1. The diet is key throughout life

In this complex process, bone tissue has an array of nutritional requirements that will need to cover food through the individual ingest.

From this point of view, pharmacology or supplementation are unimportant because, if necessary, it will be only for short periods of time and of course, can never replace what food should be provided from birth of the individual or even before that.

It is known that properly organize food from early childhood brings great benefits in terms of health, including bone and quality of life. It is therefore necessary to always emphasize the importance of nutrition education.

2. Pregnancy and lactation

Pregnancy. It is a stage of life where it is recommended to increase the intake of calcium.
During pregnancy and lactation produced a series of physiological and environmental constraints make it necessary to bring food contributions and lifestyles of this special impact on mother and child.

The change in the nutritional needs and, in particular, changes in phospho-calcium balance was largely due to hormonal changes that serve as substrate for all the processes of synthesis and maternal-fetal adaptation that develop along pregnancy, fetal maturation and during lactation to feed the child, always with the priority needs of the fetus or infant.

As a result of the changes that take place before fetal skeletal mineralization is favored progressive retention of calcium to meet the increasingly growing demand for fetal skeletal mineralization.

Most of the works consulted during lactation indicate that bone mass is lost, studies show that in the early months of breastfeeding reduces the mother’s bone density between 3 and 5%, especially in the spine and hip , which is recovered upon cessation of breastfeeding.

At this stage we suggest the consumption of milk and dairy products to ensure a proper calcium RDA (3-4 servings/day, preferably suitable semi-or fat). Dairy products are a good way of incorporating nutritional amounts of vitamins and polyunsaturated fatty acids, especially in women with incomplete dietary profiles.

It is not necessary pharmacological supplementation of vitamin D, since a normal balanced diet and sun exposure allow adequate synthesis of this vitamin. Nor is recommended supplementation with vitamin A, or the additional intake of food especially rich in it, such as liver, cod liver oil, etc., the recommendations for vitamin A can be met through consumption of milk, eggs and plant foods rich in provitamin A. It is also essential to take daily five servings of fruits or vegetables in season.

3. Childhood and adolescence

Adolescence. At puberty is the period of greatest increases bone density.
During childhood and adolescence produces growth of the organism with the formation of bone from growth cartilage and subsequent ossification, strengthening it. To acquire optimal development is necessary to maintain adequate nutritional status.

With prevention in childhood is to attain a higher degree of bone mass and ensure a better ossified bone during the stage of old age. Puberty is the period of greatest increases bone density, and in this period which gets called “peak bone mass, whose quality is essential to avoid further risks.

Bone mineral density may be modifiable by diet and exercise up to 20%. Assumes great importance a balanced input of proteins (both over the defect in this sense may contribute to bone resorption), the contribution of vitamins through the abundant fruit and vegetables and intake of minerals like calcium, phosphorus and magnesium. The dietary calcium should be obtained primarily from dairy foods, as well as fortified.

The continued exercise is one of the most important factors involved in regulating bone mass, it will improve bone strength and endurance, which is continuously subjected to microtrauma. It also encourages organic synthesis in bone mineral deposition and bone architecture more resilient.

4. Adulthood

Objectives. Improving bone health and prevent the development of osteoporosis in the future.
He believes that a healthy diet is when you get a supply of nutrients in sufficient quantity to meet the needs of the organism.

At present, moreover, requires that the measure serves to promote health, improve welfare and reduce the risk of disease, the chronic type, such as cardiovascular, cancer and osteoporosis are those who benefit most from a proper diet.

A diet rich in dairy and protein and salt adjusted may improve bone health and prevent the development of osteoporosis in the future.

Deserves special attention in this chapter the menopause in women, hormonal changes process which requires special supplemental calcium and vitamin D and healthy lifestyle habits and physical exercise to maintain the balance of the skeleton.

5. Aging

Age is the most important determinant of bone density and it is known that there is an overall decrease in the amount of bone, causing the so-called “physiologic osteopenia” linked to age. The accumulated loss at the age of 80-90 years is 30% in men and 40-50% in women.

