Osteoporosis: The Missing
By J.C. Fitzherbert
Standford University's, Professor Stryer in his world acclaimed text
Biochemistry (published by W. H. Freeman and Co, 1995) states "Collagen
tissue is essential for the deposition of calcium phosphate to form bone".
Meaning, it is collagen tissue that provides the infrastructure of bone.
It is onto this structure that calcium is deposited to form bone. It is
presence of collagen which is critical for bone strength and density.
Without it, all the calcium in your diet has nowhere to go.
Collagen - holding it all together
Collagen tissue is one of the most widespread tissue in your body. It forms
the background tissue of all your organs, making them firm and resilient.
It is easy to study the state of your own collagen tissue by looking at
and feeling your skin. When skin starts to wrinkle and lose elasticity
you can be sure that the cells which form your collagen tissue are not
as active as they should be. Your hair will also lose its gloss. This is
part of the aging process but if you don't take steps to prevent it, it
can be permanent.
To make up for the loss of collagen under your skin, it is possible to
have injections of collagen. However, it is not possible to inject collagen
into your bones. Nor does injected collagen persist. It is only temporary.
In your body, collagen turns over slowly. To hold back the aging process,
it is necessary to reform and replace collagen as it is lost.
Collagen tissue has a very remarkable structure. After a surgical operation,
fibroblasts, the specialised cells around the wound are activated to form
collagen, to seal and close the wound. This collagen is so strong that
a weight of 10 kilograms is need to break a fibre of collagen 1mm in diameter.
As the ligaments around joints are made up of thousands of strands of
collagen, you can appreciate how powerful the force is that holds the joint
together. Each strand of collagen is made up of protein structures called
amino acids. The most abundant are named proline and glycine. It can take
thousands of these amino acids protein structures to form one strand. The
strength of collagen tissue is further increased as some of the proline
molecules are strengthened by a biochemical process initiated by vitamin
C. The proline molecules are changed to hydroxy proline which is very important
as it helps to stabilise the whole collagen structure. If the change is
not made, the bones soften resulting in the development of scurvy.
Three single strands of collagen are, initially, twisted in spiral fashion
around one another, forming a triplet. Three of these triplets are then
taken and twisted around each other to form a super cable. Each strand
is also bonded to adjacent strands by cross-linking. The combination is
called a collagen super-helix.
It is into this collagen structure that calcium phosphate is deposited
to form your bones. Bone therefore consists of collagen (an organic protein
live material) and calcium phosphate (an inorganic product).
Collagen ages slowly, to be replaced with new collagen tissue. To ensure
this process continues it is important to ensure your intake of protein
and micronutrients are adequate to reform and replaced the progressively
Zinc - the critical nutrient
It is not possible to heal wounds, unite fractures of bone, form collagen
tissue or prevent osteoporosis from developing if your intake of zinc is
below minimal requirements. For the formation of collagen tissue, an adequate
intake of zinc is essential. Several other micronutrients are also essential
but zinc is the most critical.
The recommended daily allowance of zinc is 12-15 mg, the level increasing
during pregnancy. Meat and poultry provide the majority of zinc in the
Western diet. Other food sources include beans, nuts, and oysters. Dietary
phytates, which are found in whole grain cereals and unleavened bread,
may significantly decrease the body's absorption of zinc. There is also
a possibility that increasing your calcium level inappropriately can interfere
with zinc absorption.
Zinc can be taken as a supplement and should be taken as a simple salt,
such as zinc sulphate, combined with vitamin C. Zinc is best absorbed after
eating a meat meal, preferably not at breakfast which could contain food
with a high fibre content.
Zinc deficiency can occur when zinc intake is inadequate, when there
are increased losses of zinc from the body for example during intensive
exercise, or when the body's requirement for zinc increases for example
during pregnancy. Signs of zinc deficiency include poor appetite, weight
loss, delayed healing of wounds, taste abnormalities, and mental lethargy.
As body stores of zinc decline, these symptoms worsen and are accompanied
by diarrhea, hair loss, recurrent infection, and a form of dermatitis.
Zinc deficiency has also been linked to poor growth in childhood.
A paper from the John Hopkins Medical School estimates that 85 per cent
of pregnant women throughout the developed world have an intake of zinc
which is insufficient for the pregancy. During pregancy, zinc requirements
can increase by 50 per cent during the last 15-20 weeks. If there is not
adequate zinc consumed by the mother, zinc from the mother's muscles and
bones will be given to the foetus, thus starting the first stage of osteoporosis.
The reason for the emphasis on the calcium content of bones to prevent
osteoporosis, and for the neglect of zinc as the critical micronutrient
is because when bones are x-rayed, zinc and collagen are invisible. When
osteoporotic bones are x-rayed and compared with normal bone, it appears
transparent because you are unable to see the normal amounts of calcium.
Doctors often recommend increased calcium consumption but neglect to recommend
zinc supplementation or meat consumption to replace lost collagen. Unfortunately,
without collagen and zinc the calcium has nowhere to go, which may cause
the development of osteoporosis to continue.
The formation of bone can be understood when studying the healing of a
fracture. There are two stages in this process. Initially, after a fracture,
an extensive blood clot forms around the ends of the fractured bone. Collagen
forming-cells invade the blood clot producing a specialised form of collagen
which wraps itself around the fracture site. Slowly, the bone-forming cells
move into the collagen tissue, now called callus. These cells lay down
calcium in the collagen-type tissue.
If the patient is given zinc supplements immediately after the fracture
occurs, a large amount of collagen tissue is form very quickly as the enzymes
responsible for laying down the bone callus are activated by zinc. Zinc
is not only responsible for rapidly increasing the formation of collagen
tissue around the fracture site, it is also responsible for activating
the bone cells which deposit the calcium into the collagen tissue.
It is paradoxical that physical exercise, which is recommended for the
prevention and treatment of osteoporosis, can also increase the development
of the condition. People who exercise excessively can lose a significant
amount of zinc in sweat. So much so that the loss of zinc in sweat per
hour can exceed the excretion of zinc in urine in 24 hours by 50 per cent.
In America, they have colloquially labeled this condition "brittle
bones, good body". In women this condition is also often accompanied
by amenorrhoea (loss of menstruation) as zinc deficiency can retard ovarian
The early association of physical exercise with osteoporosis becomes
evident when the athlete develops stress fractures of bones in the vertebral
body or foot.
In the lead-up to menopause, the formation of collagen tends to slow
down as the activity of the hormonal body reduces. Beyond menopause, zinc
deficiency can be more pronounced with the accelerating loss of collagen
and calcium. If the loss of collagen tissue is due to zinc deficiency,
calcium excretion can increase. This can be further accentuated by the
onset of menopause with the reduction of oestrogen production .
One of effects of reduced oestrogen production is an increased excretion
of hydroxyproline. This amino acid is critical in stabilising collagen
structure. Calcium will do nothing to prevent this event occuring.
It is therefore important to guard against the rundown of your collagen
tissue at menopause by maximising the production of collagen tissue
as early as possible by maintaining an adequate intake of zinc.