Chlorogenic Acid: Food Sources, Metabolism & What Research Shows

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Chlorogenic acid is a naturally occurring phenolic compound found in coffee and a variety of fruits, vegetables, and other plant foods. Apples, pears, blueberries, plums, prunes, and cherries are among the foods in which chlorogenic acids have been identified.

Despite its name, chlorogenic acid does not contain chlorine. The name refers to a family of plant compounds formed when certain hydroxycinnamic acids—most notably caffeic acid—are esterified with quinic acid.

Chlorogenic acids have been studied extensively in laboratory, animal, and human research. Areas of interest include absorption and metabolism, antioxidant chemistry, glucose-related measurements, vascular function, and other metabolic outcomes.

However, research involving purified chlorogenic acid, green coffee extract, brewed coffee, whole fruit, fruit juice, and other foods should not automatically be treated as interchangeable.

What Is Chlorogenic Acid?

Chlorogenic acid is a member of a family of naturally occurring compounds known collectively as chlorogenic acids.

The compound most commonly called “chlorogenic acid” is 5-O-caffeoylquinic acid (5-CQA), an ester formed between caffeic acid and quinic acid.

Chlorogenic acids belong to the larger group of plant compounds commonly described as phenolic acids or polyphenols.

The terminology can be confusing because older scientific literature sometimes used different numbering systems for caffeoylquinic-acid isomers. Modern nomenclature generally refers to the major compound as 5-CQA.

Chlorogenic Acid vs. Chlorogenic Acids

The singular term chlorogenic acid often refers specifically to 5-CQA.

The plural term chlorogenic acids refers to a larger family of related compounds in which hydroxycinnamic acids are joined to quinic acid.

This family can include:

• Caffeoylquinic acids — including 3-CQA, 4-CQA, and 5-CQA.
• Dicaffeoylquinic acids — containing two caffeic-acid-related groups attached to quinic acid.
• Feruloylquinic acids — related compounds containing ferulic acid.
• p-Coumaroylquinic acids — related compounds containing p-coumaric acid.

These compounds differ in structure, abundance, absorption, and metabolism, so findings involving one chlorogenic-acid isomer should not automatically be applied to every member of the family.

How Is Chlorogenic Acid Related to Caffeic Acid?

Chlorogenic acid and caffeic acid are closely related, but they are not the same molecule.

Caffeic acid is a hydroxycinnamic acid.

Chlorogenic acid is formed when caffeic acid is esterified with quinic acid.

During digestion and metabolism, chlorogenic acids can be transformed into caffeic-acid-related and other phenolic metabolites.

This relationship is one reason research involving chlorogenic acid frequently measures caffeic acid, ferulic acid, dihydrocaffeic acid, and related metabolites after consumption.

Learn more in our Caffeic Acid guide.

What Foods Contain Chlorogenic Acid?

Chlorogenic acids occur widely in plants, although concentrations vary substantially among foods, cultivars, growing conditions, plant tissues, processing methods, and storage conditions.

Commonly reported dietary sources include:

• Coffee — one of the richest and most extensively studied dietary sources of chlorogenic acids.
• Apples — chlorogenic acid is an important hydroxycinnamic acid in apple flesh and other apple tissues.
• Pears — chlorogenic acid is commonly identified among the major phenolic compounds in pears.
• Blueberries and other berries — chlorogenic-acid-related compounds have been identified in several berry species.
• Plums and prunes — reported sources of chlorogenic and related caffeoylquinic acids.
• Cherries — chlorogenic and neochlorogenic acids occur among the phenolic acids identified in sweet and tart cherries.
• Potatoes — chlorogenic acids can represent an important portion of potato phenolics.
• Artichokes and eggplant — additional well-documented vegetable sources.

A food appearing on this list does not establish a specific chlorogenic-acid concentration. Quantitative content requires analytical measurement of the particular food or finished product.

Chlorogenic Acid in Fruit

Although coffee receives most of the attention in chlorogenic-acid research, these compounds are also part of the phenolic profile of many fruits.

Apples

Chlorogenic acid is one of the major hydroxycinnamic acids reported in apples. Concentrations can vary by cultivar, maturity, growing conditions, fruit tissue, storage, and processing.

