## 4 Discussion
Delays in novel food production, beyond our control, further impacted the planned study timeline for Group IV, necessitating a shortened intervention and data collection period. This limitation holds significant importance, emphasizing the necessity for conducting a new interventional study of extended duration. Such a study is imperative to ensure the validity and robustness of the findings concerning the impact of the novel food product on the tested biomarkers. Future studies could identify the role of novel-produced food for a long period of time. Another limitation of the study was the absence of a control group. However, Group III, which received conventional therapy alongside supplements, could serve as a positive control group for comparisons with additional supplements or novel food. Expanding the recruitment of volunteers to encompass diverse regions within the country, including urban, rural, and island locales, would enhance the robustness of conclusions drawn for the Greek population. Nevertheless, the incorporation of data from multiple locations, including Lemnos, the Attica region, and Tripoli city in the Peloponnese, may have introduced potential confounding variables linked to data collection practices, especially given the disruptions posed by the COVID-19 pandemic. Therefore, it is imperative for future studies to establish standardized protocols and procedures for data collection across all study sites. Moreover, the inclusion of self-reported questionnaires, necessitated by contingency planning for COVID-19, introduces further potential confounding factors such as response bias, recall bias, temporal changes, perception of health, inconsistency in reporting, variability in interpretation, and lack of specificity. Despite proactive measures to support participant adherence to interventions, including virtual check-ins and electronic reminders, challenges stemming from the COVID-19 pandemic, such as disruptions in daily routines, heightened stress levels, and limited access to resources, may have impacted adherence. Another limitation concerns the scope of the study, which focused solely on evaluating whole-body BMD. This decision was influenced by the challenges presented by the COVID-19 pandemic, resulting in the omission of DXA examination at anatomical sites such as the femoral neck and lumbar spine, which also serve as reference points for osteoporosis diagnosis. Furthermore, the study's analysis was restricted to BMD, overlooking other key biochemical markers of bone tissue remodeling, including NTX, CTX, b-ALP, and OC. Consequently, the investigation primarily examined general health biomarkers rather than specific bone health indicators in postmenopausal women with osteopenia or osteoporosis. Moreover, future studies could explore the potential benefits of including an additional group receiving bisphosphonates and functional foods, thus providing an avenue for further investigation. The study also encountered limitations related to differences in mean age between groups, as well as the failure to consider postmenopausal duration as a key determinant of bone density. Additionally, bisphosphonates were not analyzed in plasma, and regression analysis was not conducted to elucidate the effects of individual supplements, postmenopausal status, bisphosphonates, and physical activity on BMD. One other limitation of the study is the performance of a unique statistical analysis without comparison between the subgroups of osteopenia and osteoporosis. The analysis was also performed only within groups and without modeling to adjust for age, physical activity and BMI. These limitations collectively contribute to potential sources of variability and complexity in observed patterns. While we acknowledge these limitations, the insights gained from the available data still provide valuable information on the effects of polyphenol-rich novel-food supplementation on whole-body BMD and bone health indicators.