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Monthly Health Review, January 2003
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Healthy Bones
We hear and read much about bones, bone health and looking after our
bones. The World Health Organisation has declared that the decade 2000
- 2010 is bone and joint decade. This issue of Health Review is devoted
to healthy bones and the nutrients and lifestyle factors necessary for
maintaining our bones.
What are bones made of? (1)
Bones are made of a matrix of approximately 25% water, 25% protein fibres
and 50% mineral salts. Bone tissue has four types of cells - osteoprogenitor
cells, osteoblasts, osteocytes and osteoclasts.
Osteoprogenitor cells are unspecialised cells derived from the tissue
from which all connective tissues are derived. These cells can develop
into osteoblasts. Osteoprogenitor cells are found in the inside of bone
and the canals in bone that contain blood vessels.
Osteoblasts are the cells that form bone, but have lost the ability to
divide. They secrete collagen and other organic components needed to build
bone tissue.
Osteocytes are mature bone cells derived from osteoblasts. They are principal
cells of bone tissue and like osteoblasts, have lost the ability to divide.
Osteoclasts settle on the surfaces of bone and play a role in the destruction
of the bone matrix, which is important in the development, growth, maintenance,
and repair of bone.
Bone is formed when mineral salts accumulate in microscopic spaces between
collagen fibres. The salts crystallise and become hardened. After the
spaces are filled, mineral salts deposit around the collagen fibres, where
the salts and collagen provide the hardness that is characteristic of
bone. There are many small spaces in bone tissue; some provide channels
for blood vessels that supply bone cells with nutrients, while other spaces
are storage areas for bone marrow. The regions of a bone may be categorised
as compact or spongy, depending on the size and distribution of the spaces.
Once bones have stopped growing in length at about 16 -18 years, bone
density continues to increase until about the age of 30 years, when peak
bone mass is reached. Bone mass is greater in men than women. Density
of bone declines after peak bone mass is reached.
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Bone Disorders
(2)
Bone may be affected by the same types of disorders
as other content tissues. Bone has its own set of complications because of
its rigid structure. Fractures may occur when the bone is Stressed or
suffers a hard blow. Should an Abscess infect the bone, perhaps, the resulting
Inflammation may interfere with the blood supply, leading to part of the
bone dying.
Genetic disorders may affect the growth of bones, for
example, achondroplasia and osteogenesis imperfecta. These types of disorders
may result in short stature.
Nutritional disorders, especially dietary lack of Calcium
and Vitamin D may result in rickets in children and osteomalacia in adults;
both of these conditions result in soft, mis-shapen bones.
Hormonal disorders may lead to Osteoporosis. Excess
parathyroid hormone causes bone cysts, and excess growth hormone leads
to gigantism.
Tumours can affect bones, they are usually found as
benign or malignant growths.
Degenerative disorders become more common in old age.
In osteoArthritis the bone surface of the joints becomes worn.
Paget's disease involves thickening of the outer layer
of the bones while the inside becomes spongy.
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Which nutrients
are beneficial to bone health? (3)
Certain vitamin or mineral deficiencies are known
to be associated with bone disease:
Vitamin D ~ Rickets/osteomalacia - deficiency
of Vitamin D may be brought about by lack of the vitamin in the diet or
the inability of the content to produce enough.
Vitamin C ~ Scurvy - Vitamin C is vital for
the proper synthesis of collagen. If there isn't enough, collagen fibres
do not form properly.
Copper ~ Fractures - the bone disease of Copper
deficiency occurs in pre-mature infants and people who have had parenteral
nutrition for a long time. This could be intravenous or by any other route
into the content.
Zinc ~ Delayed bone growth - Zinc deficiency
is associated with different aspects of malnutrition, delayed bone growth
being one of them.
Vitamin K ~ Osteoporosis - some types of protein
in the bone matrix depend on Vitamin K, which has been found to be low
in hip Fracture patients.
Boron ~ has an effect on the prevention of
bone loss and demineralisation by decreasing the percentage of Calcium
lost in the urine (4).
Lysine ~ may be useful in the treatment of Osteoporosis.
