Risk Factors for Osteoporosis
Osteoporosis is a systemic disease that is characterized by low bone mass and deterioration of the microarchitecture of bone, resulting in an increased risk of fracture in postmenopausal women and men over 50 years old. Several factors have been identified that contribute to the risk of osteoporosis, and oxidative stress has now emerged as one of the most important life style risk factor associated with loss of bone mass. Phytochemicals as antioxidants have been shown to counteract the deleterious effects of oxidative stress in the risk of osteoporosis. This review will include an overview on osteoporosis, the deleterious effects of oxidative stress and the beneficial effects of phytochemical antioxidants, with emphasis on the results of our clinical studies on the phytochemical lycopene and polyphenols present in nutritional supplements.
2. Osteoporosis – An overview
Osteoporosis is a metabolic bone disease known as “the silent thief” because the gradual loss of bone associated with this disease usually occurs over the years, and there are usually no noticeable symptoms until the bones are so fragile that a fracture occurs . Osteoporosis is “a major public health threat” that is projected to results to 8.1 million fractures (78 % women, 22 % men) during the period between 2010 and 2050 . Approximately 1 in 2 women and 1 in 5 men older than 50 years will eventually experience osteoporotic fractures . The condition costs our healthcare system $18 billion per year . Newer findings on all aspects of osteoporosis have increased exponentially. The more importantly ones are discovering an ever increasing number of risk factors including oxidative stress, opening up new knowledge on the involvement of the bone forming cells osteoblasts and the bone resorbing cells osteoclasts in the development of osteoporosis, the introduction and improvement of more sensitive diagnostic instruments, and finding new drugs and the nutritional alternatives for the prevention and treatment of osteoporosis. Advances in the knowledge on osteoporosis is not without pitfalls. Hormone Replacement Therapy (HRT), once a first line of treatment for osteoporosis has been discontinued due to side effects . It is becoming more evident that the drugs known as bisphosphonates, although effective in stopping the resoption of bone and preventing osteoporosis in women, are associated with a number of side effects [6, 7]. Because of this, a number of women are now resorting to other modes of treatment, including that from natural food components. Our laboratory has carried out studies on the use of phytochemical antioxidants such as lycopene and polyphenols present in nutritional supplements as possible alternatives and/or complementary to drugs in the treatment and prevention of osteoporosis. This chapter will include an overview on osteoporosis, oxidative stress as a risk factor in the development of osteoporosis and a review of studies on the use of antioxidants in counteracting oxidative stress in the prevention of osteoporosis. These topics should put our research in perspective and offer a rationale to our study approaches. Finally we will highlight our pioneering clinical studies on the lipid-soluble phytochemical antioxidant lycopene and the water-soluble antioxidant polyphenols present in a nutritional supplement in the prevention of risk for osteoporosis in postmenopausal women.
2.1. Risk factors for osteoporosis
Some of the risk factors for osteoporosis [8, 9] are presented in Table 1 . The risk factors that are of interest in our studies are the oxidative stress-generating factors, including nutrition deficiency, low antioxidant status, smoking, alcohol intake, excessive sports activity and caffeine intake.
|Low body weight
Low lifetime calcium intake
High Alcohol intake
Low antioxidant status
Excessive sports activity
Excessive caffeine intake
2.2. Prevention and treatment of osteoporosis
Until 10 years ago, the first line of treatment for women who have gone through menopause and were diagnosed with osteoporosis was hormone replacement therapy (HRT). However, results of the Women’s Health Initiative (WHI) revealed that women taking HRT had higher risks for breast cancer, cardiovascular events, blood clots, cognitive decline, and more . This treatment for osteoporosis has since been discontinued and is prescribed only for a short period of time to alleviate hot flashes in menopausal women . The current treatments which inhibit bone resorption that are approved by the Food and Drug Administration (FDA) include a number of bisphosphonates under specific trademarks . Some are taken daily while others are formulated for weekly, monthly or intermittent oral use [13, 14]. The newer bisphophonates are injectables such as Zoledronate and Ibandronate . Other drugs available include calcitonin; Raloxifene (Evista), the Selective Estrogen Receptor Modulator (SERM) and strontium renalate . Parathyroid hormone, PTH1-34 or teriparatide (Forteo), is the only anabolic agent currently approved for use by the FDA [16, 17]. The new class of osteoporosis drug now approved for use is a human monoclonal antibody (Denosumab) which bind to RANKL, imitating the effects of OPG and acting as an inhibitor of RANKL . Other drugs are still being tested clinically for osteoporotic treatment and prevention .
