Bone Health - ExtraLyfe

[vc_row][vc_column][vc_column_text woodmart_inline=”no” text_larger=”no”]Bone is rigid body tissue consisting of cells embedded in an abundant hard intercellular material. The two principal components of this material, collagen and calcium phosphate, distinguish bone from such other hard tissues as chitin, enamel, and shell. Bone tissue makes up the individual bones of the human skeletal system and the skeletons of other vertebrates.

Functions

The functions of bone include (1) structural support for the mechanical action of soft tissues, such as the contraction of muscles and the expansion of lungs, (2) protection of soft organs and tissues, as by the skull, (3) provision of a protective site for specialized tissues such as the blood-forming system (bone marrow), and (4) a mineral reservoir, whereby the endocrine system regulates the level of calcium and phosphate in the circulating body fluids.[/vc_column_text][vc_column_text woodmart_inline=”no” text_larger=”no”]

Significance

Bone is found only in vertebrates, and, among modern vertebrates, it is found only in bony fish and higher classes. Although ancestors of the cyclostomes and elasmobranchs had armoured headcases, which served largely a protective function and appear to have been true bone, modern cyclostomes have only an endoskeleton, or inner skeleton, of noncalcified cartilage and elasmobranchs a skeleton of calcified cartilage. Although a rigid endoskeleton performs obvious body supportive functions for land-living vertebrates, it is doubtful that bone offered any such mechanical advantage to the teleost (bony fish) in which it first appeared, for in a supporting aquatic environment great structural rigidity is not essential for maintaining body configuration. The sharks and rays are superb examples of mechanical engineering efficiency, and their perseverance from the Devonian Period attests to the suitability of their nonbony endoskeleton.

In modern vertebrates, true bone is found only in animals capable of controlling the osmotic and ionic composition of their internal fluid environment. Marine invertebrates exhibit interstitial fluid compositions essentially the same as that of the surrounding seawater. Early signs of regulability are seen in cyclostomes and elasmobranchs, but only at or above the level of true bone fishes does the composition of the internal body fluids become constant. The mechanisms involved in this regulation are numerous and complex and include both the kidney and the gills. Fresh and marine waters provide abundant calcium but only traces of phosphate; because relatively high levels of phosphate are characteristic of the body fluids of higher vertebrates, it seems likely that a large, readily available internal phosphate reservoir would confer significant independence of external environment on bony vertebrates. With the emergence of terrestrial forms, the availability of calcium regulation became equally significant. Along with the kidney and the various component glands of the endocrine system, bone has contributed to development of internal fluid homeostasis—the maintenance of a constant chemical composition. This was a necessary step for the emergence of terrestrial vertebrates. Furthermore, out of the buoyancy of water, structural rigidity of bone afforded mechanical advantages that are the most obvious features of the modern vertebrate skeleton.

Depending upon species, age, and type of bone, bone cells represent up to 15 percent of the volume of bone; in mature bone in most higher animals, they usually represent only up to 5 percent. The nonliving intercellular material of bone consists of an organic component called collagen (a fibrous protein arranged in long strands or bundles similar in structure and organization to the collagen of ligaments, tendons, and skin), with small amounts of proteinpolysaccharides, glycoaminoglycans (formerly known as mucopolysaccharides) chemically bound to protein and dispersed within and around the collagen fibre bundles, and an inorganic mineral component in the form of rod-shaped crystals. These crystals are arranged parallel with the long axes of collagen bundles and many actually lie in voids within the bundles themselves. Organic material constitutes 50 percent of the volume and 30 percent of the dry weight of the intercellular composite, with minerals making up the remainder. The major minerals of the intercellular composite are calcium and phosphate. When first deposited, mineral is crystallographically amorphous, but with maturation it becomes typical of the apatite minerals, the major component being hydroxyapatite. Carbonate is also present—in amounts varying from 4 percent of bone ash in fish and 8 percent in most mammals to more than 13 percent in the turtle—and occurs in two distinct phases, calcium carbonate and a carbonate apatite. Except for that associated with its cellular elements, there is little free water in adult mammalian bone (approximately 8 percent of total volume). As a result, diffusion from surfaces into the interior of the intercellular substance occurs at the slow rates more typical of diffusion from surfaces of solids than within liquids.

