Green coffee is a term that refers to raw, unroasted coffee beans. Proponents claim that green coffee (or green coffee extract) can offer a variety of health benefits. In addition, green coffee is often touted as a natural weight loss aid.
Green coffee contains chlorogenic acid, an antioxidant substance that breaks down when coffee beans are roasted. Some research suggests that chlorogenic acid may be responsible for the health effects of consuming green coffee.
Since coffee's distinctive aroma and flavor is developed during the roasting process, green coffee beans tend to lack aroma and bear a slightly bitter flavor.
Uses for Green Coffee
Green coffee is purported to prevent or treat the following health problems:
- colorectal cancer
- heart disease
- high blood pressure
- metabolic syndrome
- Parkinson's disease
Green coffee is also said to promote weight loss, reduce inflammation, and slow the aging process.
Benefits of Green Coffee
Although research on the health effects of green coffee is fairly limited, there's some evidence that green coffee may offer certain health benefits. Here's a look at some key findings from the available studies on green coffee:
1) Green Coffee and Weight Loss
Green coffee extract may be somewhat beneficial to those trying to lose weight, according to a 2011 research review published in Gastroenterology Research and Practice. For the review, investigators focused on the available clinical trials testing green coffee extract's efficacy as a weight loss supplement.
Looking at data from the three clinical trials that met their criteria, the investigators found that green coffee extract was significantly more effective than placebo in lowering participants' body weight. However, the authors caution that most of the reviewed studies were of poor quality and that more research is needed before green coffee extract can be recommended for weight loss.
In preliminary research on animals (including a 2006 study from BMC Complementary and Alternative Medicine), scientists have demonstrated that green coffee extract may protect against weight gain by fighting fat absorption and promoting the liver's metabolism of fat.
2) Green Coffee and Blood Pressure
Green coffee may benefit people with slightly elevated blood pressure, a 2005 study from Hypertension Research suggests. For the study, 117 men with mild hypertension (high blood pressure) received either a placebo or green coffee extract every day for 28 days. By the study's end, those given green coffee showed a significantly greater decrease in blood pressure compared to members of the placebo group.
3) Green Coffee and Alzheimer's Disease
Animal-based research indicates that green coffee extract could possibly play a role in Alzheimer's disease. In a 2012 study from Nutritional Neuroscience, tests on mice revealed that decaffeinated green coffee extract helped protect against impaired energy metabolism in the brain (a risk factor for Alzheimer's disease). In addition, the study found that green coffee extract helped fight insulin resistance.
Is Green Coffee Safe?
Although drinking green coffee is generally considered safe, there's some concern that long-term consumption of green coffee may increase levels of homocysteine (an amino acid linked to heart disease when it occurs at elevated levels). Additionally, green coffee may interfere with blood sugar control. Given these health concerns, it's important to seek medical advice prior to consuming green coffee in the long term.
It should also be noted that little is known about the safety of long-term consumption of supplements containing green coffee extract.
Where to Find Green Coffee
Green coffee can be found in many natural-foods stores and in some grocery stores. It's also widely available online. In addition, green coffee extract is sold in supplement form online and in many stores specializing in dietary supplements.
Should You Use Green Coffee for Health Purposes?
Due to a lack of scientific support, it's too soon to recommend green coffee for treatment of any health condition or for weight loss. If you're considering the use of green coffee in treatment of a chronic condition, make sure to consult your physician. It's important to note that self-treating a chronic condition with green coffee and avoiding or delaying standard care may have serious consequences.
Farah A, Monteiro M, Donangelo CM, Lafay S. "Chlorogenic acids from green coffee extract are highly bioavailable in humans." J Nutr. 2008 Dec;138(12):2309-15.
Ho L, Varghese M, Wang J, Zhao W, Chen F, Knable LA, Ferruzzi M, Pasinetti GM. "Dietary supplementation with decaffeinated green coffee improves diet-induced insulin resistance and brain energy metabolism in mice." Nutr Neurosci. 2012 Jan;15(1):37-45.
Kozuma K, Tsuchiya S, Kohori J, Hase T, Tokimitsu I. "Antihypertensive effect of green coffee bean extract on mildly hypertensive subjects." Hypertens Res. 2005 Sep;28(9):711-8.
Onakpoya I, Terry R, Ernst E. "The use of green coffee extract as a weight loss supplement: a systematic review and meta-analysis of randomised clinical trials." Gastroenterol Res Pract. 2011;2011. pii: 382852.
Shimoda H, Seki E, Aitani M. "Inhibitory effect of green coffee bean extract on fat accumulation and body weight gain in mice." BMC Complement Altern Med. 2006 Mar 17;6:9.