Keratin, a strong protein forming the structure of hair, skin, and nails, can be attacked by various factors. These factors can be broadly classified as mechanical, chemical, or biological.
Mechanical Attacks on Keratin
Mechanical forces can damage the keratin structure, weakening its integrity. Examples include:
- Hard brushing: Aggressive brushing can cause physical damage to the hair shaft.
- Blow-drying (too hot): Excessive heat from blow dryers can weaken and break down keratin chains.
- Sunlight (too much): Prolonged exposure to UV radiation can degrade keratin fibers.
Chemical Attacks on Keratin
Chemical substances can react with keratin, altering its structure and causing damage. This includes:
- Perms: Chemical processes involved in perming hair drastically alter the keratin structure.
- Hair coloring and bleaching: These processes use harsh chemicals that can damage and weaken keratin.
- Aqueous MEA (Monoethanolamine): Studies show that aqueous MEA, found in some hair treatments, causes damage to keratin fibers. See: https://pubs.acs.org/doi/full/10.1021/acsomega.8b01189
Biological Attacks on Keratin
Certain organisms and biological processes can target and break down keratin:
- Batrachochytrium dendrobatidis (Bd): This chytrid fungus infects the keratin layer of amphibian skin, causing chytridiomycosis. See: https://cwhl.vet.cornell.edu/disease/chytridiomycosis
- Immune system (in certain diseases): In some autoimmune conditions, the body's immune system may attack keratin proteins. For example, Keratin 8 is considered a potential self-antigen in coronary artery disease. See: https://pmc.ncbi.nlm.nih.gov/articles/PMC6392305/
- Cancer cells: Some carcinomas create a coating that suppresses the immune system’s attack, involving keratin-19. See: https://pubmed.ncbi.nlm.nih.gov/35046049/
Summary
Numerous factors, including mechanical stress, harsh chemicals, and certain biological agents, can damage and weaken keratin. Understanding these factors is crucial for maintaining the health and integrity of keratin-rich tissues like hair, skin, and nails.
