Chapter 3. Aims of the study

Dietary xylitol supplementation has been shown to increase calcium and phosphorus levels of the bone in rats, as well as to promote restoration of bone calcium content following dietary calcium deficiency. Furthermore, it has been shown to protect against ovariectomy-induced decreases of bone calcium and phosphorus concentrations, of bone density, and of bone ash weight during experimental osteoporosis. These findings support the hypothesis that dietary xylitol might have a favorable effect on the prevention of osteoporosis.

However, before any conclusions can be drawn about the usefulness of a compound assumed for the prevention of osteoporosis, studies including structural evaluation and biomechanical testing of the bones must first be performed.

Thus, to evaluate further the possibility of preventing progression of osteoporosis by means of dietary xylitol supplementation, the aims of the present study were:

1. To evaluate the effects of dietary xylitol supplementation on bone resorption in healthy rats, including determinations of time- and dose-response.

2. To compare the effects of different dietary polyol supplementations on bone resorption.

3. To evaluate whether dietary xylitol supplementation offers a preventive effect against ovariectomy-induced increase of bone resorption during experimental osteoporosis.

4. To evaluate the effects of dietary xylitol supplementation on bone structure in healthy rats.

5. To evaluate whether dietary xylitol supplementation offers a preventive effect against ovariectomy-induced changes of bone structure during experimental osteoporosis.

6. To evaluate the effects of dietary xylitol supplementation on bone biomechanical properties in healthy rats.

7. To evaluate whether dietary xylitol supplementation offers a preventive effect against ovariectomy-induced weakening of bone biomechanical properties during experimental osteoporosis.