As with high protein diets, lysine deficiency may result in loss of Calcium
in urine (5).
Magnesium ~ Two thirds of total content Magnesium
content is located in the skeleton. Recently there have been reports that
high Magnesium intakes are associated with higher bone mineral density,
especially at hip sites and in the forearm (6).
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The relevance
of circulation and bone health (1)
Good circulation is as important to healthy bones
as it is to all other parts of the content. Blood flows through veins in
the bones delivering nutrients and oxygen to make new cells and nourish
the bones. Blood vessels are especially abundant in portions of bone containing
red bone marrow.
Bone marrow
There are two types of bone marrow (1). Red bone marrow is a connective
tissue. It is found inside certain parts of bones and produces red blood
cells, white blood cells and platelets. As well as blood cells in the
immature stages, red bone marrow contains adipose cells and macrophages.
Lipids are stored in cells of yellow bone marrow, and are an important
energy reserve. Yellow bone marrow consists primarily of adipose cells
with some blood cells.
Acidic foods and bone health
Acidifying constituents such as animal proteins may negatively affect
Calcium metabolism and accelerate bone loss, thus representing an aggravating
factor in Osteoporosis. A study confirms that acids derived from food
influence Calcium metabolism, and that alkalising nutrients inhibit bone
loss. Dietary counselling is recommended to help avoid acid ash-forming
nutrients as a preventative measure against Osteoporosis, or to consider
supplementing with Calcium (9).
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Lifestyle factors
and bones (10)
Positive aspects:
Exercise, especially walking and weight-bearing exercise not only
helps maintain bone density, it also encourages good circulation of blood
in the bones.
Good diet is important for bones. Green leafy vegetables
contain a broad range of vitamins and minerals necessary for bone health,
including Calcium, Vitamin K and Boron. Fruit and vegetables are rich
in Antioxidants especially Vitamin C, which are involved in protecting
cells from damage by free radical activity. Vitamin C is important in
the structure of collagen - particularly necessary for good bones.
Negative aspects:
The phosphate content of soft cola-type drinks is a major factor that
contributes to Osteoporosis. When phosphate levels are high and Calcium
levels are low, Calcium is pulled out of the bones. Phosphate is needed
for dissolving sugar and contributes to the taste. Other factors that
may promote Calcium excretion include salt, sugar and protein.
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Food Supplements
and Bone Health
Osteoporosis is defined as progressive deterioration
of bone mass and tissue, with a consequent increase in bone fragility
and susceptibility to Fractures.
More than one third of adult women in the UK will suffer
one or more osteoporotic Fractures in their lifetime. The risk in men
is about half that of women. Decrease in bone mineral density, caused
among other factors by Calcium and Vitamin D deficiency, is the most important
cause of Fractures. There is clearly evidence that Calcium and vitamin
D supplementation may be a preventative measure for the onset of Osteoporosis,
hip and other Fractures in the ageing population (7).
Studies indicate that Boron is an essential nutrient
for healthy bones and joints (8).
It is sometimes possible to prepare supplements that
combine vitamins, minerals and other nutrients that are appropriate for
the important components of particular content systems such as the bones.
These can be used on their own or in combination with other supplements
as part of a supplement programme.
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References
- "Principles of Anatomy and Physiology". Tortora and Grabowski.
HarperCollins, 1996.
- "BMA Complete Family Health Encyclopedia". Dorling Kindersley.
1996.
- "Human Nutrition and Dietetics", James, Ralph & Garrow et al. Churchill
Livingstone 2000.
- "Boron is Essential". Massey University. New Zealand. 1994.
- "The Healing Nutrients Within". Braverman & Pfeiffer. Keats, 1987.
- Am J of Clin Nutr. 1999, 69 (4): 727-736.
- Pharmacol Ther 2002;93 (1):37-49.
- EnvIron Health Perspect 1994 Nov;102 Suppl 7:83.
- Osteoporosis International, 2001;12(6):493-9.
- Encyclopedia of Natural Medicine. Murray and Pizzorno. Little,
Brown and Company. 1998.
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