Chromium & Health
What is Chromium & What Does it Do?
Chromium, like all minerals, is found in the Earth’s crust where it makes its way into plants and then animals. Unlike vitamins, minerals are not created by living organisms, but like vitamins, minerals are essential for life. Chromium is a trace metal that our bodies seemingly use to aid insulin in moving glucose from our blood into our cells for the creation of energy.
Admittedly, the body’s use of and need for chromium are not very well understood at this time; however, as we continue our quest to better understand ourselves and our relationship with the world around us through scientific inquiry, we hope to learn more.
Outside of the body, chromium is used like other metals and is used in the production of stainless steel, pigments, leather tanning, and more. (1) In its hexavalent form, chromium is toxic to life when inhaled. The form our bodies use is a trivalent form, and this small change in chemical structure makes all the difference! (2)
Chromium Deficiency:
Chromium is another ubiquitous substance, so deficiency is hard to find. At this time, we have no animal models of chromium deficiency, and we have only seen potential cases in patients being fed medical diets without supplemental chromium - this is not standard practice. In these cases, patients developed symptoms of insulin resistance similar to what we find in individuals with type 2 diabetes. (2)
A Side-Note on Insulin Resistance:
Insulin resistance develops in genetically susceptible individuals, meaning it tends to run in families. It is also highly influenced by diet, exercise, and stress tolerance. Left untreated, insulin resistance leads to a variety of conditions including obesity, cardiovascular disease, fatty liver disease, metabolic syndrome, gestational diabetes, polycystic ovarian syndrome, and eventually type 2 diabetes. (3)
So, what exactly is insulin resistance? First let’s look at what insulin does:
Insulin is a hormone released by the pancreas in response to rising blood glucose (sugar) levels. Its job is to move glucose out of the blood and into cells for storage or energy production. This glucose can be moved into any cell with mitochondria to make energy, or it can be stored as glycogen by the liver or muscles or as fat in adipocytes for later use.
Insulin resistance develops when our cells no longer respond very well to insulin. Think of insulin as the key that opens a door into the cell and lets glucose in. With insulin resistance, that lock is getting jammed leaving lots of glucose stuck on the outside.
Where does chromium come in? It helps cells respond to insulin. (2) Think of chromium as the WD-40 that lubricates the lock, making it easier to use. It can’t fix all possible causes of the jam, but it can help if “lubrication” is what is needed.
Other ways to increase insulin sensitivity include fat loss, increased muscle mass, exercise, avoidance of simple carbohydrates, and some medications. Insulin resistance tends to come on about ten to fifteen years before type 2 diabetes, so catching it early is important for prevention!
Prevention of Disease:
In theory, chromium may play a role in the prevention of diabetes, but we do not have the scientific studies to back this claim up. Additionally, as we see above, chromium is just one piece of the puzzle when it comes to insulin resistance and diabetes.
Disease Treatment:
When it comes to using chromium supplementation to treat disease, the evidence is all over the map. Studies work with different populations, different forms of chromium, different doses, and different durations of treatment. This can create quite a bit of confusion with interpretation.
That being said, I’ve found a few meta analyses (studies of the studies) showing some support for the role of chromium in the treatment of the following conditions:
Polycystic Ovarian Syndrome:
“This systematic review and meta-analysis shows that using Cr picolinate supplementation has beneficial effects on decreasing BMI, fasting insulin and free testosterone in PCOS patients.” (4) Each of the measures listed above are elevated in polycystic ovarian syndrome and are targets for treatment.
High Cholesterol:
“Our meta-analysis reveals that there was only an overall significant association between chromium supplementation with decreases in the concentration of TC [total cholesterol].” (5) This finding showed a lowering of total cholesterol but not LDL “bad” cholesterol.
High Blood Pressure:
“The current meta-analysis, indicated that supplementation with chromium significantly decreased [Systolic Blood Pressure] and [Diastolic Blood Pressure]. In subgroup analysis, administration of chromium yeast and brewer's yeast resulted in greater reduction in SBP.” (6) Here we see a study that looked at the difference between a chromium supplement vs a food-based form of chromium with the food source having a greater effect!
Diabetes mellitus:
“The use of chromium supplements can reduce the glycosylated hemoglobin of type 2 diabetic patients to a certain extent, but it cannot effectively improve the fasting blood glucose and blood lipid levels of type 2 diabetic patients.” (7)
“ In conclusion, chromium supplementation decreased oxidative stress in diabetes mellitus.” (8) Remember, oxidative stress is associated with inflammation and tissue damage, so this is important information.
“Chromium supplementation may significantly improve lipid profile in patients with T2DM by decreasing [triglycerides] and [total cholesterol] and increasing HDL. However, based on our analysis, chromium failed to affect LDL. It should be noted that the lipid-lowering properties of chromium supplementation were small and may not reach clinical importance.” (9)
“The present systematic review and meta-analysis shows that supplementation with chromium at dose of 200-1000 μg/day may reduce [diastolic blood pressure] and MDA [measure of lipid oxidation] in T2DM [type two diabetes] patients.” (10)
“ The results of the current meta-analysis study might support the use of chromium supplementation for the improvement of glycemic control indices in T2DM patients.” (11)
“Cr supplementation with brewer's yeast may provide marginal benefits in lowering [fasting glucose] in patients with T2DM compared to placebo however it did not have any effect on A1C.” (12) Here we see the same results as the first study in this list.
Please also note that for each of the studies quoted above, there were additional studies that found little or no effect from chromium supplementation for the same conditions. This may be another case where a balanced diet that includes chromium has a greater effect than supplementation alone.
