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Chromium Picolinate and Weight Loss
Description/Source of Chromium: Continued from Chromium Part I
Chromium [Greek, chroma, color; Chemical symbol, Cr; Atomic number, 24; Atomic weight, 52] is an extremely hard, lustrous, brittle metallic trace element, and essential dietary bioelement in human nutrition. 1415 Chromium is classified as a heavy metal. Although the human body only contains a total of about 6 milligrams of chromium, a recent study conducted by the U.S. department of Agriculture found that 90% of Americans are deficient in this trace mineral. The average American's diet supplies only 14 micrograms of chromium per 1,000 calories consumed, requiring the consumption of over 3,000 calories daily to achieve the National Academy of Sciences' minimum recommended dose of 50 micrograms of chromium daily. 1416 Chromium is essential to human metabolism, 1415 and supports efficient insulin function. Insulin, in turn, regulates the metabolism of proteins (the building of muscle), fats (energy storage) and carbohydrates (the major source of energy). Chromium enhances the body's sensitivity to insulin and facilitates the absorption of glucose and protein and the metabolism of fat. Research has demonstrated that in obese individuals, chromium may help to increase abnormally low blood glucose levels, increase tissue insulin sensitivity, normalize or control appetite, and usually stimulates fat loss. 845, 1237, 1250 It seems to have an effect on the satiety center of the hypothalamus, reducing the desire to over-eat. Chromium is a serotonin potentiator. Chromium increases insulin sensitivity, stabilizes blood glucose levels, and facilitates the synthesis of the neurotransmitter serotonin by insulin. Because serotonin potentiators such as chromium theoretically act as partial antidepressants, 1255 they may be beneficial in reducing the anxiety/aggressive component of the depressive syndrome. Chromium also seems to increase the thermogenic effects of carbohydrate foods, and enhances thermogenic reactions by activating the sympathetic nervous system (which increases caloric burning). Chromium picolinate is classified as an ergogenic substance, and when taken orally, may increase muscle levels of creatine phosphate and enhance energy performance and exercise performance.
The body manufactures Glucose Tolerance Factor, GTF from dietary chromium and niacin. Chromium is supplied naturally in the diet when it is absorbed from the soil by plants which are later consumed as food. Dietary chromium levels are adversely effected by both the mineral content of soil (soil depletion), and the degree of processing that a food has undergone. According to estimates of nutritional experts, a majority (some estimates run as high as 90%) of the American population consumes diets which are deficient in chromium. The average American ingests only half of the recommended amount of 50 mcg daily. According to nutritional research, ninety-eight percent of spaghetti, bread, pancakes, and pastries are made with white flour which has been stripped of both nutrients and fiber. Products made with white flour have only 28% of the natural chromium found in whole wheat. Additionally, soil-depleting farming techniques may be responsible for much of the American chromium deficiencies. Because plants do not require chromium for normal growth, the mineral is rarely replaced in soils which have been depleted by decades of over-farming. Processing foods further depletes their chromium content, and to further compound these problems, dietary chromium is not easily absorbed by the body. Studies show that chromium levels decrease with age, and may be depleted by strenuous aerobic exercise and endurance training. Individuals undertaking strenuous training programs may require chromium supplementation. 1237, 1238, 1239, 1240 Additionally, chromium excretion increases with infection, pregnancy, stress, and a high-sugar diet.
Chelates of chromium include Chromium-Picolinate and Chromium-Nicotinate Glycinate (A chromium-niacin chelate also known as Glucose Tolerance Factor, GTF). Chromium Picolinate was developed and patented in 1982 by the U.S. Department of Agriculture, which developed the process for bonding picolinic acid to elemental chromium to improve bioavailability. Picolinic acid is a normal amino acid metabolite manufactured in the liver and kidneys, which binds to trace minerals such as chromium, zinc, and iron, and assists in their absorption. Picolinate is a niacin derivative which chelates elemental chromium, making it more fat soluble, and increasing its intestinal absorption (by as much as five times), bioavailability, and delivery into the cells. Chromium is crucial to carbohydrate and fat metabolism, and nutritionally supports insulin's uptake of amino acids, which influences neurotransmitter levels and brain function. Chromium theoretically helps insulin transport glucose and amino acid molecules inside the cells for energy production and tissue synthesis. Chromium binds insulin to a special receptor site on cellular membranes, and research has demonstrated that a lack of chromium can cause insulin resistance in both human clinical and isolated tissue studies. When tissues become highly resistant to insulin, the level of insulin in the blood rises, which stimulates the increased storage of fat. The increased storage of fat occurs because insulin increases the activity of a fat storage enzyme, adipose tissue lipoprotein lipase (AT-LPL). AT-LPL transports fat molecules into fat cells, and the higher the insulin levels, the more fat which is transported into the cell. Because chromium increases tissue sensitivity to insulin, it decreases insulin levels in the body, and subsequently decreases fat storage in the tissues. Some limited animal research suggests that chromium supplementation may reduce blood glucose levels by 25% and the levels of glycated proteins (damaged proteins associated with degenerative disease and early death) by as much as 60 percent.
