Proteins in Hair

The Role of Proteins in Hair Structure

Hair is primarily composed of proteins, making them fundamental to its structure, strength, and overall health. The most abundant protein in hair is keratin, a fibrous protein that accounts for approximately 90% of a hair strand's weight. This complex protein forms the basic building blocks of the hair shaft, providing its tensile strength, elasticity, and protective outer layer.

Keratin is a highly organized protein, consisting of polypeptide chains that coil together to form alpha-helices. These helices then intertwine to create protofibrils, which further combine to form microfibrils and macrofibrils. This intricate arrangement gives hair its remarkable durability and resilience.

Beyond keratin, hair also contains smaller amounts of other proteins, such as those that contribute to hair's pigmentation (melanin) and those involved in its growth and maintenance. These proteins work in concert to ensure the structural integrity and biological functions of the hair.

Types of Proteins and Their Function

While keratin is the dominant protein, it's important to understand the different forms and their specific roles:

• Alpha-Keratin: This is the primary type of keratin found in human hair. It is characterized by its helical structure and is responsible for hair's elasticity and ability to stretch without breaking. The disulfide bonds between cysteine amino acids in alpha-keratin are crucial for maintaining the hair's shape and strength. These bonds can be temporarily broken by heat or water and permanently altered by chemical processes like perming or relaxing.
• Keratin-Associated Proteins (KAPs): These are a diverse group of non-keratinous proteins that surround and interact with keratin filaments. KAPs play a vital role in bundling keratin fibers, further contributing to the hair's mechanical strength and rigidity. They also influence hair texture and diameter.
• Melanin: Although not a structural protein in the same way as keratin, melanin is a pigment protein produced by melanocytes in the hair follicle. It determines hair color, with eumelanin responsible for black and brown tones, and pheomelanin for red and yellow tones.

Protein Damage and Its Causes

Hair proteins, particularly keratin, can be damaged by various factors, leading to weakened, brittle, and unhealthy-looking hair. Understanding these causes is crucial for preventing and addressing protein loss.

Common causes of protein damage include:

• Chemical Treatments: Perms, relaxers, bleaching, and coloring agents can penetrate the hair cuticle and break down the disulfide bonds and peptide chains within the keratin structure. This weakens the hair's internal matrix, leading to increased porosity and susceptibility to breakage.
• Heat Styling: Excessive use of heat tools like flat irons, curling irons, and blow dryers can denature proteins, causing them to lose their natural structure. This results in dryness, brittleness, and a loss of elasticity.
• UV Radiation: Prolonged exposure to sunlight can degrade proteins in the hair, leading to a loss of strength, color fading, and increased dryness.
• Mechanical Stress: Aggressive brushing, tight hairstyles, and excessive friction can cause physical damage to the hair shaft, leading to cuticle lifting and protein loss.
• Environmental Factors: Pollution, chlorine from swimming pools, and saltwater can also contribute to protein degradation over time.

Recognizing Protein Deficiency and Repairing Hair

Signs of protein-deficient hair include:

• Lack of elasticity: Hair that snaps easily when stretched.
• Excessive shedding and breakage: Hair strands breaking off well before the root.
• Dullness and lifelessness: Hair lacking its natural shine and bounce.
• Frizziness and tangling: The cuticle becomes rough and raised, leading to increased friction.
• Gummy or mushy texture when wet: Indicates severe protein loss and internal damage.

To repair protein-deficient hair, it is essential to reintroduce proteins and strengthen the hair structure. This is typically achieved through products that contain hydrolyzed proteins, which are proteins broken down into smaller components (peptides and amino acids) that can penetrate the hair shaft more effectively.

Key protein ingredients to look for in hair products include:

Protein Type	Benefits
Hydrolyzed Wheat Protein	Penetrates hair easily, adds elasticity, and repairs damage.
Hydrolyzed Soy Protein	Strengthens and mends hair fibers, adds shine, and improves manageability.
Hydrolyzed Keratin	Directly replenishes lost keratin, improving strength, elasticity, and reducing breakage.
Collagen	Adds strength and flexibility, can help improve hair thickness and volume.
Amino Acids	Building blocks of proteins, support repair and contribute to overall hair health.

Using protein-rich conditioners, masks, and occasional protein treatments can significantly improve the health and appearance of damaged hair. However, it is possible to over-proteinize hair, which can lead to stiffness and increased breakage. A balanced approach, often alternating protein treatments with moisturizing treatments, is generally recommended.

Watermans hair products are formulated to support optimal hair health by incorporating beneficial proteins that nourish and strengthen the hair from within. Consistent use of such products can help maintain the integrity of the hair's protein structure, promoting stronger, healthier-looking hair. Regular trims and minimizing exposure to damaging factors also play an important role in preserving protein integrity.

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Find these ingredients in Watermans products

• Wheat Amino Acids — you will find this ingredient in our Heat Protection Spray.