A decrease in bone formation, in part related to the general aging of the osteoblast (the cell responsible for bone formation), is coupled with decreased absorption of calcium.

This malabsorption could be related to vitamin D deficiency, since the transformation of this is produced in the kidney and the capacity to age renal function deteriorates. Physical activity, which decreases significantly with aging, is an important factor in bone formation.

There are several studies that demonstrate the role of calcium, vitamin D and protein in preventing bone fractures.

Statistics show that in Argentina between 40 and 50 per cent of teenagers of both sexes, and between 30 and 40 percent of those over 25 years consume less than 50 percent of the recommended calcium dose for age.

This calcium deficiency and its persistence throughout life, warning about a widespread nutritional problem, it is one of the agents responsible for the high incidence of osteoporosis in adulthood, and the frequency of fractures, says Dr. Maria Luz de Portela, Professor, Chair of Nutrition Faculty of Pharmacy and Biochemistry, UBA.

The recommended calcium intake for adults is 1000 milligrams a day. However, according to figures from the National Institute of Statistics and Censuses (INDEC) on the availability of foods that provide calcium in Argentina is less than 75 percent of the recommended per capita.

Nutritional studies showed that Argentines observe a high protein, low consumption of milk, and low fruit and vegetable. All this results in an inadequate intake of calcium and vitamin A. However, in comparison with previous work, in the last twenty years there was a gradual increase in calcium intake, a trend that manifested itself in increased sales of milk in the 90s, researchers say.

An essential mineral

Calcium is an essential mineral in the composition of the teeth and bones. These consist of approximately 70 percent of this mineral chemically combined with others such as phosphorus, that give them strength. Calcium is also essential for muscle contraction, transmission of nerve impulses and blood clotting.

The 99 percent of calcium in the body is part of the bones, which is a repository to preserve vital functions. The calcium stored in bones can be mobilized (bone resorption) to maintain levels in blood and tissues within physiological limits.

At first, the skeleton that forms in the embryo of a child is cartilaginous, and then the bone tissue grows with time, its calcium content. The bone hardening process called ossification is completed in about 25 years old. The last bone to ossify is the sternum. For this reason it is so important calcium intake in childhood and adolescence.

Brittle bones

One disease of high incidence in Argentina and is caused by a calcium deficiency is osteoporosis. It is characterized by decreased bone mass. The affected bones are more porous and break more easily than normal bone. Are common wrist fractures (radio), vertebrae and hip, but can affect any bone.

Osteoporosis affects women especially after menopause, but also occurs in men. Adequate intake of calcium from childhood helps prevent this disease.

Another disease caused by calcium deficiency is rickets, which causes skeletal deformities. Rickets is caused by a decrease in the mineralization of bone and cartilage due to low levels of calcium and phosphorus in the blood resulting from a deficiency of vitamin D.

It is believed that to attain optimal calcium levels need to increase the consumption of dairy products and certain vegetables that are rich in calcium, such as soybeans, broccoli and peas. Milk is the best source of calcium because it also has vitamin D which increases the absorption of the mineral. For a boy, ideally drink four glasses of milk a day.

The high fiber foods have little effect on calcium absorption. Moreover, excessive consumption of caffeine, salt and animal protein increases calcium excretion in urine.

In short, for healthy bones, experts advise increasing consumption of dairy products and also physical activity. In this sense, it seems that a half-hour walk or 45 minutes three times per week can be very helpful.

Matter of degree

How much calcium is necessary to eat to preserve the health of bones and teeth?

