Flavanol-rich chocolate may boost blood flow in the brain and reduce the risk of dementia, experts have told attendees at the annual meeting for the American Association for the Advancement of Science (AAAS).
The research, supported by confectionary giant Mars, extends previous studies linking consumption of flavanol-rich cocoa products to improved cardiovascular health. Mars has been very active in this research area, supporting numerous studies in the area for more than 15 years.
The link between cocoa flavanols and cardiovascular health has been linked to the improving blood flow via increased production of nitric oxide, a molecule used by the endothelium to signal surrounding muscle to relax.
According to two presentations at the AAAS annual meeting, boosting blood flow may also have implications for cognitive function, particularly learning and memory.
The results suggest that specialty flavanol-rich cocoa products could be increasingly targeted at the 'baby boomers' (people born between 1946 and 1964), an age-group that forms the biggest age-bracket of the population in both the US and Europe, and who are increasingly aware of potential heart disease and cognitive decline, including Alzheimer's, a disease that is expected to quadruple in prevalence by 2047.
During the session entitled, The Neurobiology of Chocolate: A Mind-Altering Experience? Ian A. Macdonald from the University of Nottingham Medical School reported that the consumption of a specially formulated flavanol-rich cocoa beverage (supplied by Mars) resulted in regional changes in blood flow in study participants.
"Our study showed that acute consumption of this particular flavanol-rich cocoa beverage was associated with increased blood flow to grey matter for 2 to 3 hours," said Macdonald.
"This raises the possibility that certain food components like cocoa flavanols may be beneficial in increasing brain blood flow and enhancing brain function among older adults or for others in situations where they may be cognitively impaired, such as fatigue or sleep deprivation," he said.
Also presented at the session were new results from ongoing research with the Kuna Indians of Panama, a population who consume large amounts of cocoa and who have unusually low rates of hypertension and cardiovascular disease.
Norman Hollenberg from Harvard Medical School and Brigham and Women's Hospital presented new data, also published in the current issue of the International Journal of Medical Sciences, used death certificates to compare the cause of death of island-dwelling Kuna to those who live on mainland Panama, who do not regularly drink the flavanol-rich cocoa.
Hollenberg reported that the relative risk of death from heart disease on the Panama mainland was 1,280 per cent higher than on the islands and death from cancer was 630 per cent higher, compared to the islanders.
"Although the findings are comparable with effect of the flavanol-rich cocoa on health, clearly a large number of alternative possibilities exist involving diet, physical activity, stress and genetic factors," wrote Hollenberg and his colleagues in the International Journal of Medical Sciences.
"An observation study of this kind cannot prove causality. Indeed, only a randomised, controlled clinical trial in which all of these factors can be controlled will lead to a definitive conclusion," they said.
Some data does exist on the effect of feeding the flavanol-rich cocoa to healthy volunteers. A US-based study by Hollenberg and his colleagues reported a "striking blood flow response" that evolved over several weeks.
"Since this cocoa preparation is so well tolerated, it raises hope that the brain blood flow response it stimulates can result in maintenance of healthy brain function and cognition, which is an issue that unfortunately plagues many older adults today," said Hollenberg at the AAAS annual meeting.
The results were welcomed by Harold Schmitz, Mars' chief science officer and organiser of the Neurobiology of Chocolate symposium, who said: "This research is impressive in that multiple laboratories are coming to the same conclusion about this flavanol-rich cocoa, and the findings give us completely new insights into how this flavanol-rich cocoa may impact health in a variety of ways not previously known.
"The findings raise the possibility that products utilizing this cocoa could be developed to help maintain healthy brain function throughout several life stages. More research examining the potential of this cocoa in this important area of public health need is clearly warranted."
Experts counsel moderation for consumption of chocolate due the calorific load.
Journal reference: International Journal of Medical Sciences
Volume 4, Pages 53-58
"Does flavanol intake influence mortality from nitric oxide-dependent processes? Ischemic heart disease, stroke, diabetes mellitus, and cancer in Panama"
Authors: V. Bayard, F. Chamorro, J. Motta, N.K. Hollenberg