PRESENTLY AVAILABLE IN THIS ARCHIVE:
NUTRITION 101: LESSON THIRTEEN
www.milkandhoneyhealthfoods.com/archieve15.html for lesson ten through twelve.
NEWSLETTER: APRIL 2008
NUTRITION 101: LESSON THIRTEEN
CHROMIUM
In our the March 2008 Newsletter, we competed our discussion of macro minerals which are minerals the body needs in excess of 100 milligrams per day as opposed to micro minerals (trace minerals) which the body needs in less than 100 milligrams per day. Trace minerals are often needed in just micrograms per day. There are 1000 micrograms to one milligram. This month we begin a discussion of the micro minerals. We will begin with the mineral Chromium.
CHROMIUM:
Chromium is found primarily as trivalent chromium which is the biologically active form found in food and the form used by the body. It is also found as hexavalent chromium which is a form used in industry that is toxic to the body including being a carcinogen when inhaled. Hexavalent chromium is derived from trivalent chromium by heating it at an alkaline pH. At low levels, hexavalent chromium is readily reduced to trivalent chromium by certain reducing agents in foods and the acidic environment of the stomach, which serve to prevent the ingestion of hexavalent chromium. Vitamin C converts the toxic hexavalent form of chromium to the beneficial trivalent form and may increase the absorption of chromium. The average human body contains 6,000 mcg (6 mg) of chromium. The average daily intake of Chromium from dietary sources is 80 - 100 mcg. The average rate of absorption of dietary chromium is 0.5% - 2.0%. Up to 10 mcg of Chromium is excreted via the feces and urine each day.
CHROMIUM AND BLOOD SUGAR:
A major dynamic of chromium is to help facilitate the function of insulin in regulating blood glucose. Insulin is secreted by specialized cells in the pancreas in response to increased blood glucose levels after eating a meal. Glucose is the sugar produced when carbohydrates are consumed and broken down. Insulin binds to insulin receptors on the surface of cells which activates the receptors and stimulates glucose uptake by cells. Through its interaction with insulin receptors, insulin provides cells with glucose for energy and prevents blood glucose levels from becoming elevated. In addition to its effects on carbohydrate metabolism, insulin also influences the metabolism of fat and protein. A decreased response to insulin by insulin receptors, also known as insulin insensitivity or impaired glucose tolerance, can result in elevated glucose in the blood leading to type 2 diabetes (hyperglycemia) where high blood sugar is a constant problem.
While the exact mechanism for the effect of chromium on insulin action is still being researched, all indications are that chromium plays a role in enhancing the response of insulin receptor sites to insulin. This allows cells to receive glucose to be utilized for cellular activity. Research has shown that chromium deficiency does reduce the ability of insulin to remove glucose from the blood into the cell and when chromium intake is increased this problem is often corrected or at least reduced. Individuals with type 2 diabetes have been found to have higher rates of urinary chromium loss than healthy individuals, especially those with diabetes of more than two years duration.
In twelve out of fifteen controlled studies of people with impaired glucose tolerance, chromium supplementation was found to improve some measure of glucose utilization or to have beneficial effects on blood lipid profiles. About 25 to 30 percent of individuals with impaired glucose tolerance eventually develop type 2 diabetes. It has been found that chromium supplementation at doses of 200 to 1000 mcg per day for two to three months has been found beneficial in enhancing better glucose metabolism. In a placebo-controlled study conducted in
On the other hand, claims that chromium supplementation can have a direct benefit in increasing muscle mass and reduction of body fat has not been sufficiently demonstrated in research to date. Any increase in muscle mass or loss of body fat may occur when supplementing with chromium can be attributed to better insulin activity thus leading to better carbohydrate and fat metabolism. Some research has shown that elevated chromium intake lowers LDL cholesterol levels. Animal studies suggest that chromium may help improve blood pressure. This has yet to be tested on people. Until more information is available, use of chromium for this purpose is not currently recommended.
It is sometimes believed that chromium supplementation will also help low blood sugar called hypoglycemia. Low blood sugar can occur when there is not enough glucose producing foods available from the diet or the body’s stored carbohydrate (glycogen) has been depleted. Low blood sugar can also be caused when the body is producing too much insulin which results in too much glucose being removed to quickly from the blood. Since chromium helps insulin to remove glucose from the blood into the cell it is not a “cure” for low blood sugar. If anything, it can compound the problem by facilitating greater insulin activity and further reduce already low blood sugar.
