New York, Apr 25 (IANS): Consuming dark chocolate can reduce stress and inflammation, as well as improve memory, immunity and mood, results from experimental trials have shown.

This is due to the high concentration of cacao -- a major source of flavonoids.

The flavonoids found in cacao are extremely potent antioxidants and anti-inflammatory agents, with known mechanisms beneficial for brain and cardiovascular health, the researchers said.

"For years, we have looked at the influence of dark chocolate on neurological functions from the standpoint of sugar content -- the more sugar, the happier we are," said lead investigator Lee S. Berk, from Loma Linda University in California, US.

"This is the first time that we have looked at the impact of large amounts of cacao in doses as small as a regular-sized chocolate bar in humans over short or long periods of time, and are encouraged by the findings," Berk added.

Further, dark chocolate was also found to affect human gene expression. It regulates cellular immune response, neural signalling, and sensory perception.

Cacao consumption up-regulates multiple intracellular signalling pathways involved in T-cell activation, cellular immune response and genes involved in neural signalling and sensory perception -- the latter potentially associated with the phenomena of brain hyperplasticity.

"These studies show us that higher the concentration of cacao, the more positive the impact on cognition, memory, mood, immunity and other beneficial effects," Berk noted.

The findings were presented at the Experimental Biology 2018 meeting in San Diego, US.

For the trial, the team for the first time examined the impact of large amounts of cacao in doses as small as a regular-sized chocolate bar in humans over short or long periods of time.

The team assessed the electroencephalography (EEG) response to consuming 48 g of dark chocolate (70 per cent cacao) after an acute period of time (30 minutes) and after a chronic period of time (120 minutes), on modulating brain frequencies 0-40Hz, specifically beneficial gamma frequency (25-40Hz).

Berk said the studies require further investigation, specifically to determine the significance of these effects for immune cells and the brain in larger study populations.