Dark chocolate and cocoa beverages may modestly reduce blood pressure

A review of earlier studies suggests that cocoa drinks and dark chocolate can modestly lower blood pressure when eaten for at least two weeks. The effect was more pronounced for dark chocolate in one of the measurements reviewed.

The analysis provides a closer look at cocoa flavanols, naturally occurring plant compounds that may affect blood vessel function. It does not indicate that regular chocolate products can take the place of established treatment for high blood pressure.

Researchers led by Isaac Amoah examined 31 eligible studies published through 2021. Those studies looked at cocoa consumed as drinks or as dark chocolate in people with normal or elevated blood pressure.

Blood pressure is measured with two numbers. Systolic pressure, the higher number, shows the force when the heart pumps, while diastolic pressure reflects the pressure between beats.

Across the studies, cocoa intake for at least two weeks was associated with lower readings in both measurements. The researchers also compared the effects of different forms of cocoa consumption.

Dark chocolate was associated with an average drop of 3.94 millimeters of mercury in resting systolic pressure. Cocoa drinks were linked to a smaller decrease of 1.54 millimeters of mercury in the same measure.

The review also found greater reductions in studies that used higher amounts of certain cocoa compounds. These included at least 900 milligrams a day of flavanol intake or at least 100 milligrams of epicatechin intake.

These amounts describe the study conditions, not a recommended daily chocolate serving. Cocoa products differ widely in their flavanol content, and the article does not establish how much commercial chocolate would provide the same exposure.

Earlier cocoa research has often been small and has used different methods, which makes it harder to determine the best dose or whether the observed reductions are large enough to affect long-term cardiovascular outcomes.

The researchers published their review in Foods and called for more work to clarify clinically meaningful effects. The findings suggest a possible modest benefit, rather than a proven way to prevent heart attacks or strokes.

The main point concerns cocoa compounds and blood pressure measurements, not a broad health claim about sweetened chocolate. More consistent trials would help identify which preparations, amounts and participants are most likely to benefit.

Because chocolate products can contain a lot of sugar and calories, the results cannot be applied to every chocolate bar or cocoa drink. Future studies will need to separate the effects of flavanols from the many other ingredients in these products.