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Archive for March, 2010

Zinc

Zinc formulations have been used since the time of Ancient Egyptians to enhance wound healing.  The clinical significance in human nutrition and public health was recognized relatively recently.  It’s deficiency in humans was first describes in 1961, when the consumption of diets with low zinc was associated with “adolescent nutritional dwarfism” in the Middle East.  Since then, the deficiency of zinc has been recognized by a number of experts as an important public health issue, especially in developing countries.

Zinc is also an essential trace element for all forms of life.  As it is necessary for the functioning of over 300 different enzymes and plays a vital role in an enormous number of biological processes.

Numerous aspects of cellular metabolism are zinc-dependant.  Zinc plays important roles in growth and development, the immune response, neurological function, and reproduction, in the structure of proteins and cell membranes.

The immune system is adversely affected by even moderate degrees of zinc deficiency.  It was found that severe zinc deficient depresses the immune function.  Zinc is required for the development and activation of T-lymphocytes, a kind of white blood cell that helps fight infection.  When zinc supplements are given to individuals with low zinc levels, the numbers of T-cells lymphocytes circulating in the blood increase and the ability of lymphocytes to fight infection improves.  Zinc supplements are often given to help heal skin ulcers or sores, but they do not increase rates of wound healing when zinc levels are normal.

There is no single laboratory test that adequately measures zinc’s nutritional status.  Medical doctors who suspect a zinc deficiency will consider risk factors such as inadequate caloric intake, alcoholism, digestive diseases, and symptoms such as impaired growth in infants and children when determining a need for zinc supplementation.  Vegetarians may need as much as 50% (1.8 mg/daily) more zinc than non-vegetarians because of the lower absorption of zinc from plant foods, so it is very important for vegetarians to include good sources of zinc in their diet.

Zinc is found in oysters, and to a far lesser degree, in most animal proteins, beans, nuts, almonds, whole grains, pumpkin and sunflower seeds.  A turkey’s neck and beef’s chunk or shank also contains significant amount of zinc.  Phytates, which are found in whole grain breads, cereals, legumes and other products, have been known to decrease zinc absorption.  Fortunately, a healthy diet can provide you with as much zinc as you need.  However, the truth of the matter is that only about 30% of the zinc that you intake can get absorbed by your body.

Chromium

Chromium is a mineral that humans also require in trace amounts, although its mechanisms of action in the body and the amounts needed for optimal health are not well defined.

Although trivalent chromium is recognized as a nutritionally essential mineral, scientists are not yet certain exactly how it functions in the body.

Chromium has long been of interest for its possible connection to various health conditions.  Among the most active areas of chromium research is its use in supplement form to treat diabetes, lower blood lipid levels, promote weight loss, and improve body compositions.

It is believed that chromium affects glucose metabolism by enhancing the effects of insulin.  Insulin is secreted be specialized cells in the pancreas in response to increased blood glucose levels, such as after a meal.  A decreased response to insulin or decreased insulin sensitivity may result in impaired glucose tolerance or type 2 diabetes.  However, the value of chromium supplements for diabetics is inconclusive and controversial.  Randomized controlled clinical trails in well-defined, at-risk populations where dietary intakes are known, are needed to determine the effects of chromium on markers of diabetes.

The effects of chromium supplementation on blood lipid levels in humans are also inconclusive.  The mixed research findings may be due to difficulties in determining the chromium status of subjects at the start of the trails and the researchers’ failure to control for dietary factors that influence blood lipid levels.

Some claim that chromium supplements reduce body fat and increase lean (muscle) mass.  Yet a recent review of numerous studies that examined the effects of 200 to1,000g/day of chromium on body mass or composition found no significant benefits.  Another recent review of randomized, controlled clinical trails did find supplement of chromium picolinate to help with weight loss when compares to placebos, but the differences where small and of debatable clinical relevance.

