Back in the 1950s, US Department of Agriculture researchers discovered that brewer’s yeast contained an unknown compound that prevented diabetes in lab animals. That compound, which they called glucose tolerance factor (GTF), was eventually identified as the biologically active form of the trace mineral chromium.
Twenty years later, a patient who was unable to eat and was being fed intravenously developed severe diabetes. Recalling the earlier animal studies, doctors added chromium to the patient’s IV, and within two weeks the signs and symptoms of diabetes resolved. This led to clinical trials on supplemental chromium, demonstrating its ability to lower blood sugar in individuals with diabetes.
Yet, it wasn’t until 2001 that chromium was recognized as an essential nutrient for humans, required for normal carbohydrate metabolism. Let’s take a closer look at this long-overlooked nutrient, the importance of chromium in diabetes, and how to make sure you are getting enough of this crucial trace mineral.
How Does Chromium Lower Blood Sugar?
The benefits of chromium for blood sugar control are believed to be due to its effects on insulin—it binds to insulin receptors and enhances insulin activity. Chromium may also increase the number of insulin receptors and improve beta-cell sensitivity in the pancreas.
If this explanation seems a little vague, it’s because the precise mechanism of action is still under investigation. What is clear, however, is that chromium is essential for carbohydrate metabolism. Low chromium status is associated with an increased risk of developing type 2 diabetes. Plus, numerous studies involving individuals with diabetes have shown that boosting levels with supplemental chromium improves insulin sensitivity and blood sugar control.
The study that really piqued interest in chromium as a useful supplement for blood sugar concerns was a clinical trial published in Diabetes in 1997. Men and women with type 2 diabetes were randomly divided into three groups and assigned to take 100 mcg or 500 mcg of supplemental chromium or placebo capsules twice a day for four months. The high-chromium group had the greatest improvements. After four months, their fasting blood sugar averaged 128 mg/dL, compared to 159 mg/dL in the placebo group. A1C also improved, and cholesterol levels declined as well.
Not all subsequent studies have had such significant effects—which I suspect reflects adequate chromium status of study participants prior to supplementation. Yet, the low dietary intake of chromium of many Americans, as discussed below, makes chromium an excellent addition to your program for supporting healthy blood sugar levels.
Additional Health Benefits of Chromium
Supplemental chromium has also been evaluated as a potential therapy for additional conditions, most of them related to insulin resistance and therefore more common in individuals with diabetes:
- Weight & fat loss/muscle gain: Chromium is no magic bullet for weight loss, but a 2019 meta-analysis of 21 placebo-controlled clinical trials found that study participants who took chromium supplements had small but statistically significant improvements in weight, BMI, and percentage of body fat.
- Cholesterol & triglycerides: Low chromium levels have been linked with elevations in cholesterol. In addition, some studies have demonstrated marked increases in protective HDL cholesterol and reductions in LDL cholesterol and triglycerides with supplemental chromium.
- Fatty liver disease: In patients with fatty liver disease, chromium has been shown to improve oxidative stress and weight as well as levels of leptin and adiponectin—hormones that are commonly disrupted in metabolic disorders.
- Polycystic ovary syndrome (PCOS): Chromium has significantly reduced BMI, fasting insulin, and hormone levels in women with this condition. This is important because PCOS causes infertility, obesity, elevated testosterone, and increased risk of diabetes and heart disease.
These additional benefits are especially important if you are dealing with blood sugar issues because they are either risk factors or complications of diabetes.
Are You Getting Enough Dietary Chromium?
Chromium-rich foods for diabetics and others include whole grains, bran cereals, nuts, egg yolks, meat, vegetables, and fruit. It is also present in brewer’s yeast and some beer and wine. Levels vary dramatically, however, depending on where the food was grown and how it was processed.
Processed foods such as refined grains are low in chromium. Nutrition surveys reveal that the average adult gets just 50–60% of the minimum recommended intake chromium from food—a reflection of the sad state of the diets of many Americans. Furthermore, some research suggests that sugar actually increases chromium losses in the urine.
Suboptimal chromium status is especially common in older people, with average levels reported to be 25–40% lower than in younger individuals. Diabetes, pregnancy, infections, injuries, and strenuous exercise are also associated with chromium depletion. This is why I recommend supplemental chromium for most everyone, but especially for those who have diabetes.
Chromium Supplements: How Much to Take
Most multivitamins contain 35–120 mcg of chromium, although some advanced formulas have more. It comes in various forms such as chromium picolinate, chromium polynicotinate, and Crominex 3+—a newer type blended with botanicals for increased bioavailability. Chromium is also available as a single-ingredient supplement, and it is a common component of multi-ingredient supplements for blood sugar control.
Supplemental chromium is so safe that the Food and Nutrition Board—the arm of the National Academy of Medicine that sets RDAs (recommended daily allowances) and ULs (tolerable upper limits)—didn’t even set a UL, since no adverse effects were found at any level. They did note that high doses could be problematic for people with liver or kidney disease, and it is conceivable, though unlikely, that it could drive blood sugar too low when taken with diabetes drugs or by those prone to hypoglycemia.
The dose of chromium used in the clinical trials ranged from 200 mcg to 1,000 mcg per day. My usual recommendation is 400–600 mcg, taken in divided doses two or three times a day.