Pears

Pears also contain chlorogenic acid, with considerable variation among cultivars and stages of ripeness. Both peel and flesh can contain chlorogenic acid and other phenolic compounds.

Blueberries

Chlorogenic-acid-related compounds have been identified in blueberries. Blueberries also contain many other polyphenols, including anthocyanins and flavonols, so a finding from whole blueberry should not automatically be attributed to chlorogenic acid.

Tart Cherries

Studies of tart cherry composition have identified chlorogenic acid and neochlorogenic acid among the fruit's phenolic acids, alongside anthocyanins, flavonols, flavanols, and other compounds.

As with other fruits, cultivar, maturity, processing, extraction method, and analytical technique can influence the concentrations reported.

Plums and Prunes

Plums and prunes are also reported sources of chlorogenic and neochlorogenic acids. Drying and other processing steps can alter the final composition compared with fresh fruit.

Is Chlorogenic Acid an Antioxidant?

Chlorogenic acids demonstrate antioxidant activity in laboratory chemical systems.

Researchers have studied their ability to interact with reactive chemical species, participate in redox reactions, and influence lipid oxidation under controlled experimental conditions.

However, laboratory antioxidant activity does not establish that consuming chlorogenic acid produces a specific antioxidant health effect in humans.

After chlorogenic acids are consumed, they undergo extensive digestion and metabolism. Many of the compounds eventually circulating in blood or appearing in urine are metabolites rather than the original chlorogenic-acid molecule.

This distinction between chemical antioxidant activity and demonstrated effects in people is discussed further in our Antioxidants, Free Radicals & Oxidative Stress guide.

How Is Chlorogenic Acid Absorbed and Metabolized?

Human studies show that chlorogenic acids are absorbed and extensively metabolized after consumption.

Some chlorogenic-acid compounds can be absorbed in the small intestine, while a substantial portion reaches the colon, where gut microorganisms contribute to their breakdown and transformation.

Researchers have identified metabolites related to caffeic acid, ferulic acid, isoferulic acid, dihydrocaffeic acid, dihydroferulic acid, and other phenolic compounds after chlorogenic-acid consumption.

These metabolites may then undergo additional processes such as sulfation and glucuronidation before circulating or being excreted.

Human studies also show considerable individual variation in absorption and metabolism.

This means that the biological exposure following a food containing chlorogenic acids cannot be understood simply by measuring the original amount present in the food.

Chlorogenic Acid & Human Research: What Has Been Studied?

Chlorogenic acid has been investigated for many possible biological effects, but much of the overall literature consists of laboratory and animal research.

Human studies often use purified chlorogenic acid, coffee enriched in chlorogenic acids, decaffeinated coffee, or green coffee extracts. Those interventions should not automatically be treated as equivalent to eating fruit that naturally contains smaller and more complex mixtures of chlorogenic acids.

Blood Pressure and Vascular Measurements

Human trials have examined chlorogenic acids in relation to blood pressure and vascular measurements.

A systematic review and meta-analysis of randomized clinical trials reported a reduction in systolic blood pressure across the included studies, but the trials varied in quality, formulation, dose, duration, and participant characteristics.

The authors also noted substantial variation among studies. These findings therefore do not establish that chlorogenic acid-containing foods prevent or treat hypertension.

Glucose and Post-Meal Metabolism

Researchers have also examined chlorogenic acid and chlorogenic-acid-rich coffee preparations in relation to glucose and insulin responses.

In one small randomized crossover trial involving 15 overweight men, purified chlorogenic acid altered glucose and insulin measurements shortly after an oral glucose challenge compared with placebo.

However, the study did not find significant differences in the overall glucose or insulin area-under-the-curve measurements across the full test period.

This is an example of why individual time-point differences and overall metabolic responses should not be treated as the same outcome.

Green Coffee Extract Research

A substantial portion of human research marketed as “chlorogenic acid research” actually involves green coffee extract.

Green coffee extract can contain chlorogenic acids along with caffeine and other naturally occurring coffee compounds. Products also vary in chlorogenic-acid concentration and formulation.

