India, Aug. 29 -- "Doctor, my cortisol is acting up." It is a sentence I hear often. A patient recently came to see me with fatigue, disturbed sleep, and some weight gain. Searching the internet, she was convinced that her "cortisol was too high" and had discovered a bewildering array of advice on how to "lower cortisol naturally".

Cortisol has become one of the most talked-about hormones on social media. It is blamed for abdominal obesity, poor sleep, anxiety, ageing, and lack of energy. Numerous websites and holistic practitioners promote coconut water, apple cider vinegar and rhodiola as ways of reducing cortisol. However, there is no good evidence that these remedies reliably lower or manage cortisol.

The irony is that cortisol is n...