Chrome

Chromium is a shiny white-bluish heavy metal with the atomic number 24 in the periodic table of elements and the chemical symbol Cr. It does not occur on earth in elemental form. The most important chromium-containing ore is chromite (chrome iron ore). Red lead ore (PbCrO4) should also be mentioned, but this is of lesser importance for chromium extraction. Chromium is the 20th most common element in the earth's crust and is found in soils in a concentration of between 10 and 90 mg per kilogram of soil, depending on the type of soil and region. The French chemist Louis Nicolas Vauquelin (1763 - 1829) discovered the element in 1797. In industry, chromium is the most important alloying metal for the production of stainless chromium steels and is also used in the production of dyes, e.g. as chromium oxide green. Chromium is a mineral that exists in various forms. Although hazardous forms of chromium are found in industrial contaminants, a safe form is found in food (1). This safe form - trivalent chromium - is typically considered essential for the human body, meaning that it must be supplied through the diet. Although some scientists question whether this mineral is truly essential, it has many important functions in the body (2). For example, chromium is part of a molecule called chromodulin, which helps the hormone insulin to exert its effects in the body (3, 4). Insulin is a hormone produced by the pancreas and is important for the processing of carbohydrates, fats and proteins in the body (5). Interestingly, the absorption rate of chromium in the digestive tract is very low and is less than 2.5% of the amount of chromium consumed in the diet (1). However, there is a modified form of chromium known as chromium picolinate that is better absorbed by the body. For this reason, chromium picolinate is found in many dietary supplements (3, 6). Chromium picolinate is a chromium molecule to which three molecules of picolinic acid have been attached (3).

Functions in the body

Chromium is an essential trace element, but excessive doses or intakes can also lead to health problems such as allergies and even cancer. In the human body, chromium plays an important role in the metabolism of carbohydrates. Chromium is stored in internal organs such as the liver and spleen, but is also increasingly found in bones, fat and muscles. It is a cofactor of some enzymes and is involved in carbohydrate (sugar) and fat metabolism. Chromium promotes the transport of amino acids to the cells of the heart and liver and also enhances the effect of insulin. As a result, it promotes muscle building and increases the breakdown of fat. Large amounts of chromium are also present in the cell nuclei (nuclei), where DNA is read and replicated. Chromium can be seen here as a direct cofactor of enzymes in various places. Finally, chromium probably influences the maintenance and functionality of the cornea and the lens of the eye.

Potential health benefits

Chromium has a number of potential health benefits, which we will look at in more detail in the following sections along with the scientific evidence.

Chromium could improve blood sugar levels

In healthy people, the hormone insulin plays an important role in signaling the body to transport blood sugar into the cells. In people who suffer from diabetes, there are problems with the normal response to insulin. Several studies suggest that taking chromium supplements can improve blood sugar levels in diabetics (7, 8). One study found that 200 µg of chromium per day over a 16-week period was able to lower blood glucose and insulin levels while improving the body's response to insulin (8). Other studies have shown that people with higher blood glucose levels and lower insulin sensitivity responded better to chromium supplements (9, 10). In addition, a large study of 62,000 adults found that those who took chromium supplements were 27% less likely to develop diabetes (11). However, other studies with three or more months of chromium supplementation did not show any improvement in blood glucose levels in adults with type 2 diabetes (12). In addition, studies conducted with healthy adults who did not suffer from diabetes concluded that 1,000 µg of chromium picolinate did not improve the body's response to insulin (13). Another study of 425 adult volunteers also concluded that chromium supplements did not alter blood glucose or insulin levels (14). All in all, the greatest benefits of chromium supplements were observed in diabetics. However, although some studies have not observed benefits in blood glucose levels and insulin sensitivity in healthy people without deficiency symptoms, this may be quite different in people who have a suboptimal supply of chromium or chromium deficiency due to an increased need for chromium or for other reasons, as chromium deficiency can severely impair insulin sensitivity and blood glucose control. Summary: For diabetics, chromium supplements may be effective in improving the body's response to insulin or lowering blood glucose levels. However, the results are mixed and these benefits have typically not been observed in people without diabetes. However, this is likely to be different for people with an inadequate chromium supply.

