It is interesting that many of the flavonoids found in fruit are highly protective to bone. This is a primary reason why a diet high in fresh fruits and vegetables is linked to better bone health, regardless of calcium intake. Science has demonstrated that many different flavonoids have bone enhancing properties including quercetin (apples and onions), fisetin (strawberries), pomegranate, plums, blueberries, and grapes (grape seed extract and resveratrol). Not surprisingly, nobiletin and tangeretin, the polymethoxylated flavones of citrus, also demonstrate excellent bone protecting properties.
Japanese researchers have conducted three separate studies and concluded that the polymethoxylated flavones “could be beneficial to bone health in postmenopausal women” and “provide a new therapeutic approach for periodontal bone loss.”
Their first two studies used ovariectomized mice, a standard model for studying the effects of the sudden drop of estrogen on bone health in postmenopausal women. The first few years after menopause is a high risk time for bone loss even in healthy women. The first study showed that nobiletin was able to suppress the core inflammatory gene signal within bone (NF-kappaB), slowing down the rate of excessive osteoclast activity that is associated with bone loss. A second study showed that nobiliten was so effective at this role that it restored the natural balance of bone rejuvenation, guiding bone to maintain its integrity despite the jolt associated with the drop in estrogen.
Oral health involves the integrity of the jaw bones that hold your teeth. A common stress is imbalanced or hostile bacteria within the oral cavity that secrete inflammatory compounds that damage the bone all the time, causing periodontal problems. As bacteria divide, their cell walls release a toxin called lipopolysaccharide (LPS), in turn causing excessive activity of the osteoclasts that induce the bone loss. In this study, both nobiletin and tangeretin suppressed LPS-induced osteoclast formation and bone loss, by inhibting NF-kappaB. In this mouse model of experimentally induced periodontal bone loss, nobiliten was actually able to restore the bone mass.
Collectively these studies show that nobiletin and tangeretin, especially nobiletin, are highly protective to bone health at the most fundamental level of gene signaling.


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