GETTY Snacking daily on dark chocolate could stave off Alzheimer's disease

Cocoa is rich in antioxidants called flavonols that boost blood flow to the brain. Older people who ate the nutrient daily performed better in mental tasks. It means regularly treating themselves could combat the devastating neurological condition, say scientists. They found chocolate increases the amount of blood in a particular area of the brain known as the dentate gyrus, which is crucial to memory.

Interestingly, the best effects on cognition of long term consumption of cocoa flavanols was seen in the elderly. Their mental function was improved by a daily intake, whereas the benefit for younger counterparts was much more subtle. Factors such as attention, processing speed, working memory and verbal fluency were greatly affected. These were, however, most pronounced in older adults whose memory had already started to decline, or who had other mild cognitive impairments which can lead to Alzheimer's. Neuroscientists Professor Michele Ferrara and Valentia Socci, a PhD student, said this was exactly the most "unexpected and promising" result. The researchers, who are based at the University of L'Aquila, central Italy, said: "This result suggests the potential of cocoa flavanols to protect cognition in vulnerable populations over time by improving cognitive performance.

GETTY Factors such as attention, processing speed, working memory and verbal fluency were greatly affected

GETTY Dark chocolate 'is a rich source of flavanols'

"If you look at the underlying mechanism, the cocoa flavanols have beneficial effects for cardiovascular health and can increase cerebral blood volume in the dentate gyrus of the hippocampus. "This structure is particularly affected by ageing and therefore the potential source of age related memory decline in humans." They said their findings suggest cocoa could become a dietary supplement to improve our cognition. Prof Ferrara and Ms Socci said: "Regular intake of cocoa and chocolate could indeed provide beneficial effects on cognitive functioning over time. "There are, however, potential side effects of eating cocoa and chocolate. "Those are generally linked to the caloric value of chocolate, some inherent chemical compounds of the cocoa plant such as caffeine and theobromine, and a variety of additives we add to chocolate such as sugar or milk." But the scientists are the first to put their results, published in Frontiers in Nutrition, into practice.

GETTY Cocoa is rich in antioxidants called flavonols that boost blood flow to the brain

They said: "Dark chocolate is a rich source of flavanols. So we always eat some dark chocolate. Every day." Prof Ferrara and Ms Socci came to their conclusion after reviewing all the available literature for the effects of cocoa flavanols on different cognitive functions. A press release issued by the university stated: "Cocoa and chocolate are not just treats - they are good for your cognition." It added: "Cocoa can be seen as a dietary supplement to protect human cognition and can counteract different types of cognitive decline." The researchers said a phrase often used to justify the world's favourite confectionery is that a 'balanced diet is chocolate in both hands.' But it is now shown to actually harbour some truth, as the cocoa bean is a rich source of flavanols, natural compounds that have neuroprotective effect. Prof Ferrara and Ms Socci looked specifically at what happens to your brain up to a few hours after you eat cocoa flavanols, and the effect of sustaining such an enriched diet for a prolonged period of time. They said although randomised controlled trials investigating the acute effect of cocoa flavanols are sparse, most of them point towards a benefit to mental performance. Participants showed, among others, enhancements in working memory performance and improved visual information processing after having had cocoa flavanols. And for women, eating cocoa after a night of total sleep deprivation actually counteracted the cognitive impairment - in other words, less accuracy in performing tasks - that such a night brings about. These were also promising results for people that suffer from chronic sleep deprivation or work shifts. It has to be noted though, that the effects depended on the length and mental load of the used cognitive tests to measure the effect of acute cocoa consumption.

Signs and symptoms of Alzheimer's Tue, August 23, 2016 There are more than 520,000 people in the UK with Alzheimer's disease. Here are 10 early signs and symptoms including memory loss and problem-solving to look out for. Play slideshow Getty Images 1 of 10 Changes in mood and personality - If you notice a loved one become easily upset, confused, depressed or anxious they could be suffering from Alzheimer's so talk to them and book an appointment with the doctor