Chromium is perhaps best known for its enhancement of insulin function, but it also influences protein and fat metabolism.
It has been hypothesized that chromium facilitates the transfer of insulin across cell membranes. Many studies have shown that chromium might be useful for controlling blood glucose among individuals with diabetes, although no benefit is seen in people without diabetes. Some research has shown that chromium may help with polycystic ovarian syndrome (PCOS), which is linked to insulin resistance and drastically increases the risk of developing diabetes. It might be that chromium only helps those who are deficient in the nutrient and is not helpful to those who already have adequate levels. A meta-analysis of 15 trials, including 618 participants, found that chromium supplementation did not affect either glucose or insulin concentrations in those without diabetes, and it didn’t reduce these levels in those with diabetes. The American Diabetes Association states that there is insufficient evidence to support the routine use of chromium.
In some studies, chromium supplements have decreased total and low-density-lipoprotein (LDL) and triglyceride levels, while increasing high-density lipoprotein (HDL) cholesterol in subjects with atherosclerosis or elevated cholesterol among those taking a beta-blocker drug. However, in other studies, supplements have had no favorable effects.
A review of 24 studies found no beneficial effects on body fat or muscle composition from chromium supplementation, but this hasn’t stopped people from popping chromium on the way to the gym every morning. In a few studies, chromium supplements appeared to reduce food craving and intake among overweight and obese women. Overall, though, there is not enough evidence to support chromium supplementation as a weight-loss strategy.
Chromium deficiency is rare among young Americans who eat a varied and adequate diet. Older individuals appear to be more vulnerable to chromium deficiency compared to younger adults.
Chromium is found in many different foods because there is chromium in the water and soil. The following foods contain chromium, and grape juice, broccoli, and processed turkey ham contain exceptionally high amounts.
- Brazil nuts
- Dried dates
- Grape juice
- Whole-wheat bread
- Bran cereals
- Pork chops
- Turkey breast
- Processed turkey ham
- Egg yolks
- Brewer’s yeast
Vitamin C and niacin increase the absorption of chromium from food. Diets high in simple sugars increase chromium excretion, as does infection, exercise, pregnancy and lactation, and physical stress or trauma.
It is thought that adult men and women need between 20 and 35 mcg of chromium each day, although no recommended dietary allowance (RDA) has been established. Some experts have suggested that the upper limit be 200 mcg of chromium/day. Chromium has been said to cause side effects, including irregular heartbeats, diarrhea, vertigo, hives, sleep disturbances, headaches, and mood changes. Individuals with liver or kidney problems are urged to avoid chromium supplements. Chromium might interact with a variety of medicines, including antacids, acid reflux medications, corticosteroids, beta-blockers, thyroid medications, nonsteroidal anti-inflammatory medications, prostaglandin inhibitors, and drugs used to treat diabetes.