Sharleen St. Surin-Lord, Dermatologist06.01.20
Spring has sprung and summer arrives later this month in the Northern Hemisphere. Stay at home orders or not, some of us will get some sun exposure—masked faces and all. And that’s why I’m writing about hair oxidation and chelators. We all know that our hair gets lighter, even blonde, during the summer. It is well known that prolonged exposure to sunlight results in hair damage, ultimately leading to tensile strength loss, brittle hair, color changes, loss of luster, split ends, and increased surface friction.1 This process occurs via a free radical chain reaction that is initiated by the high-energy UV wavelengths present in sunlight and propagated in the presence of atmospheric oxygen.1 This results in oxidation of the protein and lipid components in hair. Trace metals, especially copper ions absorbed into the hair fibers from tap water, increase the rate of free radical oxidation. In pigmented hair, melanin granules partially protect the protein and lipid components from oxidation, although the hair becomes lighter as melanin is oxidized.1
What about air pollution and its effect on hair? Air pollution via phototoxic polycyclic aromatic hydrocarbons (PAH) is not only a human health risk factor, but it also damages the hair cuticle and cortex.2 Less damaged fibers with increased PAH contamination show increased damage after UV treatment.2 UV absorption by PAHs leads to excited states and production of reactive oxygen species.2
So how can we protect the hair from UV light resulting in free radical damage? UV protectants are ideal for active people, for going to the beach where sand and water amplify UV radiation, and especially helpful for gray hair which tends to discolor (usually turning yellowish) in sunlight.1 All hair benefits from UV protection because direct sunlight increases hair’s porosity.1 Antioxidants, free radical scavengers and metal chelators used in synthetic polymers to provide protection from the free radical oxidation process are also needed for their antioxidant effects.1
What Works
UV absorbers, such as quaternium compounds, which demonstrate broad spectrum absorption such as quaternium-95 (and) propanediol, and astaxanthin are effective in preventing the formation of free radicals.
Millington and Marsh conducted a study to determine the impact that the addition of a redox metal, copper, antioxidant and metal chelators on the formation of free radicals in natural white Caucasian hair subsequently exposed to ultraviolet light.1 They discovered that hair doped with copper ions produced significantly higher levels of peroxide radicals when it was wet.1 The application of N-acetylcystine (NAC) reduced hair yellowing after UV exposure in both dry and wet hair.1
Vitamins E and C are powerful antioxidants. Vitamin C, ascorbic acid, is a well-known antioxidant used in skin care products. However, when virgin Caucasian white hair snippets were exposed to UVA, copper and antioxidants as well as chelators, ascorbate was found to be a pro-oxidant at low doses.1 Ascorbic acid had antioxidant properties in black hair, but pro-oxidant properties in red hair,1 making vitamin C a poor choice for an antioxidant.
Caffeine is also a potent antioxidant.3 In one study, where samples of human scalp skin were irradiated, they found that UVR inhibited keratinocyte proliferation in the outer root sheath (ORS) of the hair follicle, reduced growth factors in the ORS, and induced the catagen phase (the transition from anagen (actively growing hair) to telogen (resting hairs), and promoted apoptosis.3 This all negatively affects hair growth. In this same study, it was determined that topically applied 0.1% caffeine prevents catagen development, upregulated growth factors.3 However, 0.1% topical caffeine did not prevent apoptosis, but actually promoted apoptosis ex-vivo.3 This was heavily dependent on whether the concentration of the caffeine that actually reached the hair bulb was too high or too low.3 Caffeine is still effective, but the concentration of the caffeine used is key in obtaining favorable results.
Chelators/Chelants
I have covered UV absorbers and antioxidants; now let’s talk chelators/chelants. Chelants are often used as a way transport or control the chemistry of metals.4 A chelant is an active compound capable of forming a strong complex with metals and typically the best chelants contain carboxylate or phosphonate groups that interact at multiple locations with the metal ions.4 In one study, where several chelants were screened for their effectiveness in removing copper from hair and preventing copper buildup, two high-performing chelants were identified—N,N’-ethylenediamine disuccinic acid (EDDS) and histidine. In this study, the efficacy of EDDS and histidine in preventing copper buildup was confirmed over 20 cycles for hair washed in tap water containing 0.6 ppm copper.4 The authors demonstrated that copper buildup in hair can be prevented by adding chelants to the shampoo and conditioner.4 It also showed that for histidine, this enabled by its ability to penetrate inside hair.4
Thank you for your time and attention. A lot of information was jam-packed into this single column. The environment, water sources and daily hair grooming practice all damage hair—even before adding bleaching agents and hair color. I hope that this information will provide some solutions and some hope because some of us will not give up the beach or the sun—once the quarantine ends, of course. Stay well.
References
Sharleen St. Surin-Lord
Dermatologist
derm@visagederm
www.visagederm.com
Dr. Sharleen St. Surin-Lord is a board-certified dermatologist who has been practicing for more than 13 years. She is in private practice at Visage Dermatology, Largo MD. She also practices at the University of Maryland Capital Regional Health System in Maryland and she is an assistant professor of dermatology at Howard University College of Medicine. Dr. Sharleen is a member of the American Hair Research Society and you can follow her on Twitter, Instagram, and Facebook as DermHairDoc.
