Many of my patients are interested in the health benefits of chromium. Chromium is promoted for use in common lifestyle related health conditions such as obesity, diabetes, dyslipidemia and cognitive impairment, in addition to the related polycystic ovarian disease.
It would be way too easy (and unfair) to write these people off as wannabe modern day Bacchus lookalikes; meaning that these are people who want to overindulge, laze about and offset all the health damage with a single pill (in this case chromium).
I have so many patients who are trying so hard to juggle the demands of family, work, healthy living and find that their weight, their waist or their fasting glucose is not quite good enough and they want something to help give them an invisible lift towards better health.
The question that we have to answer is whether chromium could be that magic pill and if it could be worth the cost (especially when finances are tight)?
Table of Contents
- 1 Introduction
- 2 What Is Chromium?
- 3 Is There Any Research?
- 3.1 Does Chromium Control Blood Sugar and Prevent Diabetes?
- 3.2 Does It Reduce Weight Gain or Overeating or Boost Metabolism?
- 3.3 Does It Reduce High Cholesterol?
- 3.4 Does it Improve Brain Health? Fight Cognitive Decline?
- 3.5 Is it good for the eyes?
- 3.6 Does It Help Skin? Prevent Acne?
- 3.7 Does It Help Bones?
- 4 Is Chromium (and or Supplementation) Safe?
- 5 Conclusion
What Is Chromium?
Chromium was discovered by French pharmacist, Louis Nicolas Vauquelin, in 1797. The very talented Monsieur Vauquelin also discovered berrylium. ‘Incroyable’ as my near neighbours in France would say.
Chemically speaking, chromium is designated as Cr and occupies position 24 on the periodic table. (Like many of you, I spent many hours memorizing that periodic table for school exams and never use the information).
The name ‘chromium’ is derived from the fact that chromium comes in many colors and ‘chroma’ means color in Greek. Chromium is mined predominantly in South Africa, Kazakhstan, India, Russia, and Turkey. It is used in the stainless steel industry and has magnetic properties.
Warning, if you read the next paragraph and this song sticks in your head all day, please don’t blame me. Billy Joel included ‘chromium’ in the lyrics of his song ‘Allentown’.
(No they never taught us what was real,
Iron and coke,
And chromium steel,
And we’re waiting here in Allentown ).
Chromium is an essential micronutrient. It was first identified in human health in 1957 and was initially called ‘glucose tolerance factor’. The exact physiological role of chromium in the body is poorly understood but it is believed to play a key role in carbohydrate, fat and protein metabolism.
There are two main forms of chromium:
- chromium 3+ or trivalent chromium which is the biologically active form found in food
- chromium 6+ or hexavalent chromium which is a toxic form and environmental pollutant.
Physiologically speaking, chromium is excreted in bile and urine with little organ retention. In blood, it is divided between red blood cells and plasma. Blood, urine and saliva levels of chromium do not accurately reflect body stores which makes it difficult to assess chromium deficiency.
Chromium deficiency can occur if patients are unable to eat and are receiving total parenteral nutrition i.e. patients are receiving all their nutrients intravenously. Deficiency can also be seen in people with acute infections, during pregnancy and lactation or during intense exercise activity. Chromium deficiency can result in a microcytic anemia and/or poor glucose control.
There are two main types of chromium supplements:
glucose-tolerance factor (GTF) chromium and chromium picolinate.
Chromium is a very popular supplement. It is estimated that sales of chromium are of the order of $85 million per year which accounts for almost 6% of the supplement market. The dosing range of chromium supplements is 200-1000mcg per day. It is best to take chromium supplementation one hour before or 3 hours after thyroid medication as chromium can bind to thyroid hormone and reduce the bioavailability of the hormone.
There are over 1000 chromium products for sale on Amazon and a 500 mcg capsule costs in the order of $0.10.
Can You Get Chromium From Food?
Chromium is found in many foods but usually only in small amounts i.e. less than 2 mcg per serving. The adequate daily intake for chromium ranges from 50 – 200mcg for adults. The adequate daily intake is used when there is insufficient information to make a more formal recommended dietary intake.
