The search for and discovery of a natural diet product, with all its connotations of safety and purity and well, naturalness, should be expected. After all, for many people, weight loss is both a necessity and an obsession. So when Oprah-spinoff Dr. Oz recently publicized garcinia cambogia extract as a supplement that could hasten weight loss efforts, many dieters snapped it up immediately.

The herbal product is extracted from the dried fruit rind of garcinia cambogia, also known as Malabar tamarind, which is a source of hydroxycitric acid (HCA). Although sour in taste, HCA has been used for centuries by Southeastern Asian cooks to make dishes, in particular curries and chutneys, more filling. Tamarind, a small, pumpkin-shaped fruit, is native to Indonesia and also grown in India, Southeast Asia, and West and Central Africa. The fruit is sometimes used to cure fish as well as to preserve foods.

Researchers claim that HCA can double or triple one's weight loss without stimulating the central nervous system. In other words, garcinia cambogia extract is a kind of anti-ephedra. Dr. Oz recommends the herbal supplement for emotional eaters. He noted that those who participated in a particular study showed increased serotonin levels so the product may also improve mood and sleeping patterns.

How It Works

The HCA extract not only helps to block fat, but also suppresses the appetite.

Essentially, it stops the body from producing fat cells by inhibiting an enzyme, citrate lyase, that your body requires to convert fat from carbohydrates. Usually carbohydrates or sugars are not immediately used or stored turn into fats. When HCA inhibits citrate lyase, the process is interrupted and the production of LDL (bad cholesterol) as well as triglycerides decrease. In cell studies, the extract is shown to inhibit the cytoplasmic lipid accumulation and adipogenic differentiation of preadipocytes.

HCA also suppresses appetite by increasing levels of serotonin, a neurotransmitter in the brain that makes you feel good. It is believed that low levels of serotonin compel people to eat reactively (emotionally); in fact, because low levels of serotonin may make you feel depressed or anxious, serotonin is the target of many antidepressant medications. By increasing serotonin levels, HCA improves mood and suppresses the drive to react to stressful situations with food. As you eat less, your body releases stored fat in your fat cells.

One randomized placebo-controlled study, referred to by Dr. Oz, followed 60 obese persons for eight weeks. Sticking to a calorie-restricted diet (1200 kcal/day) and taking a dose of 1320 mg of HCA each day, the experimental group lost an average of 14 lbs., outdoing the placebo group who, on average, lost a mere 6.1 lbs. Participants in this study also reported reduced appetites.

Recommended Use

Although considered generally safe, this herbal supplement should not be taken by those who are pregnant or breastfeeding, those who are taking a diabetic medication (like insulin or glyburide), those who are taking a statin (cholesterol-lowering drug), and those who have been diagnosed with Alzheimer's disease or other forms of dementia.

The list of ingredients in whatever product you buy should be reviewed so as to avoid fillers and artificial ingredients. Dr. Oz reports that experts believe newly available HCA potassium salts are more effective than the other formulations. A dieter should take 500-1,000 mg before each meal, without taking more than 3,000 mg total per day. With no other changes to your diet or exercise routine, you may lose 2 to 4 lbs. within one month.

Side Effects

According to Zhion, garcinia cambogia did not show serious side effects in some animal studies. For instance, one study involving rats treated for a period of 90 days showed HCA results in a reduction in body weight, but did not cause any side effects of hepatic and testicular lipid peroxidation, DNA fragmentation, or histopathological changes. Another study of rats found that administration of HCA-SX (dosages up to 2,500 mg/kg/day) for a period of 90 days caused a significant decrease in body weight and reduction in feed consumption without any serious side effects.

Not all studies proved HCA innocuous, though. One study of male Zucker obese rats found that high dosages of garcinia cambogia extract caused potent testicular atrophy and toxicity.

Additionally, some dieters have reported these side effects when using garcinia cambogia extract:

  • Mild nausea
  • Digestive tract discomfort and/or more frequent bowel movements
  • Mild headaches and/or dizziness

As with any untested product, it is recommended dieters consult with their doctors before use. Although garcinia cambogia extract is natural and considered safe, the possibility of frequent bowel movements may not be the kind of weight loss you have in mind.

Source: Márquez F, Babio N, Bulló M, Salas-Salvadó J. Evaluation of the safety and efficacy of hydroxycitric acid or Garcinia cambogia extracts in humans. Critical Reviews in Food Science and Nutrition. 2012.