Meta-analyses have reported differences in selected metabolic measurements in some green-coffee-extract trials, while other outcomes were not significantly changed and study heterogeneity has often been substantial.

Those results should not automatically be attributed to chlorogenic acid alone or applied to fruits containing chlorogenic acid.

Inflammatory and Oxidative-Stress-Related Research

Laboratory and animal studies have extensively investigated chlorogenic acid in relation to inflammatory signaling and oxidative processes.

Human research in this area is less extensive and often uses coffee or concentrated extracts containing many compounds in addition to chlorogenic acid.

Changes in an inflammatory or oxidative-stress-related biomarker should also not be interpreted automatically as improvement in symptoms, function, or long-term health.

Coffee Research vs. Fruit Research

This distinction is particularly important for chlorogenic acid because coffee accounts for much of the human research.

Coffee contains chlorogenic acids, but it also contains caffeine, trigonelline, diterpenes, melanoidins, and numerous other compounds whose amounts depend on the bean, roast, brewing method, and preparation.

Fruit has a very different composition.

For example, blueberries and tart cherries contain anthocyanins and other flavonoids in addition to phenolic acids, while apples contain flavanols, procyanidins, dihydrochalcones, and quercetin glycosides.

A result from a coffee intervention therefore should not automatically be applied to an apple, blueberry, tart cherry, prune, juice, or fruit concentrate simply because all can contain chlorogenic acid.

Does Processing Affect Chlorogenic Acid?

Yes. Chlorogenic-acid concentrations can change during processing and storage.

Relevant factors include:

• Heat — roasting, cooking, pasteurization, and other thermal processes can alter chlorogenic-acid profiles.
• Oxidation — exposure to oxygen and enzymatic reactions can change phenolic composition.
• Ripeness and storage — maturity and storage conditions can influence concentrations in fruits.
• Juicing and extraction — different plant tissues and extraction methods can produce different measured levels.
• Drying — dehydration can change concentration on a weight basis while also causing chemical transformations.
• Fermentation — microbial activity can transform chlorogenic acids and related phenolics.

Coffee provides a familiar example: green coffee beans generally contain substantially more chlorogenic acids than heavily roasted coffee because roasting changes and degrades portions of the chlorogenic-acid profile.

The same general principle applies to fruit products: knowing that the starting fruit contains chlorogenic acid does not establish the amount present in a finished juice, concentrate, dried fruit, or extract.

Does Chlorogenic Acid Contain Caffeine?

No. Chlorogenic acid and caffeine are different chemical compounds.

They frequently occur together in coffee, which is why they are sometimes discussed together, but chlorogenic acid itself is not caffeine.

Fruit sources of chlorogenic acid do not become caffeinated simply because chlorogenic acid is present.

Is Chlorogenic Acid Safe?

Chlorogenic acids occur naturally in many commonly consumed foods and beverages.

Concentrated supplements and extracts can provide amounts and combinations that differ substantially from normal food intake.

Safety information from one purified preparation or green coffee extract should not automatically be applied to every supplement or dose.

Anyone considering a concentrated chlorogenic-acid or green-coffee-extract supplement—particularly someone who is pregnant, breastfeeding, managing a medical condition, or taking medication—should discuss individual questions with an appropriate healthcare professional.

Frequently Asked Questions About Chlorogenic Acid

How to Evaluate Chlorogenic Acid Research

When reading research about chlorogenic acid, first identify exactly what researchers tested.

A study may involve:

• Purified 5-CQA or another individual chlorogenic acid
• A mixture of chlorogenic-acid isomers
• Green coffee extract
• Regular or decaffeinated coffee
• A whole fruit or vegetable
• Fruit juice or another processed food

These preparations are not interchangeable.

It is also useful to consider:

• Study population — Were participants healthy, overweight, hypertensive, or living with another condition?
• Dose — Was the amount typical of food intake or a concentrated research dose?
• Duration — Was it a single-dose experiment or a longer intervention?
• Other compounds — Did the preparation contain caffeine, anthocyanins, flavonoids, or other substances?
• Primary outcome — Was the study measuring absorption, a biomarker, blood pressure, glucose, cognition, body weight, or a clinical outcome?
• Formulation — Was the chlorogenic acid purified, extracted, brewed, or consumed as part of a whole food?

