Heres How Chromium Can Help Diabetes

Chromium: Essential Nutrient or Toxic Compound?

Chromium, the element, is a gray, steely, shinning, odorless, tasteless, hard metal. It forms a number of compounds but the most important chromium ions to human nutrition and health are the trivalent and hexavalent ions.

The trivalent ions of chromium are found in food and water in trace amounts. Trivalent chromium is the healthful form of the mineral. Hexavalent chromium is toxic and known to cause contact dermatitis.

It is still unclear whether chromium is an essential mineral in the body. This is because the biological roles of chromium are not conclusively proven. On the other hand, chromium deficiency has been shown to affect glucose tolerance. Therefore, some experts do believe that chromium is essential to the body in trace amounts.

The cell only needs a very small amount of trivalent chromium. To ensure that only this amount gets through, the body has a specific transport mechanism that ferries only limited amounts of chromium into cells.

A high concentration of chromium can cause DNA damage. This toxicity is not achievable with dietary sources of the mineral but toxicity can result from taking 1-5 – 3.3 mg/kg of oral chromium supplement.

In 2001, the daily dietary requirement for chromium was lowered in the United States. The current guidelines stipulate a daily chromium uptake of 30 - 35 micrograms for adult males and 20 - 25 micrograms for an adult female. The old values ranged from 50 micrograms to 200 micrograms for adults.

Only 2% of the chromium ingested in foods and supplements is absorbed while the rest is excreted without entering the blood circulation. Because only a very little chromium is absorbed while most of it is excreted, acute toxicity is unlikely to result from chromium supplementation.

However, the absorption of chromium can be improved by vitamin C, niacin or vitamin B3 and amino acids. Once absorbed, chromium preferentially accumulates in the spleen, bone, and liver.

The most commonly used chromium salts used as supplements are chromium picolinate and chromium polynicotinate.

Chromium: Dietary Sources and Deficiency

A common source of dietary chromium is stainless steel (18% chromium) from cooking pans and product cans.

Chromium deficiency is rare and has only been reported in long-term care patients fed with liquid foods through parenteral infusions.

However, foods rich in simple sugars can leach chromium from the body by increasing its excretion.

People with a high risk of chromium deficiency include pregnant women, the elderly and those who regularly do high-intensity exercises.

The major symptom of chromium deficiency is impaired glucose tolerance. When this becomes severe, it may cause nerve damage. In addition, chromium deficiency may cause unhealthy weight loss and mental confusion.

Chromium Supplements and their Health Claims

Health experts recommend either chromium picolinate or chromium polynicotinate for improving blood sugar control by diabetics. Another chromium supplement, chromium chloride, is generally not recommended because it is very poorly absorbed.

Chromium picolinate is made from chromium and picolinic acid (a metabolite of the amino acid, tryptophan). On the other hand, chromium polynicotinate is a proprietary chromium supplement made from chromium and nicotinic acid.

Some believe that chromium polynictotinate is superior to chromium picolinate because the nicotine in the former improves absorption and bioavailability of chromium. However, others are concerned that the improved bioavailability of chromium from the polynicotinate salt may increase the risk of acute chromium toxicity.

Both of these chromium supplements are believed to improve blood sugar control by reducing food craving and also by improving insulin sensitivity. Manufacturers of chromium supplements claim that the mineral can

• reduce insulin resistance in diabetics
• promote weight loss
• promote bodybuilding among athletes by increasing lean muscle mass and decreasing body fat mass

There are no studies supporting the use of chromium as a weight loss supplement.

In addition, a review of 12 placebo-controlled and well-designed studies shows that chromium does not increase lean muscle mass and is, therefore, not useful for bodybuilding.

Chromium and Type 2 Diabetes

There is considerable evidence to suggest that chromium can improve blood sugar control and insulin sensitivity among diabetics. Most studies found no such effects for non-diabetics though.

People suffering from type 2 diabetes have high blood sugar levels. They may also have higher levels of insulin than healthy people. However, diabetics also suffer from insulin insensitivity. This means that the cells do not respond well to insulin, and therefore, glucose is not driven efficiently into these cells.

Chromium enhances the actions of insulin, and chromium deficiency has been shown to impair blood glucose control.

In addition, studies have shown that diabetics have lower chromium levels than healthy individuals because they lose it via urine faster.

However, earlier studies could not confirm that chromium supplementation reduces blood glucose levels even though they showed that the trace mineral can reduce insulin levels and improve lipid profiles in diabetics.

In 1997, a Chinese study involving 180 participants suffering from type 2 diabetes found clear and reproducible benefits for chromium supplementation in diabetics.

By giving these participants placebo or chromium picolinate (200 micrograms/day and 1,000 micrograms/day) for 4 months, the researchers found that the higher chromium dose lowered blood glucose levels by almost 20%.

Blood glucose level was not the only measure of glycemic control that was lowered. Glycosylated hemoglobin levels (a measure of long-term blood glucose control) were also reduced in the chromium groups especially in the participants receiving 1,000 micrograms/day.