None of the drugs are without side effects. Side effects that emerged in clinical trials include acute phase response with iv treatment or high-dose oral therapy and esophageal irritation with oral administration. Osteonecrosis of the jaw, musculoskeletal complaints, and atypical fractures are some uncommon side effects that have been noted with wide clinical use of bisphosphonate. The number of these events are small, and a clear cause-and-effect relationship between events and bisphosphonate treatment has not been established. Accumulation of Bisphosphonates in the bone create a reservoir leading to continued release from bone for months or years and provide some residual anti-fracture reduction long after treatment is stopped . As a result, there is a recommendation for a drug holiday after 5 –10 yr of treatment with bisphosphonate [7, 19]. The length of the holiday is based on previous duration of treatment, BMD status and fracture risk. Studies with alendronate and risedronate showed that if treatment is stopped after 3–5 yr, there is at least 1–2 yr persisting anti-fracture efficacy. The consensus from expert panels  for those who are not on holiday is not to stop the use of drug since the side effects are often rare, and that the benefits outweigh the side effects. In the balance, most individuals who have osteoporosis are much better taking an osteoporosis medication .
2.3. Alternative approach to prevention and treatment of osteoporosis
Diet is now recognized as an important life-style factor in the management of bone health . Given that many nutrients have been identified as being beneficial to bone health [21, 22], there is strong scientific support for the potential benefits of incorporating therapeutic nutritional interventions with contemporary pharmaceutical treatments . As a result of the possible adverse side effects of HRT  and the ever increasing reports on the side effects of bisphosphonates that are prescribed for the management of postmenopausal osteoporosis , complementary and alternative medicine (CAM) is in demand as an alternative for the prevention and treatment of osteoporosis . CAM is the term for medical practices, services and products that are not a part of standard care. Some of the approaches include exercise, acupuncture, diet, herbs rich in polyphenols and nutritional supplements including calcium, zinc, magnesium boron and other vitamins and minerals . Recent dietary guidelines for the prevention of chronic diseases have recommended an increase in the consumption of fruits and vegetables worldwide  that are good sources of dietary antioxidants . The beneficial effects of antioxidants in bone health and osteoporosis are demonstrated epidemiologically and through clinical intervention. As will be reviewed in this chapter, our clinical studies on lycopene treatment and nutritional supplements containing polyphenols and other nutritional components showed positive results on bone health.
3. Oxidative stress and antioxidants – An overview
Oxidative stress is caused by reactive oxygen species (ROS) which are the main by-products formed in the cells of aerobic organisms that can initiate autocatalytic reactions in such a way that the target molecules get converted into free radicals causing a chain of damage . There is ample evidence to show that oxidative stress induces an increase in the rate of bone loss and is therefore a risk factor for osteoporosis. Epidemiological evidence in humans and studies in animals indicate that aging and the associated increase in reactive oxygen species (ROS) are responsible for bone loss . Oxidative stress is associated with the activity and function of both the osteoblasts and osteoclasts cells, the two major bone cells involved in the pathogenesis of osteoporosis [29, 30].
Under normal physiological conditions, the cells can fight free radical attack or oxidative stress by promoting antioxidant defenses. A number of endogenous defense mechanisms are present in the body, including the metal chelating proteins and the endogenous antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) . Exogenous antioxidants come from dietary sources present in fruits and vegetables containing several phytonutrient antioxidants two of which are the potent antioxidant lipid-soluble lycopene and the water-soluble antioxidant polyphenols . In cases where the exogenous antioxidants or antioxidants from diet fail to prevent oxidative damage, the repair antioxidants come into play which include DNA repair enzymes, protease, lipase, and transferase . When antioxidants loses its fight with oxidative stress, diseases associated with oxidative stress develop, which include cardiovascular disease, cancer, diabetes, neurological diseases and osteoporosis .
