Anthocyanins: Plant Pigments, Food Ingredients or Therapeutic Agents for the CNS? A Mini-Review Focused on Clinical Trials.

Anthocyanins are plant pigments present in flowers, leaves or fruits with polyphenolic structure belonging to the group of flavonoids. From a nutritional approach, they are the most abundant flavonoids in dietary sources responsible for the antioxidant properties of those foods. In addition, the food and pharma industries have used anthocyanins as food additives or excipients due to its colorant properties. However, beyond its antioxidant effects, anthocyanins may also act as therapeutic agents due to neuroprotective, antidiabetic and cardioprotective properties. There is a growing body of evidence suggesting the role of these compounds in the Central Nervous System (CNS). Previous in vitro and animal studies have suggested neuroprotective benefits, but we here review human interventions made with anthocyanins in relation to cognition, insomnia, anxiety or depression. Due to the link between oxidative stress and neurodegenerative disorders, human studies conducted on healthy volunteers evaluating oxidative stress parameters have also been included. As reviewed here, very few human studies (only ten) have been performed in the area of CNS; however, considering the obtained outcomes in those trials together with human interventions in relation with oxidative stress as well as data showing neuroprotective effects from preclinical experiments, we suggest that anthocyanins may have potential benefits for the CNS.