Flavonoids are compounds produced by plants and thought to confer significant health benefits on humans. In plants, they act as essential pigments and are responsible for the colors found in buds, petals, fruits and autumn leaves. Flavonoids are found in many brightly colored fruits and vegetables, including blueberries, parsley, red grapes, cranberries, cherries and citrus fruits.
Research conducted by scientists from the University of East Anglia set out to test whether supplementing people’s diets every day with cranberries (Vaccinium macrocarpon) could help improve memory and brain function in older individuals, and thereby reduce age-related neurodegeneration. Cranberries are rich in anthocyanins, a particular group of plant flavonoids that act as antioxidants.
“Dementia is expected to affect around 152 million people by 2050. There is no known cure, so it is crucial that we seek modifiable lifestyle interventions, such as diet, that could help lessen disease risk and burden,” explained lead researcher Dr. David Vauzour.
“Past studies have shown that higher dietary flavonoid intake is associated with slower rates of cognitive decline and dementia,” he continued. “And foods rich in anthocyanins and proanthocyanidins, which give berries their red, blue, or purple colour, have been found to improve cognition. Cranberries are rich in these micronutrients and have been recognized for their antioxidant and anti-inflammatory properties.”
The researchers investigated the impact of eating 100g of cranberries each day for 12 weeks. The 60 participants, all cognitively healthy individuals between the ages of 50 and 80, were divided into two groups. One group took 100g of freeze-dried, powdered cranberry (equivalent to 1 cup of berries) as a supplement every day, while the other group received a placebo.
After 12 weeks, it was found that participants who had consumed the cranberry powder showed significantly improved memory of everyday events (visual episodic memory), neural functioning and delivery of blood to the brain (brain perfusion). These results have been published by the researchers in the journal Frontiers in Nutrition.
“We found that the participants who consumed the cranberry powder showed significantly improved episodic memory performance in combination with improved circulation of essential nutrients such as oxygen and glucose to important parts of the brain that support cognition – specifically memory consolidation and retrieval,” said Dr. Vauzour.
“The cranberry group also exhibited a significant decrease in LDL or ‘bad’ cholesterol levels, known to contribute to atherosclerosis – the thickening or hardening of the arteries caused by a build-up of plaque in the inner lining of an artery,” he added. “This supports the idea that cranberries can improve vascular health and may in part contribute to the improvement in brain perfusion and cognition.”
This study is one of the first to examine cranberries and their long-term impact on cognition and brain health in humans, and the researchers hope that their findings will be used to inform future strategies for the prevention of neurodegenerative diseases such as dementia.
“Demonstrating in humans that cranberry supplementation can improve cognitive performance and identifying some of the mechanisms responsible is an important step for this research field,” said Dr. Vauzour. “The findings of this study are very encouraging, especially considering that a relatively short 12-week cranberry intervention was able to produce significant improvements in memory and neural function.”
The experts feel that their study establishes an important foundation for future research in the area of cranberries and neurological health.