Zinc and Bone Health
Zinc can do more to prevent brittle bones than any other nutrient. Collagen tissue is necessary for the deposition of calcium phosphate to form bone. That is, collagen tissue provides the infrastructure for the bone to be formed. It is into this structure that calcium is deposited to form the bone. The presence of collagen is essential for bone strength and density. Without it all the calcium in your diet has nowhere to go and zinc is an essential part of collagen formation.
Collagen holds it all together
Collagen is the most widespread tissue in the body. It forms the background of all your tissues of all your organs, making them firm and resilient. When the skin starts to wrinkle and loose elasticity you can be sure that your collagen cells are not as active as they used to be.
Each strand of collagen is made up of amino acids and it takes many of these amino acids to make up one strand. The strength of collagen tissue is increased as some of the molecules are strengthened by a biochemical process initiated by vitamin C. This process helps to stabilize the whole collagen structure. If the process does not occur the bones soften. Three single strands of collagen are, initially, twisted around one another, forming a triplet. Three of these triplets are then twisted around each other forming a super cable. Each strand is also bonded to adjacent strands by cross-linking. 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 material).
Collagen ages slowly to be replaced by new collagen tissue. To ensure that this process continues it is important to see that your intake of protein and nutrients are adequate. One of the important nutrients is zinc.
Zinc a critical nutrient
Adequate levels of zinc are necessary to form collagen tissue, unite bone fractures, heal wounds and prevent osteoporosis. For the formation of collagen tissue zinc is essential, other nutrients are also necessary, but zinc is the most important.
It is recommended that you have 12 to 15 mg of zinc a day and that this level be increased during pregnancy.
Food sources of zinc include: meat, chicken, beans, nuts and oysters.
Dietary phytates, which are found in wholegrain cereals and unleavened bread may significantly decrease the absorption of zinc. There is also the 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 salt, such as, zinc sulphate, combined with vitamin C. Zinc is best absorbed after eating a protein meal - preferably not breakfast which could contain foods high in dietary phytates.
Zinc, pregnancy and the first stage of osteoporosis
Johns Hospital Medical School estimates that 85 percent of pregnant women throughout the developed world have an intake of zinc that is insufficient for the pregnancy. During pregnancy zinc requirements increase by 50% during the last 15 to 10 weeks. If the mother does not consume sufficient zinc, then zinc in her muscles and bones will be given to the fetus, thus starting the first stage of osteoporosis. (NOTE: the British Medical Association advises that zinc sulphate be avoided or used with caution during pregnancy as safety is not established and it crosses the placenta.)
Calcium and osteoporosis
The reason for the emphasis on the calcium content of bones to prevent osteoporosis, and for the neglect of zinc as the critical nutrient, is that when X-rayed, zinc and collagen are invisible. When osteoporotic bone is X-rayed and compared to normal bone, it appears transparent because you are unable to see the normal amounts of calcium. Medical Practitioners often recommend increased calcium consumption but then neglect to recommend a zinc supplement to help replace the collagen. Unfortunately, without the collagen and zinc the calcium has nowhere to go, which will see the development of the osteoporosis to continue.
Fractures and zinc
There are two stages to the healing of bone:
Initially, after the fracture, an extensive blood clot forms around the ends of the fractured bone. Collagen forming cells invade the blood clot producing a specialized form of collagen which wraps itself around the fracture. Slowly, the bone forming cells move into the collagen tissue, now called a callus. These cells lay down the calcium, giving the bone its strength again.
If the patient is given zinc supplements immediately after the fracture occurs, a large amount of collagen tissue is formed quickly, as the enzymes responsible for laying down the bone callus are activated by zinc. Zinc is not only responsible for rapidly increasing the amount of collagen tissue around the fracture, it is also responsible for activating the bone cells which deposit the calcium into the collagen tissue.
Exercise and zinc
It is paradoxical that physical exercise which is recommended for the prevention and treatment of osteoporosis can also increase it if the person exercising has insufficient nutrients - in particular zinc. People who exercise excessively lose a significant amount of zinc in sweat. The loss of zinc in sweat per hour can exceed by 50% the excretion of zinc in urine in 24 hours.
In America this condition is labelled 'brittle bones, but good body'. In women the condition is also accompanied by amenorrhea (cessation of menstruation) as a zinc deficiency can decrease ovarian activity.