SUPPLEMENTATION:
Trivalent chromium is available as a supplement as chromium chloride, chromium nicotinate, chromium picolinate, high-chromium yeast and other forms. These are available as stand-alone supplements or in combination with other blood sugar control nutrients. Doses typically range from 50 to 200 mcg of elemental chromium. Chromium nicotinate and chromium picolinate may be more bioavailable than chromium chloride. In much of the research on impaired glucose tolerance and type 2 diabetes, chromium picolinate was the source of chromium. Some research indicates that chromium picolinate in high doses can be toxic.
DOSAGE:
NEWSLETTER: MAY 2008
NUTRITION 101: LESSON FOURTEEN
SELENIUM
In our last Newsletter, we discussed the micro mineral chromium. This month we will look at the mineral selenium. Remember, micro minerals are minerals which the body needs in less than 100 milligrams per day. Such minerals are often needed in just micrograms per day. There are 1000 micrograms to one milligram.
SELENIUM:
Other selenoproteins help regulate thyroid function and play a role in the immune system. Selenium is necessary for the production of interleukin-2 which activates the T-cells of our immune system. Selenium will also block the effects of the toxic metal mercury. The average human body contains a total of 21 mg of selenium.
FORMS OF SELENIUM: Selenium is also found in several other forms. Sodium selenite and sodium selenate are inorganic forms of selenium. Selenate is almost completely absorbed, but a significant amount is excreted in the urine before it can be incorporated into proteins. Selenite, which contains 45.7% selenium bound to 54.3% sodium, is only about 50% absorbed but is better retained than selenate once it is absorbed. Selenite should not be consumed in conjunction with zinc or copper as it combines with and interacts with those minerals in a manner that causes the selenium to become useless. Selenite forms of selenium should not be consumed at the same time as vitamin C as vitamin C neutralizes the effects of selenite. Both inorganic and organic forms of selenium can be metabolized to selenocysteine by the body and incorporated into selenoenzymes.
DAILY REQUIREMENT:
The RDA (Recommended Daily Allowance) for selenium is based on the amount of dietary selenium required to maximize the activity of glutathione peroxidase in the blood plasma. For adults this is 55 mcg (micrograms) per day. The average dietary intake of adults in the
SELENIUM AND CANCER:
There is a great deal of evidence indicating that selenium supplementation at high levels reduces the incidence of cancer in animals. More than two-thirds of over 100 published studies in 20 different animal models of spontaneous, viral, and chemically induced cancers found that selenium supplementation significantly reduces tumor incidence. Geographic studies have consistently observed higher cancer mortality rates in populations living in areas with low soil selenium and relatively low dietary selenium intakes.
Some studies have reported that low dietary selenium intakes are associated with increased risk of prostate cancer. One study involving over 50,000 male health professionals in the
The richest food sources of selenium are organ meats and seafood, followed by muscle meats. In general, there is wide variation in the selenium content of plants and grains because plants do not appear to require selenium. Thus, the incorporation of selenium into plant proteins is dependent only on soil selenium content. Brazil nuts grown in areas of
SUPPLEMENTATION:
As is true with all nutrients, it is best to obtain them from food. Since our soils are very deficient in selenium, supplementation may be necessary to maintain optimal levels. Brewers or Nutritional yeast is a good source of selenium. This mineral is also available in capsule form as selenium aspartate, picolinate, sodium selenate, selenomethionine and several other forms. Scientists continue to debate the virtues of organic versus inorganic selenium. Both organic and inorganic forms of Selenium possess unique or specific therapeutic benefits. Some forms are more potent in protecting against cancer while others are more potent in retarding the aging process. For example, sodium selenate has been shown to be more effective for the prevention of cancer compared with the Selenomethionine form. Based on current scientific knowledge, it is best to get several forms of selenium to maintain the best overall protection.
TOXICITY:
Organic Selenium can be supplemented at up to 1,000 micrograms per day without adverse effects occurring. Long-term use of sodium selenite at doses of 1,000 micrograms per day causes toxicity. The most common symptoms of selenium overdose are hair and nail brittleness and loss. Other symptoms may include gastrointestinal disturbances, skin rashes, a garlic breath odor, fatigue, irritability, and nervous system abnormalities.
NEWSLETTER: JUNE 2008
NUTRITION 101: LESSON FOURTEEN
ZINC Zinc is found in almost every cell of the body. It stimulates the activity of approximately 100 enzymes, which are important specialized proteins that facilitate biochemical reactions in the body. Zinc is needed for wound healing, helps maintain our sense of taste and smell, and is needed for DNA synthesis. Zinc also supports normal growth and development during pregnancy, childhood, and adolescence.
ZINC AND IMMUNITY:
Zinc is very important to proper immune function. The immune system is adversely affected by even moderate degrees of zinc deficiency. Zinc is required for the development and activation of T-lymphocytes which are important in fighting infection. Zinc increases T-lymphocytes by significantly increasing the body's production of the thymus hormone thymulin which causes the further replication of T-lymphocytes within the thymus gland. Zinc also increased the activity of natural killer lymphocytes.