Chromium has a very low bioavailability. This means that only a very small percentage of the ingested chromium is actually absorbed into the body. It is estimated that between 0.4% – 2.5% of ingested chromium is absorbed. Put another way, up to 99.6% of any chromium supplement is excreted and offers no health benefits. So $0.096 of every $0.10 that is spent on chromium is excreted or $81.6 million of the $85 million spent on chromium is excreted. That is a very sobering thought.
On the plus side, the bioavailability of chromium can be increased by taking it with vitamin C or niacin.
Potential food sources of chromium and typical chromium content (mcg) are as follows:
- broccoli (1/2 cup) 11
- grape juice (1 cup) 8
- beef (3oz) 2
- whole-grain bread (2 slices) 2
- garlic dried 1 teaspoon 3
- apple (unpeeled) 1
Is There Any Research?
There are over 35,000 studies on chromium which include 797 human clinical trials. As the main interest in chromium lies in the field of diabetes, let’s compare chromiums’ research track to insulin. Insulin has over 377,000 publications and almost 25,000 human clinical trials.
Does Chromium Control Blood Sugar and Prevent Diabetes?
This is the million dollar question (quite literally).
A 2014 systematic review looked at the efficacy and safety of chromium in diabetes (1).
The reviewers identified a total of 25 randomized controlled trials. Of these 25 trials, 22 were related to chromium monotherapy and 3 involved chromium plus either vitamins or biotin. Trials included in the studies were of at least 3 weeks duration.
The analysis found that chromium resulted in statistically significant improvements in glycemic control (p=0.001). The effects of chromium on glucose control was especially noted in the studies that used chromium picolinate. Optimal sugar control seemed to occur at doses of chromium of greater than 200mcg per day. Chromium supplementation also had statistically significant benefits on triglycerides and HDL-cholesterol. Longterm data on safety and efficacy could not be inferred from the studies. Overall this looks like a positive result
They state that the value of chromium in diabetes is inconclusive and insufficient to support the routine use of chromium. They especially caution against the use of chromium in people without underlying nutritional deficiencies.
I note that the Office of Dietary Supplements does not reference the 2014 meta-analysis in their chromium datasheet. Instead they base their recommendations on a 2002 review which looked at 618 participants from the 15 trials (193 participants had type 2 diabetes and 425 were in good health or had impaired glucose tolerance) (4).
The review concluded that data from trials show no effect of chromium on glucose or insulin concentrations in non diabetic subjects. Only one study in the review showed any benefit of chromium. This study was done in China and the reviewers speculated that these patients may have had baseline chromium deficiency which could explain the benefits seen in this study.
The most recent meta-analysis suggests that chromium (especially picolinate) can help in diabetes. However, neither the American Diabetes Association nor the Office of Dietary Supplements recommend chromium for diabetes and do not refer to this meta-anlaysis in their most recent guidelines.
Does It Reduce Weight Gain or Overeating or Boost Metabolism?
There is significant interest in the possible role of chromium in weight loss and chromium supplements are marketed as slimming aids. This interest represents the intersection of two things. Firstly, the modern obsession with weight loss. Secondly, the fact that there is a theoretical basis for a role for chromium in weight loss.
Chromium could potentially affect weight loss by a number of mechanisms including:
- improved metabolism of glucose and carbohydrate
- decreased body fat
- appetite stimulation and
- increased energy expenditure via thermogenesis.
If this theory is correct, then we should see weight loss in people who take chromium (assuming everything that else stays the same in their lives). A 2013 Cochrane review evaluated chromium picolinate for overweight and obese adults (5).
The Chinese team of reviewers evaluated the data from 9 trials involving 622 participants. These studies involved a follow-up time of 24 weeks on average. The review honed in on trying to identify the optimal dose of chromium versus placebo for weight loss. A number of different parameters were included in the review such as body weight, BMI, percentage fat, waist circumference).