Menopause
In the lead up to menopause the formation of collagen tends to slow down as the activity of the hormones decreases. Beyond menopause a zinc deficiency can be more pronounced with the accelerating loss of collagen and calcium. If the loss of collagen is due to the lack of zinc then calcium excretion can increase.
One of the effects of the reduced estrogen production is an increased excretion of hydroxyproline, an amino acid critical in stabilizing collagen structure. Calcium will do nothing to prevent this occurring. It is therefore important to guard against the rundown of your collagen tissue at menopause. This is achieved by maintaining an adequate intake of nutrients, including zinc.
Zinc is an important (and often underestimated) nutrient for the prevention of osteoporosis. Zinc is often deficient in the diet and in times of added need such as during pregnancy or menopause or when doing a lot of exercising the zinc levels in the body can run low.
References
Bland, J. 1996, Contemporary Nutrition. J & B Associates.
Davies, S. and A. Stewart., 1997, Nutritional Medicine. Pan.
Fitzherbert, J.C. 2002, Osteoporosis: The Missing Zinc. Wellbeing, Issue 87.
Holden, S., Hudson, K., Tilman, J. & D. Wolf, 2003, The Ultimate Guide to Health from Nature. Asrolog Publication.
Sullivan, K. 2002, Vitamins and Minerals: A Practical Approach to a Health Diet and Safe Supplementation. Harper Collins.
Comments (0) 03.03.2008. 22:29
Why do we Need to Avoid Dairy Products?
Why do we need to avoid dairy products is a question that I am often asked. Avoiding dairy products is one of the dietary changes that are a part of healthy diet recommendations. However many people who live in Western societies react with disbelief when informed that dairy foods are not essential for human health, and that most people on this planet do quite nicely without them.
The strong belief that dairy products are essential for strong bones and teeth has been thanks to dairy industry promotions and decades of government-sponsored nutrition ‘education' in schools. Many people find it even harder to believe the information that there is a solid and growing body of scientific evidence which suggests that limiting or eliminating dairy products from the diet may be important to achieving optimal health.
The dairy industry spends millions of dollars on advertising to convince us that their products are not only wholesome, but absolutely essential for our health. However, "There is no human requirement for milk from a cow," says Suzanne Havala, RD, author of the American Dietetic Association's "Position Paper on Vegetarian Diets" and several books on nutrition. "The use of milk and its products in our country is strictly a cultural tradition," she notes. "There are millions of people around the world who never consume cow's milk and are none the worse for it." The belief that dairy products are essential is incorrect. As one writer stated - ‘even cows don't drink it!'
Many people have also been lead to believe that dairy products are our only reliable source of calcium. It is true that calcium in our bloodstream is essential for our health and it plays a critical role in blood clotting, muscle contraction, heartbeat maintenance and proper nerve function. About 99 percent of calcium (roughly three pounds) is stored in our bones and teeth, which rely upon the mineral for their strength. When needed, calcium is released from our bones into the blood. Calcium is calcium, however, whether it's from broccoli or cottage cheese. "There's no best source of calcium," explains Robert Heaney, a professor with the Osteoporosis Research Center at Creighton University School of Medicine. "The sheer quantity of calcium in dairy products certainly makes them attractive sources, but they have no monopoly on calcium. There's no reason in the world why you couldn't get an adequate intake from a vegetable source."
The dairy industry presents the notion that their calcium-rich foods are veritable guarantors of unbreakable bones. However, there is little support for this assertion. There is no clear evidence that high calcium intakes alone - even the Recommended Dietary Allowance (RDA) of 800 mgs - can ensure bone health. Indeed throughout the world the people who consume the most calcium actually have the poorest bone health and the idea that dosing yourself with calcium will automatically keep your bones in good shape is just plain wrong. The nations with the greatest calcium intake have the highest rates of osteoporosis and hip fracture and there are relatively few fractures among populations where calcium levels are not so high. Of course the dairy industry disputes these findings, continuing to insist that every man, woman and child would benefit from drinking at least three glasses of milk a day.
