Bone is living, growing tissue. It is made mostly of collagen, a protein that provides a soft framework, and calcium phosphate, a mineral that adds strength and hardens the framework. This combination of collagen and calcium makes bone both flexible and strong, which in turn helps bone to withstand stress.1
More than 99 percent of the body’s calcium is contained in the bones and teeth. The remaining 1 percent is found in the blood. Throughout one’s lifetime, old bone is removed (resorption) and new bone is added to the skeleton (formation). During childhood and teenage years, new bone is added faster than old bone is removed. As a result, bones become larger, heavier, and denser. Bone formation outpaces resorption until peak bone mass (maximum bone density and strength) is reached around age 30. After that time, bone resorption slowly begins to exceed bone formation. For women, bone loss is fastest in the first few years after menopause, and it continues into the postmenopausal years.
Osteoporosis, or porous bone, is a disease characterized by low bone mass and structural deterioration of bone tissue, leading to bone fragility and an increased risk of fractures of the hip, spine, and wrist. Osteoporosis is more likely to develop if you did not reach optimal peak bone mass during your bone-building years.
Women are at a greater risk than men, especially women who are thin or have a small frame, as are those of advanced age. Women who are postmenopausal, including those who have had early or surgically induced menopause, or abnormal or absence of menstrual periods, are at greater risk. Cigarette smoking, eating disorders such as anorexia nervosa or bulimia, low amounts of calcium in the diet, heavy alcohol consumption, inactive lifestyle, and use of certain medications, such as corticosteroids and anticonvulsants, are also risk factors for osteoporopsis.2
The underlying mechanism in all cases of osteoporosis is an imbalance between bone resorption and bone formation. In normal bone, matrix remodeling of bone is constant; up to 10% of all bone mass may be undergoing remodeling at any point in time. The process takes place in bone multicellular units (BMUs) as first described by Frost & Thomas in 1963. Osteoclasts are assisted by transcription factor PU.1 to degrade the bone matrix, while osteoblasts rebuild the bone matrix. Low bone mass density can then occur when osteoclasts are degrading the bone matrix faster than the osteoblasts are rebuilding the bone. The three main mechanisms by which osteoporosis develops are an inadequate peak bone mass (the skeleton develops insufficient mass and strength during growth), excessive bone resorption, and inadequate formation of new bone during remodeling. An interplay of these three mechanisms underlies the development of fragile bone tissue. Hormonal factors strongly determine the rate of bone resorption; lack of estrogen (e.g. as a result of menopause) increases bone resorption, as well as decreasing the deposition of new bone that normally takes place in weight-bearing bones.this leads to weakening and softening of bones the bones become soft and it will prone to get fracture or collapse.
Probiotics (Bifidobacterium longum) Increase Bone Mass Density and UpregulateSparcandBmp-2Genes in Rats with Bone Loss Resulting from Ovariectomy