Chromium could reduce hunger and cravings

Most people who have tried to lose weight and maintain their new weight are very familiar with feelings of hunger and strong cravings. As a result, many are interested in foods, supplements or medications that can help fight these urges.

Several studies have investigated whether chromium picolinate could be useful in this regard. In one eight-week study, 1,000 µg of chromium per day in the form of chromium picolinate reduced food intake, hunger and cravings in healthy overweight women (15). The scientists reported that the effects of chromium on the brain may have produced these effects. Other studies have looked at people with binge-eating eating disorders or depression, as these populations may benefit most from suppressing cravings and hunger. In an eight-week study, 113 people with depression were assigned to either a group that received 600 µg of chromium in the form of chromium picolinate daily or a placebo group. The scientists found that appetite and cravings were reduced more by chromium picolinate supplements than by the placebo (16). In addition, a small study observed possible benefits in people suffering from binge eating disorder. In particular, doses of 600 to 1,000 µg could lead to reductions in the frequency of binge-eating episodes and a reduction in symptoms of depression (17).

• Summary: Although data is limited, some research suggests that 600 to 1,000 µg of chromium picolinate per day may help reduce hunger, cravings and binge eating in some people.

Could chromium help with weight loss?

Because of the role chromium plays in nutrient metabolism and the potential effects chromium may have on eating behavior, some studies have investigated whether chromium could be an effective weight loss supplement. A large meta-analysis looked at 9 studies involving a total of 622 overweight or obese people to get a full picture of whether chromium could be useful for weight loss. Up to 1,000 µg of chromium picolinate was used in these studies. Overall, these studies concluded that chromium picolinate produced a modest weight loss of about 1.1 kilograms within 12 to 16 weeks in overweight or obese people. However, the researchers concluded that the effectiveness of chromium for weight loss is questionable and further research is needed (18). A further analysis of the available research came to a similar conclusion (19). An analysis of 11 studies showed an average weight loss of 0.5 kilograms within 8 to 26 weeks of chromium supplementation. Further studies with healthy adults did not observe any effects of chromium supplements on body composition, even in combination with exercise (6).

Food sources

While chromium picolinate is typically only found in supplements, many foods contain the mineral chromium. In this context, it is important to mention that cultivation and processing methods can influence the chromium content of foods (1). For this reason, the actual chromium content of a particular food may vary and there is therefore no reliable database on the chromium content of foods. In addition, most chromium-containing foods contain very low amounts of chromium, often only in the range of 1 to 2 µg per serving (20). In the USA, the recommended daily intake of chromium is 35 μg/day for adult men and 25 μg/day for adult women (20). From the age of 50, these recommendations decrease slightly to 30 μg/day for adult men and 20 μg/day for adult women. However, it is important to note that these recommendations were developed using the estimated intakes of specific populations. For this reason, these recommendations are tentative in nature (20). Despite the uncertainty regarding the true chromium content of most foods and the uncertain intake recommendations, chromium deficiency appears to be rare (1). In general, whole grains and some fruits and vegetables are considered good sources of chromium (1, 21). Some studies have reported that broccoli is rich in chromium with about 11 µg of chromium per half cup, while oranges and apples contain about 6 µg of chromium per serving (1, 22). All in all, a balanced diet that includes a wide variety of minimally processed foods could help meet chromium needs.

Chromium deficiency

Chromium deficiency can trigger symptoms similar to diabetes mellitus (diabetes) by disrupting sugar metabolism. Here too, the connections are not yet fully understood. Coronary heart disease and an increase in fatty acid levels in the blood could also be caused by a lack of chromium. General signs: Nervousness, irritability, confusion, depression, learning difficulties; increased urination, weight loss, itching, muscle weakness.

Other known consequences of chromium deficiency are clouding of the lens and cornea and growth retardation in children.

Overdose/poisoning

Trivalent chromium is hardly absorbed by the body, which is why trivalent chromium salts are also less toxic. Hexavalent chromium, on the other hand, is better absorbed and is therefore more likely to be classified as toxic to humans.

Hexavalent chromium is contained in cement, for example, and can trigger an allergy or symptoms of poisoning in people who are exposed to it. Hexavalent chromium compounds can also be found in wood preservatives and insecticides. Pressure-treated wood in gardens is also frequently contaminated with chromium salts.

