Postoperative cognitive dysfunction and short-term neuroprotection from blueberries: a pilot study.

BACKGROUND: General anesthesia may be a risk factor for post-operative cognitive impairment, which could be counteracted by neuroprotective compounds. The aims of this study were to determine cognitive functions impaired by general anesthesia and to test blueberry juice as a neuroprotective agent against neuropsychological dysfunctions induced by general anesthesia. METHODS: Twenty-six patients undergoing elective major surgery were randomized into two groups, receiving either 500 mL/day of blueberry juice within 14 preoperative days (G1) or to a control group (G0). Neuropsychological tests were performed around 20 days before surgery (T0), as well as both three hours (T1) and 24 hours (T2) after surgery. All the scores were statistically analyzed to find significant differences between groups and within the three times. RESULTS: The control (G0) group showed a significant decrease in the performance in the Prose Memory Test (P<0.001), the Attentional Matrices Test (P<0.01), and the Trail Making Test Part B (P<0.01) after general anesthesia. Significant differences were reported in the Prose Memory test, T0 versus T1 (P<0.01), T0 versus T2 (P<0.001); in the Trail Making Test Part B, T0 versus T2 (P<0.01); and the Attentional Matrices test, and T0 versus T2 (P<0.001). The G1 group did not show any decrease in the performance of the three tests. CONCLUSIONS: General anesthesia induces a short-term impairment of verbal memory and selective and divided attention. Blueberry compounds may prevent these neuropsychological deficits through a neuroprotective action in patients undergoing general anesthesia.

Antioxidant and neuroprotective properties of blueberry polyphenols: a critical review.

OBJECTIVE: The aim of this work was to highlight the effects and the possible mechanisms of the action of blueberry polyphenols on the central nervous system (CNS). METHODS: An analysis was carried out, in a temporal order, of the most important literature about this topic and the results have been correlated with the beneficial and protective effects, mainly concerning the CNS. DISCUSSION: Over the last 10 years an increasing scientific interest has developed about polyphenols, which are very abundant in blueberries, as they have been seen to produce favourable effects related to neuroprotection and linked to a possible decrease of age-related cognitive and motor decline, as shown by the improvement of such functions in animal models with a supplemented diet. Such effects could not only be explained through a purely antioxidant action but also through more complex mechanisms related to inflammation, genic expression, and regulation of cell survival. CONCLUSIONS: Despite the wealth of data from animal studies, there is a relative lack of data concerning human beings, even if some positive results are beginning to emerge. Therefore, blueberry polyphenols could become useful pharmacological agents for various conditions including neurological diseases, but further studies are still necessary to attain this objective.