3.1. Lycopene, a lipid-soluble phytochemical antioxidant
The role of lycopene in the prevention of human diseases is supported by a number of evidence and previously reviewed [34, 35]. Since then, there have been several epidemiological as well as clinical intervention studies showing the relationship between lycopene intake and the prevention of cancers at other sites, as well as coronary heart disease, diabetes, hypertension, macular degenerative disease, neurodegenerative disease and male infertility . The role of lycopene in bone health has so far been based on its potent antioxidant properties, the well-known role of oxidative stress in bone health, the limited studies on the effects of lycopene in bone cells in culture [34, 35] and the results of epidemiological studies [36, 37]. To date our clinical intervention studies at St. Michael’s Hospital on the role of lycopene and elucidation of its mechanism in lowering the risk for osteoporosis in postmenopausal women (aged 50 to 60 years) are so far the only clinical studies reported in the literature.
3.2. Polyphenols, the water-soluble antioxidant
Polyphenols are a class of water-soluble molecules naturally found in plants . It is estimated that there are 10,000 different phytonutrients (phyto, meaning from plants). The health benefits associated with fruits, vegetables, tea, red wine, and Mediterranean diets are probably linked to the polyphenol antioxidants [21, 39, 40]. The polyphenols of interest in our study are a mixture of flavonoids such as quercetin, apigenin, kaempferol and luteolin present in the supplement greens+TM . greens+TM in combination with another supplement, bone builderTM, were used in our study on osteoblasts cells and in clinical intervention studies on the prevention of risk of osteoporosis in postmenopausal women as will be reviewed below.
4. Studies on the antioxidants polyphenols and lycopene
4.1. Studies on lycopene
The direct role of lycopene in osteoblasts and osteoclasts, the cells involved in the pathogenesis of osteoporosis, is now being unraveled. This involvement is further supported by both epidemiological and clinical intervention with lycopene in postmenopausal women who are at risk of osteoporosis [29, 30].
An epidemiological study to determine the beneficial role of lycopene in the prevention of risk for osteoporosis was carried out by Rao et al . In a cross-sectional study, 33 postmenopausal women aged 50–60 years participants were recruited and asked to provide seven-day dietary records and blood samples for analyses of total antioxidant capacity; oxidative stress parameters including lipid peroxidation and protein oxidation; and bone turnover markers including bone resorption marker NTX and bone formation marker. Their results showed that the estimated dietary lycopene had a significant and direct correlation with serum lycopene, suggesting that lycopene from the diet is bioavailable. Their conclusion that the higher serum lycopene was associated with a low NTx (
The overall conclusions that can be derived from the cross-sectional study is that lycopene has a role in the prevention of risk for osteoporosis. Further clinical studies described below support this conclusion.
Mackinnon et al  studied whether the elevated dose obtained through lycopene supplementation compared to intakes typically obtained from the usual daily diet was more beneficial in reducing bone turnover markers. Serum lycopene, bone turnover markers and oxidative stress parameter data were compared between postmenopausal women who were supplemented with lycopene and those who obtained both a low and high intake lycopene from daily food diet. Results showed that women who consumed lycopene supplement had significantly lower TBARS values than participants who obtained a low intake or high intake lycopene through their usual daily diets. These differences in TBARS value may be attributed to a significantly higher concentration of serum 5-
Another study was carried out to determine the effects of a lycopene-restricted diet on oxidative stress parameters and bone turnover markers in postmenopausal women . Results showed that restricting the participants from consuming lycopene-containing products resulted in significant decreases in serum lycopene, α-/β-carotene and lutein/zeaxanthin, with the overall change in the serum carotenoids being lower than that seen for lycopene. All configurations of lycopene (all trans, 5-cis- and other cis lycopene) were found to be decreased and the antioxidant enzymes SOD and CAT were also significantly depressed after lycopene restriction. These changes were accompanied by a significant increase in the bone resorption marker NTx. The important conclusion from this study is the possibility that the significant increase in the bone resorption marker NTx could lead to a long-term decrease in BMD and increased fracture risk as was observed by Brown et al. ; longer restriction period may be detrimental to a group of postmenopausal women who were already at high risk for osteoporosis. Therefore, shorter wash-out periods of no lycopene consumption is all that is needed in clinical trials examining the effects of lycopene on bone health .