An isotope of chromium, chromium-51, has a radioactive half-life of 27.7 days and is used as a diagnostic aid in gastrointestinal protein loss and other disorders. Chromium trioxide (CrO3) is used as a caustic in the removal of warts and other small skin growths.
Source of Chromium in the Diet:
Dietary sources of chromium include apples, cheeses, whole grains, nuts, brewers yeast, oysters, and mushrooms. 845, 1237, 1250
Normal Blood Levels:
Normal serum chromium levels average 0.004 µmol/L, or 0.02 µg/dL. 1061 Many nutrition scientists caution that blood levels of nutrients may not necessarily reflect nutrient concentrations within the tissues.
Efficacy/Beneficial Effects:
Substantiated:
Diabetes, Obesity, and Hypercholesterolemia: GTF may be beneficial in diabetics by facilitating the action of insulin. 1090 Chromium Picolinate was found repeatedly to reduce body fat without dieting or exercise in numerous clinical studies, and has also been shown to reduce elevated cholesterol, improve insulin sensitivity, and improve glycemic control in adult-onset diabetes. 1195, 1196, 1197, 1198, 1199, 1200, 1201, 1202, 1203, 1204, 1205 The substantiated benefits of chromium supplementation on improved glucose tolerance, increased lean body mass, and reduction in body fat have been primarily demonstrated among chromium deficient people. Chromium binds insulin to a special receptor site on cellular membranes, and research has demonstrated that a lack of chromium can cause insulin resistance in both human clinical and isolated tissue studies. When tissues become highly resistant to insulin, the level of insulin in the blood rises, which stimulates the increased storage of fat. The increased storage of fat occurs because insulin increases the activity of adipose tissue lipoprotein lipase (AT-LPL), an enzyme which facilitates fat storage. AT-LPL transports fat molecules into fat cells, and the higher the insulin levels, the more fat which is transported into the cell. Because chromium increases tissue sensitivity to insulin, it decreases insulin levels in the body, and subsequently decreases fat storage in the tissues, resulting in weight loss. Note: Diabetics and hypoglycemics should use chromium supplementation only under a physician's supervision because improvements in insulin sensitivity may necessitate adjustments in insulin doses for insulin-dependent diabetics, or adjustments in glucose-lowering medications. Scientific research conducted upon both humans and animals suggests that chromium (picolinate) may facilitate the loss of fat in obese persons, and a trend toward the maintenance of lean mass. 845, 1237, 1250
Appetite control: Because chromium increases insulin sensitivity, it may contribute to a decrease in appetite by stabilizing blood glucose levels and by facilitating the synthesis of the neurotransmitter serotonin by insulin. Studies have demonstrated that increased levels of serotonin in the brain can lessen hunger pangs by creating a sensation of fullness and satisfaction.
Fatigue, Hypoglycemia: Supplementation with chromium may be beneficial in patients suffering from hypoglycemia. Hypoglycemia may be caused or exacerbated by chromium deficiencies. 1267 Chromium facilitates the conversion of blood glucose to glycogen by insulin. Glycogen is stored in the liver and muscles. In the liver, low glycogen levels may result in low blood glucose levels. This can cause fatigue, mental fatigue, inability to concentrate, and light-headedness. The glycogen stored in the skeletal muscles is used for strenuous physical activities. When competitive athletes refer to "hitting the wall" at their exhaustion point, they are referring to the point at which the body's muscle glycogen stores are depleted, resulting in mental and physical exhaustion. Because of its ability to increase liver and muscle glycogen stores, chromium is listed as one of the 33 ergogenic substances considered unethical or illegal by the International Olympic Committee which when taken orally, may increase muscle levels of creatine phosphate and enhance energy performance and exercise performance. 1084
Depression: Supplementation with chromium may be beneficial in patients suffering from depression which is accompanied by hypoglycemia. A history of chromium and deficiencies and hypoglycemia (which may be caused or exacerbated by chromium deficiency) is present in many patients with clinical depression. Chromium facilitates the synthesis of the neurotransmitter serotonin by insulin. Because serotonin potentiators such as chromium theoretically act as partial antidepressants, 1255 they may be beneficial in the treatment of depression by reducing the anxiety/aggressive component of the depressive syndrome.
Violent Behavior: Chromium deficiencies may increase the risk of violent behavior, especially in patients with a history of depression accompanied by hypoglycemia or a high-sugar diet.
Skin: Chromium nutritionally assists insulin in the synthesis of protein, including collagen, which is the primary protein that comprises connective tissue and skin.
