Eating polyphenol-rich cranberries improves memory and neural functioning in older adults.
As many as 55 million people worldwide have dementia, a figure expected to triple in the next three decades. Evidence suggests that dietary patterns and components may reduce the risk of developing dementia. Findings from a recent study suggest that eating cranberries improves memory and neural functioning in older adults.
Cranberries, like many other red, purple, or blue fruits, are rich in bioactive compounds called polyphenols, including anthocyanins, proanthocyanidins, flavonols, and others. Robust evidence indicates that these compounds exert antioxidant, anti-inflammatory, and/or neuroprotective effects in humans.
The investigators conducted a randomized, placebo-controlled trial involving 60 healthy adults between the ages of 50 and 80 years. Half of the participants consumed 4.5 grams of freeze-dried cranberry powder (to be mixed in liquid) every day for 12 weeks. The daily portion of supplemental cranberry powder was roughly equivalent to eating about one-half cup of fresh cranberries and provided 59 milligrams of anthocyanins, 281 milligrams of proanthocyanidins, and 20 milligrams of flavonols. The other half of the participants consumed a similar-looking non-nutritive powder for the duration of the study. Before, during, and after the intervention, participants underwent cognitive testing and provided blood samples for biochemical assessment. A subset of participants underwent magnetic resonance imaging (MRI) studies.
At the end of the intervention, participants who received the cranberry powder exhibited improvements in visual episodic memory. In addition, their low-density lipoprotein cholesterol (which contributes to atherosclerosis and impaired brain function) decreased. The MRIs revealed that the supplemented group had increased blood flow to areas of the brain involved in memory formation and consolidation.
These findings suggest that polyphenol-rich cranberries improve memory and aspects of neural functioning in older adults. It is noteworthy, however, that many commercial cranberry products contain copious amounts of added sugar to counter the berries' tartness. Because sugar can have harmful effects on brain and metabolic health, consuming unsweetened cranberries (or other berries) will likely have the greatest benefits on cognition.