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Does dark chocolate lower blood pressure?

Flavanol-rich dark chocolate lowered blood pressure by about 2 points in short trials. The effect is small and the evidence is limited.

Published October 2026

Short answer

A small, short-term dip in blood pressure in trials. The evidence is limited, and long-term heart benefits have not been shown. Evidence grade C (Limited). Meta-analyses of randomised trials; downgraded for unexplained heterogeneity and because blood pressure is a surrogate marker.

Key takeaways

  • Across 35 trials, flavanol-rich chocolate and cocoa lowered systolic and diastolic blood pressure by about 2 mmHg in the short term [1].
  • The drop was larger in people with high blood pressure; in people with normal readings the difference was not significant [1].
  • Blood pressure is a marker, not a heart outcome, and the Cochrane authors say long-term trials of heart events are still needed [1].

The short version

Does dark chocolate lower blood pressure? Only a little, and only in the short term. Trials of flavanol-rich dark chocolate and cocoa found systolic and diastolic blood pressure about 2 mmHg lower than with control products, in studies lasting 2 to 18 weeks [1]. Results varied widely between trials, so the size of the effect is uncertain [1].

What the studies show

Two large meta-analyses of randomised trials point the same way. The Cochrane review pooled 35 trials with 1,804 mostly healthy people and found systolic pressure fell by 1.76 mmHg and diastolic by 1.76 mmHg [1]. A 2024 meta-analysis of 31 trials with 1,986 people, which used cocoa extract or dark chocolate of at least 70% cocoa for at least four weeks, reported drops of 2.52 mmHg systolic and 1.58 mmHg diastolic [2].

A 2025 review of flavan-3-ol foods found office blood pressure fell by 2.8 mmHg systolic and 2.0 mmHg diastolic after regular intake [3]. Cocoa was one of several sources in that review, so it is indirect evidence for chocolate.

Blood vessel function also improved in trials. Flow-mediated dilation, a measure of how well blood vessels widen, rose by 1.17% across 15 trials in a 2019 meta-analysis [4].

Cholesterol results are mixed. A 2024 meta-analysis reported total cholesterol about 8 mg/dL lower and LDL about 9.5 mg/dL lower, with no change in HDL or triglycerides [2]. A 2021 systematic review found triglycerides improved but no significant difference on the other outcomes it measured [5].

Chocolate did not change body weight on average. A 2019 meta-analysis of 35 trials found no significant change in weight, BMI or waist size [6]. Its authors reported drops in weight and BMI in a subgroup eating 30 g or more a day for four to eight weeks, but said the overall effect was not significant [6].

The nuances

The blood pressure benefit appears to depend on starting point. The Cochrane review found a systolic drop of about 4 mmHg in people with hypertension, but no significant difference in people with normal blood pressure, and the test for that difference was borderline [1]. A 2020 meta-analysis of middle-aged and older adults found a systolic drop of 2.77 mmHg, with very high variation between studies, and could not show a benefit in people with normal or elevated readings [7].

Not every review agrees. A 2021 systematic review, which relied on short trials of low-to-moderate quality, found no significant difference in blood pressure between chocolate and control groups [5].

Doses varied widely. Trials gave 30 to 1,218 mg of flavanols a day, with an average of 670 mg [1]. A dose-response analysis of endothelial trials found a non-linear pattern, with the best result near 710 mg of total flavanols [4].

Habits may matter. In a study of 17 healthy volunteers, one large dose (1 g per kg of body weight) of 70% dark chocolate lowered a measure of resistance in the kidney's blood vessels. Systolic pressure rose from 115 to 122 mmHg in people who rarely ate chocolate, but not in people who eat more than 50 g a week [8].

Funding and ties. Two authors of the Cochrane review had run trials it included. Excluding trials with industry-linked authors made the effect smaller, which the authors read as some reporting bias [1]. Two authors of the 2025 flavan-3-ol review are employed by food and tea companies, Unilever and Lipton [3].

Contamination. A 2024 analysis of 72 dark chocolate and cocoa products bought between 2014 and 2022 found lead above California's Proposition 65 limit in 43% of products and cadmium above it in 35%; none exceeded the limit for arsenic [9]. Median levels were below those limits, and the authors say a single serving may not pose appreciable risk for most people, but more than one serving a day, combined with other sources, could add up [9]. Organic products were more likely to have higher cadmium and lead [9]. The authors work for ConsumerLab.com, a product-testing company [9].

Side effects were mild. Stomach upset and nausea were reported by 1% of people eating cocoa products and 0.4% of controls [1].

Gaps. The studies cited here do not address interactions with blood pressure medicines, pregnancy or breastfeeding. The kidney study was in healthy volunteers, not people with kidney disease [8]. Sugar, calories and caffeine are not covered by these studies.

What this means for you

If you hope chocolate will help your blood pressure, the honest reading is a small, short-term effect. Long-term trials of cardiovascular events are still needed [1]. If you take blood pressure medicine or have a kidney condition, ask a doctor before relying on chocolate, and count its sugar and calories as part of your daily intake.

Go deeper

  • Dark Chocolate — Flavanol-rich dark chocolate and cocoa lower blood pressure by about 2 mmHg in short trials.

References

  1. Effect of cocoa on blood pressure.. Cochrane Database Syst Rev, 2017.
  2. Effects of Cocoa Consumption on Cardiometabolic Risk Markers: Meta-Analysis of Randomized Controlled Trials.. Nutrients, 2024.
  3. Impact of flavan-3-ols on blood pressure and endothelial function in diverse populations: a systematic review and meta-analysis of randomized controlled trials.. Eur J Prev Cardiol, 2025.
  4. Dose-response relationship between cocoa flavanols and human endothelial function: a systematic review and meta-analysis of randomized trials.. Food Funct, 2019.
  5. The Health Effects of Chocolate and Cocoa: A Systematic Review.. Nutrients, 2021.
  6. Does cocoa/dark chocolate supplementation have favorable effect on body weight, body mass index and waist circumference? A systematic review, meta-analysis and dose-response of randomized clinical trials.. Crit Rev Food Sci Nutr, 2019.
  7. Cocoa Consumption and Blood Pressure in Middle-Aged and Elderly Subjects: a Meta-Analysis.. Curr Hypertens Rep, 2020.
  8. The Acute Effect of Dark Chocolate on Blood Pressure and Renal Hemodynamics as Assessed With Doppler Ultrasound in Healthy Volunteers.. J Ren Nutr, 2025.
  9. A multi-year heavy metal analysis of 72 dark chocolate and cocoa products in the USA.. Front Nutr, 2024.