New research suggests that blueberries, which are packed full of vitamin C, can reduce the risk of Alzheimer's disease. A team of University of Cincinnati scientists led by Dr. Robert Krikorian says the healthful antioxidants within blueberries provide a real benefit in improving memory and cognitive function in some older adults. Based on their work, they believe adding blueberries to your diet may help you prevent neurocognitive decline.
Blueberries acquire their deep color from anthocyanins, a type of flavonoid that acts as an antioxidant within the fruit, explains the U.S. Highbush Blueberry Council. Generally, antioxidants help to prevent age-related damage at the cellular level within the plants. While some scientists believe consuming foods rich in antioxidants will help delay aging, not all scientists, including those at the National Institutes of Health, entirely support that theory.
Following up on earlier clinical trials showing blueberries boost cognitive performance, Krikorian and colleagues conducted two new studies. The first involved 47 adults, 68 years old or older and beginning to show signs of mild cognitive impairment — a risk factor for Alzheimer's. First, the researchers conducted tests and a brain scan for each participant. Then, after forming two groups, one group of participants ate a placebo powder once a day for 16 weeks, while the other consumed a freeze-dried blueberry powder (equivalent to a single cup of berries).
Conducting the same tests and comparing the groups, Krikorian and his colleagues observed comparative improvement in cognitive performance and brain function among the adults who ate blueberry powder.
The team’s second study included 94 people between the ages of 62 and 80, all confessing to some memory problems. The researchers believed these participants to be in better cognitive “shape” than the first group, however no objective measurements verified this. For this study, the researchers divided the participants into four groups. Each group received either blueberry powder, fish oil, fish oil and powder, or placebo.
A hoped-for replication of the first study did not occur. Cognition proved somewhat better for those taking either blueberry powder or fish oil separately, yet memory barely improved, certainly not as much as in the first study, Krikorian noted. Even the scans showed similar lukewarm results. The team believes participants’ less severe cognitive impairments contributed to this weakened effect.
Blueberries may not show measurable benefit for those with minor memory issues or who have not yet developed cognitive problems, the combined results of the two studies suggest. Perhaps blueberries effectively treat only those patients who already show signs of mental impairment.
Nevertheless, Krikorian says, the very same ingredient that bestows color may provide blueberries with their brain benefits; in past animal studies, scientists have shown anthocyanins improve cognition.
Source: Krikorian R, et al. Blueberry Fruit Supplementation in Human Cognitive Aging. Meeting of the American Chemical Society. 2016.
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