**9. Conclusions and future directions**

Although the role of soy in CVD, lowering cholesterol, and improving bone has been questioned, there is ample evidence to suggest that soy improves symptoms of OA by at least three mechanisms, including (1) acting as a SERM, thereby modulating estrogen receptors; (2) increasing circulating levels of IGF-1, thereby regenerating cartilage and/or preventing further damage; (3) and inhibiting production of inflammatory molecules, such as COX-2, TNF-α. The authors believe that soy plays an important role in the healthy aging process by decreasing the incidence of OA, and allowing those who are afflicted to achieve greater mobility, thus decreasing their chances of developing other chronic diseases that would have resulted from decreased mobility. Therefore, we suggest that consumption of soy and soy isoflavones is crucial for healthy aging and improved QOL throughout the aging process.

We have demonstrated that both leptin and estrogen have a significant role in the etiology, progression, and treatment of OA, but the specifics of that role remain uncertain. The above studies also indicate a positive effect of soy supplementation on cartilage metabolism, inflammation, and indices of pain, likely through the modulation of the aforementioned factors. Soy appears to be promising in the treatment of OA symptoms, but its ability to prevent the disease is questionable. While isoflavones are known to act as SERMs, it is reasonable to suspect that the protein content of soy as a whole in conjunction with isoflavone content is responsible for positive effects in this population. Though the literature indicates that soy supplementation may be helpful in decreasing usage of NSAIDs, slow cartilage degradation, and increase functionality in individuals afflicted with OA, determining the safety as well as the efficacy of soy or its isoflavones as a long-term OA intervention is the next logical step. Any intervention that can improve the QOL of individuals afflicted with OA is worth pursuing, but it is paramount that researchers uncover the exact etiology of the disease so as to prevent future occurrences.

The literature referenced here also indicates that soy can be promising for other chronic disease states, without necessarily posing a risk for increased instance of breast cancer. However, there is still much confusion about which populations are

**37**

*Evidence for the Effectiveness of Soy in Aging and Improving Quality of Life*

at higher risk for breast cancer when consuming soy. The multiple health benefits appear to outweigh breast cancer risk for most women, even decreasing the chance of breast cancer, but further interventional, rather than strictly epidemiological

We want to thank Dr. Shirin Hooshmand and Jenna Schmidt for collecting and

*DOI: http://dx.doi.org/10.5772/intechopen.85664*

**Acknowledgments**

**Conflict of interest**

**Author details**

analyzing part of the data.

and cell culture studies, need to be established.

The authors have no conflict of interest to declare.

Bahram Herman Arjmandi1,2\* and Elizabeth Marie Foley1,2

\*Address all correspondence to: barjmandi@fsu.edu

provided the original work is properly cited.

Sciences, Florida State University, Tallahassee, FL, United States

1 Department of Nutrition, Food and Exercise Sciences, College of Human

2 Center for Advancing Exercise and Nutrition Research on Aging (CAENRA), College of Human Sciences, Florida State University, Tallahassee, FL, United States

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

*Evidence for the Effectiveness of Soy in Aging and Improving Quality of Life DOI: http://dx.doi.org/10.5772/intechopen.85664*

at higher risk for breast cancer when consuming soy. The multiple health benefits appear to outweigh breast cancer risk for most women, even decreasing the chance of breast cancer, but further interventional, rather than strictly epidemiological and cell culture studies, need to be established.
