Green coffee beans are coffee seeds (beans) of Coffee fruits that have not yet been roasted. The roasting process reduces amounts of a chemical called 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 for obesity, diabetes, high blood pressure, and other conditions, but there is no good scientific evidence to support most of these uses.
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.
Uses & Effectiveness
Insufficient Evidence for
- High blood pressure. Early research suggests that taking green coffee extract for up to 12 weeks modestly reduces blood pressure in adults with mild high blood pressure.
- A grouping of symptoms that increase the risk of diabetes, heart disease, and stroke (metabolic syndrome). Early research suggests that taking green coffee extract reduces blood pressure and blood sugar by a small amount in adults with this condition. But blood sugar and levels of cholesterol and other fats were not improved.
- Obesity. Taking green coffee extract for 8-12 weeks seems to reduce weight by a very small amount in overweight adults or adults with obesity.
- High cholesterol.
- Alzheimer disease.
- Other conditions.
More evidence is needed to rate green coffee for these uses.
When taken by mouth: Green coffee is POSSIBLY SAFE when taken appropriately. Green coffee extracts taken in doses up to 480 mg daily have been used safely for up to 12 weeks. Also, a specific green coffee extract (Svetol, Naturex) has been used safely in doses up to 200 mg five times daily for up to 12 weeks.
Green coffee contains caffeine. There is much less caffeine in green coffee than in regular coffee. But green coffee can still cause caffeine-related side effects similar to coffee. These include 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 and Warnings
Pregnancy and breast-feeding: There isn’t enough reliable information to know if green coffee is safe to use when 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.
Epilepsy: Green coffee contains caffeine. People with epilepsy should avoid using caffeine in high doses. Low doses of caffeine should be used cautiously.
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.
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 green coffee or other sources regularly.
Irritable bowel syndrome (IBS): Green coffee contains caffeine. The caffeine in green coffee, especially when taken in large amounts, might worsen the diarrhea some people have with 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. Taking calcium supplements may help to make up for calcium that is lost. If you are generally healthy and getting enough calcium from your food or supplements, taking up to 400 mg of caffeine daily (about 20 cups of green coffee) doesn’t seem to increase the risk of getting osteoporosis. Postmenopausal women who have an inherited condition that keeps them from processing vitamin D normally, should be especially cautious when using caffeine.
The appropriate dose of green coffee beans depends on several factors such as the user’s age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for green coffee (in children/in adults). Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.