The mineral crystals are responsible for hardness, rigidity, and the great compressive strength of bone, but they share with other crystalline materials a great weakness in tension, arising from the tendency for stress to concentrate about defects and for these defects to propagate. On the other hand, the collagen fibrils of bone possess high elasticity, little compressive strength, and considerable intrinsic tensile strength. The tensile strength of bone depends, however, not on collagen alone but on the intimate association of mineral with collagen, which confers on bone many of the general properties exhibited by two-phase materials such as fibre glass and bamboo. In such materials the dispersion of a rigid but brittle material in a matrix of quite different elasticity prevents the propagation of stress failure through the brittle material and therefore allows a closer approach to the theoretical limiting strength of single crystals.

The fine structure of bone has thus far frustrated attempts to determine the true strength of the mineral-matrix composite at the “unit” structural level. Compact (cortical) bone specimens have been found to have tensile strength in the range of 700–1,400 kg per square cm (10,000–20,000 pounds per square inch) and compressive strengths in the range of 1,400–2,100 kg per square cm (20,000–30,000 pounds per square inch). These values are of the same general order as for aluminum or mild steel, but bone has an advantage over such materials in that it is considerably lighter. The great strength of bone exists principally along its long axis and is roughly parallel both to the collagen fibre axis and to the long axis of the mineral crystals.

Although apparently stiff, bones exhibit a considerable degree of elasticity, which is important to the skeleton’s ability to withstand impact. Estimates of modulus of elasticity of bone samples are of the order of 420 to 700 kg per square cm (6,000 to 10,000 pounds per square inch), a value much less than steel, for example, indicating the much greater elasticity of bone. Perfect elasticity exists with loads up to 30 to 40 percent of breaking strength; above this, “creep,” or gradual deformation, occurs, presumably along natural defects within the bony structure. The modulus of elasticity in bone is strikingly dependent upon the rate at which loads are applied, bones being stiffer during rapid deformation than during slow; this behaviour suggests an element of viscous flow during deformation.

As might be anticipated from consideration of the two-phase composition of bone, variation in the mineral-collagen ratio leads to changes in physical properties: less mineral tends ultimately to greater flexibility and more mineral to increased brittleness. Optimal ratios, as reflected in maximal tensile strength, are observed at an ash content of approximately 66 percent, a value that is characteristic of the weight-bearing bones of mammals.[/vc_column_text][vc_column_text woodmart_inline=”no” text_larger=”no”]

Bone Morphology

Grossly, bone tissue is organized into a variety of shapes and configurations adapted to the function of each bone: broad, flat plates, such as the scapula, serve as anchors for large muscle masses, while hollow, thick-walled tubes, such as the femur, the radius, and the ulna, support weight or serve as a lever arm. These different types of bone are distinguished more by their external shape than by their basic structure.

All bones have an exterior layer called cortex that is smooth, compact, continuous, and of varying thickness. In its interior, bony tissue is arranged in a network of intersecting plates and spicules called trabeculae, which vary in amount in different bones and enclose spaces filled with blood vessels and marrow. This honeycombed bone is termed cancellous or trabecular. In mature bone, trabeculae are arranged in an orderly pattern that provides continuous units of bony tissue aligned parallel with the lines of major compressive or tensile force. Trabeculae thus provide a complex series of cross-braced interior struts arranged so as to provide maximal rigidity with minimal material.

Bone Diseases

Osteoporosis affects millions of Americans. Individuals with osteoporosis are at high risk of suffering one or more fractures, which are often physically debilitating and can potentially lead to a downward spiral in physical and mental health.