When zinc supplements are given to individuals with low zinc levels, the numbers of T-lymphocytes circulating in the blood increase and the ability of lymphocytes to fight infection improves. Studies show that poor, malnourished children in
ZINC AND THE COMMON COLD:
It is generally believed that zinc is beneficial in fighting the common cold. A study of over 100 employees of the Cleveland Clinic indicated that zinc lozenges decreased the duration of colds by one-half, although no differences were seen in how long fevers lasted or in the level of muscle aches. Another study examined the effect of zinc supplements on cold duration and severity in over 400 randomized subjects. In an initial study involving these subjects, a virus was used to induce cold symptoms. The duration of illness was significantly lower in the group receiving zinc gluconate lozenges (providing 13.3 mg zinc) but not in the group receiving zinc acetate lozenges (providing 5 or 11.5 mg zinc). None of the zinc preparations affected the severity of cold symptoms in the first 3 days of treatment. Recent research suggests that the effect of zinc may be influenced by the ability of specific supplement formulas to deliver zinc ions to the oral mucosa.
The protocol to treat the common cold after symptoms have appeared is an initial dose of 50 mg of zinc followed by 25 mg every two hours using zinc lozenges or zinc tablets slowly dissolved in the mouth, but not rapidly swallowed. The form of zinc should be zinc gluconate.
ZINC AND THE PROSTATE GLAND:
Optimal zinc intake may prevent benign prostate hypertrophy. Zinc plays a role in the processing of enzymes and hormones that reduce the discomfort associated with benign prostate hypertrophy (BPH: swelling of the prostate). It inhibits the activity of 5-alpha reductase which is the enzyme that catalyzes the conversion of testosterone to dihydrotestosterone. Elevations in dihydrotestosterone are related to BPH and potential for prostate caner. Research undertaken during the 1970s demonstrated the ability of zinc to reduce the symptoms of enlarged prostate in many patients. This may occur from zinc inhibiting the activity of 5-alpha-reductase. The prostate gland concentrates more zinc (approximately ten times more) in its tissues than any other part of the body.
DIETARY ZINC:
Zinc is wide spread in the food chain. The zinc content of plant foods is usually bound to phytic acid to form a zinc-phytate complex that is less bioavailable than the zinc found in animal foods. Among animal products, oysters are very high in zinc, providing 150 mg in 100 grams of product. Beef liver and beef steak provide much less but are a good source of zinc compared to most other animal products. Wheat, rye and oats are a good source of zinc provided the soil in which they are grown is not deficient. Pecans and almonds are nut sources for zinc while vegetable provide small amount and fruit hardly any. Brewers yeast is a good source of zinc. Zinc is absorbed better when taken on an empty Stomach. About 40% to 90% of orally-ingested zinc is absorbed when the stomach is empty. Most orally-ingested zinc is absorbed through the jejunum which is the middle part of the small intestine.
DAILY REQUIREMENT:
The RDA for adult men is 11 mg and for women is 8 mg. The optimal daily allowance of zinc for adults) is 15 - 50 mg per day. The recommended therapeutic dosage of supplemental zinc for athletes is 30 - 60 mg of elemental zinc per day.
SUPPLEMENTATION WITH ZINC:
Many studies have shown that 75% of the adult population of western nations is deficient in zinc. The average zinc intake is 8 - 10 mg per day: Some 68% of adults in the
Zinc supplements appear in many forms where zinc is chelated to other substances which act as carrying agents for the zinc to facilitate absorption. Zinc chelated to amino acids consists of 80% - 90% amino acids bound to 10 - 20% elemental zinc. Zinc acetate consists of 35.5% zinc bound to 64.5% acetic acid. Zinc ascorbate consists of 10% elemental Zinc bound to 90% ascorbic acid (Vitamin C). Zinc aspartate consists of 32% elemental Zinc bound to 68% aspartic acid. Zinc gluconate consists of 14% elemental Zinc bound to 86% gluconic acid. This form of zinc is used in the manufacture of zinc lozenges and zinc nasal gel pumps for the treatment of the common cold.
Zinc monomethionine, also known as OptiZinc, consists of zinc bound to the amino acid methionine. It is a desirable form of zinc supplementation as it is easily absorbed. Zinc monomethionine, unlike other forms of zinc, does not interfere with the absorption of Copper. Zinc picolinate consists of 20% zinc bound to 80% picolinate acid. Zinc picolinate is easily absorbed and this form of zinc may be the optimal form of zinc supplementation as some clinical studies have shown zinc picolinate to be absorbed more effectively than other forms.
TOXICITY: