Weight Loss Diet Solutions

The Malabar tamarind was once just the less popular cousin of a trendy fruit, the mangosteen. But now, nutritional supplements containing extracts of the fruit with the scientific name Garcinia cambogia have become the rage, touted for their purported ability to curb appetite and stop weight gain. 

The Malabar tamarind, also known as the gambooge fruit, grows across southwest India, Myanmar and Indonesia. It ripens to a red or yellowish fruit about the size of an orange, but resembling the shape of a pumpkin.

People have long used the dried gambooge rinds for chutneys or curries, and sometimes as an aid for stomach problems. But in the late 1960s, scientists identified a substance in the rind of the fruit called hydroxycitric acid, or HCA, which has some potentially attractive qualities.

“Some studies have shown that HCA stops an enzyme that turns sugar into fat,” said Catherine Ulbricht, senior pharmacist at Massachusetts General Hospital in Boston and co-founder of Natural Standard Research Collaboration, which reviews evidence on herbs and supplements.

A fruit extract that could interfere with the body’s production of fat? The appeal is obvious. However, good results in test tubes don’t always translate to an entire person.

Does Garcinia cambogia work?

Some studies say HCA works, and some say it doesn’t. Animal studies of HCA showed that mice taking the substance ate less, lost weight and produced less fat from sugar.

Human studies had more conflicting results. One weight loss trial showed no difference between people who took Garcinia cambogia and those who took a placebo pill. Other trials linked HCA to weight loss and healthy blood lipid levels (lipids are fats).

“Further, well-designed clinical trials are needed before any firm conclusions can be made,” Ulbricht said.

If a pharmaceutical company wanted to sell HCA as a drug, the company would have to find stronger evidence that the substance worked, coming from better-designed clinical trials. Without that data, HCA wouldn’t pass U.S. Food and Drug Administration approval, Ulbricht said. But the FDA doesn’t put chemicals sold as nutritional supplements under the same burden of proof as pharmaceuticals.

In fact, supplement makers only have to make their products safe to eat and responsibly label them. Also, recent laboratory tests showed that most supplements sold online contain substantially less HCA than the label claims.

Despite the popularity of Garcinia cambogia, it is difficult to track how effective supplements containing it are.

“Preparation of products may vary from manufacturer to manufacturer, and from batch to batch within one manufacturer,” Ulbricht said. That makes it difficult to compare one brand to another or even to measure the effects of a single brand.

Is Garcinia cambogia safe?

People may safely eat the fruit, of course. And clinical trials have shown it’s safe to take Garcinia cambogia extract by mouth — at least for 12 weeks, the length of the studies.

But take caution. Garcinia cambogia has side effects — it may lower a person’s blood sugar, so it can interact with diabetes treatments. The fruit hasn’t been adequately studied in pregnant women or women who breastfeed. And Garcinia cambogia may be a problem for patients with Alzheimer’s or other forms of dementia, Ulbricht said.

In 2009, the FDA issued a safety warning after receiving more than 20 reports of severe reactions, including liver damage, in people taking the supplement Hydroxycut. At the time, Hydroxycut contained Garcinia cambogia extract and other compounds, including chromium polynicotinate and Gymnema sylvestre extract.

A case study published in 2016 in the World Journal of Gastroenterology by Keri E. Lunsford, et al., examined an instance where Garcinia cambogia caused hepatic failure resulting in the need of a liver transplant. The subject had taken the supplement for several months before his liver had failed. The researchers report that this is the first known case of acute liver failure known to be tied to Garcinia cambogia. Liver damage due to other drugs and alcohol had been ruled out, and Garcinia cambogia was the only supplement or drug that the patient had ingested. Much more research is needed in this area, according to the researchers, and in the meantime, the public should be made aware of the potential risks of taking this supplement.

Ulbricht said it’s unclear if the Garcinia cambogia extract caused the liver damage.

The bottom line is that people should tell their doctors before trying a new supplement, including Garcinia cambogia and HCA, she said.

Additional reporting by Rachel Ross, Live Science contributor.

ABB-Photo/Shutterstock

As with any diet pill dubbed a “miracle,” garcinia cambogia is probably too good to be true.

Garcinia cambogia, also called Malabar Tamarind, is a small, sweet Indonesian fruit that came to light in the late 1960s, when scientists discovered an acid it contains that closely resembles the citric acid found in fruits like oranges and lemons. The acid, called hydroxycitric acid (HCA), has built a controversial reputation ever since as a miracle weight-loss supplement.

Advocates claim that HCA blocks fat by inhibiting a key enzyme called citrate lyase, which the body needs to make fat from carbohydrates. They also claim that it can suppress appetite by boosting serotonin levels, as low levels are linked to depression and emotional or reactive overeating. The end result is a supposed decrease in belly fat and a shift in body composition by boosting lean muscle mass.

Studies have shown weak results or were inconclusive. Many of them were performed using animals, which cannot fully support the same effects in humans, and the dosages that show success in animals are typically unrealistic to replicate in people. In one study of the supplement, guinea pigs on a high cholesterol diet given a different garcinia species called atrivirdis showed a decrease in lipid compositions levels and fat deposition in the aorta. Another rat study determined that it lowered body weight gain and visceral fat buildup thanks to a reduction in food intake.

A study on people published in the Journal of the American Medical Association in 1998 involving 135 subjects split into placebo and garcinia cambogia groups found that both groups lost weight, but there was no significant difference. Though subjects were given dietary recommendations, adherence wasn’t monitored outside of a food journal. The results seemed to show the weight loss was based more on awareness as opposed to diet pill supplementation. (Don’t forget to also include these supplements on your do-not-buy list.)

Researchers published findings in the Journal of Obesity in 2011 that revealed garcinia cambogia may increase weight loss by only one to two pounds on average. The team compared people who took garcinia cambogia extract to those who didn’t, and found very little weight-loss difference.

“There’s no reliable evidence to support claims for garcinia on weight loss,” said registered dietitian and nutritionist Marisa Moore, noting that there have been no large-scale trials comparing garcinia cambogia to placebos or other supplements and therefore no objective data to consider. “It’s not something I’d recommend,” she says, adding, “Not only is the research not there, but there is concern regarding its safety.”

Indeed, a 2005 study in Food and Chemical Toxicology found that high doses of garcinia cambogia extract caused testicular atrophy and toxicity in mice. Again, not everything translates from animal studies to people, but why take the risk?

Then there’s the concern of transparency behind the marketing ploys, as most brands of garcinia cambogia extract diet pills have failed independent laboratory quality and quantity testing, and many contain far less HCA than was listed on the bottle.

Unfortunately, slimming down usually requires good old diet and exercise. These simple weight-loss tips can make it easier.