Once dismissed as a trivial pursuit, hair research has been burgeoning over the past 15 years, resulting in increased understanding about the complex biology and chemistry of human hair.
“Hair is now recognized as an important mini-organ system that gives all sorts of indications of health,” says Dr. Jerry Shapiro, clinical research director of the hair research laboratory at the University of British Columbia’s department of dermatology and skin science.
What Can Go Wrong
Dull, lifeless, brittle and damaged hair can be the result of three things: your health, your habits and your genes. You can’t do anything about your genes, but you can about the rest.
“One of the most important first steps to healthy hair is to eat a healthy, well-balanced diet,” notes Shapiro. Vitamin B and zinc deficiency, although rare, can undermine hair strength, thickness and gloss. And iron deficiency, such as through anemia, is one of the most common preventable causes of weak or thinning hair. These dietary improvements could benefit the health of your hair in about six months, says Shapiro.
However, “most hair damage is because of chemicals and heat,” notes Dr. John Gray, a U.K.-based physician, author and expert in hair science who is also a consultant to P&G Beauty, a leading hair-care product manufacturer. Both of these assault the cuticle and strip the f-layer. Here’s how: Hot hair dryers on wet hair can actually boil the moisture under the cuticle, causing blistering in the cortex and lifting of the cuticle. The chemicals in bleaches, colourants, perms, relaxants and even swimming pools can strip the f-layer, lift the shingle-like ridges of the protective cuticle and weaken the hair shaft, promoting dryness and ultimately breakage.
How To Reverse The Damage
The really new science is moving away from the traditional oil-based methods — instead, it is altering hair’s electrical charge. Neutralizing the negative charge can smooth the shaft without making hair heavy, limp or oily, and is a key concept behind breakthroughs in shampoos and conditioners over the past decade.
Companies carefully guard their formulas, but we do know that two main types of targeted conditioning ingredients can be added to shampoos or conditioners. They work individually or in combination to mimic the stripped f-layer, smooth the roughened cuticle and neutralize hair’s negative charges without adding heavy oils.
These two ingredient types are silicone derivatives and cationic polymers (which are any kind of long molecules with a positive charge). Amino silicones and positively charged silicone derivatives, such as bis-aminopropyl dimethicone, selectively deposit tiny particles into the lifted cuticle, improving smoothness and reflectivity. Guar gum derivatives and other cationic polymers — with mouthful names like guar hydroxypropyltrimonium chloride and polyquaternium—neutralize the negative charge. Positively charged particles also home in on where the negative charge — i.e., damage — is greatest, such as at hair ends, unlike the oil- and fat-based ingredients of the past.
