Water, it is the elixir of life. With out water, we are dead in about 3 days. That is us, the body, the living cells, tissues and organism. Water isn’t quite so helpful with hair though. Depending on the water chemistry, the hardness of it, what the water has dissolved in it, how long it is on hair, plays a big part in health and manageability of your hair.
Hair is naturally water repellent, like we learned in this previous post. It has lipids or oils that make it not attract water. Soaking hair in water breaks down the ability to repel water, just like when you get pruny skin in the hot tub or pool. This break down of the water repellant nature means more water gets absorbed, which makes the hair swell up and become even less water tight, allowing for even more water access, and then loss, causing dryness during the day. The result of hair swelling is the scales of the cuticle stand out like a scared puffer fish. Honestly the second pic is a much more accurate depiction of cuticle lift from water, because the amount of swelling is about 15% on healthy hair and up to 30% processed and damaged hair.
That swelling and lifting makes the scales prone to chips, cracks, breaking off, or snagging one other hair strands.
The way this all happens is pretty chemical and science-y. To be honest, breaking it down into easy to understand analogies is escaping me, but I'm going to try providing some basics for those who aren't into the science behind it all,
Water by itself is neutral, neither acidic or base. This is important because acids add positive ions to a solution or lose a positive charge from themselves, a base adds negative ions to a solution or loses a negative charge from themselves. Nature loves to find a balance naturally and constantly works to create a balance. Anytime a positive charge comes in contact with a negative charge, the things stick together, just like magnets do. The chemistry involved isn’t as important to understand as knowing the result.
We now know that the effect of water pH on hair is less than once thought. While pH does affect hair and in order to chemically alter hair, the pH must be above 9. The difference in effect from pH 4-ph 8 is quite minimal. Where water really affects hair is in the electrostatic charge.
Hair naturally has a small negative charge to it, some say undamaged hair has no charge, so the charge is minimal in healthy hair. Damaged hair has a higher negative charge, which means it is more reactive to the natural charges in things. Let’s say you have damaged hair, so more negative charge exists in it. Water is going to increase the negative charge. Even at neutral pH (pH is a scale from 0-14, 7 being neutral, under 7 being acid, over 7 being base), neutral water will increase the negative charge in your hair.
When you try to put two negative poles of a magnet together, what happens? They push against each other, right? This is what happens on your hair strands when water pH increases, even when the pH is still on the acid side but above pH of 4. This increase in negative charge results in static electricity and FRIZZ, because your hair strands are pushing each other away from themselves. The greater the damage, the greater the negative charge; the higher the pH, the greater the negative charge; the greater the negative charge, the greater the frizz and static. Yippee!!
This higher negative charge has to be neutralized or counter acted. The good news is, the right products have ingredients in them that are specifically designed to counteract the negative charges with positive ones. The charge allows things to get to and stay on your hair when you rinse them out, like your conditioner, shampoos too, but conditioner more. Styling products depending on what they are designed to do may have more or less positive charge. Some natural force repulsion can give you more volume, depending on your hair type and goal, that might be exactly what you are looking for, or that might be the bane of your existence.
The short answer is, water does affect your hair, period. The details are much bigger and deeper than that simple statement though. In about 6 minutes, your strands have absorbed about as much water as they can. In healthy hair, that amount is far less than it is in damaged hair. The more that swelling happens the more damage you are going to see happen to your hair, which increases your frustration and angst, both of which I think would be considered negative for you, and needs to be balance out.
Is water bad for your hair? No. You need the hydration that water offers to maintain elasticity and strength in your strands. The swelling that water causes is the bad part. So protect your hair from water absorption by maintaining the water repellant capability, either naturally, or by what you put on your hair before washing. Then get your hair dry quickly after washing it to minimize the amount of water uptake and swelling that occurs.
There are oils that work well to increase the water repelling ability of your hair strands. Not all are equal, natural plant based oils will always better than synthetic or petroleum based oils. Oils with small light weigh molecules actually do penetrate the hair strand and offer softness and moisturizing capabilities in addition to the water repelling effects. And a little goes a long way. You don't need to douse your hair in oil, just a light sheen of oil is helpful, then give it time to absorb. Hours are better than minute, and overnight application is even better.