A clinical fully randomized controlled intervention study was next carried out by Mackinnon et al  to investigate directly the effects of lycopene supplementation on decreasing the risk for osteoporosis. Lycopene supplements include lycopene capsules, tomato juice with normal amount of lycopene, tomato juice with high amount of lycopene. They have shown that after the 4-month duration, the LYCOPENE-supplemented group had a significant increase in total antioxidant capacity, decrease in oxidative stress parameters protein oxidation as shown by increase in thiol values and lipid peroxidation as shown by TBARS which correlated to a decrease in NTx; all changes were significantly different from the PLACEBO group. These findings suggest that lycopene obtained in the form of tomato juice or capsule exerted equivalent antioxidant potency in reducing the risk of osteoporosis in postmenopausal women .
Mackinnon et al studied whether polymorphism plays a role in the development of osteoporosis . To do this, Mackinnon et al. studied the role of 172T→A or 584A→G polymorphisms of the paraoxonase 1 (PON 1) in modulating the effects of serum lycopene on antioxidant capacity, oxidative stress parameters and bone turnover markers, and in women between the ages of 25-70 years). Their results showed that the PON1 polymorphism modified the association between lycopene and NTx and BAP, an interaction that may also moderate the risk of osteoporosis .
In another study, they showed that there was a significant interaction between PON1 genotype and change in TBARS (p<0.05) suggesting that supplementation with lycopene resulted in decreased lipid peroxidation, which interacted with the PON1 genotype to decrease bone resorption markers in postmenopausal women. These results provided a mechanistic evidence of how intervention with lycopene may act to decrease lipid peroxidation and thus the risk of osteoporosis in postmenopausal women [45, 47].
In conclusion, the demand for the use of other natural food components in the management of postmenopausal osteoporosis has increased due to reports on the adverse side effects of the conventional therapy (eg, HRT and bisphosphonates). The studies reviewed above revealed evidence that antioxidants such as lycopene can counteract the damaging effects of oxidative stress brought about by ROS that lead to the development of osteoporosis. The results of studies reviewed here indicate that lycopene maybe useful either as a dietary alternative to drug therapy or as a complement to the drugs presently approved for used by women at risk of osteoporosis.
4.2. Studies on polyphenols
It is well known that polyphenols have a role in the prevention of chronic diseases such as cancers, diabetes, cardiovascular diseases, neurodegenerative diseases, and osteoporosis. Interest on polyphenols and bone health has increased in the last 10 years [48-51]. The anabolic role of phytonutrients and especially polyphenols in bone was reviewed by Horcajada , the mechanisms of action of polyphenol in osteoblast function and its interaction with osteoclasts was reviewed by Trzeciakiewicz  and the beneficial effects of green tea polyphenols has been reviewed [52, 53].
