tuneTypical Dose
5-20 g raw cacao per day (or 500-1,000 mg cocoa flavanols)
Natural Compound
Cacao
Theobroma cacao (cocoa flavanols)
Evidence TierBWADA NOT PROHIBITED
watchEffect Window
Acute effects within ~2 hours. Sustained cardiovascular response by 4-8 weeks.
check_circleCompliance
WADA NOT PROHIBITED
Overview
Clinical Summary
Cacao is minimally processed cocoa rich in flavanols, theobromine, and minerals. It is used to support vascular function and mood through nitric oxide and polyphenol pathways.
Flavanol-rich cocoa has evidence for improved endothelial function and small reductions in blood pressure via nitric oxide signaling. Some studies report improved mood and cognitive performance, plausibly through enhanced cerebral blood flow. Minority findings include improved insulin sensitivity and reduced inflammation biomarkers. Effects depend strongly on flavanol content and added sugar, which can reverse cardiometabolic gains.
Cocoa flavanols (epicatechin) increase eNOS and nitric oxide signaling, supporting vasodilation and endothelial function. Theobromine, caffeine, and PEA contribute CNS stimulation and cerebral perfusion support.
Outcomes
What This Is Expected To Influence
Primary Outcomes
- cardiovascular health (blood pressure, endothelial function via FMD)
- cognitive support (processing speed)
Secondary Outcomes
- insulin sensitivity
- mood
Safety
Contraindications and Interactions
Contraindications
- Caffeine sensitivity
- GERD
- MAOI use
Side effects
- Mild stimulation
- Insomnia (high doses)
- GI upset
Interactions
- MAOIs (theobromine/PEA content)
- Theophylline
Avoid if
- MAOI users
- Caffeine/theobromine-sensitive individuals
- Active GERD
Evidence
Study-level References
cacao-SRC-001Meta-analysis of RCTs
Sourceopen_in_newHooper L, et al. "Effects of chocolate, cocoa, and flavan-3-ols on cardiovascular health: a systematic review and meta-analysis of randomized trials." Am J Clin Nutr. 2012.
Population: Older adults/prehypertension.
Dose protocol: Source-listed
Key findings: Chocolate or cocoa significantly improved flow-mediated dilatation, reduced insulin resistance, and reduced blood pressure (by approx 2-3 mmHg).
Paper content
Chocolate or cocoa significantly improved flow-mediated dilatation, reduced insulin resistance, and reduced blood pressure (by approx 2-3 mmHg).
cacao-SRC-002Randomized, double-blind, placebo-controlled crossover trial.
Sourceopen_in_newDaniele A, Lucas SJE, Rendeiro C, et al. Cocoa flavanols protect endothelial function during prolonged sitting in healthy older adults. Food Funct. 2026;17(3):1385-1404. doi:10.1039/d5fo02793d. PMID:41527842.
Population: Healthy older adults aged approximately 72 years.
Dose protocol: 695 mg cocoa flavanols as a single acute dose before 2 hours of sitting
Key findings: High-flavanol cocoa prevented sitting-induced decline in flow-mediated dilation in both femoral and brachial arteries in older adults.
Notes: Acute single-session crossover design in a small sample. It preserved endothelial function during prolonged sitting but did not blunt the sitting-induced blood-pressure rise.
Paper content
This crossover RCT tested whether acute cocoa flavanol intake could protect endothelial function during prolonged sitting in older adults. Twenty healthy participants consumed either a high-flavanol (695 mg) or low-flavanol (5.6 mg) cocoa beverage before sitting for 2 hours. The high-flavanol condition prevented the decline in flow-mediated dilation in both the superficial femoral and brachial arteries that occurred with the control beverage. Blood pressure elevations from sitting were not affected. The study provides acute mechanistic evidence that cocoa flavanols preserve vascular function under sedentary stress in an aging population, though it was small and single-session.
cacao-SRC-003Randomized, double-blind, placebo-controlled trial (COSMOS substudy, 2x2 factorial).
Sourceopen_in_newHamaya R, Li S, Lau J, et al. Long-Term Effect of Cocoa Extract Supplementation on Incident Hypertension. Hypertension. 2025;82(10):1653-1662. doi:10.1161/HYPERTENSIONAHA.125.25209. PMID:40832703.
