Dark chocolate is neuroprotective in rats prone to Alzheimer’s Disease

Good news for chocolate lovers as positive results of another study into the health benefits of chocolate were released.

Building on the findings that dietary polyphenols have antioxidant agents and may improve cognitive function researchers from the National Institute of Mental Health Neurosciences in Bangalore hypothesized that the cocoa and polyphenol contents in chocolate may have similar qualities. In general flavonoid rich foods, natural antioxidants abundantly present in fruits, vegetables, red wine, green tea, cocoa, and cocoa-derived products such as dark chocolate have been gaining attention as brain “boosters” or “memory enhancers”.

To test this hypothesis they fed rats dark chocolate containing 70% cocoa solids and 4% total polyphenol content for three months at a dose of 500 mg/Kg body weight per day. To mimic the effect of a typical human with an increasingly sedentary life style, mid-life obesity and type 2 diabetes leading to the risk of cognitive decline and Alzheimer disease (AD) they used a so called NTAD rat model that resembles this.

The researchers made a number of key findings. They demonstrated that dark chocolate reduced hyperglycemia (an excess of glucose in the bloodstream that is often associated with diabetes), inhibited the cholinesterase activity in the hippocampal tissue homogenates (and hence improved synthesis of acetylcholine, a neurotransmitter involved in both memory and learning), and improve the cognitive performance in spatial memory testing. In addition analyses revealed an increase in cell volume in the dark chocolate treated rats in the CA3 region of the hippocampus. The findings demonstrate the benefits of dark chocolate in enhancing cognitive function and correcting their metabolic disturbances.

If we consider chocolate like any other compound then we calculate the Human Equivalent Dose (HED) for the dark chocolate diet given to the mice. The FDA has specified guidelines for this conversion to Human Equivalent Dose (HED). Using this guideline 500 mg/kg dosing in rats translates into a HED of approx. 85mg/kg. Or into approximately 6 gram of daily dark chocolate dose for a person weighing 70kg. The good news is that this is a realistic amount to eat, but the bad news is that it doesn’t give us a reason to enjoy a full choco bar a day.

You can find the study here.



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