Bones play an important structural role in the body. They provide mobility, support and protection for the body and acts as a warehouse for essential minerals. Although some people think of bones as hard and lifeless, they are actually living, growing tissue. They are alive and constantly changing, with new bone being made and old bone lost throughout our lives. In adults, the entire skeleton is completely replaced every seven to ten years. Bones continue to grow in strength until our mid twenties, at which point bone density reaches its peak. Bones are made up of three major components that make them flexible and strong –
- Collagen, a protein that gives bones a flexible framework
- Calcium-phosphate mineral complexes that make bones hard and strong
- Living bone cells that remove and replace weakened sections of bone
Healthy bones are critical to overall health, and behaviors that promote health and disease prevention also are key to maintaining a strong and healthy skeleton. These behaviors include, for example, getting regular exercise, eating a balanced diet, not smoking, preventing falls and injuries, and drinking alcohol only in moderation. Encouraging bone health is important in helping to stem the rate and risk of osteoporosis, the most common bone disease, which currently afflicts 10 million Americans over the age of 50.
What is Osteoporosis? Osteoporosis is a chronic, debilitating disease whereby the density and quality of bone are reduced. The bones become porous and fragile, the skeleton weakens, and the risk of fractures greatly increases. The loss of bone occurs “silently” and progressively, often without symptoms until the first fracture occurs, most commonly at the wrist, spine and hip. Approximately one out of three women over 50 will have a fracture due to osteoporosis as will one out of five men over 50. Although osteoporosis typically manifests itself later in life, the roots of the disease may stretch back to early childhood and reflect a lifetime of risks and behaviors.
Other bone diseases affect the lives of many Americans and their families. Nearly 1.5 million people in the United States may have Paget’s disease, the second most common bone disease.
What is Paget’s disease? Paget’s disease is characterized by pain, skeletal deformities, increased risk for multiple fractures, and other complications such as hearing loss. Osteogenesis imperfecta is a genetic disorder that causes brittle bones that break easily. Estimates of the numbers of individuals in the United States with this disorder range from 25,000 to 50,000 – exact numbers are difficult to calculate because milder forms of the disease may go undetected.
Although these, and other rare bone diseases, may affect fewer individuals than other conditions, their importance is far reaching. It’s effects on bone health has increased the potential and importance to address bone loss, fragility, or disease.
The importance of bone health is already far greater than is widely recognized. An estimated 1.5 million people suffer an osteoporosis-related fracture each year, and over their life times, half of all women and one-quarter of all men can expect to join their ranks. Among people age 65 and older, unintentional falls account for 87% of all fractures treated in emergency departments.
Factors Affecting Bone Health
- Gender, Size & Age – Women have less bone tissue than men. If a woman’s period is absent for long stretches of time prior to menopause, she can be at increased risk for osteoporosis – and menopause itself corresponds to dramatic bone loss as estrogen decreases. In men, lower testosterone can cause lower bone mass. Also age play a role in weakened bones, as bones thin and weaken with increasing age. Maintaining a healthy body weight is important for bone health throughout life. Being underweight raises the risk of fracture and bone loss. Weight loss is associated with bone loss as well, although adequate diet and physical activity may reduce this loss.
- Genetics – If a person is of Caucasian or Asian descent, he/she is at a greatest risk for osteoporosis. A parent or sibling with osteoporosis or a history of fracture is a risk factor.
- Physical Activity – Physical activity is important for bone health throughout life. It helps to increase or preserve bone mass and to reduce the risk of falling. All types of physical activity can contribute to bone health, albeit in different ways.
- Fractures – Fractures are commonly caused by falls, and thus fall prevention offers another opportunity to protect bones, particularly in those over age 60. Several specific approaches have demonstrated benefits, including muscle strengthening and balance retraining, professional home hazard assessment and modification, and stopping or reducing psychotropic medications.
- Reproductive Problems – Reproductive issues can affect bone health. Pregnancy and lactation generally do not harm the skeleton of healthy adult women. Amenorrhea (cessation of menstrual periods) after the onset of puberty and before menopause is a very serious threat to bone health and needs to be attended to by individuals and their health care providers.
- Calcium – Calcium has been singled out as a major public health concern today because it is critically important to bone health and the average American consumes levels of calcium that are far below the amount recommended for optimal bone health. A diet low in calcium contributes to diminished bone density, early bone loss and an increased risk of fractures.
