What Is Keratin? (original) (raw)

Key Takeaways

• Keratin is a protein that helps keep hair, skin, and nails healthy.
• Too much keratin can cause conditions like keratosis pilaris, where it clogs pores.
• Keratin treatments can contain formaldehyde, which may harm your health.

Essential for strong hair, skin, and nails, keratin also serves as a popular ingredient in beauty products, especially those aimed at hair conditioning and treatment.

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Types of Keratin

Keratin is a protein in the cells on the surface of the skin. The fingernails, hair, and skin need keratin to grow, function, and stay healthy.

The body produces 54 types of keratin. These are divided into 28 type I keratins and 26 type II keratins.

Type I

Type I keratins are smaller and more acidic. They help maintain the health of epithelial cells on the body's exterior, which are exposed to the environment. Major components of hair and nails, they are also present in the mouth, urinary tract, vagina, and anus.

Type II

Type II keratins are larger with a neutral pH. They are found in internal epithelial cells, lining structures like the lungs, kidneys, liver, and digestive system.

Alpha-Keratins

Alpha-keratins are the only type of keratin found in humans and in the wool of mammals. They have a fibrous, helical structure, and both type I and II keratins can be categorized as alpha.

Beta-Keratins

Beta-keratins are categorized as polypeptide chains and are only found in birds and reptiles, although those species can also possess alpha-keratins. Both alpha and beta keratins help these animals maintain the composition of their claws, scales, beaks, skin, and feathers.

Structure and Function

In its natural form, keratin appears as long structures, with filaments arranged in bundles or fibers. These fibers are made up of individual keratin molecules that are cross-linked together, forming a tough and resilient protein. This is what gives keratin the ability to provide structure and protection to the areas of the body it inhabits.

Keratin cannot be dissolved in water, solvents, acids, or alkalines, so its structure remains largely intact when exposed to many of the body's natural chemicals.

Uses of Supplemental Keratin

Many industries have used keratin or other vitamin supplements that promote production of keratin as a form of maintaining or improving hair, skin, and nail health. The beauty industry in particular advertises keratin as a way to combat damaged hair.

Hair Treatments and Products

Hair is made up of 90% keratin, which is why it is often a component in hair treatments that are used for shinier and stronger tresses.

Keratin hair treatments provided in a salon are chemical protein treatments (sometimes called Brazilian blowouts) that reduce frizz and make the hair look shiny and silky.

A stylist will first wash your hair with a special shampoo and then apply a liquid keratin solution to your hair in small sections. Then your hair will be blown dry. The stylist will use a flat iron to seal the keratin solution.

For optimal results, you should avoid washing your hair for a few days.

Depending on the type of keratin used, the results will vary widely. Studies have found isolated animal keratin to be less efficient overall than a synthetic version of human keratin.

Many people also use shampoos and conditioners infused with keratin oil to make their hair healthier.

Keratin used in hair treatments is often cultivated from animal sources, such as feathers, hooves, and wool, and therefore are not appropriate for people who follow a vegan lifestyle.

Biotin

Biotin is a B vitamin that has also soared in popularity because it is said to have a positive impact on the body’s ability to synthesize proteins such as keratin, thus leading to healthier skin, hair, and nails.

Soluble Keratin

Keratin is not an easily dissolvable protein. A soluble form of the protein is available and has been targeted towards athletes who wish to supplement their protein intake for athletic performance.

Food Sources of Keratin

Nutrients such as biotin, vitamin A, and zinc can boost keratin production in the body. Some food sources rich in these nutrients include:

• Eggs
• Kale
• Carrots
• Mangoes
• Beef liver
• Sweet potatoes
• Salmon
• Sunflower seeds

Associated Conditions

Hyperkeratosis is an umbrella term for a variety of skin conditions that result from the excessive production of keratin proteins. This can be caused by inflammation, genetics, or for unknown reasons.

