Chromium

Chromium (in its trivalent form Cr³⁺, the dietary form) is a trace element present in tiny amounts. It was long considered necessary for insulin to work properly, via a molecule called « glucose tolerance factor ».

A fresh angle (the nutrient we doubt): a rare and interesting case, chromium’s « essential » status is now being questioned. Long classed as an essential trace element, it has been downgraded by some authorities (the European EFSA does not recognise a clearly established essential role). No chromium deficiency has been convincingly demonstrated in healthy humans eating normally.

It is a good example of the evolution of nutrition science: a nutrient once presented as important can be reconsidered as the evidence is refined. This calls for caution in the face of categorical claims.

Supplement marketing (chromium picolinate): despite these uncertainties, chromium (chromium picolinate) is sold as a supplement to « control blood sugar », « reduce sugar cravings » and « help you lose weight ». The evidence for these effects is weak and inconsistent: most serious studies show no significant benefit in people who are not deficient. An example of a supplement oversold on fragile foundations.

In practice: a varied diet provides plenty of chromium (as trace amounts), found in many foods. There is no reason to supplement without evidence of a real need.

Sources: broccoli, meat, wholegrain cereals, nuts, green beans, brewer’s yeast, and traces just about everywhere.