Isoflavones, a subgroup of phytoestrogens mainly contained in soy and soy products, are widely held to have beneficial properties, but the evidence to date is only anecdotal. This proposal addresses the potential role of natural phytoestrogens in osteoporosis prevention among postmenopausal women living in Europe. Aone-year large-scale, rnulticentre, randomised, controlled, intervention trial will be conducted in three European countries using specially-designed isoflavone-enriched foods, combined with rigorous assessments of the changes in bone metabolism. Acceptability of these foods among the target population (women 45 years of age and older) and expectations created by different nutritional claims will be addressed by conducting a survey in five EC state members.
The overall scientific objective is to provide clear scientific evidence about the effects of soy isoflavones (IF) on bone density and metabolism in Caucasian postmenopausal women living in Europe. IF could be proposed as a potential nutritional alternative to hormone replacement therapy (HRT) on the basis of their partial activity on oestrogen receptors and their bone-sparing effects in oestrogen-deficient animals, but little information exists about their role in preventing postmenopausal bone loss in humans. The knowledge acquired in this project will help to quantify the biological relevance of physiological IF consumption after menopause in osteoporosis prevention. It will also provide a scientific basis to develop IF-enriched foods specifically designed for this age group and to assess optimal IF consumption.
A secondary scientific objective is to perform geographical comparisons on the bonesparing effects that IF consumption may have after menopause. Three cohorts of 100 women each will be recruited in three European countries where genetic background, dietary habits and lifestyle are substantially different. The knowledge acquired from the above populations will help us to propose an explanatory hypothesis on the epidemiology of osteoporosis across Europe.
The technological objectives of the project refer to IF-enriched food manufacturing and improved IF analysis in food samples and biological fluids:
- Food industries will be provided with valuable information regarding how different manufacturing processes affect the IF quantity and quality of final foods, so that the processing technology can be refined accordingly.
- Delfia-technique (TR-FIA methods) will be validated against GC/MS for equol and ODMAmeasurements in plasma and daidzein, genistein, equol and ODMA in urine samples. This validation will provide researchers with a valuable tool to assess isoflavones in biological samples, which is easier to perform and less time consuming than HPLC or mass spectrometry techniques.
This project also aims to evaluate the economical relevance of increased dietary IF by:
- a careful estimation of the characteristics of the consumers' audience to which IF-enriched foods will be mainly addressed (women 45 years of age and older).
- an estimate of the cost-effectiveness of IF consumption as an osteoporosis prevention strategy compared to other existing alternatives approved in Europe. This estimation will be based primarily on the results of the main intervention trial.
- Quantitative information about the effects of dietary IF on bone density and bone metabolism in healthy Caucasian postmenopausal women living in Europe.
- Geographical comparison of these effects between three European countries with different genetic background, dietary habits, and lifestyle for explanatory hypothesis formulation.
- Information on the manufacturing process of IF-enriched foods.
- Information on consumers' perspective on the consumption of IF-rich foods.
The project deliverables may be used by food industry and regulatory authorities in deciding whether it would be appropriate to undertake large-scale product manufacturing and marketing.