Cocoa Flavanols and Brain Perfusion
Journal of Cardiovascular Pharmacology: June 2006 - Volume 47 - Issue - pp S210-S214 Fisher, Naomi D.L. MD; Sorond, Farzaneh A. MD, PhD; Hollenberg, Norman K. MD, PhD

Foods and beverages rich in flavonoids are being heralded as potential preventive agents for a range of pathologic conditions, ranging from hypertension to coronary heart disease to stroke and dementia. We and others have demonstrated that short-term ingestion of cocoa, particularly rich in the subclass of flavonoids known as flavanols, induced a consistent and striking peripheral vasodilation in healthy people, improving endothelial function in a nitric oxide-dependent manner. The vasodilator response was reversed by NG-nitro-L-arginine methyl ester, an arginine analog that blocks nitric oxide synthesis. Flavanol-poor cocoa induced much smaller responses. Because impairment of endothelial function is a nearly universal accompaniment of the aging process, we examined the peripheral vasodilator response to flavanol-rich cocoa in healthy older subjects. Observations point to a favorable response among the older. Together with peripheral vascular disease, cerebrovascular disease is responsible for significant mortality with advancing age. An association of decreased cerebral perfusion with dementia has been recently highlighted. The prospect of increasing cerebral perfusion with cocoa flavanols is extremely promising. Our still preliminary data hold out the promise that the cerebral blood supply in the elderly participates in the vasodilator response. With the modalities of transcranial Doppler and MRI, we have the capabilities of analyzing the potential benefits of flavanols on brain perfusion and, subsequently, on cognition.

Effects of Chocolate Consumption on Enhancing Cognitive Performance
Rosanna Drake, Daniel Felbaum, Lauren Matthews, Alex Reed, & Bryan Raudenbush

Previous research has found that the nutrient content of foods aids in glucose release and increased blood flow.  These increases have subsequently been implicated in augmenting cognitive performance.  The present study assessed the effects of various chocolate types on cognitive performance, mood, and task workload.  In a within-subjects design, participants completed the protocol under four conditions:  85g milk chocolate (total fat 26g, saturated fat 18g, carbohydrates 50g, fiber 2g, sugar 44g, protein 6g), 85g dark chocolate (total fat 34g, saturated fat 20g, carbohydrates 46g, fiber 6g, sugar 34g, protein 4g), 85g carob (total fat 20g, saturated fat 14g, carbohydrates 45g, fiber 11g, sugar 40g, protein 11g), and a non-consumption control condition.  After a 15 minute digestive period, participants completed a variety of computer-based neuropsychological tests assessing word discrimination, verbal memory, design memory, attention span, reaction time, problem solving, and response variability.  Mood and task workload were assessed via the Profile of Mood States (POMS) and the NASA-Task Load Index (NASA-TLX).  Gender and age served as co-variates for the analyses.  Composite scores for verbal and visual memory were significantly higher for milk chocolate than the other conditions.  Consumption of milk or dark chocolate showed improved impulse control and reaction time.  These findings provide support for nutrient release via chocolate consumption to enhance cognitive performance.

Chocolate Consumption Enhances Cognitive Performance

Original Research: http://www.wju.edu/academics/psy/recentresearchs2006.asp

Can Chocolate Lower Your Risk of Stroke?

American Academy of Neurology (2010, February 12). Can chocolate lower your risk of stroke?. ScienceDaily. Retrieved February 15, 2010,

Eating chocolate may lower your risk of having a stroke, according to an analysis of available research that was released February 11 and will be presented at the American Academy of Neurology's 62nd Annual Meeting in Toronto April 10 to April 17, 2010. Another study found that eating chocolate may lower the risk of death after suffering a stroke.

http://www.sciencedaily.com/releases/2010/02/100211163114.htm

Science Daily Article (PDF)

Does Flavanol Intake Influence Mortality from Nitric Oxide-Dependent Processes?

Bayard V, Chamorro F, Motta J, Hollenberg NK. Does Flavanol Intake Influence Mortality from Nitric Oxide-Dependent Processes? Ischemic Heart Disease, Stroke, Diabetes Mellitus, and Cancer in Panama. Int J Med Sci 2007; 4:53-58.

Substantial data suggest that flavonoid-rich food could help prevent cardiovascular disease and cancer. Cocoa is the richest source of flavonoids, but current processing reduces the content substantially. The Kuna living in the San Blas drink a flavanol-rich cocoa as their main beverage, contributing more than 900 mg/day and thus probably have the most flavonoid-rich diet of any population. We used diagnosis on death certificates to compare cause-specific death rates from year 2000 to 2004 in mainland and the San Blas islands where only Kuna live. Our hypothesis was that if the high flavanoid intake and consequent nitric oxide system activation were important the result would be a reduction in the frequency of ischemic heart disease, stroke, diabetes mellitus, and cancer – all nitric oxide sensitive processes. There were 77,375 deaths in mainland Panama and 558 deaths in the San Blas. In mainland Panama, as anticipated, cardiovascular disease was the leading cause of death (83.4 ± 0.70 age adjusted deaths/100,000) and cancer was second (68.4 ± 1.6). In contrast, the rate of CVD and cancer among island-dwelling Kuna was much lower (9.2 ± 3.1) and (4.4 ± 4.4) respectively. Similarly deaths due to diabetes mellitus were much more common in the mainland (24.1 ± 0.74) than in the San Blas (6.6 ± 1.94). This comparatively lower risk among Kuna in the San Blas from the most common causes of morbidity and mortality in much of the world, possibly reflects a very high flavanol intake and sustained nitric oxide synthesis activation. However, there are many risk factors and an observational study cannot provide definitive evidence.

Keywords: Cocoa, flavanoids, heart disease, diabetes mellitus, cancer, infectious disease

http://www.medsci.org/v04p0053

Medical News Today (PDF)
 

Cerebral blood flow response to flavanol-rich cocoa in healthy elderly humans

Sorond FA, Lipsitz LA, Hollenberg NK, Fisher NDL. Cerebral blood flow response to flavanol-rich cocoa in healthy elderly humans. Neuropsychiatric Disease and Treatment. 2008;4:433-440.

Abstract
Background and Purpose
Cerebral ischemia is a common, morbid condition accompanied by cognitive decline. Recent reports on the vascular health benefits of flavanol-containing foods signify a promising approach to the treatment of cerebral ischemia. Our study was designed to investigate the effects of flavanol-rich cocoa (FRC) consumption on cerebral blood flow in older healthy volunteers.

Conclusions
In summary, we show that dietary intake of FRC is associated with a significant increase in cerebral blood flow velocity in the MCA as measured by TCD. Our data suggest a promising role for regular cocoa flavanol’s consumption in the treatment of cerebrovascular ischemic syndromes, including dementias and stroke.

Keywords: cerebral blood flow, flavanol, cocoa, transcranial Doppler ultrasound

Original Research http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2518374/
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