Currently, most of the research on polyphenols and their effects have emerged from
Combinations of polyphenols have also been studied. One such source is the nutritional supplement greens+TM, a blend of several herbal and botanical products containing a substantial amount of polyphenols including quercetin, apigenin and luteolin  which act as antioxidants and therefore should be able to counteract oxidative stress. Thus, Rao et al  have shown that greens+
Two additional nutritional supplements have since been formulated which may prove to be good for bone health. These are the bone builderTM and the greens+bone builderTM ; the latter is the original greens+TM product that has been supplemented with the bone builderTM formula which contains several compounds including vitamins, minerals, and antioxidants. These various components have been separately shown to have some beneficial effect on bone . Using the human osteoblast SaOS-2 cells, Rao et al showed that similarly to the greens+TM, the water-soluble bone-builderTM extract had a significant dose-dependent stimulatory effect on bone nodules formation . It was additionally shown that similarly to the greens+TM, the watersoluble bone-builderTM extract had a significant dose-dependent stimulatory effect on bone nodules formation . In a later study, they have shown that when the two supplements, greens+
A clinical study was then carried out to evaluate the effect of the nutritional supplement greens+ bone builder
In summary, studies reported in the literature on the role of polyphenols in bone health have exploded in the last 10 years, but most of the reports involved in vitro studies in osteoclasts and osteoblasts, animal studies and epidemiologicai studies. There is little doubt from the excellent studies reported that oxidative stress is one of the primary culprits responsible for the pathogenesis of osteoporosis via its role in osteoclastic resoption and the detrimental effects on the bone-forming osteoblasts. To date, only four clinical intervention studies have been reported, including ours. It is easy to see why it is very difficult to evaluate the role of polyphenols since, as we learned from this review, there are at least 8,000 different polyphenols identified to date, and each one probably having different effects on humans. Additionally, polyphenols are present in food with other constituents that may also be beneficial to bone health. In our clinical study, we combined the effects of a combination of polyphenols present in the nutritional supplement from greens+TM with the nutritional components present in bone builderTM such as minerals, vitamins and other nutrients. It is possible that the effects of greens+bone builderTM in increasing total antioxidant capacity, decreasing the oxidative stress markers protein oxidation and lipid peroxidation which correlated to the decrease in bone turnover marker for bone resorption is a result of the combined effects of the different polyphenols it contained with those of the other nutritional components present in the bone builderTM. It remained for future studies to zero in on specific component that is responsible for its beneficial effect.
In conclusion, we showed that oxidative stress due to ROS that are shown to cause the development of osteoporosis may be prevented by supplementation with the antioxidants lycopene and polyphenols. Results of in vitro studies in osteoblasts and osteoclasts, animal intervention studies, epidemiological studies and clinical intervention studies on lycopene and polyphenols are evidence for their potential use as alternative or complementary agent with other established drugs approved for the prevention or treatment of osteoporosis in postmenopausal women.
Funding for this research into Oxidative Stress, Antioxidants and Bone Health is shared by H.J. Heinz Co (Canada), Kagome Co. (Japan), LycoRed Natural Product Industries, Ltd. (Israel), Genuine Health Ltd (Canada), Millenium Biologix Inc. (Canada), and matched by the Canadian Institutes of Health Research (CIHR). We sincerely thanked the valuable contributions to this research by the following students/graduate students and staff at the Calcium Research Laboratory, Department of Medicine at St Michael’s Hospital and the University of Toronto and Department of Nutritional Sciences, University of Toronto: Dr. Bala Balachandran, Jaclyn Beca, Dawn Snyder, Loren Chan, Honglei Shen, Salva Sadeghi, Ayesha Quireshi, Dr. Erin Mackinnon and Nancy Kang. Their contributions were based on their experimental data, written reports published/in press manuscripts/theses. We would also like to thank to Dr. R.G. Josse for providing us with his medical expertise as well as allowing us access to his list of patients we were able to recruit. Special thanks to Dr. H. Vandenberghe for carrying out the CTX assay and for her valuable suggestions.
Ahmed S, Elmantaser M. Secondary osteoporosis. Endocr Dev. 2009;16:170-90.
Bleibler F KA, Benzinger P, Rapp K, König H.. The health burden and costs of incident fractures attributable to osteoporosis from 2010 to 2050 in Germany-a demographic simulation model. Osteoporos Int Epub July 14 2012[Epub ahead of 2012.
Coxam V. New advances in osteoporosis nutritional prevention. Med Sci (Paris). 2005;21(3):297-301.