Acute poisoning

Due to the highly corrosive effect of chromium compounds, acute chromium poisoning is characterized by severe gastrointestinal symptoms: Vomiting of yellow to greenish masses, which may also be bloody, as well as severe pain and diarrhea. The symptoms can lead to shock and, in the worst case, death. If acute poisoning is survived, changes in the blood count can develop as well as kidney and liver damage.

Chronic poisoning

Chronic chromium poisoning is characterized by poorly healing ulcers on the skin after skin injuries as well as rhinitis and nosebleeds caused by inhaled chromium dust. Conjunctivitis can occur in the eyes. Allergies (cement allergy) can develop in people who are exposed, e.g. construction workers. Due to the carcinogenic effect of chromium compounds, people who are occupationally exposed to chromium are more likely to develop cancers such as bronchial carcinoma.

Treatment of chromium poisoning

In the case of acute poisoning, it is recommended to drink approx. 250 ml of water immediately to dilute the concentration of the poison in the gastrointestinal tract and reduce the corrosive effect. The administration of activated charcoal is not recommended, but the administration of ascorbic acid (vitamin C) is recommended in order to reduce hexavalent chromium to trivalent chromium, thereby reducing its absorption into the body. Furthermore, the loss of electrolytes and water during vomiting must be compensated for and any shock that may occur must be treated.

The treatment of chronic poisoning depends on the symptoms.

Nutritional requirements

The German Nutrition Society (DGE) specifies a daily requirement of between 30 and 100 micrograms of chromium for adolescents and adults. Pregnant women, older people, as their chromium deposits are depleted with age, malnutrition or extreme stress situations can lead to an increased need for chromium.

Need in sport

Sports scientists have found that crompicolinate combined with strength training leads to significant muscle growth and a simultaneous reduction in body fat. Football players experienced an average muscle gain of 5.69 pounds, while the body fat percentage decreased by 22%. Chromium supplementation (over 24 weeks) showed a significantly greater increase in lean body mass in swimmers and a clear reduction in body fat compared to the control group. Realistically, an additional muscle gain of 1-2 kg per year seems possible in the long term with a regular intake of chromium in bodybuilders. However, measurable effects overnight should not be expected.

My recommendation is to take 400-800mcg of chromium picolinate a day with meals. However, I must point out that chromium supplementation only pays off in the long term.

Safety and side effects

Chromium is probably safe and harmless for most adults when used appropriately for up to 6 months. Chromium is potentially safe and harmless for most people when taken for longer periods.

Possible side effects include skin irritation, headache, dizziness, nausea, changes in mood and impaired thinking, decision-making and coordination. High doses have been associated with more serious side effects including blood disorders, liver or kidney damage and other problems. However, it is not known whether chromium is actually the cause of these side effects. An upper tolerable limit, up to which harmful side effects should not be expected, has not yet been established for chromium. However, values for a recommended adequate intake have been established:

• Infants from 0 to 6 months: 0.2 mcg
• Infants from 7 to 12 months: 5.5 mcg
• Children from 1 to 3 years: 11 mcg
• Children from 4 to 8 years: 15 mcg
• Boys from 9 to 13 years: 25 mcg
• Men from 14 to 50 years: 35 mcg
• Men aged 51 and over: 30 mcg
• Girls from 9 to 13 years: 21 mcg
• Girls from 14 to 18 years: 24 mcg
• Women from 19 to 50 years: 25 mcg
• Women aged 51 and over: 20 mcg
• Pregnant women from 14 to 18 years: 29 mcg
• Pregnant women from 19 to 50 years: 30 mcg
• Breastfeeding women from 14 to 18 years: 44 mcg
• Breastfeeding women from 19 to 50 years: 45 mcg

Some studies have questioned the safety of chromium picolinate. Based on how this form of chromium is processed in the body, it can create harmful molecules called hydroxyl radicals (3). These molecules can damage DNA and cause other problems (20). Interestingly, these negative effects only seem to occur when chromium is used in the form of chromium picolinate.

