Larsson et al. investigated the association between chocolate consumption and risk of stroke in men, concluding that moderate chocolate consumption may lower the risk of stroke. [1] We performed a prospective mechanistic study that may suggest a potential mechanism for this observation. We investigated the acute effects of a bar (100g) of dark or milk chocolate upon cerebrovascular reactivity in healthy volunteers. The flavanol content of the dark and milk chocolate was 104mg and 32mg of epicatechin respectively. Using a randomized double-blind crossover design, cerebral vasomotor reactivity was measured by Transcranial Doppler ultrasound and calculated using breath-hold index (BHI). Twenty-four fasted, healthy volunteers on no regular medication (f=12, m=12, mean age 23.2 years [SD 3.29]) attended twice, each study visit at least 24 hours apart.
Chocolate caused a significant change in BHI by -0.06 units 90 minutes after chocolate ingestion (BHI pre 1.3 [SD 0.16]; BHI post 1.24 [SD 0.14]; p=0.015, n=48). Dark chocolate caused a significant reduction in BHI from baseline by -0.07 units (SD 0.17 p=0.05 n=24) though the change in BHI between dark and milk chocolate was not significant (BHI dark -0.07 [SD 0.17]; BHI milk -0.04 [SD 0.13]; p=0.431, n=24). No differences in blood sugar, heart rate or blood pressure were apparent between groups.
Acute ingestion of chocolate was associated with a measurable change in cerebral vasomotor reactivity. Regular consumption of cocoa polyphenols has been shown to reduce the risk of stroke, and antioxidant, antiplatelet, anti-inflammatory effects, together with effects on lipid profile have all been proposed as potential mediators of the effect. [2] Our data suggest that chocolate consumption is associated with an acute change in cerebral vasomotor reactivity, independent of metabolic and hemodynamic parameters. This acute effect may contribute to the observed relationship between long-term chocolate consumption and stroke risk, and is worthy of further investigation.
1. Larsson SC, Virtamo J, Wolk A.
Chocolate consumption and risk of stroke: A prospective cohort of men and meta-analysis
Neurology 2012; 0: WNL.0b013e31826aacfav1
Larsson et al. investigated the association between chocolate consumption and risk of stroke in men, concluding that moderate chocolate consumption may lower the risk of stroke. [1] We performed a prospective mechanistic study that may suggest a potential mechanism for this observation. We investigated the acute effects of a bar (100g) of dark or milk chocolate upon cerebrovascular reactivity in healthy volunteers. The flavanol content of the dark and milk chocolate was 104mg and 32mg of epicatechin respectively. Using a randomized double-blind crossover design, cerebral vasomotor reactivity was measured by Transcranial Doppler ultrasound and calculated using breath-hold index (BHI). Twenty-four fasted, healthy volunteers on no regular medication (f=12, m=12, mean age 23.2 years [SD 3.29]) attended twice, each study visit at least 24 hours apart. Chocolate caused a significant change in BHI by -0.06 units 90 minutes after chocolate ingestion (BHI pre 1.3 [SD 0.16]; BHI post 1.24 [SD 0.14]; p=0.015, n=48). Dark chocolate caused a significant reduction in BHI from baseline by -0.07 units (SD 0.17 p=0.05 n=24) though the change in BHI between dark and milk chocolate was not significant (BHI dark -0.07 [SD 0.17]; BHI milk -0.04 [SD 0.13]; p=0.431, n=24). No differences in blood sugar, heart rate or blood pressure were apparent between groups. Acute ingestion of chocolate was associated with a measurable change in cerebral vasomotor reactivity. Regular consumption of cocoa polyphenols has been shown to reduce the risk of stroke, and antioxidant, antiplatelet, anti-inflammatory effects, together with effects on lipid profile have all been proposed as potential mediators of the effect. [2] Our data suggest that chocolate consumption is associated with an acute change in cerebral vasomotor reactivity, independent of metabolic and hemodynamic parameters. This acute effect may contribute to the observed relationship between long-term chocolate consumption and stroke risk, and is worthy of further investigation.
1. Larsson SC, Virtamo J, Wolk A. Chocolate consumption and risk of stroke: A prospective cohort of men and meta-analysis Neurology 2012; 0: WNL.0b013e31826aacfav1For disclosures, contact the editorial office.