Health Benefits of Blueberries
Blueberries are packed with the antioxidant pigment Anthocyanin. These antioxidants in blueberries neutralize free radicals which can damage cells and tissues. Tissue damage can, in turn, lead to cataracts, glaucoma, varicose veins, hemorrhoids, peptic ulcers, heart disease and cancer. The blue-red pigments found in blueberries (Anthocyanins), improve the integrity of support structures in the veins and entire vascular system. Anthocyanins have been shown to enhance the effects of vitamin C and improve capillary integrity. Their mode of action is to prevent free-radical damage, inhibit enzymes which can cause tissue damage and directly cross-linking with collagen fibers to form a more stable tissue matrix. This increased integrity of the tissue matrix is one of the major beneficial effects attributed to blueberries.
Blueberry extracts have been shown in numerous studies to improve nighttime visual acuity and promote quicker adjustment to darkness and faster restoration of visual acuity after exposure to glare.
Blueberries and the Brain
Blueberries help protect the brain from oxidative stress and may reduce the effects of age-related conditions such as dementia. Researchers found that diets rich in blueberries significantly improved both the learning capacity and motor skills of aging rats, making them mentally equivalent to much younger rats.
Researchers have also found that after 8 weeks of feeding laboratory rats blueberries (2% blueberry diet), they saw a reversal of age-related declines in the rats’ ability to find their way through the Morris water maze, a measure of the animals spatial learning ability and memory.
In the rats given the blueberry-containing diet, several Anthocyanins were found in the cerebellum, cortex, hippocampus or striatum, but not in the controls. These findings confirm that the blueberries beneficial pigments can cross the blood brain barrier and localize in various brain regions important for learning and memory. Further analyses showed that the more blueberry Anthocyanin compounds found in a rat’s cortex, the better the rat did in the Morris water maze test, suggesting that the beneficial actions of blueberries’ pigments work directly on brain tissue and are dose dependant.
Protection Against Cancer
In addition to their powerful Anthocyanins, blueberries contain another antioxidant compound called ellagic acid, which blocks metabolic pathways that can lead to cancer. In a study of 1,271 elderly people in New Jersey, those who ate the most strawberries (another berry that contains ellagic acid) were three times less likely to develop cancer than those who ate few or no strawberries. In addition to containing ellagic acid, blueberries are high in the soluble fiber pectin, which has been shown to lower cholesterol and to prevent bile acid from being transformed into a potentially cancer-causing form.
Laboratory studies have shown that phenolic compounds in blueberries can inhibit colon cancer cell proliferation and induce apoptosis (cell death) in cancerous cells.
Blueberries also promote urinary tract health. Blueberries contain the same compounds found in cranberries that help prevent or eliminate urinary tract infections. In order for bacteria to cause disease, they must first adhere to the mucosal lining of the urethra and bladder. Components found in blueberries reduce the ability of E. coli, the bacteria that is the most common cause of urinary tract infections, to adhere to the lining of the urinary tract thus decreasing the ability of these bacteria to cause infections.