Healthy bones require more than simply ingesting copious amounts of calcium-rich foods. Certainly, calcium intake is important, particularly during childhood, early adulthood and up to the age of 30 - 35 when our bones achieve their peak mass and stop growing. But retaining the calcium we've stored in our bones appears to be even more vital. This is particularly the case in our late 40s or so, when our bones begin to break down faster than they can be rebuilt. Indeed, research indicates that preventing calcium loss is actually three to four times more important in determining calcium balance (that is, whether we gain, maintain or lose calcium from our bones) than is calcium intake. And one of the greatest instigators of calcium loss is a high-animal protein diet. Indeed pediatrician Charles Attwood, MD, suggests that "...milk, with its excessive protein, may be part of the calcium problem instead of a solution."
The question of how much calcium is needed by the body remains especially since the RDA for calcium is established higher than it otherwise would be in order to compensate for calcium losses due to high consumptions of protein. People worldwide develop and maintain strong bones on levels of calcium considerably below the 800 mg RDA. The World Health Organization recommends 400 - 500 mgs daily. However, because vegetarians generally have lower protein intakes and absorb and retain calcium better, they may have lower calcium needs. For most people, the RDA can quite easily be fulfilled by eating a varied diet with at least several servings of calcium-rich foods each day. Children, teens and young women should be especially careful to include these foods since their calcium needs are relatively high compared to others. Some people may choose to take supplements as added insurance. Of course one advantage of meeting calcium needs with plant foods is that many are also excellent sources of antioxidants, fiber, folic acid, complex carbohydrates, iron and other important vitamins and minerals you won't find in milk products.
Apart from the calcium question there are additional serious health concerns that are related to dairy products. These include:
Allergies: Milk is the most common cause of food allergy. A recent study found that one way to reduce the number of allergies in infants is for the breastfeeding mother to avoid consuming, or make very limited use of cow's milk. Anemia: Over reliance on milk in children can lead to anemia, as milk is very low in iron, and drinking large quantities of it can crowd iron-rich foods from the diet. In young infants, protein from cow's milk can cause intestinal bleeding, another possible cause of anemia.
Colic: Sensitivity to cow's milk can cause colic, a digestive ailment in infants. Colic can cause problems even in infants who aren't drinking cow's milk but whose mothers are.
Drug safety concerns: Dairy farmers regularly administer drugs and growth hormones (bovine somatotropic hormone BSH and others) to cows to boost milk production. Investigations have routinely found residues of these veterinary pharmaceuticals in milk and other milk products, some of which may raise cancer risks. One compound approved for use in 1993 and now widely employed by commercial dairies is the controversial genetically engineered Bovine Growth Hormone (BGH). Many feel that this compound poses grave potential health risks for consumers (including elevated antibiotic residue levels in milk).
Heart disease: Dairy products are major contributors of saturated fat and cholesterol to the diet. According to cardiologist Dean Ornish, MD, "Milk rates second only to beef as the largest source of saturated fat in the American diet." Consider, for example, that one glass of 2% milk fat has as much saturated fat as three strips of bacon. Almost half the calories in whole milk come from fat.
Insulin-dependent diabetes: Recent research indicates that consuming cow's milk throughout adolescence increases the risk of developing Type I diabetes. About 1 million Americans have this disease.
Lactose intolerance: Many people cannot stomach lactose, the sugar in milk, because they lack the necessary digestive enzyme. Some people are also sensitive to milk protein. An estimated 50 million Americans experience intestinal discomfort after consuming dairy products. Symptoms include bloating, stomach pain, cramps, gas or diarrhea.
Women's health concerns: Studies indicate that osteoporosis, which afflicts 20 million American women, and ovarian cancer are most common in those countries with the highest consumption of dairy food and lowest in those countries with low dairy intake. According to gynecologist Christiane Northrup, MD, author of Women's Bodies Women's Wisdom, other health problems associated with the consumption of dairy foods include benign breast conditions, recurrent vaginitis, acne, menstrual cramps, fibroids, chronic intestinal upset and increased pain from endometriosis.
This all indicates that dairy products are not essential for the health of humans and that all the nutrients that are contained in dairy products can be obtained from plant foods. Plant foods offer many health protecting factors while dairy foods increase the risks of many diseases. The more we learn about the affects of dairy products the harder it is to eat them with any assurance that they are doing our bodies any good.
Comments (0) 21.02.2008. 21:06
Constipation in Children
Constipation usually means difficulty in passing a stool; diminished frequency in opening of the bowels or the passage of hard, dry stools. Constipation is a common childhood problem.