The overview found that there was a favourable effect of doses of chromium (200mcg, 400mcg, 500mcg and 1000mcg) on body weight but that the quality of the evidence was low and that the clinical relevance was debatable. Yet another meta-analysis that concludes nothing in particular.
More recently, a 2015 study evaluated the effect of 4 months of treatment with a dietary supplement continuing cinnamon, chromium and carnosine versus placebo in 62 subjects with a high BMI and pre-diabetes (6). This was a single center randomised double-blind placebo controlled trial carried out at an academic centre in Paris.
Only 54 subjects completed the study as 8 subjects were non-compliant with the protocol. These study participants were unwilling to change their diet or exercise routine (the Bacchus syndrome). Body weight and BMI increased significantly in both groups over the study period but no significant differences were noted between the two groups.
Significant decreases in fat free mass (both as a percentage and as an absolute value) were noted in the treatment arm of the study. This really seems like splitting hairs to me. All study participants gained weight is the take home message. There may have been less fat in that weight gain, but weight gain it was.
This time a meta-analysis suggests some benefit of chromium for weight loss but complained about the quality of the data and a more recent study found no benefit.
Does It Reduce High Cholesterol?
Iranian investigators carried out a meta-analysis of trials relating to glucose and lipid profiles in patients with type 2 diabetes (7). A total of 13 studies were initially selected and whittled down to 7 based on quality and selection criteria. Meta-analysis of the studies showed that chromium lowers fasting blood glucose but does not impact on lipids, BMI or HbA1C.
A study from Saudi Arabia found improved lipid profiles in 44 healthy adults who received 200mg of chromium per day as opposed to placebo for 8 weeks (8). On review of the data, the researchers showed statistically significant increases in chromium levels, HDL cholesterol and triglycerides but no significant effects on total cholesterol.
The odd thing about this study is that the study says that the dose of chromium was 200mg. Chromium dose is usually in mcg. This makes me a little uneasy with this study as either the authors made an error or they used supra-physiological doses of chromium. Either way we would not be interested in the data.
An older study in 26 healthy non-obese young adults (mean age 36) compared the effects of chromium nicotinate supplementation versus placebo and found no statistically significant effect on lipids or glucose (9).
Even a sub-analysis which showed some benefit of chromium on glucose levels in people with the highest baseline sugars, failed to show any benefit on lipids in this high risk group.
The more reliable of the studies on chromium and cholesterol showed no benefits.
Does it Improve Brain Health? Fight Cognitive Decline?
A 2015 systematic review looked at 24 trials (6 on omega-3, 7 on vitamin B, 3 on vitamin E, and 8 on other topics including chromium) (10). Statistically significant differences between the intervention and control group were noted in at least one cognitive domain for chromium picolinate.
An Italian study evaluated the correlation between trace elements and cognitive function in 35 patients (11).
The patients were divided into four groups:
- a control group
- cognitive impairment with no dementia
- Alzheimer’s Disease and
- manifest dementia.
Patients underwent cognitive testing, CT scans and blood work. A positive correlation was noted between cognitive function and chromium levels.
Cognitive decline in diabetes deserves a special mention.
Insulin resistance is associated with pathophysiological changes in Alzheimer’s Disease. It is postulated that if chromium improves glucose metabolism in diabetic patients, then it could improve memory in older adults with cognitive decline.
A placebo controlled trial of chromium picolinate versus placebo for 12 weeks in 26 older patients was designed to address this question (12).
Cognitive function was assessed doing standard testing plus functional MRI scanning. Learning rates and retention were not improved but improvements were noted in learning recall and recognition memory tasks. Increased activation was noted in the right thalamic, temporal and posterior parietal areas. The authors concluded that chromium supplementation can enhance cognition in older adults at risk of neurodegenerative disease
Chromium can potentially have a deleterious effect on cognition too. A British audit of 31,171 metal on metal hip implants carried out between 2003 and 2011 found neurocognitive and depressive deficits after cobalt and chromium metalossis (toxic effects of metal in soft tissues) (13).
Data suggest that chromium can have a beneficial effect on cognitive function (unless it builds up in soft tissues).
