Chances are you’ve seen the ads, contests, and promotions for green coffee bean extract targeting women with Polycystic Ovary Syndrome (PCOS). If you’ve been wondering about the use of green coffee bean extract for helping with symptoms of PCOS, especially weight loss, then read below! I spill the beans and examine the scientific evidence of green coffee bean extract for the management of PCOS.
What is it?
Green coffee bean extract, a potential antioxidant, has high concentrations of polyphenols called chlorogenic acids (also present in roasted coffee and black tea). Chologenic acids influence glucose metabolism by inhibiting the enzyme glucose-6-phosphatase which plays a role in the liver’s glucose production. Besides weight loss and improvements in glucose, green coffee bean extract is also associated with minimizing blood pressure spikes.
Only a few human studies that use cholorgenic acid exist (none that examine the use in women with PCOS) and most had small sample sizes and poor design.
In the most recent study published in 2012 in Diabetes, Metabolic Syndrome and Obesity, overweight individuals from India were randomly assigned to a high-dose of cholorgenic acid, a low-dose of it, and a placebo for 6 weeks at a time, separated by a 2-week washout period. The chlorogenic acid content was 45.9%, and the dosage ranged from 700 to 1050 mg. No changes to diet were made. Significant reductions in body weight (an average of 10% loss), BMI, and percent body fat were found.
Many, however, question the validity of this study as it was funded by a supplement manufacturer. It had a tiny sample size (only 16 adults), lacked proper blinding and doses, had unreliable diet recalls, and repeated measurements. There was no mention of the results of those taking higher dosages of chlorgenic acid versus lower dosages. An article from Science-based Medicine summarizes the problems with this study well.
Another randomized control trial published in Nutrition and Metabolism studied the effects of 12 g decaffeinated coffee, 1 g chlorogenic acid, and placebo on glucose levels in 15 overweight men. No changes in glucose or insulin secretion were found.
There is some evidence, again from small sample sizes, that cholorgenic acid may lower blood pressure but more long-term and large sample sizes are needed.
Chlorogenic acid has been shown to raise total homocysteine concentrations in coffee and tea drinkers. (Elevated homocysteine levels is a risk factor for heart disease). Since cholorgenic acid may play a role in glucose metabolism, it could cause low blood sugar. It may also cause nutritional malabsorption issues and should not be used is you are pregnant or breastfeeding.
Don’t believe the hype or clever marketing. There is no “magic pill” for weight loss, especially one that claims weight loss without lifestyle changes. If there were, pharmaceutical companies wouldn’t be investing billions of dollars to find one.
Until more long-term and well controlled studies examining the use of green coffee bean extract in PCOS are done, it shouldn’t be recommended. Your money can be better well spent on dietary supplements that do have substantial and reliable evidence to improve reproductive and metabolic symptoms of PCOS such as n-acetyl cysteine (NAC) and myo-inositol and d-chiro inositol.