The signs that a child may have constipation include:
pain and straining when going to the toilet. A hard stool can tear the lining of the anus leading to more pain and bleeding.
diarrhoea or soiling. When the bowel is blocked, as in constipation, the body attempts to pass a bowel motion by becoming runny and going around the blocked area. The child may have marks on their underwear or soil themselves when they are undertaking physical exercise. Constipation can also lead to a lack of sensitivity in the muscle of the anus itself so that the feeling of needing to go to the toilet is lost.
stomach or abdominal aches and pains.
other problems such as headaches, skin problems, poor concentration, muscle aches, bad breath and tiredness. These are all associated with the reabsorption of toxins from the bowel and their remaining in general circulation.
What are the causes of constipation?
The most common cause of constipation is a diet high in processed food and low in roughage. These are however, not the only causes. Other causes include the following.
Not drinking enough fluids.
Food allergies or intolerance. Allergies are often associated with cereal and dairy products.
Eating too many wheat based product, such as bread and pasta.
An imbalance in the gastrointestinal bacteria. A recent course of antibiotics or a diet that has a lot of processed foods and sugars can lead to an imbalance of the intestinal flora.
Children who are too involved in what they are doing will sometimes ignore the urge to go to the toilet allowing the motion to become dry and hard to pass.
Iron sulphate is added to some foods such as rice cereals, formulas and drinks such as Milo. In children who are sensitive to this it can lead to constipation.
Stress and anxiety. Like adults the digestive tracts of children contract during stress. This can cause the bowel motion to pass through too quickly (causing diarrhoea) or too slowly, causing too much fluid to be absorbed, resulting in constipation.
Insufficient exercise. Exercise is needed to activate the muscles of the digestive tract and to move the waste material through the intestines.
What can you do about constipation?
You need to treat the existing problem, that is clear the bowel of hard bowel motions, and then work on preventing the situation from recurring. What you can do:
Massage to encourage movement through the large bowel. Have the child lie on their back and knees raised. With warm hands apply gentle pressure. Start from the lower right abdomen, work your way up towards the rib cage, then go across the stomach and down the left side. This is roughly the direction of the bowel and is helpful for stimulating the muscles to move hard stools.
Use juices to assist the intestines. The juices can include prune, apple and lemon. Spinach, watercress and dandelion leaves can be added to milder juices such as carrot, cucumber, beetroot and celery. These can be used in small amounts or diluted.
Increase the consumption of fibre rich foods. These include vegetables, fruits, nuts and seeds and at the same time reduce the intake of sweets, chocolate, cakes, bread and white rice. Don't overdo the nuts though, as this can actually be constipating.
Eat meals at a regular time so the bowel is able to get into the habit of moving at certain times.
Increase the amount of water your child drinks. Children need to drink 6 to 8 glasses per day. Using milk, cordials and soft drinks can cause further problems so use filtered water and fresh natural juices as much as possible.
Encourage plenty of physical activity.
Increase the number of friendly bacteria in the bowel by the use of probiotics.
Remind children to go to the toilet.
Change the child's position when they go to the toilet. Place a small stool in front of the toilet so they are able to have their feet on it and this will raise their knees and change the angle of the hips. This will place the child in a position that requires less pushing.. Squatting is the ideal position for all humans when defecating.
Eat plenty of magnesium rich foods. Magnesium is important for muscle contraction and a deficiency in magnesium can cause constipation. Foods rich in magnesium include nuts, whole grains and beans. (Be careful not to overdo the nuts and grains.)
Add some psyllium seeds to the diet. For children who are prone to constipation a daily supply of psyllium seeds can help. This is a fiber that helps regulate the activity of the bowel. When mixed with water or diluted juices they can create larger and softer stools. In order to work effectively the seeds need to absorb water so the child needs to drink plenty of fluids. The dosage for children from 3 years of age is 1 teaspoon twice daily added to diluted juice.
Talk to your child about any problems or stresses that they might have. Expressing concerns and receiving reassurance can greatly reduce stresses that may cause or contribute to constipation.
You will need to see a health professional if the constipation is difficult to relieve, if it is associated with a lot of pain or blood or if the child is doing all the right things and the problem is still there. Your health professional will consider the possibility of allergic problems and should explore this more thoroughly.
Comments (0) 13.02.2008. 17:21
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