Your Health by Dr. Rallie McAllister

A bowlful of blueberries is more than just a tasty treat — it's also good medicine. The results of a recent study performed by University of Michigan researchers suggest that natural compounds in blueberries help shrink belly fat, lower cholesterol levels and improve blood-sugar regulation.

For the study, researchers placed overweight laboratory rats on either a high-fat or low-fat diet. Half of the rats in each group were fed a powder made of freeze-dried blueberries, measured as 2 percent of their total diet.

At the end of the 90-day study, the rats receiving the blueberry powder were found to have significantly less abdominal fat and lower levels of triglycerides and cholesterol compared to the rats fed the blueberry-free diet. The rats in the blueberry group also had lower fasting blood sugar levels and greater insulin sensitivity, indicating an important reduction in the risk of developing diabetes.

While the health benefits of blueberries were apparent in rats consuming both high- and low-fat diets, the most pronounced effects occurred in the rats receiving a combination of the berries and a low-fat diet. After examining the rats' muscle tissue, the researchers found that blueberry intake had a measurable impact on genes related to blood sugar regulation, as well as those involved fat burning and storage.

The researchers attributed the beneficial effects of blueberries to naturally occurring antioxidant compounds known as phytochemicals, which are present in all fruits, but are especially abundant in blueberries. The results of tests performed at Tufts University show that in terms of antioxidant activity, blueberries top the list of nearly 60 popular fruits, juices and vegetables.

Preliminary findings from other studies indicate that the specific phytochemicals in blueberries, known as anthocyanins, help fight inflammation, reduce the risk of developing certain types of cancer and even ward off oxidative brain damage that can contribute to Alzheimer's disease.

In recent years, blueberries have been elevated to the status of brain food. A growing body of scientific evidence suggests that the colorful fruit can help prevent — and even reverse — some age-related memory decline.

When researchers from the University of Reading in Pennsylvania and Peninsula Medical School in England supplemented rats' regular diets with blueberries, they noted dramatic changes in the rodents' cognitive function.

Animals treated with blueberries had an 83 percent improvement on tests of memory within three weeks, and the improvement was maintained for the remainder of the 12-week study.

Other studies yielded similar results. Scientists at Tufts University in Boston found that when elderly rats were fed diets containing antioxidant-rich blueberry extracts for just two months, they showed dramatic reversals of age-related declines in both mental and physical performance.

Compared to untreated elderly rats, those treated with blueberry extracts scored highest on tests measuring balance and coordination. The blueberry-treated rodents also outperformed their untreated counterparts in terms of brain function and memory.

Although scientists haven't uncovered the precise mechanism by which blueberries benefit the brain, they're making progress. It is known that certain chemical compounds in blueberries, called flavonoids, are capable of crossing the blood-brain barrier.

Blueberry-derived flavonoids appear to boost learning and memory by enhancing communication among brain cells. Some experts speculate that these beneficial compounds may even stimulate the growth of new brain cells.

At the very least, the flavonoids in blueberries exert a strong anti-inflammatory action in the brain. Inflammation is known to play a key role in the progression of Alzheimer's and other degenerative diseases of the central nervous system.

Blueberries appear to be just as beneficial for your bowels as they are for your brain. The results of a study performed by scientists at Rutgers University and the U.S. Department of Agriculture suggest that a chemical compound in the fruit may help prevent colon cancer, the second leading cause of cancer death in the U.S.

The compound, known as pterostilbene, was found to reduce the development of pre-cancerous lesions in laboratory animals by nearly 60 percent. Pterostilbene works by reducing inflammation and inhibiting the growth and proliferation of cells, two processes that significantly increase the risk of developing colon cancer.

In spite of their sweet and delicious taste, a half-cup serving of fresh blueberries offers just over 40 calories. If you're in search of a snack that can improve your health, boost your brainpower and make your taste buds happy, a bowlful of blueberries might be your best bet.

Rallie McAllister is a board-certified family physician, speaker and the author of several books, including "Healthy Lunchbox: The Working Mom's Guide to Keeping You and Your Kids Trim." Her Website is www.rallieonhealth.com. To find out more about Rallie McAllister, M.D., and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate Web page at www.creators.com.

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