Osteoporosis - Natural Approaches
by Tiffany Eberhard, HBSc., ND
2437 Main St.
London, ON N6P 1A3
Osteoporosis is a disease of the skeletal system characterized by deterioration of bone tissue and a reduction in bone mass . Osteoporosis results from a long-term disruption of skeletal homeostasis that is secondary to nutritional, physical, genetic, endocrine, and environmental factors. Bone mass is correlated with bone strength, therefore a decrease in bone mass leads to bone fragility and an increased fracture risk. The elderly population is more prone to fracture due to their decreased bone mass, muscle strength, coordination, and proprioception. Additionally, medication- or age-related disturbances in cognition, vision, and hearing, increase the risk of fracture in this population. Osteoporosis is generally symptomless with the first symptoms being when a fracture occurs with minimal force. It typically affects the entire skeleton with a fracture being possible at any site. However, the most common sites for osteoporotic fractures are the distal radius, proximal femur (hip fracture), and the spine (vertebral compression fracture). Hip fractures are responsible for significant morbidity and mortality while vertebral fractures result in loss of spinal curvature and height as well as back pain. Women have a four-times greater risk of developing osteoporosis than men. Postmenopausal women have the greatest risk due to the reduction in estrogen production at this time . Osteoporosis diminishes quality of life in those who fear or suffer from bone fractures . Osteoporosis is preventable and treatable if the obstacles to normal skeletal homeostasis are removed .
Bone mass increases from birth and reaches a peak mass at age 30 to 35 for cortical bone and earlier for trabecular bone. This peak bone mass is controlled by genes but in order to reach its full potential optimal intake of nutrients needed for bone density are required as well as the avoidance of factors that deplete bone density. Bone is in a constant state of turnover called remodeling, which consists of bone resorption by osteoclasts and bone formation by osteoblasts. The total lifetime losses of bone mass range from 20-30% in men and up to 40-50% in women. Bone turnover is influenced by many factors, such as physical activity, nutrient intake, acid-base balance, endocrine, and local bone factors. The primary regulators of bone remodeling are parathyroid hormone (PTH), vitamin D, and calcitonin due to their role in maintaining optimal serum calcium levels. Other hormones that influence bone remodeling include estrogens, progesterone, androgens, thyroid hormone, and glucocorticoids. Estrogen increases the formation of calcitonin and therefore inhibits osteoclasts. It also stimulates calcium absorption by the intestine and facilitates vitamin D synthesis. Thyroid hormone activates osteoclasts with hyperthyroidism being associated with increased bone resorption. The adrenal glands and adipose tissues are supposed to continue supplying estrogens post-menopause, however many women arrive at menopause in a state of adrenal fatigue and therefore don’t have enough estrogen to protect their bones .
Prevention and early intervention is key due to the silent nature of osteoporosis. Dual Energy X-ray Absorptiometry (DEXA) quantifies bone density of the lumbar spine, proximal femur, and forearm. It is a quick and non-invasive test, which is used to determine current skeletal density, risk of fracture, and to monitor the efficacy of treatment .
A balanced diet rich in vegetables, fruit, and adequate protein is key in the prevention of diseases including osteoporosis. It is important to get enough calcium in the diet as well as other important minerals and vitamins needed for bone formation. Cigarette smoking and alcohol intake are associated with osteoporosis. Cigarette smoking depletes the body of ascorbic acid and exposes the body to a variety of toxins, which directly damage bone and interfere with calcium absorption. Alcohol inhibits absorption and increases excretion of calcium, magnesium, ascorbic acid, copper, and zinc. Studies have demonstrated that consuming two to three cups of caffeinated beverages a day accelerates bone loss from the spine and total body in women with calcium intakes below 800 mg per day . Another study found that consuming more than 300 mg of caffeine per day is associated with a higher rate of bone loss in postmenopausal elderly women at most skeletal sites with the most significant loss being from the spine . Excessive phosphates found in soft drinks and high protein diets can contribute to bone loss if dietary intake of calcium is insufficient .
Exercise is essential in the prevention and treatment of osteoporosis. Physical activity can regulate bone maintenance and stimulate bone formation . Peak bone mass is achieved both by consuming adequate bone-building nutrients and by mechanically loading the skeleton. Exercise builds bone mass and muscles mass, enhances coordination, flexibility, and proprioception. Exercise must be continued throughout life in order to be effective. One study found that women who participated in vigorous exercise two or more times per week or whose total activity amounted to four hours per week had significantly higher bone density than those who exercised less than two times per week or did less than four hours of physical activity per week . Combining exercise and calcium supplementation has been shown to arrest the rate of bone mineral loss. Women who walked 30 minutes, at an intensity greater than 90% of maximal effort, three times a week over a period of 8 months increased their bone mineral density (BMD) by 1.1% at the lumbar spine . Higher exercise intensities and unusual loading patterns produced BMD increases. One study looked at the effect of using high-impact strength and endurance training 4 days per week for 2 years in 55-year-old postmenopausal women. Bone density increased 1.3% above the baseline in the exercise group while the control group lost 1.2% . Brief and intermittent exercise stimulates the adaptive bone response with an unusual pattern of bone loading also being required. Additionally, adaptive bone responses require dynamic mechanical stimulation and supra-threshold intensity. Therefore, conventional flexion and extension, within expected intensity ranges, produce little if any bone growth .
