What can high-chromium foods do for you?
- Help maintain normal blood sugar and insulin levels
- Support normal cholesterol levels
What events can indicate a need for more high-chromium foods?
- Hyperinsulinemia (elevated blood levels of insulin)
- High blood pressure
- High triglyceride levels
- High blood sugar levels
- High cholesterol levels
- Insulin resistance
- Low HDL cholesterol
Concentrated foods sources of chromium include onions, tomatoes, brewer's yeast, oysters, whole grains, bran cereals, and potatoes. Many people do not get enough chromium in their diet due to food processing methods that remove the naturally occuring chromium in commonly consumed foods.
What is chromium?
This essential mineral, required by the body in trace amounts, was first discovered in 1797 by a chemist in France named Louis- Nicolas Vaquelin. Many years later, a physician and research scientist in the U.S. named Walter Mertz, discovered that chromium played a key role in carbohydrate metabolism, possibly by participating in formation of a special compound which he named "glucose tolerance factor," or GTF.
Researchers are still not clear whether GTF is an actual chemical compound or not. But they are clear that the nutrients related to GTF?even though they may not be assembled into a single chemical structure?play an important role in blood sugar balance.
These chemicals include chromium (which may be the most active component), nicotinic acid (a version of vitamin B3), and the amino acids that make up glutathione (glutamic acid,cysteine, and glycine.
What is the function of chromium?
Controlling blood sugar levels
As the active component of glucose tolerance factor(GTF), chromium plays a fundamental role in controlling blood sugar levels. The primary function of GTF is to increase the action of insulin. Insulin is the hormone responsible for carrying sugar (glucose) into the cells where it can be used for energy.
After a meal, blood glucose levels begin to rise, and, in response, the pancreas secretes insulin. Insulin lowers blood glucose levels by increasing the rate in which glucose enters the cells. To accomplish this, insulin must be able to attach to receptors on the surface of cells. GTF is believed to initiate the attachment of insulin to the insulin receptors.
Metabolizing cholesterol & nucleic acid
Chromium may also participate in cholesterol metabolism, suggesting a role for this mineral in maintaining normal blood cholesterol levels. In addition, chromium is involved in nucleic acid metabolism. Nucleic acids are the building blocks of DNA, the genetic material found in every cell.
What are deficiency symptoms for chromium?
Dietary deficiency of chromium is believed to be widespread in the United States, a consequence of food processing methods that remove most of the naturally occurring chromium from commonly consumed foods. Chromium deficiency leads to insulin resistance, a condition in which the cells of the body do not respond to the presence of insulin. Insulin resistance can lead to elevated blood levels of insulin (hyperinsulinemia) and elevated blood levels of glucose, which can ultimately cause heart disease and/or diabetes.
In fact, even mild dietary deficiency of chromium is associated with a medical condition known as Syndrome X. Syndrome X represents a constellation of symptoms, including hyper insulinemia, high blood pressure, high triglyceride levels, high blood sugar levels, and low HDL cholesterol levels, that increase one's risk for heart disease.
What are toxicity symptoms for chromium?
In 2001, the Institute of Medicine at the National Academy of Sciences conducted a thorough review of the chromium research and concluded that excessive intake of chromium from foods or supplements is not associated with any adverse effects. As a result, no Tolerable Upper Intake Level (UL) was established for this mineral. However, the Institute of Medicine noted that people with liver or kidney disease may be more susceptible to adverse effects from excessive intake of chromium, and cautioned such individuals to avoid taking chromium supplements in higher than recommended amounts.
How do cooking, storage, or processing affect chromium?
Under most circumstances, food processing methods decrease the chromium content of foods. For example, chromium naturally occurs in the bran and germ of whole grains. When whole grains are milled to make flour, the germ and bran are removed, and consequently most of the chromium is lost. Also, the refinement of sugar cane and sugar beets to make sugar (sucrose) removes most of the chromium that naturally occurs in the plants.
On the other hand, acidic foods cooked in stainless steel cookware can accumulate chromium by leaching the mineral from the cookware.
Which factors might contribute to a deficiency of chromium?
If you have diabetes or heart disease, the amount of chromium your body needs may be increased. You may also need extra chromium if you experience physical injury or trauma or mental stress. All of these conditions increase the excretion of chromium. But in addition, in the case of stress, the need for increased chromium may relate directly to blood sugar imbalance. Under severe stress, the body increases its output of certain hormones. These hormonal changes alter blood sugar balance, and this altered blood sugar balance can create a need for more chromium.
How do other nutrients interact with chromium?
Diets high in simple sugars increase the urinary excretion of chromium and rob the body of some of the chromium it needs. Diets rich in whole grains can also decrease absorption of chromium, since whole grains contain a compound called phytic acid, which can bind to chromium, form an insoluble complex, and prevent it from being absorbed.
Whole grains, however, contain significant amounts of chromium, and the activity of phytic acid in grains does not prevent us from getting chromium from whole grain foods. As a result, a diet rich in whole grains is still unlikely to increase our risk of chromium deficiency.
Ascorbic acid (Vitamin C) increases the absorption of chromium.
What health conditions require special emphasis on chromium?
Chromium may play a role in the prevention and/or treatment of the following health conditions:
- High cholesterol levels
- High triglyceride levels
- Type 2 diabetes
What foods provide chromium?
Although chromium occurs naturally in a wide variety of foods, many foods contain only 1 or 2 micrograms (mcg) of chromium per serving. In addition, food processing methods often remove the naturally occurring chromium. As a result, obtaining a sufficient amount of chromium in the diet can be difficult.
Furthermore, determining the chromium content of foods is problematic due to inadequate analytical tools. Consequently, currently available food composition databases do not contain accurate information about the amount of chromium found in various foods. Concentrated foods sources of chromium include onions, tomatoes, brewer's yeast, oysters, whole grains, bran cereals, and potatoes. Many people do not get enough chromium in their diet due to food processing methods that remove the naturally occuring chromium in commonly consumed foods. Beer and wine can accumulate chromium during fermentation and are therefore considered to be dietary sources of the mineral.