Blueberries deliver the most delicious wallop of vitamin C found on the planet (in my humble opinion). One serving supplies 25 percent of your daily C requirement plus additional heart-healthy fiber and manganese, important to bone health. A super-achiever when it comes to antioxidant strength, this fruit may also lower your risk of heart disease, cancer, and, new research suggests, even 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.

Still, eating a diet rich in fruits and veggies is unquestionably good for your health with many scientists analyzing and testing specific foods to understand whether they might prevent a particular illness. Quite a few studies, Krikorian and his colleagues note, have found blueberries beneficial in preventing dementia.

Silver Tide

One type of dementia, Alzheimer’s disease, causes problems with memory, thinking, and behavior. This neurodegenerative disorder develops in a healthy brain, its symptoms appearing slowly and then worsening over time. Eventually, this disease becomes severe enough to interfere with daily tasks and in the end disrupts even the autonomic nervous system, which controls heart rate and breathing. If they live long enough, Alzheimer’s patients die because their breathing stops. Currently 5.3 million Americans suffer from Alzheimer's disease, yet as the nation’s population grows older, that number will almost inevitably rise. The Alzheimer's Association calculates that the number of Americans with this disorder will reach more than seven million by 2025.  

How can science slow this trend?  

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 blueberry group demonstrated improved memory and improved access to words and concepts," said Krikorian in a statement to the press. Additionally, a second scan showed increased activity in the brains of those in the blueberry group.

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.