Laboratory antioxidant activity, altered metabolite concentrations, changes in a biomarker, and improvement in a clinical outcome are different levels of evidence.

Strong conclusions generally require consistent findings across multiple well-designed human trials using clearly characterized preparations and relevant outcomes.

Continue Exploring Phenolic Acids & Fruit Compounds

Chlorogenic acid belongs within a larger network of phenolic acids and polyphenols found naturally in plant foods.

Phenolic Acids →
Explore hydroxycinnamic and hydroxybenzoic acids and how these families fit into plant-food chemistry.

Caffeic Acid →
Learn about the hydroxycinnamic acid that forms the caffeic-acid portion of chlorogenic acid.

Ferulic Acid →
Explore another hydroxycinnamic acid and the related feruloylquinic acids found within the chlorogenic-acid family.

Polyphenols in Fruit →
Explore the broader family of plant compounds that includes phenolic acids, flavonoids, and other polyphenols.

Antioxidants, Free Radicals & Oxidative Stress →
Understand what antioxidant activity means and why laboratory measurements are not equivalent to demonstrated health outcomes.

Fruit Compound Library →
Browse FruitFast educational guides to phenolic acids, flavonoids, pigments, nutrients, and other naturally occurring plant compounds.

Health Information & Fruit Nutrition Research →
Explore FruitFast educational resources covering fruit chemistry, nutrition, scientific research, and how to evaluate evidence.

Scientific References & Sources

The following publications are provided so readers can examine the chemistry, dietary sources, metabolism, and human research discussed on this page. Findings involving one chlorogenic-acid preparation, coffee product, fruit, extract, or study population should not automatically be applied to another.

1. Lu H, Tian Z, Cui Y, Liu Z, Ma X. Chlorogenic acid: A comprehensive review of the dietary sources, processing effects, bioavailability, beneficial properties, mechanisms of action, and future directions. Comprehensive Reviews in Food Science and Food Safety. 2020;19(6):3130-3158. doi:10.1111/1541-4337.12620. PMID: 33337063.

2. Clifford MN, Kerimi A, Williamson G. Bioavailability and metabolism of chlorogenic acids (acyl-quinic acids) in humans. Comprehensive Reviews in Food Science and Food Safety. 2020;19(4):1299-1352. doi:10.1111/1541-4337.12518. PMID: 33337099.

3. Monteiro M, Farah A, Perrone D, Trugo LC, Donangelo C. Chlorogenic acid compounds from coffee are differentially absorbed and metabolized in humans. Journal of Nutrition. 2007;137(10):2196-2201. doi:10.1093/jn/137.10.2196. PMID: 17884997.

4. Stalmach A, Steiling H, Williamson G, Crozier A. Bioavailability of chlorogenic acids following acute ingestion of coffee by humans with an ileostomy. Archives of Biochemistry and Biophysics. 2010;501(1):98-105. doi:10.1016/j.abb.2010.03.005. PMID: 20226754.

5. van Dijk AE, Olthof MR, Meeuse JC, Seebus E, Heine RJ, van Dam RM. Acute effects of decaffeinated coffee and the major coffee components chlorogenic acid and trigonelline on glucose tolerance. Diabetes Care. 2009;32(6):1023-1025. doi:10.2337/dc09-0207. PMID: 19324944.

6. Onakpoya IJ, Spencer EA, Thompson MJ, Heneghan CJ. The effect of chlorogenic acid on blood pressure: a systematic review and meta-analysis of randomized clinical trials. Journal of Human Hypertension. 2015;29(2):77-81. doi:10.1038/jhh.2014.46. PMID: 24943289.

7. Nguyen V, Taine EG, Meng D, Cui T, Tan W. Chlorogenic Acid: A Systematic Review on the Biological Functions, Mechanistic Actions, and Therapeutic Potentials. Nutrients. 2024;16(7):924. doi:10.3390/nu16070924. PMID: 38612964.

8. Liang N, Kitts DD. Role of chlorogenic acids in controlling oxidative and inflammatory stress conditions. Nutrients. 2016;8(1):16. doi:10.3390/nu8010016. PMID: 26712785.