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chromium

What can high-chromium foods do for you?

What events can indicate a need for more high-chromium foods?

Romaine lettuce is an excellent source of chromium while onions and tomatoes are very good sources of this mineral. Other food sources of chromium include brewer's yeast, oysters, liver, 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.

Nutrient Chart

For serving size for specific foods, see Nutrient Rating Chart below at the bottom of this page.

Description

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).

How it Functions

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.

Deficiency Symptoms

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 hyperinsulinemia, high blood pressure, high triglyceride levels, high blood sugar levels, and low HDL cholesterol levels, that increase one's risk for heart disease.

Toxicity Symptoms

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.

Impact of Cooking, Storage and Processing

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 sugarbeets 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.

Factors that Affect Function

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.

Drug-Nutrient Interactions

What medications affect chromium?

Chromium supplementation can cause blood sugar levels to drop. If you are taking insulin or an oral glucose-lowering medication (for example, Diabeta or Micronase), be sure to consult your physician before taking chromium supplements, as you may need to decrease your current dose of medication to prevent your blood sugar levels from decreasing too much.

Calcium carbonate, found in calcium supplements and antacids, decreases the absorption of chromium, while aspirin is believed to increase chromium absorption.

Nutrient Interactions

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.

Health Conditions

What health conditions require special emphasis on chromium?

Chromium may play a role in the prevention and/or treatment of the following health conditions:

Form in Dietary Supplements

What forms of chromium are found in dietary supplements?

As a dietary supplement, chromium is available as chromium picolinate, chromium polynicotinate, chromium chloride, and chromium-enriched yeast. There is substantial debate about the preferred delivery form. Research studies have shown that chelated forms of chromium - like chromium picolinate, where chromium is hooked together with an organic acid called picolinic acid, or chromium polynicotinate, where chromium is hooked together with several molecules of vitamin B3 - are better absorbed into the body.

However, in the case of chromium picolinate, more chromium may also be excreted from the body as well, since picolinic acid binds chromium so tightly that it "doesn't let go," and the two substances stay bound together all the way through the bloodstream, and kidneys, and out through the urine. Because of vitamin B3's value in helping stabilize blood sugar, chromium in the polynicotinate form is often used in conjunction with blood sugar problems.

Food Sources

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. While our food rating system qualified romaine lettuce as an excellent source of chromium and onions and tomatoes as very good sources, the following foods are also believed to provide a significant amount of chromium: brewer's yeast, oysters, liver, whole grains, bran cereals, and potatoes. Beer and wine can accumulate chromium during fermentation and are therefore considered to be dietary sources of the mineral.

 

Introduction to Nutrient Rating System Chart

In order to better help you identify foods that feature a high concentration of nutrients for the calories they contain, we created a Food Rating System. This system allows us to highlight the foods that are especially rich in particular nutrients. The following chart shows the World's Healthiest Foods that are either an excellent, very good, or good source of chromium. Next to each food name, you'll find the serving size we used to calculate the food's nutrient composition, the calories contained in the serving, the amount of chromium contained in one serving size of the food, the percent Daily Value (DV%) that this amount represents, the nutrient density that we calculated for this food and nutrient, and the rating we established in our rating system. For most of our nutrient ratings, we adopted the government standards for food labeling that are found in the U.S. Food and Drug Administration's "Reference Values for Nutrition Labeling." Read more background information and details of our rating system.

World's Healthiest Foods ranked as quality sources of:
chromium
FoodServing
Size		CalsAmount
(mcg)		DV
(%)		Nutrient
Density		World's
Healthiest
Foods Rating
Romaine lettuce2 cup15.715.6813.115.0excellent
Onions, raw1 cup60.824.8020.76.1very good
Tomato, ripe1 cup37.89.007.53.6very good
World's Healthiest
Foods Rating		Rule
excellentDV>=75%ORDensity>=7.6ANDDV>=10%
very goodDV>=50%ORDensity>=3.4ANDDV>=5%
goodDV>=25%ORDensity>=1.5ANDDV>=2.5%

Public Health Recommendations

What are current public health recommendations for chromium?

The Adequate Intake (AI) levels for chromium, set in 2001 by the Institute of Medicine at the National Academy of Sciences are as follows:

References