Study Title:

Blueberries Help Build Osteoclasts

Study Abstract

Diet and nutritional status are critical factors that influences bone development. In this report we demonstrate that a mixture of phenolic acids found in the serum of young rats fed blueberries (BB) significantly stimulated osteoblast differentiation, resulting in significantly increased bone mass. Greater bone formation in BB diet–fed animals was associated with increases in osteoblast progenitors and osteoblast differentiation and reduced osteoclastogenesis. Blockade of p38 phosphorylation eliminated effects of BB on activation of Wnt signaling in preosteoblasts. Knocking down β-catenin expression also blocked the ability of serum from BB diet–fed rats to stimulate osteoblast differentiation in vitro. Based on our in vivo and in vitro data, we propose that the underlying mechanisms of these powerful bone-promoting effects occur through β-catenin activation and the nuclear accumulation and transactivation of TCF/LEF gene transcription in bone and in osteoblasts. These results indicate stimulation of molecular events leading to osteoblast differentiation triggered by P38 MAP kinase (MAPK)/β-catenin canonical Wnt signaling results in significant increases in bone growth in young rats consuming BB-supplemented diets. Liquid chromatography/mass spectrometry (LC/MS) characterization of the serum after BB feeding revealed a mixture of simple phenolic acids that may provide a basis for developing a new treatment to increase peak bone mass and delay degenerative bone disorders such as osteoporosis.

From press release of June 21, 2011,

Compounds in blueberries might turn out to have a powerful effect on formation of strong, healthy bones, if results from studies with laboratory rats turn out to hold true for humans.

Jin-Ran Chen and his colleagues are exploring this idea in research funded by the U.S. Department of Agriculture (USDA) at the Arkansas Children's Nutrition Center (ACNC) in Little Rock. Chen is a principal investigator and lead scientist at the center's Skeletal Development Laboratory, and an assistant professor in the department of pediatrics at the University of Arkansas for Medical Sciences, also in Little Rock.

Chen specializes in research on how what we eat during infancy, childhood and early adulthood affects growth and development of bones and the risk of developing osteoporosis or other degenerative bone diseases in later years.

Chen's studies with young, rapidly growing laboratory rats suggest that polyphenols, the compounds that give blueberries their blue, purple, and red coloration, might aid in building strong bones. The work has paved the way for new research that might reveal whether blueberries could be used in the future in treatments to boost development of bone mass and to help prevent osteoporosis.

Published in the Journal of Bone and Mineral Research in 2010, the investigation showed that animals fed rations that contained 10 percent freeze-dried blueberry powder had significantly more bone mass than their counterparts whose rations were blueberry-free.

When the researchers exposed laboratory cultures of bone-forming cells (osteoblasts) to blood (serum) from the animals, the scientists found that serum from the blueberry-fed rats was associated with an increase in development of osteoblasts into mature, functional bone cells.

Serum in the blueberry-fed rats was high in phenolic acids, derived from the color-impacting polyphenols. The research suggests that the phenolic acids may have had bone-building effects in the rats. Studies are needed to determine whether these benefits occur in humans, Chen noted.

Chen's research also suggests that the phenolic acids stimulated bone building via a pathway that may involve, for example, two genes, TCF and LEF,

Study Information

Jin-Ran Chen, Oxana P Lazarenko, Xianli Wu, Jie Kang, Michael L Blackburn, Kartik Shankar, Thomas M Badger, Martin JJ Ronis
Dietary-induced serum phenolic acids promote bone growth via p38 MAPK/β-catenin canonical Wnt signaling.
Journal of Bone and Mineral Research
2010 November

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