Hypertension and Green Coffee Bean Extract
Coffee is made from roasted coffee beans. Unroasted coffee beans are green. An extract made from these green coffee beans is being investigated as a possible health-promoting supplement, including as a way to lower blood pressure. Like green tea, green coffee bean extract (GCBE) contains strong antioxidants.
Recent studies suggest that Green Coffee Bean Extract may have a multitude of health benefits, mainly in dealing with health challenges that stem from oxidative stress (such as heart disease or cancer). The most convincing evidence supports the claim that GCBE may help reduce blood pressure.
The key compound within Green Coffee Bean Extract that is thought to have anti-hypertensive effects is chlorogenic acid, which is apart of the primary polyphenol antioxidants family. in green coffee bean extract are in a family known as chlorogenic acids (CGA).
Because Green Coffee Bean Extract’s popularity is a recent phenomenon, the body of research supporting its health benefits is minimal. Still, a few human studies and several more animal studies researching the impact of GCBE on hypertension have been conducted.
Animal studies have found evidence that chlorogenic acids (antioxidants) from green coffee bean extract can reduce blood pressure.1 Based on this, researchers have conducted human trials.
Positive Impact. In a double-blind, placebo-controlled study of 117 males with mild hypertension, GCBE was given for one month at 46 mg, 93 mg, or 185 mg daily.2 After 28 days, the results showed a significant improvement in blood pressure as compared to placebo in the 93 mg and 185 mg groups. The results seen were dose-related, meaning that the greater the dose, the greater the improvement.
Positive Impact. In another double-blind, placebo-controlled study, 28 Japanese with mild hypertension (defined as systolic blood pressure of 140-159 mmHg and/or diastolic blood pressure of 90-99 mmHg) were participants in a GCBE study. Over the course of 12 weeks, half of the group consumed fruit juice containing Green Coffee Bean Extract, while the other half drank fruit juice with no extract added (placebo). Around 500 mg of GCBE was added to the juice. Results showed that while the placebo group showed no reduction in blood pressure, the GCBE consuming group both had statistically significant reductions to their systolic and diastolic blood pressures4.
Positive Impact. A study on two different rat species showed that both a single oral dose and a long-term daily dose (6 week) caused a reduction in blood pressure. However, this study did not use Green Coffee Bean Extract in the study, but rather a concentrated chlorogenic acid, the essential substance within the extract. What makes this study interesting is that it compared the impact of Green Coffee Bean Extract to Roasted Coffee extract. The results showed that roasted coffee extract had no correlation with reduced blood pressure, revealing the especially unique nature of GCBE.
In the large human trial of GCBE for hypertension mentioned in this article, the extract was most effective when taken at a dose of 185 mg daily.
Since green coffee bean extract typically contains about 30% chlorogenic acids, this works out to a dose of about 60 mg of chlorogenic acids daily. Another study used 140 mg of purified chlorogenic acids daily.
- Naturopathic doctor
- Nutritionist or dietitian
- Integrative MD
The lack of large-scale human trials on Green CoffeeBean Extract has caused there to be minimal evidence on its potential long-term side effects. Generally, it is thought to be a safe substance.
In human trials, no significant adverse effects have been seen.
- In the 117 person male study that showed promising results in reducing blood pressure, no adverse effects from GCBE were shown in the physical, clinical, or medicine/history examinations. (Read more about GCBE & Blood Pressure)
- Similarly, in the study of 28 Japanese patients taking GCBE for two months, no serious side effects coincided with the extracts beneficial impact on hypertension. Long-term ingestion of the extract did not change any biochemical balances in the blood- serum iron, magnesium, copper, zinc, and vitamin B1 levels stayed in balance throughout the treatment. In this study, a physician judged the clinical safety by assessing side effects, lending credibility to the study.
Green Coffee Bean Extract has been correlated with weight loss, and as with any other weight loss substance, there is good reason to be cautious. Taking any substance meant for weight loss can have adverse side effects if used irrationally. Before choosing to use GCBE, consult your physician to see if its right for you. (Read More about GCBE & Weight Loss.)
In theory, the caffeine content of GCBE could potentially cause problems for some people. However, since GCBE contains only about 10% caffeine by weight, a high daily dose contains no more than about 20% of the caffeine content of a strong cup of coffee. If you are experiencing adverse symptoms, it is a good idea to research the side effects of caffeine, as this compound may be the reason GCBE is giving you problems.
Maximum safe doses in pregnant or nursing women, young children, or people with liver or kidney disease have not been established.
- Kozuma K, Tsuchiya S, Kohori J et al. Antihypertensive effect of green coffee bean extract on mildly hypertensive subjects. Hypertens Res. 2006;28:711-8.
- Watanabe T, Arai Y, Mitsui Y et al. The blood pressure-lowering effect and safety of chlorogenic Acid from green coffee bean extract in essential hypertension. Clin Exp Hypertens. 2006;28:439-49.
- Suzuki A, Yamamoto N, Jokura H et al. Chlorogenic acid attenuates hypertension and improves endothelial function in spontaneously hypertensive rats. J Hypertens. 2006;24:1065-73.