Weight loss | October 4, 2014 | Author: The Super Pharmacist
Garcinia cambogia is a plant rich in a chemical known as hydroxycitric acid. This molecule is linked to weight loss and obesity-related disease prevention on a number of levels. These properties have been confirmed by clinical trials, leading to the approval of hydroxycitric acid, mostly sold in the form of garcinia extract, as a weight-loss supplement.
Some reports and studies have concluded that there is an association between hydroxycitric acid and appetite suppression, body-fat reduction and changes in biological markers of obesity and cardiovascular disorders.
Hydroxycitric acid is an inhibitor of the enzyme citrate lysase, which plays an important role in the synthesis of cholesterol, fatty acids and complete fat molecules in the body. This may promote the storage of fats in body tissues rather than its breakdown to release energy as fuel. Other factors reportedly affected by garcinia extract intake include:
Actual body fat can be quantified using a number of methods, including X-ray analysis and water displacement. Some papers interpret changes in overall bodyweight as changes in body fat, but this is not necessarily the same thing. Hydroxycitric acid is associated with reductions in bodyweight, measured using various methods including the body mass index measurement system.
Trials of garcinia supplements resulted in significant decreases in the BMI of human trial subjects. and had a slightly significant, but temporary effect on weight loss.
A high concentration of dietary triglycerides (fat molecules) in the circulatory system may be associated with a higher probability of increased body fat, as these molecules end up stored in fat cells rather than being broken down as fuel. This is the basis of a disorder known as dyslipidaemia (a failure to metabolise fats), which may develop into full-blown obesity if left unaddressed. Garcinia-derived hydroxycitric acid (2.8mg three times daily before meals for 8 weeks was shown to significantly reduced triglycerides. Although another ten-week, placebo-controlled trial found garcinia extract had no significant effect on triglyceride levels.
The presence of high cholesterol in the blood is often associated with the increased risk of cardiovascular disorders. Cholesterol also forms complexes with certain proteins in the body to form lipoproteins. Low-density lipoproteins (LDLs) are associated with increased risk of disease, whereas the high-density varieties (i.e. HDLs) tend to be associated with reduced risks. Garcinia extract has been associated with significant LDL reductions, and with increased HDL.
A trial randomising 60 moderately obese subjects to hydroxycitric acid, a combination of this and other supplements linked to metabolism and obesity control, or placebo, found that LDL was significantly reduced by both the acid and the combination treatment. A trial of 86 overweight (by WHO standards, but obese by standardised Asian classification) Korean volunteers were randomised to either garcinia, soy-leaf extract (another putative weight management supplement) or placebo. There was no significant difference between the LDL or HDL levels of those on garcinia and placebo by the end of the ten-week study.
Leptin is a protein which plays a role in appetite regulation. Leptin-reducing drugs and supplements may contribute to weight management.
Garcinia-derived hydroxycitric acid was associated with significant decreases in leptin concentrations in early human trials. Although anouther study of fat cells cultured from obese women demonstrated that hydroxycitric acid increases leptin expression in adipocytes, which contributes to appetite reduction and the inhibition of fat storage.
Anouther trial comparing 30 obese women receiving 2.4g garcinia extract (providing approximately 1.2g hydroxycitric acid) to 13 women of similar body mass receiving placebo for 60 days found that there was no significant change in leptin levels for either group.
This is a neurotransmitter, or molecule which acts to regulate parts of the nervous system, which also plays a role in appetite control. Increased serotonin is indirectly associated with reduced feelings of hunger and food craving.
Animal studies suggest that hydroxycitric acid influences serotonin availability in the brain in a manner similar to some types of antidepressant. Garcinia extract significantly increased serotonin and reduced food intake in a one-way trial including 60 volunteer subjects.
Oxidation is a more favourable outcome in this case, as it is an indication that dietary triglycerides are being broken down as fuel and not stored as body fat. Animal trials suggest that garcinia extract or hydroxycitric acid increase fat molecule oxidation. Significantly increased fat oxidation, as measured by the concentration of fat breakdown products (or metabolites) in the urine of human subjects, was associated with garcinia extract in one trial.
A trial comparing the effects of exercise on six (non-athletic) women taking 250mg garcinia supplement for five days showed a moderately significant increase in fat metabolism and exercise performance, compared to the effects on exercise on the same women after five days on a placebo. A similar trial including women in ongoing training yielded similar results. A placebo-controlled human trial found that hydroxycitric acid again increased urinary fat metabolites.
Antioxidants are molecules that reduce or inhibit oxidative stress, a form of chemical deterioration at the biochemical or cellular level that is understood to contribute to atherosclerosis, blood vessel damage and damage to other tissues. Animal studies have demonstrated the ability of hydroxycitric acid to reduce oxidative stress. A human trial comparing 29 overweight subjects taking garcinia supplements to the same number receiving a placebo for ten weeks showed no significant changes in antioxidant levels for either group.
A trial may show varying results due the diverse anomalies of those being tested. The clinical data suggests hydroxycitric acid can work as an appetite suppression, reduce body fat and change biological markers of obesity and cardiovascular disorders for some people.
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