Population: Older US adults without baseline hypertension from the COSMOS trial.
Dose protocol: 500 mg/day cocoa flavanols (80 mg epicatechin) for median 3.4 years
Key findings: No overall hypertension prevention, but 24% reduction in participants with baseline SBP below 120 mmHg after 2 years.
Notes: Large COSMOS substudy (n=8,905). Overall null result tempers enthusiasm. Subgroup finding suggests benefit limited to normotensive individuals.
Paper content
This large COSMOS substudy tested whether long-term daily cocoa extract supplementation (500 mg flavanols) could prevent incident hypertension in 8,905 older adults without baseline hypertension. Over a median follow-up of 3.4 years, cocoa extract did not significantly reduce overall hypertension incidence. However, in a pre-specified subgroup of participants with baseline systolic BP below 120 mmHg, supplementation reduced hypertension incidence by 24%, with effects emerging after year 2. This is one of the largest and longest trials of cocoa flavanols for a hard cardiovascular endpoint, adding important nuance to the blood pressure story. The overall null result tempers enthusiasm, while the subgroup finding suggests potential benefit in normotensive individuals over extended use.
cacao-SRC-004Randomized, double-blind, placebo-controlled trial (COSMOS substudy, 2x2 factorial).
Sourceopen_in_newLi S, Hamaya R, Zhu H, et al. Effects of 2-year cocoa extract supplementation on inflammaging biomarkers in older US adults: findings from the COSMOS randomised clinical trial. Age Ageing. 2025;54(9):afaf269. doi:10.1093/ageing/afaf269. PMID:40966617.
Population: Older US adults from the COSMOS trial with biospecimens at baseline and years 1 and 2.
Dose protocol: 500 mg/day cocoa flavanols (80 mg epicatechin) for 2 years
Key findings: Cocoa extract reduced hs-CRP by 8.4% yearly versus placebo and increased interferon-gamma by 6.8%.
Notes: COSMOS biomarker substudy (n=598). Provides mechanistic inflammatory context for the cardiovascular mortality reduction seen in the main trial.
Paper content
This COSMOS substudy examined the effects of 2-year cocoa extract supplementation on inflammaging biomarkers in 598 older adults. The cocoa extract group showed a significant 8.4% yearly decrease in hs-CRP compared to placebo (P=0.008) and a 6.8% increase in interferon-gamma (P=0.011). The broader COSMOS trial had previously reported a 27% reduction in cardiovascular disease death. These biomarker findings provide a mechanistic window into how cocoa flavanols may reduce cardiovascular risk through anti-inflammatory pathways. The study adds valuable long-term inflammatory biomarker data to the COSMOS evidence base, though the subsample size is modest relative to the full trial.
cacao-SRC-005Systematic review and meta-analysis of randomized controlled trials
Sourceopen_in_newArisi TOP, da Silva DS, Stein E, Weschenfelder C, de Oliveira PC, Marcadenti A, Lehnen AM, Waclawovsky G. Effects of Cocoa Consumption on Cardiometabolic Risk Markers: Meta-Analysis of Randomized Controlled Trials. Nutrients. 2024;16(12):1919. doi:10.3390/nu16121919. PMID:38931273.
Population: Adults with and without comorbidities across randomized cocoa intervention trials.
Dose protocol: Cocoa extract or dark chocolate with at least 70% cocoa for 4 weeks or longer across 31 RCTs
Key findings: Lowered total cholesterol, LDL cholesterol, fasting glucose, and blood pressure, with no significant effect on body weight, triglycerides, HDL cholesterol, or HbA1c.
Notes: Best current pooled cardiometabolic summary and a better anchor than older mixed-source references.
Paper content
This meta-analysis pooled 31 randomized trials with 1,986 adults using cocoa extract or dark chocolate for at least 4 weeks. Cocoa lowered total cholesterol, LDL cholesterol, fasting glucose, and both systolic and diastolic blood pressure, while showing no significant effect on body weight, BMI, waist circumference, triglycerides, HDL cholesterol, or HbA1c. The record sharpens cacao's evidence profile toward modest cardiometabolic risk reduction rather than broad weight-loss or glycemic-normalization claims.