By Russell Martin
Benefits for Other Body Systems
Blueberries’ benefits for neurological health and vigor are so well established as to make daily consumption of the fruit a “no-brainer” for virtually everyone. Moreover, new studies continue to confirm blueberries’ remarkable health-promoting effects in other areas of the human body.
For decades, researchers in Europe have documented evidence of the ability of bilberries to combat a range of eye disorders. During World War II, French researchers who examined bilberry extract’s effects in pilots found that bilberry helped improve nighttime visual acuity, adjustment to darkness, and recovery from glare.6 In another study, all eight patients with glaucoma who were given a single oral dose of bilberry extract demonstrated improvements based on electroretinography, a measure of electrical responsiveness of the retinal cells. Bilberry’s antioxidant properties may protect against glaucoma by supporting healthy intraocular pressure.6 In a clinical study, the combination of bilberry extract with vitamin E stopped the formation of senile cortical cataracts in 48 of 50 patients.6 Researchers believe that the anthocyanins and proanthocyanidins found in blueberries might similarly offer benefits for eye health.
In an article in the Journal of Agricultural and Food Chemistry in 2004, researchers announced that they had isolated three compounds in blueberries and other dark-pigmented berries known to lower cholesterol levels.22 In a follow-up study, one of the three phytochemicals—pterostilbene—showed a particularly potent effect in stimulating a receptor protein in cells that plays an important role in lowering cholesterol and other blood fats.3 “We are excited to learn that blueberries, which are already known to be rich in healthy compounds, may also be a potent weapon in the battle against obesity and heart disease,” lead author Agnes Rimando told members of the American Chemical Society.3,22,23
Blueberry juice or extract may help avert urinary tract infections commonly suffered by women. Scientists formerly hypothesized that dark-pigmented berries such as cranberry help fight infection through an antibacterial effect caused by the acidification of urine.4 Current research suggests that berries, including cranberry and blueberry, may fight bacterial urinary infections by preventing E. coli and other forms of bacteria from adhering to cells lining the walls of the urinary tract.4,5
Blueberries also may slow the growth of cancer cells. In 2001, University of Mississippi researchers conducting in-vitro tests found that blueberry and strawberry extracts were remarkably successful in slowing the growth of two aggressive cervical cancer cell lines and two fast-replicating breast cancer cell lines, with the blueberry extract performing best against the cervical cancer cells.8 Last year, a University of Georgia study similarly demonstrated blueberry extract’s ability to inhibit cell proliferation in two separate lines of colon cancer cells, reducing by more than 50% the rate at which the cells otherwise multiplied.9 Further studies are indicated to determine whether phytochemicals from dark-pigmented berries may affect very early growth of malignant cells in the bodies of humans as well.
Although no studies to date have compared the relative efficacy of fresh blueberries versus frozen berries, canned berries, or berry extracts, each form of the fruit has been shown to contain the essential anthocyanins and proanthocyanidins that make blueberries one of the most exciting nutraceuticals being researched and consumed today. Blueberry extracts have the advantage of delivering the fruit’s phytochemicals in a simple, standardized dose, while consuming blueberries as food offers the benefit of flavor.
Regardless of how they are consumed, blueberries should be considered a mainstay of every healthy diet. This remarkable fruit, known for centuries for its medicinal properties, continues to prove itself in research laboratories around the world, demonstrating a wide array of dramatic, health-enhancing benefits.
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3. Rimando AM, Nagmani R, Feller DR, Yokoyama W. Pterostilbene, a new agonist for the peroxisome proliferator-activated receptor alpha-isoform, lowers plasma lipoproteins and cholesterol in hypercholesterolemic hamsters. J Agric Food Chem. 2005 May 4;53(9):3403-7.
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