* For men or women older than 19 years, the daily requirement of calcium is 1000 milligrams.
* For pregnant and lactating women, it is considered that there is increased intestinal absorption, and advised the same figure of 1000 milligrams daily.
* In the case of adolescents (9 to 18 years), including pregnant women, are recommended 1300 milligrams daily, explains Dr. Portela.
* With regard to infants, if they are breastfed, the experts advise from 210 to 270 milligrams a day during the first year. If fed with artificial milk, the requirement is higher: 400 to 600 milligrams daily.
* For children 1 to 3 years: 500; of 4 to 5 years: 800 milligrams daily.
* For over 5 years: 1200 milligrams a day.
* To meet these requirements must be borne in mind that milk and yogurt have, on average, 100 milligrams of calcium per 100 grams. Therefore, with a couple of glasses of milk or yogurt per day will cover 50 percent of requirements. With a little cheese and a varied diet can meet 50 per cent.

Although it is advisable to cover the needs of calcium from the body with an adequate intake of foods from childhood, if this is not possible or there is a problem specific calcium deficiency, supplements should be given medical and biochemical control.

The normal daily physical activity, not subject to specific programs is insufficient stimulus to improve bone mass. Definitely overload exercises allow significant improvements in both sexes and any age on BMD

Excessive physical activity and often highly competitive sport beyond the tolerances of bone stimulation causing negative effects on both physiology and structure of bone.

The effects of exercise on bone tissue are possible only when a food base is established. The effects of recommended intakes of calcium are enhanced by the addition of exercise. This effect is most evident in aged subjects and in women in perimenopausal period.

INTRODUCTION

Osteoporosis is a systemic disease characterized by low bone mass and architecture poor, both increase bone fragility leaving it susceptible to fracture.

One in three postmenopausal women in particular have advanced osteopenia francs osteporosis values. Interestingly, this decline in BMD was significantly correlated with levels of sarcopenia, ie loss of muscle tissue, which characterizes the sedentary elderly. This correlation is less significant in men and women of the same age but who remain physically active. Per year in Europe is recorded about 650,000 hip fractures, which cause a 20% mortality and 50% partial or complete disability.

Other variables or factors that may affect bone metabolism, bone would be the use of psychoactive drugs, loss of muscle strength. In rlacion to fractures, loss of stability and balance, and lost some senses like hearing and sight, predispose to falls and fractures.

In this article we will discuss the relationship between exercise and bone and try to give some idea about the intensity of exercise for optimizing exercise and diet for bone health. (1)

WHAT IS THE MECHANISM MEDIATOR BETWEEN THE EFFECTS OF EXERCISE AND BONE?

One of the most important factors related to structural characteristics. The functional demand imposed on the bone is a major determinant in the structural characteristics of this. The intensity of the applied stress on the bone segment affects its geometry, its microarchitecture and composition of the matrix (2). Definitely the intensity of the burden for the recently described effects is important and not the duration of effort, a minimum strain (a strain is equal to one unit of strength by amending the arquitctura moments bone) is required to produce an effect on bone. It has developed a theory which translate mecanoestatos impact force signals that allow an imbalance between osteoblast activity (which builds bone) and osteoclasts (bone absorbing). It is not clear if that signal increases or decreases osteoblastic activity osteoclastic or both. The strain imposed on the active bone osteocyte initiating an increase in the production of prostacyclin and the osteoblast produces prostacyclin and prostaglandin E2, minutes later it has been shown that the osteocyte is an increase of glucose 6 phosphate dehydrogenase and 24 hours later an increase in mRNA for growth factors (3).

AT WHAT AGE THE EXERCISE HAS AN EFFECT ON THE BONE?

First we have to take into account that the growth of bone mass is acquired until the third decade and remains more or less constant until 50 and then begins to decline, there are few studies that have highlighted that the intake of calcium with physical activity completed in the first 30 years of life allows these individuals end up at that age with a higher bone mass, cross-sectional studies have also shown that subjects until 50 years of age who participate in exercise programs have an average between 8 and 12% higher BMD than their peers without exercise, after 50 years this difference is only 6%. In subjects over 50 years has been observed in 1% increments in BMD (4).

26 children under 11 years were subjected to a gymnastics training 3 hours per day and three hours watching television. A second group of the same age was only 1 hour a day of intense exercise and 4 hours of television. We obtained a much higher correlation between BMD and number of hours of exercise in the most active group of both arms and spine. The Amsterdam study on the health and growth habit of life correlated with lumbar BMD at 30 years of age.

