Overview
Blueberries contain chemicals called polyphenols with multiple direct and indirect effects on the nervous system and brain function when eaten as part of a healthy diet. Blueberries and other plants produce polyphenols to protect against damage caused by stress conditions. Research in the lab and in animals indicates blueberry polyphenols may have possible health benefits for humans including antioxidant activity, reduced inflammation and longer life with improved quality of life.
Polyphenolic Compounds
Polyphenolic compounds produced in plants have aromatic ring chemical structures with attached chemical groups that are the active sites for chemical activity. Plants produce polyphenols to help them deal with changing and harsh environmental factors. Vegetables, grains and fruits, and beverages made from plants, like tea and wine, provide dietary sources of polyphenolic compounds. Free radicals that are released during respiration circulate in the bloodstream and damage cells. Cell damage may be reduced by antioxidants. Polyphenolic compounds may act as antioxidants to protect cells from free radicals or by other mechanisms.
Blueberry Polyphenols
Blueberries contain a mixture of polyphenol compounds including anthocyanins that produce the blue color, proanthocyanadins, catechins and others. Blueberries contain higher levels of polyphenols than many other fruits. Animal research using a diet rich in blueberries at the University of Prince Edward Island shows antioxidant protection from damage to neurons after a stroke. The University of Barcelona’s research shows anthocyanins are not broken down by digestion and are able to cross the blood brain barrier for direct action in the brain. A study completed at the National Institute on Aging shows that the proanthocyanadins lengthen life and increase the production of protective enzymes.
Antioxidant Capability of Blueberries
Blueberries protect cells from damage caused by oxygen free radicals during respiration. These free radicals circulate in the blood throughout the body, causing damage to cells. Antioxidants protect cells, and both wild and cultivated blueberries have antioxidant properties. Low-bush or wild blueberries reduce free radical production in red blood cells, and high-bush or cultivated blueberries inhibit oxidation.
Memory and Anti-inflammatory Action
Blueberry polyphenols produce an anti-inflammatory response and maintain problem solving skills in rats. Diseases of the nervous system related to reduced cell function, like Alzheimer’s, may result from long-term exposure to inflammation. Inflammation leads to multiple responses in the body releasing chemicals. These chemicals cause damage to nerve cells and may lead to reduced thinking ability and affect memory. Blueberry polyphenols reduce inflammation through a series of actions to release body-produced protective chemicals. Researchers at the Human Nutrition Research Center on Aging at Tuft’s University discovered blueberry polyphenols work as well as the non-steroidal anti-inflammatory medication piroxicam in certain aspects to improve thinking.
Genetic Signaling Increased by Blueberry Proanthocyanadins
Instead of acting on one specific anti-aging mechanism, blueberries increase general health and improve balance and coordination. With aging, stress affects cells and decreases muscle mass needed for performance. Instead of acting as an antioxidant, the polyphenol proanthocyanadin produces longer life through increased signaling for the production of genes that protect cells from stress.
Potential Health Benefits of Blueberries
There is limited research regarding the effect of blueberries on human health. However, adding blueberries as part of a healthy diet may provide health benefits. In animals, blueberries have been found to limit damage to neurons following stroke, reduce symptoms associated with aging and work as an anti-inflammatory. Polyphenols in blueberries improve memory and the ability to learn new things.
About this Author
A professional writer since 2001, Lyn Michaud has been published in educational encyclopedias, including “Encyclopedia of Global Health” and “Encyclopedia of Global Warming and Climate Change.” She holds degrees in biology and chemistry and spent three years as a board member for Weld City Board of Health.
