Investigating the Effect of Standardized Olive Extract on Bone Turnover Markers in Postmenopausal Women

Apart from estrogen deficiency, the early postmenopausal period is also characterised by an increasing inflammatory and oxidant status, which further contributes to the development of osteoporosis/osteopenia. The link between systemic inflammation and osteoporosis has only been established recently as it was found that higher circulating hsCRP levels are associated with lower bone mineral density in both healthy pre- and postmenopausal women. Furthermore, it was already known for a long time that one of the most important cytokines implicated in the pathogenesis of various metabolic bone diseases, including postmenopausal osteoporosis, is interleukin (IL)-6, which is produced by osteoblasts, monocytes and T-cells. Olive oil is the principle fat source of the traditional Mediterranean diet, a diet that has been associated with a low incidence of some diseases, including coronary heart disease and osteoporosis. In addition to the main ingredient (ie. oleic acid) extra virgin olive oil also contains phenolic compounds, such as oleuropein- and ligstroside-aglycones and their derivatives. They are formed in olives by enzymatic removal of glucose from the polar parent compound oleuropein-glycoside. A Mediterranean diet rich in olive oil supplies 10 - 20 mg of phenols per day. The main metabolic attribute of oleuropein is that it exerts both antioxidant and anti-inflammatory activity by lowering the levels of proinflammatory cytokines like IL-1, IL-6 or TNF-alpha. By inhibiting osteoclast activity, this may result in lowering the rate of bone resorption and, at least in part, protect against osteoporosis development. Formulated as a capsule it is expected that the compliance and tolerability will be improved compared to the liquid administration. The present study is designed to investigate the effect of 250 mg of a standardized extract of olive polyphenols per day on bone loss in postmenopausal women with decreased bone mass (osteopenia) .