You might think of coffee as your “vice,” but believe it or not studies show that in many instances coffee consumers have a lower risk of several serious diseases compared to non-consumers — whether we’re talking traditional coffee, mushroom coffee, or green coffee bean.
Green coffee is simply raw, unroasted coffee beans. Proponents claim that green coffee, green coffee extract, and green coffee supplements offer a variety of health benefits. While primarily used for weight loss, green coffee may help regulate blood sugar and improve cognitive and memory skills in older adults.
The roasting process of coffee beans reduces amounts of the chemical chlorogenic acid. Therefore, green coffee beans have a higher level of chlorogenic acid compared to regular, roasted coffee beans. Chlorogenic acid in green coffee is thought to have health benefits.
Green coffee became popular for weight loss after it was mentioned on the Dr. Oz show in 2012. The Dr. Oz show referred to it as “The green coffee bean that burns fat fast” and claims that no exercise or diet is needed.
People take green coffee by mouth for obesity, diabetes, high blood pressure, Alzheimer’s disease, and bacterial infections.
Does green coffee extract actually promote weight loss? There haven’t been a lot of studies on chlorogenic acids and their effectiveness as weight loss supplements. A review of human studies did show that green coffee extract may have the potential to help with weight loss. But the documented effects on weight loss were small, and the studies weren’t long term. The studies were also poorly designed. So, there isn’t enough evidence to say that the supplements are effective or safe. More research is needed.
Chlorogenic acid is a polyphenol compound found in coffee beans and different types of coffee, including green coffee.
Chlorogenic acid primarily exerts its effects by inhibiting the enzyme alpha-glucosidase, which is responsible for breaking down carbohydrates. Therefore, it reduces the uptake of carbohydrates and glucose during digestion [8, 9].
Chlorogenic acid also has a mild psychostimulatory effect, about ⅓ of caffeine. This is mediated by the breakdown products, caffeic acid and m-coumaric acid .
Oral ingestion of Green Coffee Extract may weakly reduce body weight in overweight and obese persons (mechanisms currently unknown, thought to be related to preventing carbohydrate uptake from the intestines after a meal) although the degree of weight reduction seems quite unreliable at this moment in time; studies in lean persons are nonexistent right now.*
*Sep 26, 2018
In mice, green coffee bean extract in combination with a high-fat diet significantly reduced body weight gain and fat mass [149,150]. Only a few clinical trials have examined the effects of green coffee bean on weight loss in humans, and all were of poor methodological quality. Onakpoya and colleagues conducted a meta-analysis of three trials in which overweight participants received either 180 or 200 mg/day green coffee extract for 4 to 12 weeks . The researchers concluded that green coffee extract has a moderate but significant effect on body weight (mean weight loss of 2.47 kg more than placebo), but they noted that the methodological quality of all studies included in the meta-analysis was poor.
The effectiveness ratings for GREEN COFFEE are as follows:
Insufficient evidence to rate effectiveness for…
- High blood pressure. Early research suggests that taking green coffee extracts containing 50 mg to 140 mg of chlorogenic acids daily for 4 weeks to 12 weeks can reduce blood pressure in Japanese adults with mild and untreated high blood pressure. Systolic blood pressure (the top number) appears to be reduced by 5 mmHg to 10 mmHg. Diastolic blood pressure (the bottom number) appears to be reduced by 3 mmHg to 7 mmHg.
- Obesity. Early research shows that adults with obesity who take a specific green coffee extract (Svetol, Naturex) five times daily for 8 weeks to 12 weeks, either alone or together with the regular coffee product Coffee Slender (Med-Eq Ltd., Tonsberg, Norway), lose an average of 2.5 to 3.7 kg more weight than people taking a placebo or regular coffee by itself.
- Alzheimer’s disease.
- Type 2 diabetes.
- Other conditions.
Green coffee contains chlorogenic acid, a powerful antioxidant that tends to break down when coffee beans are roasted. Some research suggests that the retention of chlorogenic acid in green coffee is largely responsible for the health benefits.
Although research is limited, there is evidence that green coffee can stimulate metabolism (the conversion of calories and oxygen into energy). Metabolism doesn’t only imply digestion; it dictates how well all cells in the body function, including those of the heart, lung, kidney, liver, and brain.
The caffeine found in green coffee has a positive effect on your mood and brain activity. According to a review published in February 2008 in “Nutrition Bulletin,” several studies have confirmed that caffeine can improve reaction time, vigilance, memory, alertness, focus, fatigue resistance and other factors of cognitive performance. Reviewers found the optimal intake of green coffee to be between 38 to 400 milligrams per day, or between approximately 1/3 cup to four cups of brewed coffee.
Green coffee extract appears to be well tolerated, but its safety has not been rigorously studied. Reported adverse effects include headaches and urinary tract infections . The caffeine naturally present in green coffee beans acts as a stimulant and can cause adverse effects, depending on the dose and whether it is combined with other stimulants (see section on caffeine above).
Studies using Green Coffee Extract (GCE) tend to be dosed based on their chlorogenic acid content, which in isolation are taken in the 120-300mg range. Based on this, recommended intakes of GCE would be approximately:
- 1,200-3,000mg for a 10% chlorogenic acid supplement
- 600-1,500mg for a 20% chlorogenic acid supplement
- 240-600mg for a 50% chlorogenic acid supplement
The optimal dosage of both GCE and isolated chlorogenic acid is not known at this moment in time.