Could cocoa hold the key to Alzheimer’s prevention?

15 Sep

Chocolate is not generally considered to be a healthful food. However, chocolate contains nutrients that could be used to maintain brain health and prevent age-related neurodegenerative disorders such as Alzheimer’s disease, according to a recent review paper published in the Journal of Alzheimer’s Disease.

Cocoa beans.
Cocoa extracts contain large quantities of micronutrients known as polyphenols that have been shown to promote healthy brain aging.

Polyphenols are the micronutrients in question, and these are found in large quantities in cocoa extracts.

Research has suggested that chocolate and cocoa could reduce the risk of heart disease. In particular, polyphenols known as flavanols have been demonstrated to have antioxidant effects that reduce cell damage caused by heart disease, while also having blood thinning properties.

In June, Medical News Today reported on a study that suggested eating up to 100 g of chocolate a day is linked to reduced risks of heart disease and stroke.

However, some studies have also shown that cocoa extract consumption can help reduce age-related cognitive dysfunction and assist healthy brain aging.

Leading author of the review is Dr. Giulio Maria Pasinetti, professor of neurology at the Icahn School of Medicine at Mount Sinai in New York, NY. He has previously worked on studies that have indicated that specific forms of cocoa extract could have a preventive effect on Alzheimer’s disease in animal models.

In these studies, cocoa polyphenols were found to help reduce the production and assist the clearance of harmful proteins that collect in the brain, such as beta-amyloid and abnormal tau aggregates.

“Therefore, emerging biomedical research experimental evidence, and new clinical translational studies all support the major interest in the development of cocoa as a botanical source for the maintenance and promotion of health, in particular, in the brain,” the authors write.

In the review, the authors report that an estimated 35.6 million people had Alzheimer’s disease in 2010, and that this figure is expected to have doubled by 2030. The treatment that is currently available for this condition can only ease cognitive decline, however, rather than slowing the progression of the disease.

Cocoa extract polyphenols and the blood-brain barrier

The authors state that research shows dietary polyphenols can cross the blood-brain barrier and reach areas in the brain that are crucial to the development of Alzheimer’s disease.

“For example, we found that one of the polyphenol metabolites, quercetin-3-O-glucoside, is capable of crossing the BBB [blood-brain barrier], accumulating in the brain, and modulating [beta-amyloid] neuropathogenic mechanisms,” they write.

Fast facts about Alzheimer’s

  • While its greatest known risk factor is age, Alzheimer’s disease is not a normal part of aging
  • The most common early symptom is difficulty remembering newly learned information
  • Alzheimer’s disease accounts for around 60-80% of dementia cases in the US.

Learn more about Alzheimer’s

In preventing abnormal accumulation of harmful proteins such as beta-amyloid, cocoa polyphenols could help prevent the loss of synapses in the brain and, therefore, help maintain functioning connections between nerve cells.

To fully harness the healthful potential of cocoa extract, Dr. Pasinetti and colleagues propose that there needs to be a multidisciplinary approach, involving collaboration between cocoa producers, wholesalers and biomedical researchers.

They state that there is currently a gap between the world’s cocoa supply and demand for cocoa of more than 1 million tons, with this gap estimated to widen in the near future on account of changes in climate, growth and diseases that affect the cocoa plant.

At present, new breeds of cocoa engineered to be more resistant to disease as well as more fruitful are in development. It is research such as this and investigations into cocoa processing procedures that the authors recommend for narrowing the gap between cocoa supply and demand.

The authors also state that more research needs to be conducted to understand fully the mechanisms behind cocoa extract’s effect on cognition. Finally, they propose that methods for extracting and analyzing cocoa polyphenols should be standardized. They conclude:

“Successful translational studies of cocoa extracts in clinical settings will require coordinated research efforts bridging together development of new sources of cocoa extract, improved standardized methodologies for quantitative detection of polyphenols from cocoa preparations, and investigations on the effect of cocoa processing and the biological availability and biological activities of cocoa polyphenols.”

Previously, MNT ran a Spotlight feature article investigating whether chocolate is good for our health or whether the potential health benefits of this food are overstated.

Written by James McIntosh

Copyright: Medical News Today

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