Lindsay R, Burge R, Strauss D. One year outcomes and costs following a vertebral fracture. Osteoporosis Int. 2005;16:78-85.
Rossouw J, Anderson G, Prentice R, LaCroix A, Kooperberg C, Stefanick M, et al. Risks and Benefits of Estrogen Plus Progestin in Healthy Postmenopausal Women Principal Results From the Women's Health Initiative Randomized Controlled Trial. JAMA 2002;288. 2002;3:321-33.
Schmidt G, Horner K, McDanel D, Ross M, Moores K. Risks and benefits of long-term bisphosphonate therapy. Am J Health Syst Pharm. 2010;67(12):994-1001.
Diab D, Watts N. Bisphosphonates in the treatment of osteoporosis. Endocrinol Metab Clin North Am (Epub 41 Epub 2012 Jun 9). 2012;3:487-506.
Monti J. Osteoporosis Risk Factors http://askhealthlinecom/health/osteoporosis-risk-factors. 2010.
Stetzer E. Identifying Risk Factors for Osteoporosis in Young Women. The Internet Journal of Allied Health Sciences and Practice. 2011;9(4):1-8.
Rao L. Will tomatoes prevent osteoporosis. Snell Endocrine Rounds 2005;5(2):1-6.
Furness S, Roberts H, Marjoribanks J, Lethaby A. Hormone therapy in postmenopausal women and risk of endometrial hyperplasia. Cochrane Database of Systematic Reviews (Epub 15 AUG 2012) 2012;8.
Bell NH, Johnson RH. Bisphosphonates in the treatment of osteoporosis: virtual symposium on osteoporosis. Endocrine. 1997;6(2):203-6.
Dempster DW, Bolognese MA. Ibandronate: The Evolution of a Once-a-Month Oral Therapy for Postmenopausal Osteoporosis. Journal of Clinical Densitometry. 2006;9(1):58-65.
Sunyecz J. Optimizing dosing frequencies for bisphosphonates in the management of postmenopausal osteoporosis: patient considerations. Clin Interv Aging (Epub 2008 December). 2008;3(4):611-27.
Lyritis GP. Fracture healing and antiosteoporotic treatments. Medicographia. 2010;32:79-85.
Hegge K, Fornoff A, Gutierres S, Haack S. New therapies for osteoporosis. Journal of Pharmacy Practice. 2009;22:53-64.
Han S, Wan S. Effect of teriparatide on bone mineral density and fracture in postmenopausal osteoporosis: meta-analysis of randomised controlled trials. International Journal of Clinical Practice. 2012;66(2):199-209.
Adler RA, Gill RS. Clinical utility of denosumab for treatment of bone loss in men and women. Clin Interv Aging (Epub 2011 May 24). 2011;6:119-24.
Watts N, DL D. Long-Term Use of Bisphosphonates in Osteoporosis. The Journal of Clinical Endocrinology & Metabolism. 2010;95(4):1555-65.
Palacious C. The role of nutrients in bone health, from A to Z. Critical Reviews in Food Science & Nutrition. 2006;46:621-8.
New S. Intake of fruit and vegetables: Implications for bone health. The Proceedings of the Nutrition Society 2003;62(4):889-99.
Lister C, Skinner M, D. H. Fruits, vegetables and their phytochemicals for bone and joint health. Curr Top Nutraceut Res. 2007;5:67-82.
Tucker K, Hannan M, Chen H, Cupples L, Wilson P, Kiel D. Potassium, magnesium, and fruit and vegetable intakes are associated with greater bone mineral density in elderly men and women. The American Journal of Clinical Nutrition. 1999;69(4):727-36.
Rees M. Management of the menopause: integrated health-care pathway for the menopausal woman. Menopause Int. 2011;17(2):50-4.
Pomerleau J, Lock K, Knai C, McKee M. Effectiveness of intervention and programmes promoting fruit and vegeta ble intake. WHO. 2005.
Rao A, Rao LG. Carotenoids and human health (Review). Pharmacological Research. 2007;55(3):207-16.
