Human blood is about 55 per cent salty water, and about 45 per cent cells - overwhelmingly red
blood cells with a tiny sprinkling of white blood cells and the like. The red blood cells give blood
its red colour.
The salty water, called plasma, is a clear slightly yellowish liquid, with high levels of sodium,
low levels of potassium, and trace amounts of other minerals. Genuine intravenous fluids are manufactured to have high sodium and low potassium.
Coconut water is not identical to the plasma. Instead, it is closer to the liquid inside the red blood cells, with low sodium and high potassium - the exact opposite. Everywhere in your body, when
you compare the liquid inside your hundreds of trillions of cells with the liquid outside these cells, the levels of sodium and potassium are opposite. In fact, each cell has myriads of sodium and potassium pumps to shove the sodium outside, and the potassium inside.
Coconut water has about one-fortieth the sodium level of plasma, while the potassium level is about 10-15 times higher. But besides the high potassium, coconut water is also loaded with calcium and magnesium, which means it's definitely not suitable for patients with kidney failure, severe bums, etc. Another problem is that it is much more acidic than human plasma. The
bottom line is that coconut water is not identical to human plasma.
However, in an emergency, coconut water can be used. One case in the recent medical literature
involved a man who had recently suffered a stroke - in the remote Solomon Islands. He had
difficulty in swallowing, choked on both liquids and solids and repeatedly vomited them up. He was rehydrated with regular IV fluids, and fed via a tube directly into his stomach. After 36 days
in hospital, he could no longer tolerate the feeding tube. Unfortunately, the hospital had run out of IV fluids, and because of its remoteness, would not get supplies for two days.
Over these next two days, the doctors infused about two-and-a-half litres of coconut water, to
tide him over the crisis. He recovered the ability to swallow, and was discharged from hospital on day 39.
So while coconut water is flavour of the month in food-fad land, taking it intravenously might be one step too far!