WHAT IS THE TYPE OF EXERCISE MORE EFFECTIVE?

Paraplegic subjects unable to walk have a 40% decrease in BMD within the pelvis and 25% in the lower limbs after a year of detention. Patients undergoing spaceflight or the absence of gravity have a 0.5% loss of bone calcium per month. It is unclear if this negative balance of bone is the result mainly due to increased absorption or a decrease in training. It has been shown that passive mechanical stress on bone of a paraplegic may decrease bone loss (5).

On the other hand, several studies have shown that athletes have between 25 and 30% more BMD than a commonplace subject with normal activity, including overhead activities including walking have a greater impact on bone than those who are swimming or cycling. Postmenopausal adult women subjected to work overload after 9 months the lumbar spine increased by 1.6% while the control women have decreased by 3.6% from baseline. In children under stress and impact activities have increased both in femoral neck BMD as radio, trochanter and lumbar spine (6).

In a longitudinal study in which 22 young cyclists were subjected to 10 hours per week of exercise bike for 2 years, BMD was lower than control subjects.

All this helps to understand that only the high-resistance exercise and short-term impact stimulates BMD and that this effect is local and not systemic thing that becomes clear when we see that the cortical area of the humerus of the active arm of a tennis player holds up to 20% more bone than the contralateral arm

Only women who walked over 10 miles per week were so slight but significant higher BMD than those who walked only 1.5 km per week. Moreover postmenopausal women after 6 months of a program that included jumps, there was an increase of 4% in BMD. Finally do 10 minutes of work load is more productive than 30 minutes without charge for bone mass, this has been clearly demonstrated also in animals.

DOES THE EFFECT OF EXERCISE IS PERMANENT?

Unfortunately not. According to the theory of bone mass mecanoestatos always needs to be adapting to the stress of mechanical load. Several major groups of adult women have been trained for 2 years increased lumbar bone mass by 6% within 1 year of rest, or normal life without regular exercise, these women were up to 1% less than the control subjects ( 7).

However, in follow-up studies in children before age 30 have an increased bone mass has been observed to have a protective effect over a lifetime.

The answer to this type of exercise that undoubtedly has an interindividual variability and possibly this in relation to genetic polymorphism, for example it was found that subjects with different amounts of Vit.D receptors have different response to the same type of stimulus.

EXERCISE IS THE EXCESS IS DANGEROUS?

There is no evidence that this type of exercise causes adverse effects or abnormal level of growth in children, however this type of exercise stimulates growth hormone synthesis achieving a more complete expression of his genes on height. But young athletes in competitive sports under the presence of oligomenorrhea and amenorrhea correlates with bone loss and bone fracture stress (8).

Approximately 50% of highly competent women have had some experience oligo-or amenorrheic compared with only 5% of the population in general.

The belief that the effect of resistance exercise produce a negative effect on the joints in old age has never been evidenced when the workload was appropriate for the level of functional ability of the musculature of each.

In osteopenic women with low BMD or inappropriate, exercises such as crunches or flexion and extension exercises column due to the effects of compression on the vertebral bodies can cause fractures.

IS THERE ANY INTERACTION BETWEEN EXERCISE AND DIET?

Studies in monozygotic twins has been established that environmental factors like diet and exercise, account for 20% of the varians of each. Several factors associated with diet, have an influence on bone mass and physiology, calcium, phosphorus, fluorine, zinc, copper, magnesium, manganese, sodium, potassium, Vit. K, and other bioactive substances such as phytoestrogens. Probably all this amount of nutrients in an adequate intake are necessary for the exercise has a positive effect on bone mass, however there are compelling studies that indicate that both the size composition and bone density in communities with low intakes calcium are similar to communities with high calcium intake (9).

