The task of losing weight is complicated and that is why many people seek to facilitate the path by consuming supplements.
The green coffee extract is one of them and, currently, one of the most popular in the world. As its name suggests, it is extracted from green coffee beans and contains a substance called chlorogenic acid, which is allegedly responsible for its effects on weight loss.
This extract was promoted by Dr. Oz in 2012. This specialist is an American doctor famous for his television appearances, and is one of the best-known "health gurus" in the world.
But the truth is that most weight loss supplements never work as promised. So, it's time to take a detailed look at the green coffee extract to see how it works and what science says about it.
green coffee cup
Green coffee beans are basically unroasted coffee beans.
Coffee is naturally green, but it is usually roasted before being put on the market and that process obscures it.
The coffee beans are full of antioxidants and active pharmacological components. Two of the most important are caffeine and chlorogenic acid.
The latter is the main active ingredient in green coffee beans, that is, the substance that makes weight loss effective (1).
Unfortunately, most chlorogenic acid is lost once the coffee bean is roasted (2). Thus, regular coffee beans do not have the same effect (although there are also many good reasons to drink coffee).
In summary: the green coffee beans are the same as the regular ones, except they have not been toasted. They have a high content of chlorogenic acid.
woman measuring waist
Green coffee beans contain a certain amount of caffeine. And several studies have shown that caffeine can accelerate metabolism between 3 and 11% (3).
However, the main active ingredient, it is believed, is chlorogenic acid.
Some studies in humans suggest that chlorogenic acid can reduce the absorption of carbohydrates in the digestive tract, which lowers blood sugar levels and insulin spikes(4).
If this is the case, taking green coffee extract would be the same as consuming a diet slightly low in carbohydrates.
Other studies (in rats) suggest that chlorogenic acid can reduce body weight, fat absorbed from the diet and fat stored in the liver, in addition to improving the functions of the adiponectin-fat-burning hormone (5).
Chlorogenic acid has also been shown to be useful in improving cholesterol and triglyceride levels in rats (6).
In summary: green coffee inhibits weight gain in animal studies. It is likely that this has to do with less absorption of carbohydrates from the diet, or via other mechanisms.
green coffee pills
One of the human studies on green coffee extract included 30 overweight individuals for 12 weeks.
They were divided into two groups: one consumed regular instant coffee, the other instant coffee enriched with 200 mg of green coffee extract. None of the two groups was instructed to change their exercise habits (7).
The group that drank instant coffee with green coffee extract lost 5.4 kilograms, while the group that drank only instant coffee lost 1.7 kilograms.
The percentage of body fat also decreased by 3.6% in the group that consumed the extract, compared with 0.7% in the other group.
Other studies have also reported significant weight loss in people who consumed green coffee extract (8).
However, it is important to keep in mind that some of these studies were sponsored by companies that make money from sales of the extract.
This does not mean that the studies are not valid, but it is known that the source of funding for a study can have significant effects on their results. For this reason, it is a good idea to be skeptical about industry-funded research (9).
Meanwhile, in 2011, a review of the evidence behind the green coffee extract concluded that "the effects of these tests are promising, but the studies are of poor methodological quality. More rigorous studies are needed to determine the utility of green coffee extract as a tool to lose weight "(10).
In summary: several controlled studies in humans show that green coffee extract can lead to significant weight loss. However, these studies were relatively small and some of them were financed by industries.
green coffee berries
Green coffee can positively affect the way the body absorbs and uses carbohydrates. As hypothesized in animal studies, chlorogenic acid appears to reduce glucose uptake (11).
This effect could play a protective role in the management of diabetes and explain the effects on weight.
The green coffee extract could also positively affect the blood vessels, which impacts on the health of the heart.
Doses between 140-720 mg per day have been shown to lower blood pressure in both rats and humans with high blood pressure (12, 13). And chlorogenic acid also works as an antioxidant (14).
In summary: the green coffee extract improves the metabolism of glucose and reduces blood pressure. This could be beneficial for people at high risk of diabetes and heart disease.
Side effects, dosage and how to use it.
According to the limited amount of available evidence, the green coffee extract seems to be quite safe.
However, some participants dropped out of a study due to headaches and urinary infections (15).
This study was too small to show if the side effects were caused by the supplement, it could have been just a coincidence.
Green coffee contains caffeine, which can have several side effects if it is consumed in large quantities. This includes anxiety, tremors and tachycardia.
If you are sensitive to caffeine, you have to be careful with the green coffee extract.
Chlorogenic acid can have a laxative effect and cause diarrhea (16).
Some people have had allergic reactions to green coffee beans. And the extract should be avoided if you have already had an allergy to coffee (17).
The safety of green coffee for pregnant or breastfeeding women has not been tested yet, and should not be consumed by children.
There is currently no study that determines an optimal dose for green coffee extract. However, the studies cited in this article used doses ranging from 120 to 300 mg of chlorogenic acid.
Depending on the concentration of this substance in the supplement, the range can then go from 240 to 3000 mg of green coffee extract per day.
It is advisable to follow the instructions that accompany the product. A common instruction is to take a dose half an hour before each meal.