- Vitamin Deficiency – In children, severe vitamin D deficiency results in delayed growth and bone deformities known as rickets, and in adults, a similar condition called osteomalacia (a ‘softening’ of the bones, due to the poor mineralization). Milder degrees of vitamin D inadequacy can lead to a higher risk of osteoporosis, and an increased likelihood of falling in older adults whose muscles are weakened by a lack of the vitamin.
- Lifestyle – Smoking can reduce bone mass and increase fracture risk and should be avoided for a variety of health reasons. Heavy alcohol use has been associated with reduced bone mass and increased fracture risk.
- Heavy Metals – The main threats to human health from heavy metals are associated with exposure to lead, cadmium, mercury and arsenic. Metal exposure lowers bone density in the arms (the area that was tested). The overall bone density of affected person is significantly lower than the healthy person.
- Hormones – Too much thyroid hormone can cause bone loss. In women, bone loss increases dramatically at menopause due to dropping estrogen levels.
- Eating Disorders – People who have anorexia or bulimia are at risk of bone loss. In addition, stomach surgery (gastrectomy), weight-loss surgery and conditions such as Crohn’s disease, celiac disease and Cushing’s disease can affect your body’s ability to absorb calcium. Caffeine increases the loss of calcium from the body; however, the negative effects can be offset by adequate calcium intake.
- Medications – Damaging to bone over long-term usage – prednisone, cortisone, prednisolone and dexamethasone (corticosteroids).
- Medical Conditions – Conditions like – Inflammatory Bowel Disease, Celiac Disease, Glucocorticoids, Anorexia nervosa have adverse effects on bone health.
Keeping Bones Healthy
Calcium Supplements – Calcium is a major building-block of the bone tissue. The human skeleton houses 99 per cent of our body’s calcium stores. The calcium in the bones also acts as a ‘reservoir’ for maintaining calcium levels in the blood, which are essential for healthy nerve and muscle functioning. Calcium requirements are high during teenage years with the rapid growth of the skeleton, and during this time, the body’s efficiency in absorbing calcium from food increases.
Vitamin D & Homocysteine – Vitamin D plays a key role in assisting calcium absorption from food, ensuring the correct renewal and mineralization of bone tissue, and promoting a healthy immune system and muscles. studies suggest that high blood levels of the amino acid homocysteine may be linked to lower bone density and higher risk of hip fracture in older persons. Vitamins B6 and B12, as well as folic acid, play a role in changing homocysteine into other amino acids for use by the body, so it is possible that they might play a protective role in osteoporosis. Further research is needed to test whether supplementation with these B vitamins might reduce fracture risk.
Vitamin A – The role of vitamin A in osteoporosis risk is controversial. Vitamin A is present as a compound called retinol in foods of animal origin, such as liver and other offal, fish liver oils, dairy foods and egg yolk. Some plant foods contain a precursor of vitamin A, a group of compounds called carotenoids.
Zinc – This mineral is required for bone tissue renewal and mineralization. Severe deficiency is usually associated with calorie and protein malnutrition, and contributes to impaired bone growth in children. Milder degrees of zinc deficiency have been reported in the elderly and could potentially contribute to poor bone status.
Magnesium – Magnesium plays an important role in forming bone mineral. Magnesium deficiency is rare in generally well-nourished populations. The elderly could potentially be at risk of mild magnesium deficiency, as magnesium absorption decreases and renal excretion increases with age, and also because certain medications promote magnesium loss in the urine.
Vitamin K – Vitamin K is required for the correct mineralization of bone. Some evidence suggests low vitamin K levels lead to low bone density and increased risk of fracture in the elderly, but more studies are needed to prove if increasing vitamin K intake would help to prevent or treat osteoporosis
Protein – Adequate dietary protein is essential for optimal bone mass gain during childhood and adolescence, and preserving bone mass with ageing. Insufficient protein intake is common in the elderly and is more severe in hip fracture patients than in the general ageing population. Protein under nutrition also robs the muscles of mass and strength, heightening the risk of falls and fractures, and it contributes to poor recovery in patients who have had a fracture.
Reference –
http://www.betterbones.com/osteoporosis/natural-approach-to-bone-health.aspx
http://nof.org/learn/prevention
http://www.caltrate.ca/keeping-bones-healthy
http://www.emedicinehealth.com/what_is_bone_loss/page3_em.htm#what_causes_bone_loss
http://www.progressivehealth.com/toxic-cadmium-damaging-bones.htm
http://bmb.oxfordjournals.org/content/68/1/167.full
http://www.ncbi.nlm.nih.gov/books/NBK45503/
http://www.caltrate.ca/what-affects-bone-health
http://www.iofbonehealth.org/sites/default/files/PDFs/good_nutrition_for_healthy_bones.pdf