A picture taken on March, 30, 2018 shows honey chocolate made by prize-winning Corsican chocolate makers Josiane and Lionel Colomb-Bereni, at their factory in Peri on the French Mediteranean island of Corsica. (Xinhua/AFP)

WASHINGTON, April 24 (Xinhua) -- A new research showed that consuming dark chocolate with a high concentration of cacao had positive effects on stress levels, inflammation, mood, memory and immunity.

Presented on Tuesday at the ongoing five-day Experimental Biology 2018 meeting in San Diego, the United States, two studies revealed for the first time 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.

"These studies show us that the higher the concentration of cacao, the more positive the impact on cognition, memory, mood, immunity and other beneficial effects," said Lee S. Berk, a researcher in psychoneuroimmunology and food science from Loma Linda University and principal investigator on both studies.

They focused on the impact of 70 percent cacao chocolate consumption on human immune and dendritic cell gene expression, with focus on pro- and anti-inflammatory cytokines. Cacao is a major source of flavonoids.

This study assessed the electroencephalography (EEG) response to consuming 48 gram of dark chocolate (70 percent 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).

Pieces of milk and dark chocolate are displayed at the Salon du Chocolat (Chocolate Fair) in Paris, France, on Oct. 28, 2016. (Xinhua/AFP)

Study findings showed that cacao consumption up-regulated multiple intracellular signaling pathways involved in T-cell activation, cellular immune response and genes involved in neural signaling and sensory perception, the latter potentially associated with the phenomena of brain hyperplasticity.

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

According to Berk, further research is in progress to elaborate on the mechanisms that may be involved in the cause-and-effect brain-behavior relationship with cacao at this high concentration.