Green Coffee Bean
Coffee – arguably the most commonly used caffeinated beverage – is integral to the productivity of everyone from college students to C.E.Os. Though it is known for its stimulating effect on the brain, its benefits expand far and wide beyond that. The components of coffee beans show promise in the inhibition of fat accumulation, promotion of weight loss, reducing blood glucose levels after meals, and keep the absorption of carbohydrates in check. It has previously been reported to help reduce the risk of Diabetes Mellitus type 2, promote fat breakdown in rodent fat cells, and increase energy expenditure in humans. Another study discovered that caffeine ingestion promotes glucose consumption associated with an increase in blood adrenaline, and when this ingestion occurs prior to exercise it can enhance respiration and fat breakdown.
These health benefits are provided mainly by the chlorogenic acids contained within the actual coffee beans [1]. Chlorogenic acid is one of the primary scientifically studied components of coffee beans. It was found to selectively impede the formation of new fat in the body. Green coffee beans are particularly well saturated with chlorogenic acid. The extract of green coffee beans (GCBE) contains 10% caffeine and 27% chlorogenic acid, which have shown a propensity for suppression of weight gain and visceral fat accumulation. Of note, roasting these beans to brew coffee was shown to diminish the chlorogenic acid content of coffee. Even though benefit can be seen with chlorogenic acid derived from coffee ingestion, supplementation is likely a more efficacious choice. The roasting process of coffee beans induces the compound HHQ, which can inhibit the actions of chlorogenic acid in the body, thereby diminishing the bioactivity of this healthy component of green coffee beans.
Delving deeper into the science behind these health benefits…
Long-term intake of cholinergic acid has been found to reduce carbohydrate uptake. One study found a roughly 7% reduction in glucose absorption in the intestines [1]. A link was observed between the amount of dietary carbohydrates and fat located in the fat reserves. This occurs secondary to the carbohydrate predominance in caloric intake in the diet; the sugar form of carbs reduces the requirement for caloric consumption from fat reserves due to normal insulin production and activity. This serves to ensure that they are metabolized first and not stored in the body. However, if the glucose concentration in the blood is in excess of that which is required, then hepatic glycogenesis occurs, and excess glucose enters into the adipocytes (fat cells) where glucose is stored as fat reserves. As a result, these fat reserves are not used for energy and an increase in adipocytes will occur instead. When a person is on a low-carb diet, this decreased carbohydrate intake results in the metabolism of fat reserves deposited in the adipocytes in order to compensate. This can in turn result in weight loss. Regulating the blood glucose level can capitalize on this mechanism by a shift of the liver to using enzymes that resulting in the release of glucose into the bloodstream (glycogenolysis). As a result, fatty deposits will not increase and can instead be used to create energy.
The formation of new fat occurs via adipogenesis – in which immature fat cells mature into adipocytes (fat cells), a process regulated by peroxisome proliferator-activated receptor γ2 (PPARγ2) and CCAAT/ enhancer-binding protein α (C/EBPα). PPARγ2 ultimately leads to adipocyte lipid binding protein (aP2) and the enzymes lipoprotein lipase (LPL) and fatty acid synthase (FAS), which work together to stimulate fat accumulation and metabolism. Deactivating these adipogenic regulators may be a novel way to suppress adipogenesis [2].
By inhibiting digestive enzymes, such as selectively impeding hepatic glucose-6-phosphatase, which is the enzyme that limits the rate at which gluconeogenesis – the formation of glucose from non-carbohydrate starting compounds – is able to take place. This causes a reduction in intestinal glucose available for absorption [3]. As a result, there will be a decrease in the amount of glucose that is available to enter into circulation, ultimately causing a decrease in blood glucose levels. An increase in glucagon-like peptide 1 occurs with a decrease in gastric inhibitory peptide. The combined effects of this peptide alteration is decreased insulin secretion, with secondary stimulation of lipolysis. Stored fat tissue is then broken down to supply energy. The combined effects of intestinal metabolism of starch and complex sugars, delayed absorption of glucose in the intestine, and release of glucose from the liver ultimately results in decreased levels of blood glucose, which can decrease the risk of diabetes and obesity [4].
Previous research found adiponectin – a protein hormone secreted by fat cells that regulates metabolism of lipids and glucose – increased fatty acid burning and energy consumption via PPARα activation. This led to reduced triglyceride content in the liver and skeletal muscle, associated with increased insulin sensitivity [5]. Plasma adiponectin level was shown to be significantly reduced in obese/diabetic mice models as well as humans. Chlorogenic acid significantly elevated the plasma adiponectin concentration and improved the adiponectin to leptin (the satiety hormone that is also released by fat cells) ratio in diet-induced obese mice. This research additionally suggested it to be a potential stimulator of hepatic fatty acid beta-oxidation.
The potential of green coffee beans to naturally decrease carbohydrate absorption, inhibit fat accumulation, reduce blood sugar, and promote weight loss makes this a supplement ingredient worth keeping an eye out for – or better yet, trying!
[1] E Thom. The effect of chlorogenic acid enriched coffee on glucose absorption in healthy volunteers and its effect on body mass when used long-term in overweight and obese people. J Int Med Res 35(6)900-8. 2007.
[2] SJ Song, S Choi, T Park. Decaffeinated Green Coffee Bean Extract Attenuates Diet-Induced Obesity and Insulin Resistance in Mice. Evid Based Complement Alternat Med. 2014.
[3] A.-S. Cho, S.-M. Jeon, M.-J. Kim et al., Chlorogenic acid exhibits anti-obesity property and improves lipid metabolism in high-fat diet-induced-obese mice. Food and Chemical Toxicology, vol. 48, no. 3, pp. 937–943, 2010.
[4] H Shimoda, E Seki, M Aitani. Inhibitory effect of green coffee bean extract on fat accumulation and body weight gain in mice. BMC Complementary and Alternative Medicine 2006.
[5] Kadowaki, T., Yamauchi, T. Adiponectin and adiponectin receptors. Endocr. Rev. 26, 439–451. 2005.
