Sunday, May 26, 2024

Does Your Hair Do The Splits?

Split ends are the result of mechanical damage. Mechanical damage comes from: Brushing, detangling, sleeping, ponytails, braids and up-styles or protective styles. Heat-styling adds the protein-damaging element of heat to the mechanical damage of styling. Sunlight exposure and washing create unique forms of mechanical damage because it makes cuticles shrink.

Green circles: Interior fibrous cortex.
Grayline: Cuticle layers.
Yellow line: 
Our hair’s inner cortex is a protein fiber is strong, but nature gives it a couple extra layers of defense - the cuticle, which is hard like thin little micro-fingernails, and the epicuticle, which is oil-based and bonded to outside of the cuticles. 

The cuticles are like shields against mechanical force - dispersing forces over the hair-surface. Preventing damage to the interior. That’s why there are multiple layers of cuticles - if some break, the ones underneath can still do the job. If something sharp hits your fingernail - it hurts, but it doesn't cut your fingertip. The same concept applies to cuticles protecting the inside of your hair.

The epicuticle is a chemical barrier against water moving in (waterlogged hair cortex is easily over-stretched), and against water moving out because dehydrated hair is brittle and vulnerable to breakage.

When epicuticle and cuticles
are damaged, the interior
of hair has much less protection.

If we lose the epicuticle from UV, from heat-styling, highlights, permanent color, permanent waving or straightening - hair is more easily waterlogged or dehydrated.

When we lose cuticles to brushing, to years of wear and tear, accelerated by heat-styling and chemical treatments - the inside of the hair is vulnerable to - well - fraying.

Let’s break mechanical damage into 2 categories: Force and Friction.

Force on hair is pressure, like from sleeping, leaning back on long hair, a shoulder-strap on your hair, a tight headband, stretching during detangling or styling. Force can cause stress at the surface and below.

With severe cuticle loss,
pieces of cortex fibers
begin to fray under force
and with friction.

Friction is rubbing - of hairs against each other during sleep, as you move, during detangling, washing and styling. Friction causes stress mostly at the surface.

When you see split ends or mid shaft splits - your hair may have lost its protective barriers. This usually happens on the ends. But it can happen anywhere there is a vulnerable place. For example - a place where you always wear a ponytail holder, or where you twirl your hair with your fingers. Or a place where there is kinking and therefore uneven dispersal of stress over the hair-surface and within the hair fiber.

That’s where hair is going to split.

Left: split end. Right: Mid-shaft splits. Top is a split,
lower is a vulnerable area beginning to fray that will
progress into a mid-shaft split.

Left: Force, represented by combing (impact, tension).
Right, friction where hairs cross (blue arrows).

How To Prevent Splits In Your Hair

- Coconut oil use (twice per week) reduces breakage in vulnerable areas near the ends - this may reduce split ends in the long term. Other oils did not produce the same benefit, and mixtures of coconut oil and other oils are intermediate in reducing breakage.

- In the same study, a conditioning cream-oil mixture applied to hair 30 minutes before washing provided substantial benefits for potentially reduced splitting as well.

- The authors allude to the penetrating effect of coconut oil, and the attraction to proteins. Other oils penetrate hair, and so may be beneficial. Coconut oil is polar and attracted to hair proteins… But a combination of a conditioner + a penetrating oil that is not coconut oil (avocado, sunflower, shea butter) might work to get the “attraction to hair proteins” benefit from the cationic conditioner. Part of the protective effect is the occlusive effect - and an oil+conditioner is a good occlusive as you go into "the wash cycle." 😁

- Protein, such as Hydrolyzed keratin, can (temporarily) “fill in” gaps in damaged hair surfaces and protect hair. Medium-weight/size proteins like Keratin, Wheat, Oat, Soy, Quinoa, Milk - can also reduce breakage by (temporarily) stabilizing the internal protein structure of hair.

Short Story on Products that Reduce Split Ends: 

  • Using coconut oil applied hours before washing, or used in hair styling can help prevent split ends.

Reduce Force:

  • Try not to sleep with your body weight on long hair. If you must - wear a sleep bonnet or use a slippery pillowcase (silk, satin) to reduce friction and distribute pressure.
  • Lubricate dry hair before detangling if dry-detangling works best for you.
  • Otherwise, detangle hair when wet, with conditioner applied (to reduce force and friction).
  • Don’t use tight ponytail holders, and/or not always in the same place. Avoid trapping your hair under the straps of backpacks or shoulder-bags.
  • Be consistent with deep conditioning and / or protein and / or oil treatments if you heat-style, highlight, perm, or color-treat your hair. 
    • In other words - don't choose treatments or products that don't fit your lifestyle or budget. Make it easy to succeed. 
  • If your hair is long, or even long-ish, give the ends extra care with conditioners and treatments.
  • For multi-day hair, prepare your hair before going to bed. That could be a hydration spray, a little leave-in conditioner rubbed in your palms, or a drop of oil applied to the ends. To get through the night - hair needs to be flexible and lubricated. 

Science-y Hair Blog © 2023 by  Wendy M.S. is licensed under CC BY-NC-ND 4.0 

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