Raman W, Khalid A, Right N. Studies on free radicals, antioxidants, and co-factors. Clinical Interventions in Aging. 2007;2(2):219-36.
Manolagas S, A. P. What old means to bone. Trends Endocrinol Metab (Epub 2010 Mar 11). 2010;21(6):369-74.
Rao LG, Rao AV. Oxidative stress and antioxidants in the risk of osteoporosis - role of the antioxidants lycopene and polyphenols. In: M V-F, editor. Topics in Osteoporosis. Croatia: InTech. p. 117-61.
Rao LG, Kang NN, AV R. Lycopene and Other Antioxidants in the Prevention and Treatment of Osteoporosis in Postmenopausal Women. In: V P, editor. Aging: Oxidative Stress and Dietary Antioxidants: Elsevier Inc; 2014. p. 247-58.
Mate JM, Perez-Gomez C, I. NdC. Antioxidant Enzymes and Human Diseases. Clinical Biochemistry. 1999;32(8):595-603.
Rao L. Lycopene and the Prevention of Osteoporosis.. In: AV R, editor. Lycopene. Scotland: Caledonia Science; 2006.
Willcox J, Ash S, Catignani G. Antioxidants and prevention of chronic disease. Crit Rev Food Sci Nutr. 2004;44:275-95.
Rao A, Rao L. Lycopene and human Health. Current Topics in Nutraceutical Research. 2004;2.
Giovannucci E. Tomatoes, tomato-based products, lycopene, and cancer: Review of the epidemiologic literature. J Natl Cancer Inst. 1999;91:317-31.
Rao L, Mackinnon E, Josse R, Murray T, Strauss A, Rao A. Lycopene consumption decreases oxidative stress and bone resorption markers in postmenopausal women. Osteoporosis International 2007. 2007;18(1).
Sahni S, Hannan M, Blumberg J, Cupples L, Kiel D, Tucker K. Protective effect of total carotenoid and lycopene intake on the risk of hip fracture: a 17-year follow-up from the Framingham Osteoporosis Study. Journal of Bone & Mineral Research. 2009;24(6):1086-94.
Quideau S, Deffieux D, Douat-Casassus C, Pouysegu L. Plant polyphenols: chemical properties, biological activities, and synthesis. Angew Chem Int Ed Engl (Epub 2011/01/13) 2011;50(3):586-91.
Puel C, Coxam V, Davicco M. Mediterranean diet and osteoporosis prevention. Med Sci (Paris). 2007;23:756-60.
Urquiaga I, Strobel P, Perez D, Martinez C, Cuevas A, Castillo O, et al. Mediterranean diet and red wine protect against oxidative damage in young volunteers. Atherosclerosis (Epub 2010 Apr 21). 2010;211(2):694-9.
Rao A, Balachandran B, Shen H, Logan A, Rao L. In Vitro and in Vivo Antioxidant Properties of the Plant-Based Supplement Greens+. Int J Mol Sci. 2011;12:4896-908.
Mackinnon E, Rao A JR, L. R. Supplementation with the antioxidant lycopene significantly decreases oxidative stress parameters and the bone resorption marker N-telopeptide of type I collagen in postmenopausal women. Osteoporosis International. 2011;22(4):1091-101.
Mackinnon E, Rao A, Rao L. Dietary restriction of lycopene for a period of one month resulted in significantly increased biomarkers of oxidative stress and bone resorption in postmenopausal women Journal of Nutrition, Health & Aging. 2011;15(2):133-8.
Brown J, Albert C, Nassar B, Adachi J, Cole D, Davison K, et al. Bone turnover markers in the management of postmenopausal osteoporosis (review). Clin Biochem. 2009;42(10-11):929-42.
MacKinnon E. The Role of the Carotenoid Lycopene as an Antioxidant to Decrease Osteoporosis Risk in Women: Clinical and in vitro Studies [PHD [dessertation]. Toronto, Ontario: : University of Toronto; 2010.