Theoretical:
Muscle Building and Increased Thermogenesis: Because chromium augments the action of insulin, the body's primary anabolic hormone, numerous sports nutritionists have theorized that chromium may facilitate muscular development and have included it in body building regimens. Chromium increases insulin's ability to transport glucose and amino acid molecules from the blood into muscle cells. Because amino acids are the building blocks of protein, researchers have theorized that this increased transport of amino acids into the muscle cells may increase muscle protein and boost muscle mass. Because muscle tissue is highly metabolically active and increased muscle mass results in increased basal metabolic rate and an increase in the rate at which the body burns calories, chromium is assumed to be a thermogenic compound. Anecdotal reports supporting this theory abound, and several clinical studies are currently being conducted, however previous clinical and animal data has been inconclusive or contradictory. One small study conducted at Bemidji State University in Minnesota showed that chromium significantly reduced body fat and increased muscle mass. Athletes taking chromium picolinate gained 44% more lean muscle mass as compared to a group of athletes taking a placebo. Additionally, those athletes taking chromium lost 23% of their body fat compared to only 7% in the placebo group. Both of these findings were statistically significant.
Special Requirements:
Stress 1417 and intensive aerobic exercise can deplete bodily stores of chromium, and individuals undertaking strenuous training programs may require supplementation. 1237, 1238, 1239, 1240, 1417
Synergistic with:
B-Complex vitamins increase the effectiveness of chromium. Chromium is synergistic with vanadyl sulfate in the increase of insulin sparing effects. Vitamin B6 aids in the pancreatic production of picolinic acid, necessary for the absorption of all forms of chromium except chromium picolinate. Vitamin C, niacin, vitamin B6, B12, magnesium, and potassium. Chromium picolinate is synergistic with ginseng, hydroxycitric acid, and other thermogenic or ergogenic substances when used in a program of weight loss or increasing lean muscle mass.
Deficiency diseases:
Trace element deficiencies in humans (except for iron deficiency) were previously thought to be rare. Recently, with the increased use of total parenteral nutrition, trace element deficiencies have been recognized more frequently. 1061
Interactions:
Extreme excesses in fiber consumption can lead to decreased absorption of minerals including chromium. 247, 668
Precautions:
Unknown.
Contraindications:
Unknown.
Side Effects:
Symptoms of chromium poisoning include dysgeusia (disagreeable or metallic taste), cramping, pain, diarrhea, uremia, and death. 1092
Recommended Dosage:
The RDA for chromium has not been defined, however the adult Estimated Safe and Adequate Dietary Intake established by the Food and Nutrition Board of the National Academy of Sciences National Research Council for chromium is 0.05 to 0.2 mg (50-200 µg). 294 Most nutritionists recommend a conservative intake of 50 to 200 µg/day of chromium (usually in the form of chromium picolinate), however several studies suggest that doses as high as 400 µg/day may be more effective. 1418, 1419 The American diet furnishes about 50 to 100 µg of chromium per day for people over seven years of age, and intake varies according to soil chromium levels and diet. More aggressive supplementation of 200 to 400 µg (mcg) per day may be beneficial in chromium deficiencies. Two to four hundred micrograms of chromium may increase the thermogenic effects of carbohydrate foods, and enhance thermogenic reactions by activating the sympathetic nervous system (which increases caloric burning). Do not exceed 400 mcg per day except on the advice of a physician or health care professional. Do not exceed the recommended dosage imprinted on the container if the chromium supplement which you are taking is combined with other trace elements (to avoid toxic levels of the combined trace element).
Toxic Level:
Sustained intakes over 400 mcg may be toxic in some individuals.
References
Grant, K.E., Chandler, R.M., Castle, A.M., & Ivy, J.L. (1997). Medicine and Science in Sports and Exercise, 29(8), 992-998.
Harris, C, Hoeger, W., Long, E.M., Welch, M., Hafner, T.L., Kjorstad, R.L., & Hopkins, D.R. (1998). Twenty five days of dietary supplementation with chroma slim augments body fat reduction. Medicine and Science in Sports and Exercise, 30(5), 62.
Krzanowski, J.J. (1996). Chromium picolinate. Journal of the Florida Medical Association, 83(1), 29-31.
Lindemann, M. D., Wood, C. M., Harper, A. F., Komegay, E. T. & Anderson, R. A. (1995). Dietary chromium picolinate additions improve gain-feed and carcass characteristics in growing finishing pigs and increase litter in reproducing sows. Journalof Animal Science, 2, 457-465.
Lukaski, H.C., Bolonchuk, W.W., Siders, W.A., & Milne, D.B. (1996). Chromium supplementation and resistence training: effects on body composition, strength, and trace element status of men.American Journal of Clinical Nutrition, 63, 954- 965.
Mooney, K. W. & Cromwell, G. L. (1995). Effects of dietary chromium supplementation on growth, carcass characteristics,and accretion rates of carcass tissues in growing-finishing swine. Journal of Animal Science,73, 51-57.
Schroeder, H.A. (1968). The role of chromium in mammilian nutrition. American Journal of Clinical Nutrition, 21, 230-244.
Trent, L.K, & Theiding-Cancel, D. (1995). Effects of chromium picolinate on body composition.. Journal of Sports Medicine and Physical Fitness, 35(4), 273-280.
Walker, L.S., Bemben, M.G., Bemben, D.A., Knehans, A.W. (1998). Chromium picolinate effects on body composition and muscular performance in wrestlers. Medicine and Science in Sports and Exercise, 30(12), 1730-1737.
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