Precautions and warnings

Pregnancy and lactation: Chromium is probably safe and harmless during pregnancy and lactation when taken orally in amounts not exceeding the recommended adequate intake (see above). However, women should not take chromium supplements during pregnancy and lactation unless prescribed by a physician. Kidney problems: There are at least three reports of kidney damage in patients who have taken chromium picolinate. You should therefore not use chromium supplements if you suffer from kidney problems.

• Liver disorders: There are three reports of liver damage in patients who have taken chromium picolinate. You should therefore not use chromium supplements if you suffer from liver problems.
• Diabetes: Chromium may lower blood sugar levels too much when combined with diabetes medications. For this reason, diabetics should use chromium products with caution and carefully monitor their blood sugar levels. It is possible that the dosage of diabetes medication may need to be adjusted.
• Chromate/leather contact allergy: Chromium supplements can cause allergic reactions in people who suffer from chromate or leather contact allergy. Symptoms include redness, swelling and flaking of the skin.

Behavioral or psychiatric disorders such as depression, anxiety or schizophrenia: Chromium could affect brain chemistry and exacerbate behavioral or psychiatric disorders. If you suffer from any of these disorders, you should be careful when using chromium supplements and watch for changes in mood.

Interactions

Care should be taken when combining chromium with the following medications:

Insulin

Chromium could lower blood sugar. Insulin is also used to lower blood sugar levels. Taking chromium in combination with insulin could result in an excessive drop in blood sugar levels. For this reason, blood glucose levels should be carefully monitored. It is possible that the dosage of diabetes medication may need to be adjusted.

Levothyroxine

Chromium may reduce the amount of levothyroxine absorbed by the body. This could reduce the effectiveness of levothyroxine. To avoid this interaction, levothyroxine should be taken 30 minutes before or 3 to 4 hours after chromium.

Care should be taken when combining chromium with the following medications:

Non-steroidal anti-inflammatory drugs

Non-steroidal anti-inflammatory drugs are used to reduce pain and swelling. Non-steroidal anti-inflammatory drugs may increase chromium levels in the body and the risk of side effects. For this reason, non-steroidal anti-inflammatory drugs and chromium should not be taken at the same time.

Conclusion

Chromium Picolinate is the form of chromium found in most supplements available. Chromium may be effective in improving the body's response to insulin and lowering blood sugar levels in diabetics or people with reduced insulin sensitivity. In addition, chromium could help reduce hunger, cravings and binge eating. However, chromium does not appear to be effective in producing significant weight loss - at least unless there is a chromium deficiency.

Chromium deficiency appears to be rare and there are also concerns that excessive amounts of chromium may have harmful effects.

References

1. https://ods.od.nih.gov/factsheets/Chromium-HealthProfessional/
2. https://www.ncbi.nlm.nih.gov/pubmed/21086001
3. https://academic.oup.com/jn/article/130/4/715/4686593
4. https://www.ncbi.nlm.nih.gov/pubmed/22423897
5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1204764/
6. https://www.ncbi.nlm.nih.gov/pubmed/12656641
7. https://www.ncbi.nlm.nih.gov/pubmed/24635480
8. http://www.ncbi.nlm.nih.gov/pubmed/16784965
9. https://www.ncbi.nlm.nih.gov/pubmed/20022616
10. https://www.ncbi.nlm.nih.gov/pubmed/20425574
11. https://www.ncbi.nlm.nih.gov/pubmed/26446484
12. https://www.ncbi.nlm.nih.gov/pubmed/23683609
13. http://www.ncbi.nlm.nih.gov/pubmed/19422140
14. https://academic.oup.com/ajcn/article/76/1/148/4689472
15. https://www.ncbi.nlm.nih.gov/pubmed/18715218
16. https://journals.lww.com/practicalpsychiatry/Abstract/2005/09000/A_Double_Blind,_Placebo_Controlled,_Exploratory.4.aspx
17. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4358897/
18. https://www.ncbi.nlm.nih.gov/pubmed/24293292
19. https://www.ncbi.nlm.nih.gov/pubmed/23495911
20. https://www.nap.edu/read/10026/chapter/8
21. https://medlineplus.gov/ency/article/002418.htm
22. https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/food-chromium-content-dietary-chromium-intake-and-related-biological-variables-in-french-free-living-elderly/4F0CE38A26B0B4863078F508F3A69351

