Do blueberries and fish oil give our brains a boost?

Research in recent years suggests that certain foods can give our brain a boost—dark berries, like grapes and blueberries, and cold water fish like salmon, just to name a few. With studies showing cognitive benefit from a diet rich in these foods, researchers at the University of Cincinnati (UC) set out to investigate whether steady long-term supplementation of blueberries and fish oil, either alone or combined, would show improvements in older adults with complaints of mild neurological deficits, like forgetfulness.

The answer they got, surprisingly, was yes and no. Separately, participants in the fish oil study group and in the blueberry consumption group both showed fewer cognitive symptoms with objective memory improvement for those in the blueberry group; however, those in the group taking both blueberry and fish oil supplements showed no objective or subjective cognitive enhancement. These results are published in the journal Neurobiology of Aging (April 2018).

“We wondered whether combining fish oil and blueberry supplementation might produce enhanced benefit as opposed to either supplement alone. Our findings, showing an absence of benefit, were surprising, particularly in the context of our findings of benefit with the individual treatments. Perhaps it’s possible that long-term daily supplement of both on an otherwise restricted diet may have been ineffective through sustained rather than intermittent activation of shared antioxidant mechanisms,” says Robert Krikorian, PhD, professor of psychiatry and behavioral neuroscience at the UC College of Medicine and corresponding author on the study.

New Studies on Berries, Diet and Cognition

Now, Krikorian has launched three new trials in a slightly younger population to look further into how diet may affect the brain, perhaps even prevent neurological deficit.

His studies include a continuation of blueberry supplementation, a new study with strawberry supplementation and now, a ketogenic diet that strictly limits carbohydrate consumption, to evaluate how it may affect cognition. The studies range from 8 to 12 weeks.

“Studies have shown that older adults with subjective cognitive complaints are at an increased risk for future dementia and a subset of these individuals exhibit early cognitive decline,” he says. “Because of this, we see an increasing interest in evaluating healthy interventions in midlife to prevent or delay future dementia.”

“Since our studies target middle-aged individuals with greater risk for late-life dementia, we included being overweight as one of our criteria,” says Krikorian. “This is often associated with insulin resistance, hyperinsulinemia, and other features (such as high blood pressure) that are typical of the metabolic syndrome. While not all overweight people will have metabolic syndrome, a high proportion will. And, all of these features—hyperinsulinemia, high blood pressure, and others—are risks for Alzheimer’s and other forms of dementia.”

Criteria for participants of the current studies must be between the ages of 50-65, have a BMI of 25 or greater, and are aware of mild memory decline such as forgetfulness or short-term memory difficulty.

Featured image at top, and within story: Blueberries. Photos/Colleen Kelley/AHC Communications Services