The most common form of osteoporosis is known as “primary osteoporosis.” It is the result of the cumulative impact of bone loss and deterioration of bone structure as people age. This bone loss can be minimized and osteoporosis prevented through adequate nutrition, physical activity, and, if necessary, appropriate treatment.

There are a wide variety of diseases and certain medications and toxic agents that can cause or contribute to the development of osteoporosis. If recognized as a potential threat, this form of the disease known as secondary osteoporosis can often be prevented through proper nutrition and physical activity, along with appropriate therapy if needed.

A number of childhood diseases cause rickets, a condition that results from a delay in depositing calcium phosphate mineral in growing bones. This delay leads to skeletal deformities, especially bowed legs. In adults, the equivalent disease is called osteomalacia. Both diseases can generally be prevented by ensuring adequate levels of vitamin D, but they can have devastating consequences for affected individuals.

Patients with chronic renal disease are at risk for developing a complex bone disease known as renal osteodystrophy. While dialysis and transplantation have extended the life-expectancy of these patients, it may not prevent further progression of bone disease.

Paget’s disease of bone is a progressive, often crippling disorder of bone remodeling that commonly involves the spine, pelvis, legs, or skull (although any bone can be affected). If diagnosed early, its impact can be minimized.

A large number of genetic and developmental disorders affect the skeleton. Among the more common of these is osteogenesis imperfecta (OI). Patients with this condition have bones that break easily.

Some skeletal disorders tend to develop later in life. One of the most common of these acquired skeletal disorders is a malignancy of the bone. These malignancies can dfdgate in the bone (primary tumors) or, much more commonly, result from the seeding of bone by tumors outside of the skeleton (metastatic tumors). Primary bone cancer also occurs in children. Both types of tumors can destroy bone.

The body systems that control the growth and maintenance of the skeleton can be disrupted in different ways that result in a variety of bone diseases and disorders. These include problems that can occur at or before birth, such as genetic abnormalities and developmental defects, as well as diseases such as osteoporosis and Paget’s disease of bone that damage the skeleton later in life. In addition to conditions that affect bone directly, there are many other disorders that indirectly affect bone by interfering with mineral metabolism. This chapter reviews some of the more common diseases, disorders, and conditions that both directly and indirectly affect bone.

There are a wide variety of diseases and certain medications and toxic agents that can cause or contribute to the development of osteoporosis. If recognized as a potential threat, this form of the disease—known as secondary osteoporosis—can often be prevented through proper nutrition and physical activity, along with appropriate therapy if needed.

A large number of genetic and developmental disorders affect the skeleton. Among the more common of these is osteogenesis imperfecta (OI). Patients with this condition have bones that break easily.

The body systems that control the growth and maintenance of the skeleton,can be disrupted in different ways that result in a variety of bone diseases and disorders. These include problems that can occur at or before birth, such as genetic abnormalities and developmental defects, as well as diseases such as osteoporosis and Paget’s disease of bone that damage the skeleton later in life. In addition to conditions that affect bone directly, there are many other disorders that indirectly affect bone by interfering with mineral metabolism. This chapter reviews some of the more common diseases, disorders, and conditions that both directly and indirectly affect bone.

Osteoporosis

As pointed out in osteoporosis is a disease characterized by low bone mass and deterioration of bone structure that causes bone fragility and increases the risk of fracture. For practical purposes, the World Health Organization has defined osteoporosis as a bone mineral density value more than 2.5 standard deviations below the mean for normal young White women. Osteoporosis is a common disease affecting millions of Americans. As described in and it can have devastating consequences. Individuals with osteoporosis are at high risk of suffering one or more fractures, injuries that can often be physically debilitating and potentially lead to a downward spiral in physical and mental health. Generalized osteoporosis is the most common form of the disease, affecting most of the skeleton. Osteoporosis can also occur in localized parts of the skeleton as a result of injury or conditions that reduce muscle forces on the bone, such as limb paralysis. There are a variety of different types of osteoporosis. The most common form of osteoporosis is known as “primary osteoporosis”—that is, osteoporosis that is not caused by some other specific disorder. Bone loss caused by specific diseases or medications (see below) is referred to as “secondary osteoporosis.” Each of these major categories of osteoporosis is discussed in more detail on the following pages.