Calcium is an integral part of any approach to osteoporosis. Calcium intake as a child and young adult helps in achieving peak bone mass. A large percentage of the population does not meet the recommended intake of calcium and therefore supplementation is often necessary . Adequate calcium intake becomes more important in women after the age of 40 when bone loss becomes more pronounced. Bone loss occurs at a rate of about 1% per year in the late postmenopausal years. Calcium supplementation becomes necessary during this time due to the decline in estrogen and the subsequent effect on estrogen facilitated intestinal and renal calcium absorption . Supplementation significantly decreases bone loss in the lumbar spine in both premenopausal women and in early perimenopausal women and reduces cortical bone loss during the first five years of menopause. Additionally, calcium supplementation produces a sustained reduction in the rate of total body bone loss in women at least three years after menopause, however it doesn’t appear to slow the rapid loss of trabecular bone during the first few years of menopause .
Evidence supports the use of calcium, or calcium in combination with vitamin D supplementation, as preventative treatment for osteoporosis for people 50 years or older. Calcium and calcium in combination with vitamin D were associated with a 12% risk reduction in fractures of all types and a reduced bone loss of 0.54% at the hip and 1.19% in the spine. Authors of a meta-analysis recommended a minimum daily dose of 1200 mg of calcium and 800 IU of vitamin D in this population . Calcium supplementation without co-administration of vitamin D is associated with an increased risk of myocardial infarction. Calcium supplementation was found to be associated with approximately a 30% increase in the incidence of myocardial infarction and smaller, non-significant increases in the risk of stroke and mortality. Studies have shown that high dietary calcium intake does not increase cardiovascular risk; therefore the cardiovascular risk from high calcium intake might be restricted to calcium supplementation. Calcium supplements acutely increase serum calcium levels where serum calcium levels have been positively associated with an increased incidence of myocardial infarction. Vascular calcification is an established risk factor for cardiovascular disease and calcium supplements may increase this calcification .
Vitamin regulates intestinal and renal absorption of calcium and increasing calcium resorption along with PTH. Vitamin D deficiency is very common and occurs in about 25% of elderly patients presenting with hip fracture. Vitamin D deficiency can be due to decreased absorption, impaired hepatic and renal conversion to 1,25(OH)-2D, and/or deficient sun exposure . A review did not find vitamin D supplementation without calcium to be of benefit in preventing or treating osteoporosis. However, in individuals with low serum vitamin D levels it may be beneficial . Vitamin D supplementation demonstrated a slightly protective effect in myocardial infarction and therefore could be important to take when supplementing calcium .
Vitamin K is important in the maintenance of healthy bone. Vitamin K deficiency has been observed in osteoporotic women. Supplementation has been shown to reduce urinary calcium and increase osteocalcin binding to hydroxyapatite in post-menopausal women. The majority of vitamin K is made by the intestinal flora and therefore frequent or long-term antibiotic treatment can lead to impaired vitamin K status . Vitamin K1 is a major type of dietary vitamin K while vitamin K2 is the major form of vitamin K in the tissues, including bone. Vitamin K2 is synthesized by bacteria in the gut but can be found in specific foods such as cheese and fermented soy beans .
Magnesium, Boron, and Trace Minerals
Magnesium depletion impairs mineral homeostasis by reducing renal and skeletal sensitivity to PTH and by reducing vitamin D activation. Supplementation appears to significantly increase bone density and reduce the incidence of fracture. The ratio of calcium to magnesium remains controversial with some recommending a 2:1 ratio and others recommending a 1:1 ratio. Boron interacts with other nutrients and plays a regulatory role in bone metabolism. Supplementation has been found to reduce the urinary excretion of calcium and magnesium while elevating the concentration of serum 17-beta estradiol and serum testosterone. There are several trace minerals such as copper, zinc, and manganese that are essential in bone metabolism due to their roles as co-factors for enzymatic reactions needed to develop and mineralize osteoid .
Osteoporosis is a preventable and treatable condition. There are a variety of factors that can lead to bone loss such as poor diet, insufficient calcium intake, inactivity, etc. Given the risks associated with some of the conventional approaches to osteoporosis many people seek out natural alternatives. Calcium has been established to be beneficial in the prevention and treatment of osteoporosis. It should be consumed through the diet, if possible, and supplemented when necessary. Supplementing with vitamin D, vitamin K2, magnesium, and other nutrients mentioned in this article show promise but more research is needed at this time.