Blueberries may help strengthen bones, prevent osteoporosis

Coming on the heels of several similar investigations, a new study of polyphenols - which give blueberries and other fruits their color - has determined that they may boost bone growth or even prevent osteoporosis.

Appearing in the Journal of Bone and Mineral Research, the paper announced that these compounds appear to promote bone growth by speeding up the rate at which specialized cells called osteoblasts build bone minerals.

Likewise, scientists noted that blueberry-based polyphenols appear to retard the action of osteoclasts, which break down bone minerals.

It may be surprising that this fruit reputedly improves bone health, considering that blueberries contain no calcium or vitamin D, according to the Centers for Disease Control and Prevention.

The National Osteoporosis Foundation states that adults over 50 should consume 1,200 milligrams of calcium and 1,000 international units of vitamin D every day in order to promote strong bones.

Without these nutrients, how do blueberries improve bone density? The study's authors, who hail from the University of Arkansas for Medical Sciences, said that the berry's polyphenols likely activate two genes and a protein that are involved in a critical bone-building molecular pathway.

The genes, called TCF and LEF, promote the expression of the protein, beta-catechin. This molecule in turn encourages osteoblasts to mature faster and produce more bone mineral.

Researchers cited this polyphenol-TCF/LEF-beta-catechin pathway after studying what happened when they fed young laboratory rodents a diet composed of 10 percent freeze-dried blueberry powder.

The team reported that animals fed this diet formed significantly greater bone mass, compared to those fed typical rodent feed. Scientists concluded that blueberry consumption may improve human bone density or even lower the risk of osteoporosis.

Theirs was hardly the first study to link polyphenol consumption to a decreased likelihood of progressive bone loss.

Research conducted at Texas Tech University determined that consuming 500 milligrams of green-tea-based polyphenols relieved inflammation and decreased the risk of osteoporosis among postmenopausal women.

Before that, scientists from Spain's University of Granada had announced that polyphenols found in olive oil appear to improve cellular health, reduce oxidative damage and prevent osteoporosis.