Previous studies have already shown that introducing more nuts into the Mediterranean diet can protect against age-related cognitive decline and help preserve memory. But how do nuts really affect brain activity? A team of researchers from Loma Linda University in Beaumont, California (USA) set out to find out.
Led by expert Lee Berk, the scientists started from the observation that nuts have high concentrations of flavonoids – antioxidants believed to have anti-inflammatory, anti-cancer and heart-protective effects. In the same way, flavonoids also access the areas of the brain’s hippocampus that are responsible for learning and memory.
Scientists believe that these flavonoids induce neuroprotective effects, leading to “neurogenesis” or the “birth” of new neurons, as well as improving blood flow to the brain.
But how would these benefits translate into electrical activity in the brain? To find an answer, they asked study participants to regularly consume nuts to allow an electroencephalogram (EEG) to measure their brain activity. Specifically, the volunteers ate almonds, peanuts, pecans, pistachios, cashews and walnuts regularly.
Walnuts induce strong gamma and delta waves
Brain waves were measured while undergoing a “sequence of enhancement of sensory awareness tasks ranging from cognition of past experience, visualization, smell, taste, and finally nut consumption,” the authors comment.
These sequences were varied so that the EEG could measure brain activity in nine different cortical regions.
“This study provides objective evidence that [brain wave strength] for different EEG brain wave bands is modulated differently for different types of nuts. These data appear to support an association of fruit health benefits. dry with an increase in [delta waves] and [gamma waves], “they explain.
Specifically, peanuts produced the strongest delta wave response (associated with a healthy immune response and deep non-REM sleep), while pistachios produced the highest response in gamma waves (associated with perception, rapid eye movement (REM) sleep and information processing and retention, and is generally believed to enhance cognitive processing). Delta and gamma waves were higher with pecans.
The researchers also looked at the antioxidant concentration of each type of nut and found that walnuts had the highest levels of this substance, followed by pecans and cashews.
Overall, all six varieties of nuts had high levels of beneficial antioxidants.
“This study provides significant beneficial findings by showing that nuts are as good for your brain as they are for the rest of your body,” says Lee Berk.
The authors hope that the following studies will reveal new benefits of nuts for both the brain and the nervous system.
Referencia: Nuts and Brain Health: Nuts Increase EEG Power Spectral Density (μV&[sup2]) for Delta Frequency (1–3Hz) and Gamma Frequency (31–40 Hz) Associated with Deep Meditation, Empathy, Healing, as well as Neural Synchronization, Enhanced Cognitive Processing, Recall, and Memory All Beneficial For Brain Health. THE FASEB JOURNAL 2017 fasebj.org/content/31/1_Supplement/636.24
