The Science of New Hair Texture After Chemo
Many men and women who’ve undergone chemotherapy tend to end up with chemo hair. Chemo hair is basically new hair growth that looks nothing like the natural/original hair that a person had prior to receiving chemotherapy and/or radiation. Generally, the person will lose all or most of their hair and then the new, chemo hair is what grows in its place.
Generally, when the hair grows back, you might find the following hair changes:
- Straight hair will be curly
- Kinky hair will be soft and “lamb-like” and might eventually become more wavy.
- Light colored hair might become darker
- Gray hair might become grayer.
- A full head of hair might grow in very thin and wispy in appearance.
No one seems to understand the science behind why this phenomenon occurs. And if you scour the Internet—and I do mean the whole World Wide Web, there is only a tiny amount of information out there.
However, I will try to offer a theory as to why chemo hair might occur—starting with the 4 stages of hair growth.
Stages of Hair Growth
There are 4 hair growth stages: The anogen stage, the catagen phase, the telogen phase and the exogen phase. Some of the hair that you see on your head is in the exogen phase and is anchored onto your hair shaft waiting to shed away. Also, during this time, new hair follicles are developing—These new follicles are the reason your hair will shed because as the new follicles expand, they push out the dead hair (that you see on your head).
Therefore, when you undergo chemotherapy, those new follicles that have hair growing within them will be damaged during the process. But note, the hair still hasn’t emerged yet.
Remember, under normal circumstances, these new hair follicles should be expanding in their natural, respective shapes. So if you have straight hair, the follicle will be round and if you have curly hair, the follicle will be an elliptical shape.
Chemo Affect on Straight Hair
However, if chemotherapy interrupts that cell division/expansion, the shape of the follicle could possibly be damaged or altered and instead of being round, it could become more elliptical, which would allow the cystine proteins to come in closer proximity to each other. Thus, providing a greater probability for increasing the amount of disulfide bonds. The increased disulfide bonding would account for the change in hair texture from straight to wavy/curly. Also, it will account for why the hair might be more coarse.
Chemo Affect on Curly Hair
But what if you have curly hair? How does chemo change it to a loser curl pattern? Curly hair has a greater amount of disulfide bonds than straight hair. However, if the patient underwent chemotherapy and radiation, it is the latter that is the most likely contributor to the change in hair pattern. There are some studies that suggest the absorption of radiation can cleave disulfide bonds. Radiation at the cellular level creates free radicals that with donate an electron and facilitate the breaking of the disulfide bond. The keratin protein begins to unravel, and a wavy/curly hair pattern is the result.
If you’ve undergone chemotherapy and/or radiation, how did it affect your hair and how long did it take for it to revert back to its normal texture?