA has actually been the subect of scientific research puts it significantly ahead of many weight loss supplements.

Garcinia cambogia is a fruit native to Asia and India. The rind, which has a sour flavor similar to tamarind, is traditionally used in curries and other condiments. The fruit also contains a compound called Hydroxycitric Acid (HCA), which has been studied as a potential weight loss agent.  The fact that HCA has actually been the subect of scientific research puts it significantly ahead of many weight loss supplements. But what did the research reveal? 

Research on Garcinia Cambogia for Weight Loss

Early research on garcinia and HCA was actually sort of promising. High doses appeared to suppress the accumulation of fat in lab rats and a couple different plausible mechanisms were identified. It was enough to build a believable story--and when it comes to weight loss supplements, that's really all you need to be off and running.

Unfortunately, subsequent research on humans was significantly less encouraging.  In one study, researchers put 135 overweight people on a high-fiber,  low-calorie diet for 12 weeks. Half of them took garcinia cambogia and half took a placebo.  Everybody in the study lost a significant amount of weight, thanks to the low-calorie diet. But there was no difference between the two groups. That study was published in JAMA in 1998.

Over the next decade or so, a couple dozen additional studies were done. Many of them were small. Some of them weren't particularly well designed. And the results varied. Some studies found positive effects, which helped bolster its reputation and spur supplement sales.  Other studies, however, failed to find any benefit from taking garcinia. So, what should we believe?

When you have a whole bunch of studies on the same subject, researchers will often attempt to pool the data from all the studies and re-crunch the numbers.  This is called a meta-analysis and the results are generally considered to be more reliable than the individual studies. And in 2011, researchers conducted meta-analysis of all the published studies on HCA as a weight loss aid for humans...

Researchers concluded that, when taken along with a reduced calorie diet, HCA does seem to enhance weight loss compared to a placebo. However, the impact was slight, amounting to about two pounds. There also isn't much evidence to suggest that the benefits are lasting. 

These disappointing findings don't seem to have put much of a dent in garcinia sales. Why not? Well, that's one big difference between the research lab and the consumer marketplace. Scientists are always looking for a reason to disbelieve a hypothesis. Consumers, on the other hand, are always looking for a reason to believe--especially when it comes to weight loss miracles.

Does Garcinia Suppress Appetite?

As I said earlier, my friend Carly has the impression that garcinia takes the edge off her appetite, so I was curious to see whether any of the studies had looked at this claim. Five of the studies reviewed for the meta-analysis did collect data on hunger and appetite. Two reported an appetite-reducing effect. Three other studies, however, found no effect compared with placebo. 

So, is my friend Carly wasting her money on this supplement? That's hard to say. In terms of statistical probability, it doesn't appear to offer much benefit. But statistics don't always predict an individual's experience. After all, at least a few of the subjects in a few of these trials reported positive effects from garcinia. Carly admits that the benefits she perceives might be purely psychological, but that she'd still consider that money well spent. 

More importantly, Carly doesn't expect garcinia to do all the work for her. She exercises almost every day, doesn't keep sweets or snacks in the house, and is very disciplined about her eating habits. 

Are There Safety Concerns with Garcina?

The meta-analysis also looked at the adverse effects reported in all the studies. Most of the time, complaints such as gastro-intestinal symptoms or headaches were reported just as often with placebo as they were with the garcinia and everyone's blood work looked fine. Based on that, it would appear that short-term use is fairly safe. However, there have been some reports of liver toxicity associated with long-term use of HCA. Based on that, I would advise against taking garcinia every day for more than a couple of months. And if you decide to experiment, be sure not to exceed the recommended dosage.

Also, be realistic about your expectations. There's no such thing as will-power-in-a-pill or a supplement that will let you eat all you want and still lose weight. Weight managment takes patience, diligence, and restraint. At best, weight loss supplements might offer a slight edge to those who are already doing the hard part.  

Diet Pill image courtesy of Shutterstock

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