via the Beauty Brains

Lilypad asks:
I’m transitioning from relaxed to natural hair and a lot of blogs and video bloggers tout grape seed oil as a heat protectant when blowdrying or flat ironing hair because it has a high smoke point (about 420 °F). Is there any truth to this claim? The smoke point refers to the oil’s use in cooking but does it apply to hair as well?

Read On!>>>

The Right Brain responds:
We’ve blogged before about how to protect your hair from heat damage and there’s more to it than just the how much heat the ingredients can take.

What to look for in a good heat protectant
Heat tolerance (in this case measured by smoke point of the oil) is only one factor to consider. You also need to look at how the product lubricates hair. You can experiment with oils if you want DIY heat protection but be careful: oils alone can create drag which could slow down the flat iron as it passes through your hair so it could end up doing MORE damage.

Good heat protectants should also help offset the drying effects of heat. Ideally you want a combination of glycerine or other moisturizers to lock in water and a low molecular weight polymer that can penetrate and help prevent heat from cracking the cuticles. (See the link above more more discussion and scientific references.)

Which oils can stand a lot of heat
But back to your question about smoke point. This site lists grape seed at 485F with soy bean oil at 495F, safflower oil at 510F, and avocado oil at a startling 520F! Wikipedia lists slightly different values: Cottonseed and virgin olive oil are in the same range as grape seed while almond, peanut, sunflower, and our cold friend coconut oil are higher. We’re not sure which values are more accurate, but either way it looks like you have some options to try that offer an even higher smoke point than grape seeds.

Which ingredients really work to protect against heat?

There are dozens (hundreds? thousands?) of products that claim to protect hair from heat damage. Do they really work? The scientific literature shows only a few chemical compounds that have been studied and shown to provide a real, measurable benefit. For best results, look for leave-in treatment products that have these ingredients in listed toward the top of the ingredient list (in the first 5 ingredients, or so):

  • PVP/DMAPA acrylates copolymer
  • Hydrolyzed wheat protein
  • Quaternium 70

(This doesn’t mean these are the ONLY ingredients in the universe that really work, but these are the only ones that have published data. Strong reducing ingredients that work by the oxidation-prevention mechanism described above are not recommended because they may cause other types of hair damage.)

Which heat protectant do you use?