Further information

1. Hepburn DD, Vincent JB. In vivo distribution of chromium from chromium picolinate in rats and implications for the safety of the dietary supplement. Chem Res Toxicol. 2002 Feb;15(2):93-100
2. Cefalu WT, Wang ZQ, Zhang XH, Baldor LC, Russell JC. Oral chromium picolinate improves carbohydrate and lipid metabolism and enhances skeletal muscle Glut-4 translocation in obese, hyperinsulinemic (JCR-LA corpulent) rats. J Nutr. 2002 Jun;132(6):1107-14
3. Wilson BE, Gondy A. Effects of chromium supplementation on fasting insulin levels and lipid parameters in healthy, non-obese young subjects. Diabetes Res Clin Pract. 1995 Jun;28(3):179-84
4. Urberg M, Benyi J, John R. Hypocholesterolemic effects of nicotinic acid and chromium supplementation. J Fam Pract. 1988 Dec;27(6):603-6
5. Urberg M, Zemel MB. Evidence for synergism between chromium and nicotinic acid in the control of glucose tolerance in elderly humans. Metabolism. 1987 Sep;36(9):896-9
6. Vincent J. The potential value and toxicity of chromium picolinate as a nutritional supplement, weight loss agent and muscle development agent. Sports Med. 2003;33(3):213-30
7. Campbell WW, Joseph LJ, Anderson RA, Davey SL, Hinton J, Evans WJ. Effects of resistive training and chromium picolinate on body composition and skeletal muscle size in older women. Int J Sport Nutr Exerc Metab. 2002 Jun;12(2):125-35
8. Campbell WW, Joseph LJ, Davey SL, Cyr-Campbell D, Anderson RA, Evans WJ. Effects of resistance training and chromium picolinate on body composition and skeletal muscle in older men. J Appl Physiol. 1999 Jan;86(1):29-39
9. Pittler MH, Stevinson C, Ernst E. Chromium picolinate for reducing body weight: meta-analysis of randomized trials. Int J Obes Relat Metab Disord. 2003 Apr;27(4):522-9
10. Amato P, Morales AJ, Yen SS. Effects of chromium picolinate supplementation on insulin sensitivity, serum lipids, and body composition in healthy, nonobese, older men and women. J Gerontol A Biol Sci Med Sci. 2000 May;55(5):M260-3
11. Joseph LJ, Farrell PA, Davey SL, Evans WJ, Campbell WW. Effect of resistance training with or without chromium picolinate supplementation on glucose metabolism in older men and women. Metabolism. 1999 May;48(5):546-53 [abstract]
12. Volpe SL, Huang HW, Larpadisorn K, Lesser II. Effect of chromium supplementation and exercise on body composition, resting metabolic rate and selected biochemical parameters in moderately obese women following an exercise program. J Am Coll Nutr. 2001 Aug;20(4):293-306
13. Kareus SA, Kelley C, Walton HS, Sinclair PR. Release of Cr(III) from Cr(III) picolinate upon metabolic activation. J Hazard Mater. 2001 Jun 29;84(2-3):163-74
14. Manygoats KR, Yazzie M, Stearns DM. Ultrastructural damage in chromium picolinate-treated cells: a TEM study. Transmission electron microscopy. J Biol Inorg Chem. 2002 Sep;7(7-8):791-8. Epub 2002 Mar 23.
15. Bagchi D, Bagchi M, Balmoori J, Ye X, Stohs SJ. Comparative induction of oxidative stress in cultured J774A.1 macrophage cells by chromium picolinate and chromium nicotinate. Res Commun Mol Pathol Pharmacol. 1997 Sep;97(3):335-46
16. Hepburn DD, Xiao J, Bindom S, Vincent JB, O'Donnell J. Nutritional supplement chromium picolinate causes sterility and lethal mutations in Drosophila melanogaster. Proc Natl Acad Sci U S A. 2003 Apr 1;100(7):3766-71. epub 2003 Mar 20
17. Lanca S, Alves A, Vieira AI, Barata J, de Freitas J, de Carvalho A. Chromium-induced toxic hepatitis. Eur J Intern Med. 2002 Dec;13(8):518-520
18. Clarkson PM. Effects of exercise on chromium levels. Is supplementation required? Sports Med. 1997 Jun;23(6):341-9