A diet rich in phytochemicals from berries could help improve brain health in several ways, such as improving communication pathways and protecting against oxidative stress, say researchers.
The review – published in the Journal of Agricultural and Food Chemistry – suggest that strong scientific evidence exists to support the beneficial effects of berries on the brain. The study reported that consumption of blueberries, blackberries, strawberries and other berry fruits has beneficial effects on the brain, and could help prevent age-related memory loss and other changes.
The researchers, led by Barbara Shukitt-Hale from the USDA Agricultural Research Service’s human nutrition research centre on aging at Tufts University, said that berry fruits possess neuroavailable, neuroactive phytochemicals “that offer antioxidant, anti-inflammatory, and direct effects on the brain.”
“A growing body of preclinical and clinical research has identified neurological benefits associated with the consumption of berry fruits,” said the reviewers.
“In addition to their now well-known antioxidant effects, dietary supplementation with berry fruits also has direct effects on the brain. Intake of these fruits may help to prevent age-related neurodegeneration and resulting changes in cognitive and motor function,” they added.
Shukitt-Hale and her colleagues pointed out that longer life-spans are raising concerns about the human toll and health care costs of treating Alzheimer's disease and other forms of mental decline. They explained that recent research has increasingly shown that eating berry fruits can benefit the aging brain.
Their new review analysed the strength of the evidence for these effects from berry fruits. The researchers said they extensively reviewed cellular, animal and human studies on the topic to judge the evidence for the suggested benefits.
The review found that berry fruits could help the brain to remain healthy in several ways, said Shukitt-Hale. The team noted that berry fruits contain high levels of antioxidants that they suggest protect the brain from oxidative stress produced by harmful free radicals.
In addition, the review finds that berries alter the way neurons in the brain communicate. Shukitt-Hale and her colleagues said these changes in signalling can prevent inflammation in the brain that contribute to neuronal damage and improve both motor control and cognition.
“In cell and animal models, berry fruits mediate signalling pathways involved in inflammation and cell survival in addition to enhancing neuroplasticity, neurotransmission, and calcium buffering, all of which lead to attenuation of age- and pathology-related deficits in behaviour,” they wrote.
Shukitt-Hale and her team suggested that further research will reveal whether these benefits are a result of individual compounds shared between berry fruits or whether the unique combinations of chemicals in each berry fruit simply have similar effects.
“Each type of berry fruit is composed of a unique combination of phytochemical,” they noted.
“Currently, researchers possess an incomplete picture of the neuroavailability and mechanisms of action for the wide variety of phytochemicals present in berry fruit and their respective metabolites.”
“More research is required to demonstrate each constituents' availability and mechanism of action specific to individual brain subregions,” they concluded.
Source: Journal of Agricultural and Food Chemistry
Published online ahead of print, doi: 10.1021/jf2036033
“Berry Fruit Enhances Beneficial Signaling in the Brain”
Authors: M.G. Miller, B. Shukitt-Hale