In a longitudinal study in postmenopausal women, in women treated with exercise only had a decrease in BMD of the forearm, the other group treated with exercise and calcium showed the same phenomenon, while the group treated with exercise and estrogen present in increased BMD. This forces us to consider hormone replacement therapy as an additional factor for success in the exercise plan designed to preserve or increase bone mass in postmenopausal women.

Other studies have clearly demonstrated that the increase in BMD was positively correlated with calcium intake was only when accompanied with an exercise program (10).

Finally it is interesting that the intestinal absorption of calcium is reduced when bone mechanical demands are low. In children when calcium demands are met exercise is the most important determining factor in bone mass.

Special mention needs zinc and its influence on estrogen receptors and Vit.D, on the metabolism of nucleic acids on collagen and mucopolysaccharide metabolism on the activity of collagenase, on carbonic anhydrase on alkaline phosphatase and prostaglandins, all factors involved in the mechanisms of bone metabolism. Groups of animals treated with the same exercise programs and diet, femoral neck BMD was higher in those with a zinc supplement in the diet.

credit to: García Pan, D., Saavedra C.

1. Osteoporosis, the great enemy
Sport. Exercise helps strengthen bones.  Not only women should worry about maintaining bone density. Although bone loss is identified as a problem that affects women after reaching menopause, in fact, osteopenia or bone loss affects both men and women. No difference between sexes, such as wrinkles.

After a certain age, our bones, joints, skin, hair, brain and other tissues deteriorate. The problem is that women are more likely to have osteoporosis when they reached the menopause by the lack of production of estrogen, and therefore, more socially conscious women to keep the bone that the bone men.

Men are also attacked by the quiet that is eating rodent bones, osteoporosis. From the 45 or 50 years, more men with symptoms of osteoporosis than prostate cancer.

But if both men and women look after the quality of bone from young, we reach the critical age with higher bone density than other people, and with stronger bones and stronger.

If you start to strengthen your bones from youth, invest in the best pension plan to continue to reap sporting merit in the category of veterans or veterans.

Do not forget that …
Women reach peak bone mass between 30 and 35 years thereafter, bone density decreases by 10% approximately every 10 years. A woman of 70 years may lose 45% of bone mass, if he does nothing about it.
Men begin to lose bone mass from 45-50, and are most fortunate to only lose 4.4% every 10 years.

2. Mind your bones throughout life
There are years that fractured bones are poor diet and lack of exercise, responsible for developing osteoporosis at the time of retirement. Strong bones and strong, not the heritage of youth, diet or fitness training throughout life and strengthen your bones throughout life shield.

Before you whine about the lost bone, begins to invest capital in your bones, your best sports insurance. Osteoporosis in old age is not inevitable. Your bones can take you to where you want, if you care for a lifetime.

Now do not talk only of bone density also starts to talk about bone strength, ie not only important quantity, we must also consider the quality of bone. The bone must not only be strong, must also adapt to change and carry the loads for longer, for it is necessary to preserve the flexibility and elasticity of bone and muscle.

3. The sun’s energy
Sol is a great ally for the bones and is therefore beneficial to take it occasionally.
Without vitamin D, calcium can not be absorbed in the intestine and the bone is demineralized. Vitamin D is one of the few vitamins that can synthesize naturally in the body. The key is in the sun, when you are exposed to UV rays, the skin produces a provitamin D which is transformed in the liver and kidneys to active vitamin D to develop its functions.

Take a few minutes of sun each day is an inexpensive way to get vitamin D naturally. Take advantage of sunny winter days for outdoor sports shorts, so will you with a good supply of this vitamin for a couple of winter months.

4. Follow a healthy lifestyle
Factors that increase the risk of developing osteoporosis. Not only by genetics, mainly by lifestyle. The eating disorders, restrictive diets, thyroid problems, treatment with steroids, alcohol problems, stress, smoking, sedentary lifestyle, low testosterone levels in men and women athletes with amenorrhea (absence of menstruation), tall and thin constitution, premature menopause and whites, predisposes to increased bone fragility.