Chromium I widely distributed in the food supply, but most foods provide only small amounts.  Processed meats, whole grain products, ready-to-eat bran cereals, green beans, broccoli, and species are relatively rich in chromium; however the content of the mineral is substantially affected by agricultural and manufacturing process.

Absorption of chromium from the intestinal tract is low, ranging from less than 0.4% to 2.5% of the amount consumed, and the reminder is excreted through bodily waste.  Vitamin C and niacin might enhance the mineral’s absorption.  Absorbed chromium is then stored in the liver, spleen, soft tissue, and bone.

 

Until next time…Stay Healthy

  

Katarzyna

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How much do you know? By Milan Frohlich, MSc., A.Sc.T., R&D Scientist Akuna Regulatory Affairs Coordinator

We have all heard at some point or another that minerals are important to our health.  However, not all of us are sure of why this is the case.  This lack of information may be a factor why an estimated 90% of North Americans suffer from a mineral deficiency or imbalance. 

Thanks to the extensive research conducted regarding the relationship between minerals and our health, it has become evident that sustaining a balanced level of minerals in every organ, tissue and cell of the human body may be prominent key to maintaining a healthy existence.  Unfortunately in today’s world, naturally occurring, nutrient-rich foods are becoming a thing of the past.  Fortunately, thanks to all this research and development, we can turn to nutritional supplements to support our health.

We tend to hear a lot about minerals such as calcium and magnesium but are often not familiar with the importance of some of these minerals which our bodies also require.  Trace minerals or trace elements are generally, uncommon minerals that practically all organisms need in minute quantities in order to trigger the production of enzymes and hormones for growth, reproduction and health maintenance of the animal or plant body. 

Nutritionally speaking, trace minerals by definition are those which are required by the human body in micro amount, i.e. in 100 milligrams (mg) dosages per day, or less.

Below is a closer look at three trace minerals, their function and their importance to the human body.

Manganese

The natural importance of manganese was discovered in 1936-37, when researches reported the development of bony malformation in poultry fed on a manganese-free diet.  Later studies also demonstrated the relationship of manganese to growth, bone development, reproduction, and the functioning of the central nervous system.

Manganese is an essential trace nutrient in all forms of life.  The human body contains about 10 to 20 mg of manganese, which is widely distributed throughout the tissues, stored mainly in liver and kidneys.  It plays an important role in a number of physiological processes as a constituent of some enzymes and an activator of their enzymes which are involved in the metabolism of carbohydrates, fats, and proteins.  In combination with choline, it helps in the digestion and utilization of fat.

Manganese helps to nourish the nerves and brain and assist in the proper coordinative action between the brain, nerves and muscles in every part of the body.  It is also involved in normal reproduction and function of mammary glands.

On the other hand, manganese deficiency has been observed in a number of animal species.  Signs of manganese deficiency include impaired growth, impaired reproductive function, skeletal abnormalities, impaired glucose tolerance, and altered carbohydrate and lipid metabolism.  In humans, demonstration of a manganese deficiency syndrome has been less clear. 

A child on long-term total parenteral nutrition (fed intravenously) lacking manganese developed bone demineralization and impaired growth that were corrected by manganese supplementation.  However, the human body obtains sufficient manganese through normal dietary intake, so a deficiency syndrome is rare. 

It has been documented that women with osteoporosis have increased plasma levels of manganese and also an enhanced plasma response to an oral dose of manganese. Estimated average dietary manganese intakes range from 2.1 – 2.3 mg/day for men and 1.6 – 1.8 mg/day for women. 

People eating vegetarian diets and western diets emphasizing whole grains may have manganese include whole grains, nuts, leafy vegetables, and teas.  Foods high in phytic acid, such as beans, seeds, nuts, whole grains, and soy products, or foods high in oxalic acid, such as cabbage, spinach, and sweet potatoes, may slightly inhibit manganese absorption.

 

To be continued…

 

Until next time…Stay healthy

Katarzyna

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