What is it and why does it want to kill me? Sodium

By Emma Deloughery on October 3, 2015

That’s the stuff I’m not supposed to eat too much of.

Sodium is one half of table salt, sodium chloride. It’s an element, meaning it can’t be broken down into smaller parts without losing its properties. One of those properties is the tendency to acquire a positive charge. In sodium chloride, sodium has the positive charge while chloride is negative.

So what makes it so bad for you?

Sodium is actually necessary for proper functioning of your nervous system. Like your computer, microwave or car, your brain and nerves run on electricity, which is simply the movement of charged particles. Sodium has a charge, and the movement of sodium through nerves causes changes that enable you to think and move. Sodium also regulates blood volume, pressure and acidity.

Then shouldn’t I eat more of it?

Your body likes balance. Consuming too much salt can lead to fluid retention and eventually hypertension, where your blood pressure is abnormally high, which can result in heart disease and stroke. However, having too little sodium is also very bad in a more immediate way, causing seizures and heart, liver and kidney failure.

This is very confusing.

It is, and the best way to think of it is to take sodium entirely out of the equation. Sodium levels in your body are inversely related to water levels. When you’re dehydrated, you have higher levels of sodium because the sodium is dissolved in a smaller volume of water. When you drink a lot of water, sodium levels are low because they’re diluted in a large volume of water. So, don’t worry about sodium, and just make sure you stay properly hydrated.

But not too much water.

Exactly. Drink when you’re thirsty and stop when you’re not. Sports drinks brag about having electrolytes—charged particles such as sodium—to replace what you lose through sweat, but the evidence supporting their use is pretty slim.