What is Bone and What influences Bone Health

Series I

Bone is one of the hardest structures in the human body with a degree of toughness and elasticity. A remarkable organ, it serves as structural function, provides mobility, supports protection for the body and is a reservoir for storing minerals. It may seem as if bone is delicate, but is actually strong as “steel”.

The primary tissue of bone (osseous tissue) is relatively a hard but lightweight composite material. It is made of Calcium Phosphate (hydroxyappetite) which gives bone its rigidity. It consists of (bone) marrow, cartilage, nerves and blood vessels. Even though bone is essentially brittle, it also demonstrates a degree of elasticity due to collagen.

Bone mass continuously changes throughout life in response to mechanical stress and function. Bone will actually weaken if not subjected to adequate weight bearing function for sufficient periods of time. So, in the case of space travelers, weightlessness could cause rapid bone loss. This is where the saying comes into play- “use it or lose it”.

Bones, muscles and joints are the integral part of our musculoskeletal system. Any problems with any of these “parts” could affect the entire system. Therefore, weakness of muscles could lead to loss of bone and joint damage and degeneration of joints could lead to changes in the underlying bone.

So, what may result if there are changes in bone health? Several factors such as genetics, diet, environment and lifestyle influence the outcome of bone structure and its functionality. Impairment or dysfunction of any of the above may lead to what is known as “metabolic bone disease”.

• Genetic abnormality- (1) Abnormalities in collagen protein which weakens bone matrix and predispose multiple fractures; (2) Abnormality in bone density may lead to defect of bone marrow production.
• Nutrient deficiency- (1) Decreased vitamin D, Calcium and Phosphorus can result in weak, poorly mineralized bone; (2) In children, decreased vitamin D may result in Rickets whereas in adults low vitamin D may cause softening of the bone (which may cause fractures and skeleton deformities).
• Hormone disorders- (1) Hyper parathyroid gland promotes excess bone break down which may result in higher risk of fractures; (2) Decreased growth hormone inhibits skeletal development (short body stature); (3) Loss of gonad function in small children and young adults may cause osteoporosis due to the loss of testosterone and estrogen.
• Inflammation- (1) Will in bone loss around affected joints in those with arthritis; (2) Bacterial infections, such as gingivitis, may result in bone loss around the teeth; (3) Osteomylitis will result in bone loss at the site of any infection.
• Blood sugar imbalances- (1) Type I Diabetes may result in modest reductions in bone mineral density; (2) Type II Diabetes may result in increased bone mineral density which may result in fractures of the hip and feet; (3) Obesity, insulin sensitivity or insulin resistance, increased concentration of advanced glycation end products (AGEs) in bone collagen, increased Calcium and glucose excretion in urine and impaired function of the kidneys may contribute to bone loss; (4) Reduced blood flow to bone as a result of Diabetes may lead to bone loss and fragility; (5) Osteoblasts (bone builders) are defective as result of reduced osteocalcin in Diabetics, which can reduce bone formation and increase fracture healing time.
• Finally, Medications may cause bone loss!) Glucocorticoids (asthma), corticosteroids, thyroid hormones, blood thinners (heparin, warfarin), gonadotropin releasing hormone agonists (prostate cancer treatment), contraceptives, Lithium (bi-polar treatment), anti-convulsants, aluminum-containing antacids and tetracycline are a number of such medications. Other medications such as anti-depressants, sedatives, and tranquilizers increase risk of osteoporotic fractures.

***Please look at this Lactoferrin study

***Please return to learn about lactoferrin and how it affects bone health in series II