Toxicity:
There is some evidence that high level supplementation of chromium picolinate (the most studied and supplemented form) may have negative consequences for some people. Measures of DNA damage may be elevated, kidney failure may be triggered, and liver function may be decreased. This isn’t true for everyone, but we also do not know who is at increased risk for these side effects. (2)
Where to Find Chromium:
Foods particularly rich in chromium include: (1),(2)
Fruits, especially grapes
Vegetables, especially broccoli
Grains, especially wheat germ
Organ Meats
Mushrooms
Nutritional/Brewer’s yeast
Applications:
Our takeaways this week are:
Chromium seems to play a role in insulin sensitivity.
Insulin resistance is most affected by genetics and lifestyle and often precedes type 2 diabetes by 10 - 15 years. Chromium may play a role here too.
The evidence on chromium’s role in disease prevention and treatment is spotty at best.
There are possible negative side effects from long-term high level supplementation of chromium picolinate.
Daily Intake:
Since we do not have a good way of measuring chromium levels in people and we have not seen many cases of chromium deficiency, we do not have enough information to set an RDA for chromium intake. Alternatively, as with other nutrients in similar situations, an Adequate Intake (AI) level of 20-35 mcg has been established for adults. (2)
Medication and Nutrient Interactions:
Again, not much is known in this realm. We do see Vitamin C aiding in the absorption of chromium and simple carbohydrates increasing the excretion of chromium. Chromium supplementation may also interfere with the absorption of levothyroxine and iron, so high doses should be taken away from both of these substances. (2)
Next week:
Next week we will investigate copper.
To our health!
References:
USGS Mineral Resources Program, “Chromium--Makes Stainless Steel Stainless” Fact Sheet 2010-3089, September 2010, Accessed Nov 23, 2021, https://pubs.usgs.gov/fs/2010/3089/pdf/fs2010-3089.pdf
Higdon, J, “Chromium” Linus Pauling Institute, 2000; last update: 2014; accessed November 23, 2021; https://lpi.oregonstate.edu/mic/minerals/chromium
Freeman AM, Pennings N. Insulin Resistance. 2021 Jul 10. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–. PMID: 29939616.
Fazelian S, Rouhani MH, Bank SS, Amani R. Chromium supplementation and polycystic ovary syndrome: A systematic review and meta-analysis. J Trace Elem Med Biol. 2017 Jul;42:92-96. doi: 10.1016/j.jtemb.2017.04.008. Epub 2017 Apr 21. PMID: 28595797.
Tarrahi MJ, Tarrahi MA, Rafiee M, Mansourian M. The effects of chromium supplementation on lipid profile in humans: A systematic review and meta-analysis of randomized controlled trials. Pharmacol Res. 2021 Feb;164:105308. doi: 10.1016/j.phrs.2020.105308. Epub 2020 Nov 14. PMID: 33197598.
Lari A, Fatahi S, Sohouli MH, Shidfar F. The Impact of Chromium Supplementation on Blood Pressure: A Systematic Review and Dose-Response Meta‑Analysis of Randomized‑Controlled Trials. High Blood Press Cardiovasc Prev. 2021 Jul;28(4):333-342. doi: 10.1007/s40292-021-00456-8. Epub 2021 Jun 3. PMID: 34081296.
Zhao F, Pan D, Wang N, Xia H, Zhang H, Wang S, Sun G. Effect of Chromium Supplementation on Blood Glucose and Lipid Levels in Patients with Type 2 Diabetes Mellitus: a Systematic Review and Meta-analysis. Biol Trace Elem Res. 2021 Mar 30. doi: 10.1007/s12011-021-02693-3. Epub ahead of print. PMID: 33783683.
Kooshki F, Tutunchi H, Vajdi M, Karimi A, Niazkar HR, Shoorei H, Pourghassem Gargari B. A Comprehensive insight into the effect of chromium supplementation on oxidative stress indices in diabetes mellitus: A systematic review. Clin Exp Pharmacol Physiol. 2021 Mar;48(3):291-309. doi: 10.1111/1440-1681.13462. Epub 2021 Jan 18. PMID: 33462845.
Asbaghi O, Naeini F, Ashtary-Larky D, Moradi S, Zakeri N, Eslampour E, Kelishadi MR, Naeini AA. Effects of chromium supplementation on lipid profile in patients with type 2 diabetes: A systematic review and dose-response meta-analysis of randomized controlled trials. J Trace Elem Med Biol. 2021 Jul;66:126741. doi: 10.1016/j.jtemb.2021.126741. Epub 2021 Mar 23. PMID: 33813266.
Asbaghi O, Naeini F, Ashtary-Larky D, Kaviani M, Rezaei Kelishadi M, Eslampour E, Moradi S, Mirzadeh E, Clark CCT, Naeini AA. Effects of chromium supplementation on blood pressure, body mass index, liver function enzymes and malondialdehyde in patients with type 2 diabetes: A systematic review and dose-response meta-analysis of randomized controlled trials. Complement Ther Med. 2021 Aug;60:102755. doi: 10.1016/j.ctim.2021.102755. Epub 2021 Jul 5. PMID: 34237387.
Asbaghi O, Fatemeh N, Mahnaz RK, Ehsan G, Elham E, Behzad N, Damoon AL, Amirmansour AN. Effects of chromium supplementation on glycemic control in patients with type 2 diabetes: a systematic review and meta-analysis of randomized controlled trials. Pharmacol Res. 2020 Nov;161:105098. doi: 10.1016/j.phrs.2020.105098. Epub 2020 Jul 28. PMID: 32730903.
Yin RV, Phung OJ. Effect of chromium supplementation on glycated hemoglobin and fasting plasma glucose in patients with diabetes mellitus. Nutr J. 2015 Feb 13;14:14. doi: 10.1186/1475-2891-14-14. PMID: 25971249; PMCID: PMC4430034.
