Make Hair Turn Gray Faster

Fashionable man with gray hair
Q: Will not washing my hair properly make it turn gray faster? How about the opposite? Will washing my hair with hot water too often make it turn gray faster?
A: Gray hair is caused by decreasing melanin in the hair. Melanin is basically the color or pigmentation that is present in your hair. It gives your hair its certain color. There are two types of melanin; namely eumelanin and pheomelanin.
Eumelanin is the type of melanin/pigmentation that causes hair to be very dark/black or brown. People with less eumelanin present in their hair will have light brown hair. Pheomelanin is the type of melanin/pigment that causes people to have red or blonde hair. If you have a lot of pheomelanin, you will have deep red hair. If you have very little pheomelanin, you’ll have light blonde hair.
People who are naturally blonde, tend to become gray much faster than people with naturally dark hair. As people age, most have a combination of hair that still has pigmentation/melanin left in it, and hair that has no pigmentation present in the shaft; thus white hair. This combination of white and colored hair gives the hair its gray appearance. As the amount of white hair increases, it will sport a progressively gray appearance until the hair is completely white.
Normal water or shampoo shouldn’t be able to strip your hair of its pigmentation. The pigmentation isn’t particles that sit superficially on the surface of the hair. The pigmentation is attached to the inner structure of the hair, and is covered by hair cuticles. A strong chemical process must be present to open the hair’s cuticles, penetrate towards the cortex of the hair shaft, and strip the hair of its natural pigmentation/color, to be able to turn the hair lighter/ have a graying effect.
This being said, there are some overpowering elements in the areas of some countries that can have a dulling, breaking or even lightening effect on your hair. I know of many people who live in the United Arab Emirates who complain of dull, lifeless and breaking hair. This is because 70% or the UAE uses desalinated water. Desalinated water is seawater that is stripped of its salt content, with added chlorine etc. The chlorine in this water can cause a lightening effect on the hair when coupled with continuous contact with direct strong sunlight, as is often the case in areas with a desert or semi-desert climate.
It’s not only the countries with desalinated water that add chlorine to their water. Chlorine is added to almost all water that you will get out of the tap in your home. This is to cleanse the water and kill any harmful bacteria etc. that may be present in the water. Unfortunately chlorine can have a damaging effect to your hair.
There is a residue of chlorine left on your hair even after you have rinsed all the water from your hair. When you apply heat (blow drying, sun, flat iron etc.) to your hair, the heat may cause a chemical reaction when coupled with the residue chlorine, which strips the hair of some of its pigmentation, thus making the hair appear lighter or increasingly gray.
See also:
Going gray
Gray hair myths
The difference between gray and white hair