Nobody had to stand over Oklahoma study participants and say, "Drink your anti-aging elixir. Drink your heart-saving juice."
Those folks drank their blueberry beverage.
The researchers were surprised at the results.
Blueberry juice drinkers' blood pressure dropped significantly — a whopping eight points — in just eight weeks of gulping the stuff.
Dr. Tim Lyons, a principal researcher and director of the Harold Hamm Oklahoma Diabetes Center at the University of Oklahoma Health Sciences Center, said the research showed impressive blood pressure drops across the board. The average systolic or top blood pressure number was 130.
At eight weeks, the average dropped to 122.
The work was done under controlled conditions and is statistically significant and biologically relevant, researchers said.
"We were surprised at the significance of the results," Lyons said.
The General Clinical Research Center at the OU Health Sciences Center and Oklahoma State University principal investigator Arpita Basu's team recruited research subjects at OU and OSU.
Basu, a vegetarian who also eats dairy products, said Oklahoma is a good setting for such research because so many Oklahomans have diabetes or heart disease and so few residents eat the recommended five fruits and vegetables per day.
The researchers reviewed scientific literature and found that few studies considered the effectiveness of polyphenol, the apparent health-enhancing and aging-reducing chemical in berries and other fruits. So the Oklahoma scientists recruited 48 obese people, including women with waists measuring more than 35 inches and men with waists exceeding 40 inches who were at risk for diabetes and cardiovascular disease.
Twice a day, half the subjects drank two cups of freeze-dried whole blueberries mixed into two cups of water and a hint of Splenda sweetener or vanilla. The other half drank the same amount of water.
The research indicates heart and anti-diabetic benefits of the polyphenol in blueberries, which go hand in hand with anti-aging benefits. Basu called blueberries an anti-aging elixir. Basu said eating right, exercising and choosing foods such as polyphenol- and antioxidant-rich blueberries can help decrease or reverse signs of age-related cellular damage. Cell damage accelerates the natural aging process.
"If you can do it on a regular basis, then some of this age-related damage can be reversed," said Basu, assistant professor of nutritional sciences.
Basu and Lyons said a combination of fruits containing polyphenol and vegetables is important to staying healthy. But after the results came in, they said they became even more adamant about including blueberries in their cereal, salads and on top of pancakes.
Akin's Natural Food Market sells a 12-ounce blueberry juice mixed with other fruits for $19.95 and a 32-ounce jug of organic blueberry juice for $12.99. Grocery stores sell blueberry juice, too, but Basu cautioned that consumers should read labels because many blueberry juices contain only 20 to 30 percent blueberry juice, while the rest is fructose syrup or another sugary liquid.
Rather than blueberry juice, choose fresh blueberries, or if they're unavailable, frozen blueberries, Basu said. Look for the highest polyphenol-containing mature blueberries with deeply colored skin and flesh.
"I would strongly suggest at least one or two servings of berry fruits a day," she said. "If you like blueberries, that's even better."
The results of the study come out next month in the Journal of Nutrition.