THE "CALCIUM" DILEMMA-BONE VS HEART

Women and old people after the age of 60 years are prime candidates for Calcium supplements as they are considered vulnerable to bone related problems that include thin bones, brittle bones, frequent fractures, misshaped bones, osteomalacia and osteoporosis. Normally these supplements are supposed to deliver 500-800 mg Calcium per day. As Calcium is involved in formation and growth of bones, routinely these supplements are prescribed by orthopedists to many people and excess intake is not considered harmful hitherto. While high intake of Calcium is not known to be toxic, what other adverse effect it can have is a matter of conjecture with different reports indicating divergent views. Though a daily intake of 700 mg of Calcium is recommended for sound bone health, most of this requirement comes from every day foods like milk, cheese, yogurt, greens, leafy vegetables and fish with edible bones like sardines. It is believed that many older people do not get enough of this mineral increasing the risk of osteoporosis leading to thin and weak bones which can break easily, Same is true with women also at even younger ages due to hormonal changes during menopause. It is acknowledged that intake of Calcium supplements does increase bone strength but what is doubtful is whether it will really prevent fracture.

According to a recent review of some of the best scientific papers on Calcium in New Zealand, excess intake of this mineral can have other unintended consequences which calls for a re-look at the way Calcium supplements are prescribed in a routine way without realizing the long term consequences. Supplying Calcium over and above the intake through the food route can increase the risk of heart attack and strokes as increased levels of Calcium can affect the heart functions adversely, at least in some people. A study of 12000 people taking Calcium supplements, more than 500 mg per day regularly, has indicated that they faced a 30% increased chance of a heart attack during the period they took the supplement. Treatment of 1000 people with calcium supplements for a period of 5 years is estimated to cause 14 heart attacks, 10 strokes and 13 deaths but can prevent 26 fractures. also alarming is the finding that vulnerability to heart attack increased with higher dosage of Calcium supplement.Though the conclusion of the study is indeed alarming, a more careful analysis of the data indicates that out of the 12000 participants on Calcium supplement only 166 had heart attacks while 130 under the control and how significant this can be is uncertain. But qualitatively it does show the relevance or otherwise, of Calcium supplements in general, especially amongst those with even mild heart disease. As these studies were based on double-blinded controlled trials, there is no doubt about their reliability. Deciding on the risk-benefit aspects of Calcium supplements is indeed a tricky task. While bone fractures are not generally fatal, heart attacks can be and hence the dilemma for the health authorities in taking any decision.

One of the variables that has not been taken into consideration is about the complimentary effect of Vitamin D on the effect of Calcium intake as both of them are prescribed in most of the case because of the involvement of the former in bone development. Calciferol ( Vitamin D) is a critical vitamin formed under the skin from precursors already present in the body through exposure to Ultra Violet rays in the wave length range 270-300 nm and its bio-active form Calcitriol is known to reduce inflammation. Now that a shadow of doubt has been cast on the safety of Calcium supplements, it is necessary that these findings are validated through more thorough scientific studies to arrive at a reliable conclusion.

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com

BONE HEALTH- THE SILICON "CONNECTION"

The word silicon conveys different things to different people. It is the very foundation of the IT industry with silicon chips becoming indispensable for the computing industry. For a chemist it is an element in the Periodic Table, some what inert, a major constituent of sand and the raw material for making glass. Silicon oil is much valued by the machine operators because of its lubricating properties even at high temperatures. Silicon rubber, high temperature resistant is becoming a part of modern kitchen accessories. Silicon implants raises the vision of beauty for women through implants that improve the vital statistics. Presence of sand and pebbles in foods is an aversion for consumers. Till recently nutritionists were unconcerned about silicon as it was thought to have no role in human health.

A recent report that eulogized the practice of drinking beer regularly for the beneficial effect it has on health has kindled more interest in the role of silicon in human metabolism. According to National Institute of Health, USA beer is a major contributor of the micro nutrient and trace mineral silicon which is important for the growth of bone and connective tissue. Some medical experts even suggest that moderate consumption of beer may help in meeting the challenge posed by osteoporosis which affects the skeletal system through low bone mass and weak bone tissue. Of course this observation has some relevance in Western countries where beer is a part of regular life style. The advent of "Growlers" in cities like New York where beer is sold through taps in the vending outlets, to be taken out with large 64 oz glass containers looking like an over sized mug, possibly may improve the bone health and other disorders attributed to silicon significantly.

Silicon shot into prominence during 1970s when its role in animal nutrition was discovered and since then lot of work has gone into unraveling the mystery that surrounds involvement of silicon in human health. Silicon is a macro nutrient for plant cell growth and plant foods contain this mineral in good concentrations. Silicon deficiency is known to cause abnormal bone formation in experimental animals though its deficiency in humans has not yet been extensively documented. But human body contains about 7 gm of silicon on an average, demonstrating an important role for this chemically inactive inorganic material. Scattered studies involving silicon's role in human metabolism have demonstrated its role in developing strong bones and cartilages, aiding skin growth and ensuring strong joints. Further it is believed to be helpful in boosting the benefits of calcium, glucosamine and vitamin D in developing stronger bone.

Silicon present in tissues has been found to be bonded to glycoproteins like cartilage while blood silicon is in the form of free orthosilicic acid or linked to small compounds for ready use. The mechanism of action seems to be through reduction in permeability of extra cellular matrix in connective tissues including arteries, trachea, tendon, bone, teeth and skin. It also has catalytic role in bone mineralization, facilitation of healing process and building immune system. Data on silicon intake amongst population are limited. In the US the average intake is reported to be 19 mg per day through diet for women and 40 mg for men. Though there is not yet any universally acceptable daily intake value, a level of 5 mg to 50 mg per day has been suggested by various experts. No harm is anticipated even if consumption reaches 700 mg per day.

Water is a major source of silicon and normally 2 liters of drinking water can provide the daily needs of this trace mineral. Silicon content in water can vary between 6.4 mg to 56.5 mg per liter depending on its source. Extreme purification of potable water can remove most of the silicon present, a practice not considered desirable. Foods like oats (4.25 gm per kg), barley (2.54 gm per kg) and whole cereals many fruits and vegetables, nuts, milk and honey. Human milk has significant levels of silicon with very high bioavailability where as silicon from other sources has very low bioavailability. Modern processing of cereals into refined products by removing the husk and the bran makes them still worse as a source of silicon. It is no wonder that those babies on mothers' milk for a minimum of 6 months grow to become healthy for their entire life duration, compared to those weaned away or do not have the benefit of breast feeding.

Beer is now considered as one of the most important sources of silicon which is derived from the barley and hops used for brewing. Pale colored barley has highest silicon content and during brewing process the bioavailability of silicon increases significantly. Attempts to market low alcohol or alcohol free beer by the industry raises the inevitable question whether such products will contain same levels of silicon as normal ones because the actual mechanism involved in increasing the bioavailability during brewing is not fully understood. Probably lot of new developments can be expected on silicon nutrition in the coming years. The day may not be too far away when the humble beer is promoted as a health product rather than as a refreshing alcoholic beverage!

V.H.POTTY
http://vhpotty.blogspot.com/
http://foodtechupdates.blogspot.com