Ever feel woozy in the head when thirsty? That’s because the dehydration causes brain fatigue. The brain is easily about 75% water, and it’s not just sloshing around in the skull for no reason. If the body (and brain) doesn’t get enough water, acid levels become higher and inflammation develops, which leads to a host of diseases. The brain is, therefore, not immune to such a hostile environment and begins to deteriorate (leading to dementia).

Forget the adage that drinking eight glasses of water on a daily basis is all it ever takes. The actual (American) calculation that led to this oversimplified statement is that however many pounds someone weighs is to be multiplied by 67% to produce the total fluid ounces of water intake per day. It just so happens that for most people, it comes out to about 8 cups (of 8 ounces, about 250ml) per day. Instead of the formula being circulated (which would mean that everyone would have a slightly different result because their body weight is different), the answer was circulated instead and most people are consuming too much or not enough water – and their brains are suffering. Add to this confusion the fact that a person’s activity level should also be factored in: add 12 fluid ounces (about 375ml) for every 30 minutes of exercise.

Calculations aside, it should be common sense and experience that minor headaches and dizziness can often be alleviated by drinking water. The same goes for certain pangs of hunger (which is often dehydration in disguise), which also goes away after drinking water. It’s the brain crying out for hydration the way wilting plants are signalling for attention. These instances of dehydration accumulate over a lifetime, and it is often after six, seven, or eight decades of life that the consequences (in the form of dementia) can be truly visible.