Named Bioactive Compounds · Compound
Caffeic acid
Moderate Evidencecompound
Hermetica Superfood Encyclopedia
Caffeic acid is a hydroxycinnamic acid phenolic compound that inhibits α-glucosidase enzymes and modulates glucose metabolism pathways. Clinical studies demonstrate its ability to reduce systolic blood pressure by 3.87 mmHg and decrease fasting glucose by 0.45 mmol/L.
Caffeic acid (3,4-dihydroxycinnamic acid) is a naturally occurring hydroxycinnamic acid found widely in coffee beans, fruits (apples, berries), vegetables (artichokes, potatoes), and herbs (thyme, sage). It is typically extracted from plant sources via ethanol or hot water extraction followed by purification, yielding yellow crystals that are slightly soluble in water.
Human clinical evidence for caffeic acid is limited, with most data from chlorogenic acid-rich coffee extracts. A 2010 RCT (PMID: 20730802) found 5 g/day chlorogenic acid-enriched coffee reduced body fat in 30 obese adults over 12 weeks. A 2017 meta-analysis (PMID: 28631011) of 14 RCTs (n=457) showed modest reductions in blood pressure and fasting glucose from 100-600 mg/day chlorogenic acid sources.
Clinically studied doses: 100-500 mg/day oral caffeic acid equivalents (from 200-400 mg chlorogenic acid sources), divided 2-3 times daily. Topical formulations use 0.1-1% caffeic acid in creams. No standardized extracts are common; studies used coffee polyphenols with 5-30% caffeic acid content. Consult a healthcare provider before starting any new supplement.
Caffeic acid (3,4-dihydroxycinnamic acid) is a hydroxycinnamic acid polyphenol with molecular weight of 180.16 g/mol. It is not a macronutrient or micronutrient itself but a bioactive phytochemical compound. Typical dietary intake ranges from 50–200 mg/day in individuals consuming polyphenol-rich diets. Common dietary sources include coffee (approximately 50–150 mg per 200 mL cup, primarily as chlorogenic acid ester), wine (5–40 mg/L), sunflower seeds (~1–3 mg/g), thyme (~0.9 mg/g fresh weight), and various fruits and vegetables. In food, caffeic acid exists predominantly in esterified forms (e.g., chlorogenic acid = caffeic acid + quinic acid), which affects bioavailability. Free caffeic acid bioavailability is relatively high (~95% absorption in small intestine based on ileostomy studies); however, esterified forms require hydrolysis by gut esterases and colonic microbiota before absorption, reducing overall bioavailability to approximately 33–95% depending on the food matrix. Peak plasma concentration after 200 mg oral dose reaches approximately 0.5–1.5 µmol/L within 1–2 hours. It undergoes extensive phase II metabolism (methylation, glucuronidation, sulfation) in intestinal epithelium and liver, with dihydrocaffeic acid as a primary metabolite. No caloric contribution, fat, protein, or fiber content is attributed to caffeic acid as an isolated compound. Key bioactive properties include catechol ring-mediated ROS scavenging (ORAC value approximately 1,500 µmol TE/g) and ferric/cupric ion chelation activity.
Caffeic acid inhibits α-glucosidase and α-amylase enzymes, reducing carbohydrate digestion and glucose absorption. It activates AMP-activated protein kinase (AMPK) pathways, enhancing glucose uptake in skeletal muscle. The compound also inhibits angiotensin-converting enzyme (ACE) activity and promotes nitric oxide synthesis, contributing to vasodilation and blood pressure reduction.
A meta-analysis of 14 randomized controlled trials (n=457) demonstrated caffeic acid's ability to reduce systolic blood pressure by 3.87 mmHg and decrease fasting glucose by 0.45 mmol/L. A separate RCT with 30 obese adults showed improvements in body fat reduction and glucose tolerance with moderate evidence quality. Most studies used doses ranging from 200-400mg daily for 8-12 weeks. Evidence strength is considered moderate due to limited sample sizes and study duration variability.
Caffeic acid is generally well-tolerated with minimal reported side effects at typical supplemental doses. It may enhance the hypoglycemic effects of diabetes medications, requiring blood glucose monitoring. The compound can potentiate antihypertensive drugs due to its ACE-inhibitory properties. Safety during pregnancy and lactation has not been established, and use should be avoided without medical supervision.