Forms of hyperkeratosis include:

• Keratosis pilaris ("chicken skin"): Keratosis pilaris occurs when keratin clogs pores and blocks hair follicles, giving the skin a bumpy appearance. It is not dangerous in any way.
• Actinic keratosis: This skin condition is very common and is associated with sun exposure. It causes lesions on the body that can feel like rough sandpaper. The lesions are considered a precursor to skin cancer. Your healthcare provider may monitor your skin and/or treat the lesions.
• Epidermolytic hyperkeratosis: This form of hyperkeratosis is inherited and it is present in infants at birth.
• Lichen planus: This is a type of inflammatory disorder that most commonly affects the flexor (inner) surfaces of the arms and legs. It looks like a purple rash with flat, itchy areas.
• Calluses and corns: Calluses and corns appear on the foot, especially where there is daily pressure and friction. This creates micro-injuries that lead to an overproduction of keratin, causing lesions to form.
• Chronic folliculitis: Hyperkeratosis can cause chronic folliculitis, which is an inflammation of the hair follicles that occurs when the follicles become blocked.
• Atopic dermatitis (eczema): This is a chronic inflammatory skin condition that causes an itchy rash to appear on the skin.
• Psoriasis and psoriasiform dermatitis: Psoriasiform dermatitis is a chronic condition that causes thick, silvery scales to appear on the skin. Psoriasis is the most common form of psoriasiform dermatitis.
• Lichenoid dermatitis: Lichenoid dermatitis is a chronic skin condition that causes itchy, red scales to appear on the skin. It can appear on any part of the body but is most common on the scalp, face, neck, arms, and legs.
• Ichthyoses: This is a group of skin disorders characterized by scaly, red, dry, itchy skin. The condition is usually genetic but some medical conditions and medications can also cause ichthyosis.

Treatment

Treatment of hyperkeratosis depends on the specific condition:

• Keratosis pilaris is treated with exfoliants containing salicylic acid and retinols. Creams containing urea are also effective. These products are available over-the-counter.
• For lichen planus, a corticosteroid cream may be prescribed by your healthcare provider.
• Actinic keratosis treatments include prescription creams (such as Effudex, Aldera, and others), cryosurgery with liquid nitrogen, photodynamic therapy, chemical peels, and CO2 laser ablation. Very thick lesions may be removed with curettage or scraping followed by heating the area to ensure the lesion has been destroyed.
• Epidermolytic hyperkeratosis may be treated with sea salt baths, oral retinoids (and possibly experimental treatments involving gene therapy).
• Calluses and corns: Calluses and corns are usually removed manually. They can be treated at home by soaking the affected area and rubbing the callus or corn with a pumice stone or emery board. Thicker calluses and corns may need to be removed by a healthcare provider with a surgical blade.
• Atopic dermatitis: Treatment may include topical creams or ointments such as a corticosteroid or tacrolimus ointment, light therapy, or oral or injectible prescription medication. Taking good care of your skin by bathing regularly and choosing gentle cleansers and moisturizers can also help improve symptoms.
• Psoriasis: Psoriasis can't be cured, but it can be treated with topical medications such as steroid creams and non-steroid alternatives such as anthralin. Oral medications and light therapy can also help.
• Ichthyoses: There is no cure for ichthyosis, but the symptoms can be controlled with hydrating creams and ointments and/or oral or topical retinoids.

Risks and Side Effects

Although there is not a lot of evidence suggesting that using keratin by itself is dangerous to hair, skin, and nail health, the chemicals that may be added to keratin hair treatments can have adverse effects. Formaldehyde exposure has been a problem for those who use hair products with keratin regularly.

The use of formaldehyde in these products can lead to health issues, including:

• Itching and stinging eyes
• Nose and throat irritation
• An allergic reaction
• Itchy skin with or without a rash
• Scalp irritation that may present with burns or blisters
• Mood changes
• Hair loss and damage

Extended exposure to formaldehyde has also been shown to have carcinogenic (cancer-causing) effects.

Opt for keratin treatments that are free of unwanted chemicals and substances such as formaldehyde to avoid unnecessary risks to your overall health.