CHLOROGENIC ACID: PROPERTIES, FOODS, SIDE EFFECTS - CHEMISTRY - 2024

The chlorogenic acid (CGA) is a phytochemical compound found in foods such as coffee beans, coffee drinks, mate tea. Although the term is commonly used to describe a single compound, there are a dozen isomers of this substance, each with different sensory characteristics.

Its name evokes chlorine but it is not related. It arises from the first observations for its characterization: there ferric chloride was added to green coffee extracts. The chlorogenic acids in coffee are polyphenolic compounds, formed by the esterification of cinnamic acids -such as caffeic, ferulic and p-coumaric acids- with quinic acid.

The presence of CGA is associated with the bitter and metallic taste in some coffees. Data obtained from in vivo and in vitro experiments show that CGA mainly exhibits antioxidant and anticancer activities. Its anti-inflammatory, analgesic and antipyretic potential has been under evaluation.

Associated studies

Polyphenolic compounds are numerous and abundant in the plant kingdom and are often present in health-promoting foods. Epidemiological studies report that the consumption of foods rich in polyphenols reduces the incidence of cancer, coronary heart disease and inflammation.

Although scientists discovered AGCs in the 1930s, the research is relatively recent. This is evidenced by verifying that in many aspects there is still no precise and scientific answer on the metabolic activity of these substances.

CGA is one of the most abundant polyphenolic compounds in the human diet. Its production in plants responds to several factors, including changes in environmental conditions such as stress and the presence of pests.

This probably explains why the CGA concentration is almost double in robust coffee, which grows under more difficult conditions, relative to the CGA content in arabica coffee.

Chlorogenic acid properties

A number of health benefits have been associated with consuming CGA in recent years. These include the following:

- Modulation of glucose metabolism in humans; therefore, CGAs would have an antidiabetic effect in type 2 diabetes. They have been shown to have positive effects in rats, such as enhancing the action of insulin, but the doses in food are not sufficient to guarantee their effects in the care and prevention of diabetes.

- Prevention of the development of cataracts as a consequence of its potential antidiabetic effect. This aspect has been pointed out by results of studies in laboratory animals.

- Anti-obesity role due to its ability to inhibit the accumulation of fat and body weight. This has not yet been scientifically proven.

- Reduction of the relative risk of cardiovascular disease and improvement in human vasoreactivity.

- Antihypertensive action in rats and humans.

- Reduction of the risk of producing gallstones.

- Decrease in the incidence of Alzheimer's disease.

- Potential antibacterial activity.

In laboratory tests, chlorogenic acids have been shown to have possible antioxidant effects, preventing cell damage. However, the scientific evidence of the preventive effects against chronic non-communicable diseases remains weak, since AGCs break down very quickly in the body.

In general, mild to moderate improvements in glucose metabolism, weight control, heart health, and mental health have been reported with increasing ingested doses of CGA.

Foods that have chlorogenic acid

Green coffee

Despite the great distribution of some AGCs in the plant kingdom, green coffee remains the main recognized source to date. Its content matches and is sometimes surpassed by the green leaves of mate (Illex paraguayensis).

Green coffee beans normally contain between 6 and 7% of the CGA, and in roasted coffee beans this value is reduced, since roasting transforms chlorogenic acid into other molecules.

The latter could explain why drinking a cup of coffee doesn't produce the same weight loss results as taking green coffee supplements.

Tea

Tea (Camellia sinensis) is another important source of CGA; however, the amount of green tea that must be consumed for health benefits is approximately 10 cups per day.

Jamaica flower

Chlorogenic acid has also been found in the leaves of Hibiscus sabdariffa (a plant popularly known as Jamaica flower), as well as in the pulp of eggplant, peaches, and plums.

Some isomers of CGA have been found in potatoes. Apples contain a variety of polyphenols, which include CGAs.

Side effects

CGAs have been reported to have a laxative effect, and may even cause stomach pain, nausea, vomiting, and diarrhea. Some sensitive people have had allergic reactions to green coffee beans.

CGAs share some similar reactions to caffeine but with less potency. These include stimulant effects, anxiety, nervousness, rapid heart and breathing rate, and headache, among others. If a person is sensitive to caffeine, they should take green coffee bean extract with caution.

CGAs can contribute to the decrease in the absorption of carbohydrates ingested through food.

Contraindications

AGCs interact with mood-modulating medications and antidepressants. Therefore, it is necessary to consult with the doctor if you are taking medications against anxiety and depression, or if you feel headache, irritability, insomnia, nausea and vomiting.

In order not to compromise the quality of sleep, it is suggested not to ingest food or supplements containing AGC in the afternoon or evening. Some of the substances that AGCs interact with are alcohol, adenosine, anticoagulants, alendronate, and quinolone-based antibiotics.

It also reacts to clozapine, dipyridamole, disulfiram, stimulant drugs, ephedrine, estrogens, fluvoxamine, lithium, asthma medications, pentobarbital, phenylpropanolamine, riluzole, theophylline, and verapamil.

References

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