Chrome
A trace element marketed as an appetite suppressant and fat burner. It is also one of the most extensively tested slimming supplements — and the total amount of it weighs less than a kilo.
Benefits
- Improves glycaemic control in type 2 diabetes: a reduction of 0.6 per cent in glycated haemoglobin and 1.0 mmol/l in fasting blood glucose levels across 41 randomised trials — but no benefit was observed in non-diabetic individuals
- Results in an average weight loss of 0.75 kg in overweight people (21 trials, 1,316 participants), with a reduction of −0.40 BMI points and −0.68 per cent body fat: a genuine effect, although the authors themselves consider its clinical significance to be uncertain
- Reduces insulin resistance in polycystic ovary syndrome and improves the rate of ovulation (10 trials, 683 women)
Precautions
Loose stools, dizziness, headaches and hives have been reported in clinical trials, although meta-analyses have not identified an increased risk of adverse effects at standard doses. Medical advice is essential for those with treated diabetes: chromium affects blood glucose levels and its effect is additive to that of the treatment. In women with polycystic ovary syndrome, a meta-analysis of six trials reports a significant increase in total and free testosterone. It is also important to note – and this is key – that the more chromium is tested, the less remains. An umbrella review of eight meta-analyses found no effect on total cholesterol, LDL, HDL or triglycerides. A meta-analysis of ten trials found no effect on blood pressure. A dose-response meta-analysis of fourteen trials found no effect on body fat, BMI, waist circumference or weight in people with diabetes. In 36 men who undertook eight weeks of strength training, strength and lean body mass increased independently of chromium. Furthermore, a 2019 review concluded that neither the trials, nor the meta-analyses, nor the systematic reviews have shown any clinically significant effect in humans, with the mechanism of action still unclear.
Recommended dosage
Trials use between 200 and 1,000 µg per day, most commonly in the form of chromium picolinate — the most widely studied form. Dietary intake meets requirements in the vast majority of cases: the only deficiency documented here occurred during long-term parenteral nutrition.
Did you know?
An isolated chromium deficiency, which has been little documented to date, can lead to glucose intolerance, an inability to use glucose for energy, and even neuropathy, even with normal insulin levels.
What the studies say
Cette revue systématique et méta-analyse de 20 essais cliniques randomisés a évalué l'efficacité de la supplémentation en chrome chez les personnes en surpoids et obèses. Les résultats ont montré une réduction statistiquement significative du poids corporel en faveur du chrome par rapport au placebo (-0,50 kg). Bien que l'effet soit statistiquement significatif, son ampleur est faible et sa pertinence clinique reste incertaine. Des effets indésirables comme des selles liquides, vertiges, maux de tête et urticaire ont été rapportés.
Onakpoya I, Posadzki P, Ernst E. — Obesity reviews : an official journal of the International Association for the Study of Obesity (2013) — View the source study
For information only: not a substitute for medical advice. Dietary supplements are not a replacement for a varied, balanced diet. Learn more