Green coffee beans are coffee beans that have not yet been roasted. 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 for heart disease, diabetes, weight loss, and others.
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.
How does it work?
Green coffee beans are coffee beans that have not yet been roasted. These coffee beans contain a higher amount of the chemical chlorogenic acid. This chemical is thought to have health benefits. For high blood pressure it might affect blood vessels so that blood pressure is reduced.
For weight loss, chlorogenic acid in green coffee is thought to affect how the body handles blood sugar and metabolism.
Possibly Effective for:
- High blood pressure (hypertension). Some research shows that people with mild high blood pressure who take a specific green coffee extract (Svetol, Naturex) 93 mg daily or 185 mg daily have reduced blood pressure after 28 days of treatment. Other studies evaluating the effects of a different green coffee extract or a certain component of green coffee found similar results.
- Weight loss. Some research shows that taking green coffee extract (Svetol, Naturex) 80-200 mg daily might cause modest weight loss over a period of 12 weeks. However, the research so far is preliminary and poor quality.
Side Effects & Safety
Green coffee is POSSIBLY SAFE based on the limited research that has been done in people so far. In clinical research, no serious side effects were reported when green coffee or green coffee extract was taken by mouth at appropriate doses.
Green coffee extract is LIKELY UNSAFE when inhaled due to adverse respiratory effects.
Also, it is important to understand that green coffee contains caffeine, similar to regular coffee. Therefore, green coffee can cause caffeine-related side effects similar to coffee.
Caffeine can cause insomnia, nervousness and restlessness, stomach upset, nausea and vomiting, increased heart and breathing rate, and other side effects. Consuming large amounts of coffee might also cause headache, anxiety, agitation, ringing in the ears, and irregular heartbeats.
Special Precautions & Warnings:Pregnancy and breast-feeding: There isn’t enough reliable information about the safety of taking green coffee if you are pregnant or breast feeding. Stay on the safe side and avoid use.
Abnormally high levels of homocysteine. Consuming a high dose of chlorogenic acid for a short duration has caused increased plasma homocysteine levels, which may be associated with conditions such as heart disease.
Anxiety disorders: The caffeine in green coffee might make anxiety worse.
Bleeding disorders: There is some concern that the caffeine in green coffee might make bleeding disorders worse.
Diabetes: Some research suggests that caffeine contained in green coffee might change the way people with diabetes process sugar. Caffeine has been reported to cause increases as well as decreases in blood sugar. Use caffeine with caution if you have diabetes and monitor your blood sugar carefully.
Diarrhea: Green coffee contains caffeine. The caffeine in coffee, especially when taken in large amounts, can worsen diarrhea.
Glaucoma: Taking caffeine which is contained in green coffee can increases pressure inside the eye. The increase starts within 30 minutes and lasts for at least 90 minutes.
Heart disease: When taken at high doses over a short time period, a certain component of green coffee may increase the levels of a particular amino acid in the body (known as homocysteine) that is associated with an increased risk of heart disease. Also, other components of green coffee (known as diterpenes) have been associated with increased cholesterol levels, which are also associated with an increased risk of heart disease.
High blood pressure: Taking caffeine found in green coffee might increase blood pressure in people with high blood pressure. However, this effect might be less in people who consume caffeine from coffee or other sources regularly.
High cholesterol. Certain components of unfiltered coffee have been shown to increase cholesterol levels. These components can be found in green coffee as well. However, it is unclear if green coffee can also cause increased cholesterol levels.
Irritable bowel syndrome (IBS): Green coffee contains caffeine. The caffeine in coffee, especially when taken in large amounts, can worsen diarrhea and might worsen symptoms of IBS.
Thinning bones (osteoporosis): Caffeine from green coffee and other sources can increase the amount of calcium that is flushed out in the urine. This might weaken bones. If you have osteoporosis, limit caffeine consumption to less than 300 mg per day (approximately 2-3 cups of regular coffee). Taking calcium supplements may help to make up for calcium that is lost. Postmenopausal women who have an inherited condition that keeps them from processing vitamin D normally, should be especially cautious when using caffeine.
The following doses have been studied in scientific research:
- High blood pressure: a specific green coffee extract (Svetol, Naturex) 93 mg daily or 185 mg daily.
- Weight loss: a green coffee extract (Svetol, Naturex) 80-200 mg daily. Or another green coffee extract (GCA, Applied Food Sciences), 700 mg daily or 1050 mg daily.