Is it good for the eyes?
There are two human study linking chromium to issues related to eyes.
This 1994 study showed that holmium-chromium laser may be beneficial in uncontrollable glaucoma but this has nothing to do with our interests (14).
A Turkish study showed that aqueous humour and serum levels of chromium were statistically significantly lower in patients with diabetes and cataracts as compared to patients with senile cataracts (15).
Preliminary data from rats suggests that chromium exerts an antidiabetic effects in a rat model of diabetic retinopathy by regulating the glucose metabolism and suppressing retinal tissue damage (16).
There is no science to support a role for chromium in eye health.
Does It Help Skin? Prevent Acne?
A search for the terms ‘chromium’ and ‘acne’ brings up 12 results. The majority of these results related to environmental exposure to toxins.
One of these papers was published in a journal called Hypotheses in 1984 and rationalized that antioxidant drugs help acne and by extrapolation, chromium could have a similar effect (17). A 2007 paper (again in the journal Hypotheses) hypothesized that chromium could influence the psychological sequelae of acne (18).
The link between acne and psychology was explored in a 2008 series of 5 case reports that involved self-administration with omega-3 and antioxidant nutrients (which included chromium). Based on the positive results on inflammatory acne and global well-being, the authors concluded that these case reports provide the scientific basis for further in-depth clinical studies (19).
More recently, a 2015 study of 1000mcg of chromium picolinate for 6 weeks in 35 girls with polycystic ovarian disease showed no benefits in terms of acne or hirsutism (20).
A randomized controlled trial of 60 patients with polycystic patients with polycystic ovarian syndrome compared chromium 200mcg/day or placebo for 8 weeks. Statistically significant improvements in acne in the chromium arm of the study was noted (21).
There are no studies in the general population (outside of people with polycystic ovarian disease) showing that chromium supplementation helps with acne. At this stage any link between acne and chromium is just a ‘hypothesis’.
Does It Help Bones?
There are 80 studies relating to chromium and bones. Having trawled through these studies, I discovered that the majority of these studies related to surgical comparisons between zirconium and cobalt chromium in total knee replacements which is hardly relevant to our interests.
Chromium has not been proven to help bone health.
Is Chromium (and or Supplementation) Safe?
Chromium is generally considered to be safe.
Given the fact that the fact that chromium may affect blood sugar, it is advisable that people with diabetes or people who are taking medications to control glucose should take extra care when considering chromium supplements and should ideally only do so under medical supervision.
There are some case reports of kidney injury in people who took chromium picolinate. Exposure to chromium via the respiratory tract is a potential occupational hazard. Chromium allergy and dermatitis is well documented especially in the construction industry (22). Acute toxicity can present with a wide range of symptoms including teratogenicity, carcinogenesis, hematological toxicity, coma, renal and liver failure.
There are a number of potential drug-supplement interactions with chromium.
Drugs which reduce stomach acidity e.g. proton pump inhibitors, H2 antagonists and antacids can all impair the absorption of chromium. Other drugs that can have clinically significant drug interactions with chromium include vitamin C, NSAIDS, steroids and beta-blockers.
I suspect that there have been more studies looking at chromium in the stainless steel industry than in the field of human health. There is evidence to support the use of chromium for cognitive function. The American Diabetes Society do not recommend the routine use of chromium for diabetes and remind us all that we should aim to meet our daily micronutrient needs from our diet. I wholeheartedly agree.
However, I think that we should acknowledge the results of the 2014 meta-analysis which showed that chromium can help with glycemic control in diabetes. If you are going to take chromium, then the #healthybutsmart way to do it would be to use the science that we discussed;
- consult with your physician,
- measure your baseline chromium levels (notwithstanding the limitations of relating plamsa levels to body stores),
- go for a good quality brand,
- choose a picolinate formulation at a minimum dose of 200mcg
- take with vitamin C or biotin.
In order to manage your expectations, it would not be reasonable to expect to see improvements in bone health, eye health, lipid profile or weight as the evidence does not support these indications for chromium.