Coffee secrets

Too much coffee gives me excruciating cramps. And, of course, I can’t sleep. The question to the resident dietician was whether the diuretic effect of coffee causes dehydration, and whether then the cramps are a symptom of that. And, whether attempting to remedy the situation by rehydrating with salt and quinine (in tonic water) can help. Here’s the definitive response:

Caffeine is in lots of things – coffee, tea, chocolate (and decaffeinated coffee but less of it). It does act as a diuretic by increasing blood pressure (slightly) and causing kidneys to basically ‘make urine’ (strong accent here) more frequently. However, coffee doesn’t dehydrate you – in fact it is an important source of fluids for much of our population (as is tea for old ladies). (Alcohol is a diuretic because it decreases the release of Anti-diuretic hormone from the adrenal glands). Boiled coffee has been associated with increased cholesterol but coffee has also been linked with reduced risk for diabetes and Alzheimer’s (if I remember rightly it is specifically Alzheimer’s). It is also associated with increased gastroesophageal reflux disease – the very painful (can feel like a heart attack, upper chest pains) reflux of stomach acid into the upper digestive tract (all types of coffee thought perhaps to relax the oesophageal sphincter by interfering with the binding of GABA (calming hormone) to its receptors. Also increases release of stress hormones (adrenaline, noradrenaline, cortisol). Does that help? Could your symptoms be gastroesophageal reflux disease instead? I doubt it but worth considering. And if you want to sleep better perhaps could avoid dark chocolate also (caffeine content is 20mg/25g – coffee = 60-100mg/cup). (Water itself could be classed as a diuretic – it causes you to pee more). Be careful with making up hypotonic solutions – increasing salt incorrectly = increased blood pressure = diuretic effect!)