In a recent review of new studies investigating the benefits of chromium for diabetics, 13 of the 15 studies examined showed that chromium picolinate can improve at least one of the measures of glycemic control in diabetics.

Chromium and Other Types of Diabetes

Studies investigating the benefits of chromium for gestational diabetes only found modest benefits.

Gestation diabetes affects 2% of pregnant women during the 2^nd and 3^rd trimester. It increases the risks of type 2 diabetes later in life (30% – 40% of these women develop type 2 diabetes within 5 - 10 years).

While one study found that serum chromium levels did not affect insulin resistance or blood glucose levels during later pregnancy, another study found that 4 micrograms/day of chromium picolinate supplement reduced insulin and fasting blood glucose levels in women with gestational diabetes.

Other studies have also established that chromium supplementation can improve certain measures of glycemic control in individuals suffering from type 1 diabetes and steroid-induced diabetes.

A rather curious, but related, health benefit of chromium supplementation is its antidepressant effect. A small study found that chromium improved the moods of 15 patients who suffered from atypical depression.

Although a larger, follow-up study did not find such a strong antidepressant effect of chromium supplementation, it did find that depressed patients with high carbohydrate cravings did respond well to chromium.

The study showed that chromium picolinate can reduce sugar cravings, improve satiety and (by an unknown mechanism) relieve the symptoms of depression. A third study reproduced this antidepressant effect of chromium on this subset of patients but found that chromium reduced craving for fats too.

More Studies on Chromium and Diabetes

Factors Affecting Chromium Levels in the Body

A 1986 study published in the journal, Metabolism: Clinical and Experimental investigated the effects of diets rich in simple sugars on chromium levels. The 37 participants recruited for this study ate a nutritionist-formulated balanced diet for the first 12 weeks of the trial. Thereafter, they were given high sugar diets for another 6 weeks.

The study showed that the sugar-rich diet increased chromium excretion from the body by as much as 300% when compared to the reference balanced diet.

The study found no difference in the extent or rate of chromium loss between men and women.

Another study published in the journal, Clinical Physiology and Biochemistry, in the same year also reached the same conclusions. This study also identified physical and emotional stress as well as pregnancy and strenuous exercise as other factors that can increase chromium loss in diabetics.

High Dose vs. Low Dose Chromium

A 1997 study published in the journal, Diabetes, investigated the benefits of high doses of chromium in the treatment of type 2 diabetes.

For this study, 180 individuals suffering from type 2 diabetes were recruited and divided into 3 groups. The first group received placebo; the second group got 100 micrograms of chromium picolinate two times daily, and those in the third group were given 500 micrograms of chromium picolinate two times daily.

The participants were allowed to continue with their medications, diets, and lifestyles for the duration of the study.

The results of the study showed that the levels of glycosylated hemoglobin fell in the high-dose chromium group after 2 months and in both groups after 4 months. In addition, fasting and 2-hour blood glucose levels, as well as lipid levels, were significantly reduced in chromium groups after 2 and 4 months.

This study indicates that very high doses (higher than the daily required intake) of chromium are required to for quick and effective glycemic control in people with type 2 diabetes.

The Benefits of Chromium Combinations

A 2006 study published in the same journal provided a deeper insight into the effects of chromium on glycemic control and insulin sensitivity.

In this study, 37 type 2 diabetes patients were recruited and placed on 5mg/day glipizide (a sulfonylurea diabetes drug) plus placebo for 3 months. They were then randomly assigned glipizide + placebo or glipizide + 1,000 micrograms/day of chromium picolinate for another 6 months.

Insulin sensitivity, glycemic control, and body fat composition were measured at the beginning of the study, at the 3-month point before chromium was introduced and at the end of the study.

The results showed that chromium picolinate improved insulin sensitivity and glucose control when taken with glipizide. These improvements surpassed those experienced by participants who only took glipizide.

Furthermore, chromium supplementation reduced the weight gain and fat accumulation associated with glipizide.

A 2001 study published in the Journal of the American College of Nutrition investigated the benefits of combining zinc with chromium in the treatment of diabetes.

As an antioxidant mineral, zinc can help reduce the increased oxidative stress associated with diabetic states. However, long-term zinc supplementation may affect the absorption of other minerals especially copper.

In this study, the group of type 2 diabetes patients was each given 30 mg/day zinc gluconate or 400 micrograms/day of chromium pidolate or both zinc and chromium or placebo for 6 months.

The results showed that zinc and chromium can reduce oxidative stress to the same degree but the combination of both minerals produced better results.

In addition, this study found that zinc supplementation did not significantly reduce the levels of copper or HDL cholesterol in the body.

These results suggest that zinc supplementation can be safely added to chromium to help prevent the oxidative damage to different organs including the pancreas. This may well improve insulin sensitivity and prevent the destruction of the insulin-producing beta cells of the pancreas.