What about air pollution and its effect on hair? Air pollution via phototoxic polycyclic aromatic hydrocarbons (PAH) is not only a human health risk factor, but it also damages the hair cuticle and cortex.2 Less damaged fibers with increased PAH contamination show increased damage after UV treatment.2 UV absorption by PAHs leads to excited states and production of reactive oxygen species.2
So how can we protect the hair from UV light resulting in free radical damage? UV protectants are ideal for active people, for going to the beach where sand and water amplify UV radiation, and especially helpful for gray hair which tends to discolor (usually turning yellowish) in sunlight.1 All hair benefits from UV protection because direct sunlight increases hair’s porosity.1 Antioxidants, free radical scavengers and metal chelators used in synthetic polymers to provide protection from the free radical oxidation process are also needed for their antioxidant effects.1
What Works
UV absorbers, such as quaternium compounds, which demonstrate broad spectrum absorption such as quaternium-95 (and) propanediol, and astaxanthin are effective in preventing the formation of free radicals.
Millington and Marsh conducted a study to determine the impact that the addition of a redox metal, copper, antioxidant and metal chelators on the formation of free radicals in natural white Caucasian hair subsequently exposed to ultraviolet light.1 They discovered that hair doped with copper ions produced significantly higher levels of peroxide radicals when it was wet.1 The application of N-acetylcystine (NAC) reduced hair yellowing after UV exposure in both dry and wet hair.1
Vitamins E and C are powerful antioxidants. Vitamin C, ascorbic acid, is a well-known antioxidant used in skin care products. However, when virgin Caucasian white hair snippets were exposed to UVA, copper and antioxidants as well as chelators, ascorbate was found to be a pro-oxidant at low doses.1 Ascorbic acid had antioxidant properties in black hair, but pro-oxidant properties in red hair,1 making vitamin C a poor choice for an antioxidant.
Caffeine is also a potent antioxidant.3 In one study, where samples of human scalp skin were irradiated, they found that UVR inhibited keratinocyte proliferation in the outer root sheath (ORS) of the hair follicle, reduced growth factors in the ORS, and induced the catagen phase (the transition from anagen (actively growing hair) to telogen (resting hairs), and promoted apoptosis.3 This all negatively affects hair growth. In this same study, it was determined that topically applied 0.1% caffeine prevents catagen development, upregulated growth factors.3 However, 0.1% topical caffeine did not prevent apoptosis, but actually promoted apoptosis ex-vivo.3 This was heavily dependent on whether the concentration of the caffeine that actually reached the hair bulb was too high or too low.3 Caffeine is still effective, but the concentration of the caffeine used is key in obtaining favorable results.
Chelators/Chelants
I have covered UV absorbers and antioxidants; now let’s talk chelators/chelants. Chelants are often used as a way transport or control the chemistry of metals.4 A chelant is an active compound capable of forming a strong complex with metals and typically the best chelants contain carboxylate or phosphonate groups that interact at multiple locations with the metal ions.4 In one study, where several chelants were screened for their effectiveness in removing copper from hair and preventing copper buildup, two high-performing chelants were identified—N,N’-ethylenediamine disuccinic acid (EDDS) and histidine. In this study, the efficacy of EDDS and histidine in preventing copper buildup was confirmed over 20 cycles for hair washed in tap water containing 0.6 ppm copper.4 The authors demonstrated that copper buildup in hair can be prevented by adding chelants to the shampoo and conditioner.4 It also showed that for histidine, this enabled by its ability to penetrate inside hair.4
Thank you for your time and attention. A lot of information was jam-packed into this single column. The environment, water sources and daily hair grooming practice all damage hair—even before adding bleaching agents and hair color. I hope that this information will provide some solutions and some hope because some of us will not give up the beach or the sun—once the quarantine ends, of course. Stay well.
References
- Millingron, KR and Marsh, JM. UV damage to hair and the effect of antioxidants and metal chelators. International Journal of Cosmetic Science. 2020, 42, pp 174-184.
- Naudin, G. et al. Human pollution exposure correlates with accelerated ultrastructural degradation of hair follicles. PNAS, September 10, 2019, Vol 116, no. 37, pp 18410-18415.
- Gherardini, J. et al. Transepidermal UV radiation of scalp skin ex vivo induces hair follicle damage that is alleviated by the topical treatment with caffeine. International Journal of Cosmetic Science, 2019, 41, pp 164-182.
- March, J.M. et al. Preserving fibre health: reducing oxidative stress throughout the life of the hair fibre. International Journal of Cosmetic Science, 2015, 37 (suppl. 2), pp 16-24.
Sharleen St. Surin-Lord
Dermatologist
derm@visagederm
www.visagederm.com
Dr. Sharleen St. Surin-Lord is a board-certified dermatologist who has been practicing for more than 13 years. She is in private practice at Visage Dermatology, Largo MD. She also practices at the University of Maryland Capital Regional Health System in Maryland and she is an assistant professor of dermatology at Howard University College of Medicine. Dr. Sharleen is a member of the American Hair Research Society and you can follow her on Twitter, Instagram, and Facebook as DermHairDoc.