Heat - always damaging?

[nappywomyn]

I've been thinking about this and wanted to run it past you ladies.

In your personal (or scientific opinion) is any use of heat damaging over the long term, or can you, by using the right serums & protectants and lower temperatures, occasionally use heat without having to worry about any damage over the long term?

[Iylivarae]

Ok... scientific:

Hair is actually protein. Protein is damaged if the temperature is higher than a certain specific denaturation temperature (which differs from protein to protein). The damage is irreversible!

And, if you want to change the structure of your hair, you need to change the structure of the hair protein. If you do that too often, it irreparably changes the structure of the protein -> damage!

[nappywomyn]

Interesting! Do you have any idea what the denaturation temperature is for hair, which is primarily keratin?

[akurah]

I suspect if you keep the temperature below boiling point for water AND below the denaturation point for the keratin in the hair, the heat styling would be harmless. The problem is I don't know the denturation point for the protein...

[nappywomyn]

Yeah - knowing what that point is would make things SO much clearer.

[savi]

The denaturation point of a hair strand depends on it's contents of keratin and cystein (the main proteins that hair consists of) so each is different. The denaturation point of protein is higher than the boiling point of water, but I can't remember the temperature right now. All I found was this :



Keratin melting Keratin melting
Active substance point [° C.] point [° C.]
(1% in water) for Alkinco 6633 for Alkinco 6634

-, Permanent-waved 143.5 149.8
reference sample
Pyridoxine 144*  152.1
Pyridoxal 147.7 152
Pyridoxamine 147.9 152.2
Pyridoxal-5-phosphate 148.3 152.7

http://www.freepatentsonline.com/6787128.html
http://www.patentstorm.us/patents/6787128/description.html
But there the point of denaturation i already lowered as the hair is affected with alcalic water. (Which loosens the structure of proteins makin them more vulnarable to damage.)

I'd like to sugest trying indirect source of heat (those heat caps or etc.), that would be atleast less damaging.

[Curlsgirl]

This is VERY unscientific but I sort of use a blow dryer by how the heat doesn't feel uncomfortable on my arm and hold it that far away from my hair. I also use a diffuser but not sure if that makes any difference. I also test it from time to time to see if it is still not too hot. I don't do this at all in the summer and not too much in the winter and I really don't notice any damage. I am pretty sure any kind of iron would have to be a tiny bit damaging no matter how it is used but like I said this is NOT a scientific opinion. I'm an accountant :D

[ravenmerlita]

I don't think that ANY use of heat is damaging but I think that most uses are. I use a heated bonnet to help deep condition and I don't consider that damaging. But blow dryers, curling irons even heated rollers have all caused problems for my hair.

[Buddaphlyy]

No, heat isn't always damaging, but serums, lower temperatures, etc. don't always work. It really depends on the persons hair. I think the point about denaturing the protein is really interesting because my hair really likes protein and can handle higher temperatures without damage.

[Nightshade]

I guess part of it will be a very individual result. For instance, lets say you want to straighten your hair with a blowdryer on a cooler setting as Curlsgirl talked about. If your hair has weak curl or waves it may be possible to get the effect you want from it without coming near the denaturation point of the hair. Others, however, may not be able to get the result they want without crossing that temp line.

So, more or less, it's possible, but it depends on your hair and what you're trying to make it do. I think that an indirect heat source would be less damaging than, say, a flat iron, but part of that is that it's direct heat, and another part is the abrasive action of the iron itself. I know serums are supposed to make that heat/friction combo LESS but it is by no means eliminating it.

[redcelticcurls]

I say it depends on a combination of the hairtype and the heat.

I have coarse hair that is very forgiving even though I use chemical color and diffuse on medium or low heat. I still haven't had any problems gaining length. I only cut because I tire of it. I've gotten more breakage from updos than from a diffuser since some updos work against the textue and kinks of curly strands. Each head is different.

Others with different hair can't get away with as much.