The green coffee extract is one of them and, currently, one of the most popular in the world. As its name suggests, it is extracted from green coffee beans and contains a substance called chlorogenic acid, which is allegedly responsible for its effects on weight loss.
This extract was promoted by Dr. Oz in 2012. This specialist is an American doctor famous for his television appearances, and is one of the best-known "health gurus" in the world.
But the truth is that most weight loss supplements never work as promised. So, it's time to take a detailed look at the green coffee extract to see how it works and what science says about it.
What are green coffee beans?
green coffee cup
Green coffee beans are basically unroasted coffee beans.
Coffee is naturally green, but it is usually roasted before being put on the market and that process obscures it.
The coffee beans are full of antioxidants and active pharmacological components. Two of the most important are caffeine and chlorogenic acid.
The latter is the main active ingredient in green coffee beans, that is, the substance that makes weight loss effective (1).
Unfortunately, most chlorogenic acid is lost once the coffee bean is roasted (2). Thus, regular coffee beans do not have the same effect (although there are also many good reasons to drink coffee).
In summary: the green coffee beans are the same as the regular ones, except they have not been toasted. They have a high content of chlorogenic acid.
How does the green coffee extract work?
woman measuring waist
Green coffee beans contain a certain amount of caffeine. And several studies have shown that caffeine can accelerate metabolism between 3 and 11% (3).
However, the main active ingredient, it is believed, is chlorogenic acid.
Some studies in humans suggest that chlorogenic acid can reduce the absorption of carbohydrates in the digestive tract, which lowers blood sugar levels and insulin spikes(4).
If this is the case, taking green coffee extract would be the same as consuming a diet slightly low in carbohydrates.
Other studies (in rats) suggest that chlorogenic acid can reduce body weight, fat absorbed from the diet and fat stored in the liver, in addition to improving the functions of the adiponectin-fat-burning hormone (5).
Chlorogenic acid has also been shown to be useful in improving cholesterol and triglyceride levels in rats (6).
In summary: green coffee inhibits weight gain in animal studies. It is likely that this has to do with less absorption of carbohydrates from the diet, or via other mechanisms.
What do human studies say?
green coffee pills
One of the human studies on green coffee extract included 30 overweight individuals for 12 weeks.
They were divided into two groups: one consumed regular instant coffee, the other instant coffee enriched with 200 mg of green coffee extract. None of the two groups was instructed to change their exercise habits (7).
The group that drank instant coffee with green coffee extract lost 5.4 kilograms, while the group that drank only instant coffee lost 1.7 kilograms.
The percentage of body fat also decreased by 3.6% in the group that consumed the extract, compared with 0.7% in the other group.
Other studies have also reported significant weight loss in people who consumed green coffee extract (8).
However, it is important to keep in mind that some of these studies were sponsored by companies that make money from sales of the extract.
This does not mean that the studies are not valid, but it is known that the source of funding for a study can have significant effects on their results. For this reason, it is a good idea to be skeptical about industry-funded research (9).
Meanwhile, in 2011, a review of the evidence behind the green coffee extract concluded that "the effects of these tests are promising, but the studies are of poor methodological quality. More rigorous studies are needed to determine the utility of green coffee extract as a tool to lose weight "(10).
In summary: several controlled studies in humans show that green coffee extract can lead to significant weight loss. However, these studies were relatively small and some of them were financed by industries.
Do you have any extra health benefits?
green coffee berries
Green coffee can positively affect the way the body absorbs and uses carbohydrates. As hypothesized in animal studies, chlorogenic acid appears to reduce glucose uptake (11).
This effect could play a protective role in the management of diabetes and explain the effects on weight.
The green coffee extract could also positively affect the blood vessels, which impacts on the health of the heart.
Doses between 140-720 mg per day have been shown to lower blood pressure in both rats and humans with high blood pressure (12, 13). And chlorogenic acid also works as an antioxidant (14).
In summary: the green coffee extract improves the metabolism of glucose and reduces blood pressure. This could be beneficial for people at high risk of diabetes and heart disease.
Side effects, dosage and how to use it.
According to the limited amount of available evidence, the green coffee extract seems to be quite safe.
However, some participants dropped out of a study due to headaches and urinary infections (15).
This study was too small to show if the side effects were caused by the supplement, it could have been just a coincidence.
Green coffee contains caffeine, which can have several side effects if it is consumed in large quantities. This includes anxiety, tremors and tachycardia.
If you are sensitive to caffeine, you have to be careful with the green coffee extract.
Chlorogenic acid can have a laxative effect and cause diarrhea (16).
Some people have had allergic reactions to green coffee beans. And the extract should be avoided if you have already had an allergy to coffee (17).
The safety of green coffee for pregnant or breastfeeding women has not been tested yet, and should not be consumed by children.
There is currently no study that determines an optimal dose for green coffee extract. However, the studies cited in this article used doses ranging from 120 to 300 mg of chlorogenic acid.
Depending on the concentration of this substance in the supplement, the range can then go from 240 to 3000 mg of green coffee extract per day.
It is advisable to follow the instructions that accompany the product. A common instruction is to take a dose half an hour before each meal.