Mackinnon E, El-Sohemy A, Rao A, L. R. Paraoxonase 1 polymorphisms 172T->A and 584A->G modify the association between serum concentrations of the antioxidant lycopene and bone turnover markers and oxidative stress parameters in women 25-70 years of age. Journal of Nutrigenetics & Nutrigenomics. 2010;3(1).
Rao L, Mackinnon E, El-Sohemy A, V. R, editors. Postmenopausal Women with PON1 172TT Genotype Respond to Lycopene Intervention With a Decrease in Oxidative Stress Parameters and Bone Resorption Marker NTx Annual Meeting of the American Society for Bone and Mineral Research (ASBMR); 2010; Toronto, Ontario.
Everitt A, Hilmer S, Brand-Miller J, Jamieson H, Truswell A, Sharma A, et al. Dietary approaches that delay age-related diseases. Clin Interv Aging. 2006;1(1):11-3.
Horcajada M, Offord E. Naturally plant-derived compounds: role in bone anabolism. Curr Mol Pharmacol. 2012;5(2):205-18.
Trzeciakiewicz A, Habauzit V, Horcajada M. When nutrition interacts with osteoblast function: molecular mechanisms of polyphenols. Nutr Res Rev (Epub 2009 Feb 26). 2009;22(1):68-81.
Scalbert A, Manach C, Morand C, Rémésy C, Jiménez L. Dietary polyphenols and the prevention of diseases. Crit Rev Food Sci Nutr. 2005;45(4):287-306.
Cabrera C, R A, Giménez R. Beneficial effects of green tea--a review. J Am Coll Nutr. 2006;25(2):79-99.
Yang C, Landau J. Effects of tea consumption on nutrition and health. J Nutr. 2000;130(10):2409-12.
Rao L, Kang N, Rao A. Polyphenols and bone health: A review.. In: Rao A, editor. Phytochemicals. Rijeka, Croatia: In Tech Open Access Publisher 2012. p. 958-73.
Rao L, Balachandran B, A. R. Polyphenol Extract of Greens+™ Nutritional Supplement Stimulates Bone Formation in Cultures of Human Osteoblast-like SaOS-2 Cells. J Diet Suppl. 2008;5(3):264-82.
Rao L, Balachandran B, A. R. The stimulatory effect of the polyphenols in the extract of Greens+TM herbal preparation on the mineralized bone nodule formation (MBNF) of SaOS-2 cells is mediated via its inhibitory effect on the intracellular reactive oxygen species (iROS).. 27th Annual Meeting of the American Society of Bone and Mineral Research; September 23-27, 2005; 2005.; Nashville, Tennesse2005.
Graci S. The Bone Building Solution. Mississauga, Ontario: John Wylie And Sons Canada, Ltd; 2006.
Rao L, Snyder D, Balachandran B, Beca B, Shen H, Sedeghi S, et al. Herbal extract and nutritional bone-building supplement synergistically stimulate bone formation in human osteoblast cells in vitro. IOF Regionals - 1st Asia-Pacific Osteoporosis Meeting; December 10-13, 2010; Singapore2010.
Snyder D, Rao A, Balachandran B, Beca J, Shen H, Sadeghi S, et al. Extracts of the Nutritional Supplement, bone builderTM, and the Herbal Supplement, greens+TM, Synergistically Stimulate Bone Formation by Human Osteoblast Cells in VitroOntario2010. Annual Meeting of the American Society for Bone and Mineral Research (ASBMR; October 13 - 16, 2010; Toronto, Ontario2010.
Kang N, Rao A, De Asis K, Chan L, Rao L. Antioxidant effects of a nutritional supplement containing polyphenols in postmenopausal women: a randomized controlled study. Journal of Aging: Research and Clinical Practice. 2012;1(3):183-87.
Kang NN, Rao AV, Josse R, Vandenberghe H, De Asis K, Chan LA. Dietary polyphenols combined with micronutrients may be a good alternative to or complement with approved drugs for the prevention of risk of osteoporosis in postmenopausal women. The Journal of Phytochemistry. 2014;115:291300.