Primary Osteoporosis

Primary osteoporosis is mainly a disease of the elderly, the result of the cumulative impact of bone loss and deterioration of bone structure that occurs as people age. This form of osteoporosis is sometimes referred to as age-related osteoporosis. Since postmenopausal women are at greater risk, the term “postmenopausal” osteoporosis is also used. Younger individuals (including children and young adults) rarely get primary osteoporosis, although it can occur on occasion. This rare form of the disease is sometimes referred to as “idiopathic” osteoporosis, since in many cases the exact causes of the disease are not known, or idiopathic. Since the exact mechanisms by which aging produces bone loss are not all understood (that is, it is not always clear why some postmenopausal women develop osteoporosis while others do not), age-related osteoporosis is also partially idiopathic. A brief review of “idiopathic” primary osteoporosis and a more detailed review of the more common condition of age-related osteoporosis follows.

Tips to improve Bone health

Use more Vegetables

Vegetables are great for your bones. They’re one of the best sources of vitamin C, which stimulates the production of bone-forming cells. In addition, some studies suggest that vitamin C’s antioxidant effects may protect bone cells from damage

Vegetables also seem to increase bone mineral density, also known as bone density.Bone density is a measurement of the amount of calcium and other minerals found in your bones. Both osteopenia (low bone mass) and osteoporosis (brittle bones) are conditions characterized by low bone density. A high intake of green and yellow vegetables has been linked to increased bone mineralization during childhood and the maintenance of bone mass in young adults. Eating lots of vegetables has also been found to benefit older women.

A study in women over 50 found those who consumed onions most frequently had a 20% lower risk of osteoporosis, compared to women who rarely ate them. One major risk factor for osteoporosis in older adults is increased bone turnover, or the process of breaking down and forming new bone

Eat protein rich meal

Getting enough protein is important for healthy bones. In fact, about 50% of bone is made of protein. Researchers have reported that low protein intake decreases calcium absorption and may also affect rates of bone formation and breakdown. However, concerns have also been raised that high-protein diets leach calcium from bones in order to counteract increased acidity in the blood. Nevertheless, studies have found that this doesn’t occur in people who consume up to 100 grams of protein daily, as long as this is balanced with plenty of plant foods and adequate calcium intake In fact, research suggests that older women, in particular, appear to have better bone density when they consume higher amounts of protein. In a large, six-year observational study of over 144,000 postmenopausal women, higher protein intake was linked to a lower risk of forearm fractures and significantly higher bone density in the hip, spine and total body

What’s more, diets containing a greater percentage of calories from protein may help preserve bone mass during weight loss.

Exercise regularly

Engaging in specific types of exercise can help you build and maintain strong bones. One of the best types of activity for bone health is weight-bearing or high-impact exercise, which promotes the formation of new bone. Studies in children, including those with type 1 diabetes, have found that this type of activity increases the amount of bone created during the years of peak bone growth. In addition, it can be extremely beneficial for preventing bone loss in older adults.

Studies in older men and women who performed weight-bearing exercise showed increases in bone mineral density, bone strength and bone size, as well as reductions in markers of bone turnover and inflammation. However, one study found little improvement in bone density among older men who performed the highest level of weight-bearing exercise over nine months Strength-training exercise is not only beneficial for increasing muscle mass. It may also help protect against bone loss in younger and older women, including those with osteoporosis, osteopenia or breast cancer[/vc_column_text][/vc_column][/vc_row]