A daily prebiotic supplement, an enriched inulin powder, increased bone mineral density by increasing calcium retention and accretion in bones by 15 percent after one year.
Osteoporosis, the bone-wasting disease, affects an estimated 75 million people in Europe, USA and Japan, according to the International Osteoporosis Foundation.
Previous studies have shown that taking 8g/day of oligofructose-enriched inulin increased the calcium absorbed from the diet by up to 20 percent.
The new study, carried out by Professor S. Abrams from the Baylor College of Medicine and the Texas Children's Hospital in Houston, shows a significant 15 percent increase of calcium retention and accretion within the bones of the 100 girls and boys, aged nine to 13, after one year of supplementation.
Dr Anne Franck, vice president of science and technology at Orafti, said: "If effects are not long-term they have little clinical benefit. The Abrams research is physiologically significant as it provides an insight into the longer-term effect of [prebotic] RaftiloseSynergy1 and demonstrates that it can be highly beneficial in increasing bone mineral density." She added that standard inulin and oligofructose also improve mineral absorption, but only at higher dosages, so they are not suitable for related health claims. "With the patented RaftiloseSynergy1, calcium absorption and bone density claims are possible with only 8g/day," said Dr Franck.
For the study, half of the boys and girls were provided with 8g/day of RaftiloseSynergy1 to consume with breakfast each day for a year, while the other half were provided with a placebo. Prior to the start of the research, all participants underwent measurements of calcium absorption and retention, via blood and urine samples, and bone mineral content and density, via X-ray body scans. These tests were repeated after two months and at the end of the year-long study.
Regular checks were also made on the participants' average daily diet in order to ensure that no significant changes in calcium intake occurred. Calcium intake was maintained throughout the study at usual levels around 900 mg/day.
The prebiotic is thought to work by changing the flora in the colon, with the more slowly fermented inulin acting as a selective 'fuel' for this modified flora, which is kept metabolically active further in the gut.
This selective fermentation pattern results in the production of short chain fatty acids, which decrease the pH within the colon, improving the solubility of the calcium present. The calcium is then better absorbed into the body.
Press Release, Orafti Group, March, 2005