头发变白 · 色素是怎么停下的

参考文献 · 12

1. Kumar, A. B., Shamim, H., & Nagaraju, U. (2018). Premature graying of hair: review with updates. International Journal of Trichology, 10(5), 198-203. Narrative review. Premature graying is defined as graying before 20 years in Caucasians and before 30 years in African Americans (average onset 34 and 43.9 years); hair is pigmented only in anagen, melanogenesis is switched off in catagen and absent in telogen; a definition for Asian populations is lacking, and some authors suggest 25 years for the Indian subcontinent; each bulb melanocyte serves about 5 keratinocytes versus 36 in the epidermis; white hair lacks melanosomes, grey hair has sparse ones. Associations reported, mostly from small case-control or older studies: vitamin B12 deficiency (about 55% of patients with pernicious anemia grayed before 50 versus 30% of controls), low thyroid hormone, vitiligo, smoking, lower copper in one study that did not find lower zinc or iron, and lower ferritin, calcium and vitamin D3 in a study of young Indians; the exact cause remains unknown. Treatment should address the cause (B12 or thyroid replacement); vitamins and minerals such as biotin, calcium pantothenate, zinc, copper and selenium have not given promising results; hair dyes remain the main option, and some people get irritant dermatitis (commonly from p-phenylenediamine) or hair loss from dyeing. Some authors suggest testing serum B12, folic acid and thyroid in people with no family history of premature graying. Sudden whitening (canities subita) has been associated with alopecia areata, telogen effluvium, vitiligo and psychogenic causes. 10.4103/ijt.ijt_47_18
2. O'Sullivan, J. D. B., Nicu, C., Picard, M., Chéret, J., Bedogni, B., Tobin, D. J., & Paus, R. (2021). The biology of human hair greying. Biological Reviews, 96(1), 107-128. Narrative review. Human greying invariably begins with a gradual decline in melanogenesis in the anagen hair bulb (reduced tyrosinase activity, defective melanosome transfer, apoptosis of bulb melanocytes), so it is a primary event of the bulb, not the bulge; eventually the bulge melanocyte stem cell pool becomes depleted as well, at which stage greying becomes largely irreversible. Oxidative damage likely is a crucial driver. But there is still no universally accepted model of human hair greying, the extent of genetic contributions remains unclear, and how psychoemotional stress impacts the process, and how to retard or reverse greying, are open questions. 10.1111/brv.12648
3. Nishimura, E. K., Granter, S. R., & Fisher, D. E. (2005). Mechanisms of hair graying: incomplete melanocyte stem cell maintenance in the niche. Science, 307(5710), 720-724. Using melanocyte-tagged transgenic mice and aging human hair follicles, hair graying is caused by defective self-maintenance of melanocyte stem cells in the bulge niche; physiologic aging of melanocyte stem cells was associated with ectopic pigmentation or differentiation within the niche (the reserve cells mature where they should stay dormant), accelerated by Mitf mutation, and Bcl2 deficiency causes selective apoptosis of the stem cells. Mostly mouse genetics; the human part is histology of aging follicles, not an intervention. 10.1126/science.1099593
4. Rosenberg, A. M., Rausser, S., Ren, J., Mosharov, E. V., Sturm, G., Ogden, R. T., Patel, P., Kumar Soni, R., Lacefield, C., Tobin, D. J., Paus, R., & Picard, M. (2021). Quantitative mapping of human hair greying and reversal in relation to life stress. eLife, 10, e67437. 397 hairs from 14 healthy donors (aged 9-65) were profiled for pigment along their length. White/grey hairs that naturally regain pigmentation were found across sex, ethnicities, ages and body regions; greying and reversal can occur in parallel with self-reported psychological stressors; grey hairs upregulated proteins of energy metabolism, mitochondria and antioxidant defenses; a computational model suggests a threshold-based mechanism for temporary reversibility, most likely in hairs near their greying threshold. A small descriptive study: it shows that reversal happens and can coincide with stress, not that stress causes greying or how common reversal is. 10.7554/eLife.67437
5. Sun, Q., Lee, W., Hu, H., Ogawa, T., De Leon, S., Katehis, I., Lim, C. H., Takeo, M., Cammer, M., Taketo, M. M., Gay, D. L., Millar, S. E., & Ito, M. (2023). Dedifferentiation maintains melanocyte stem cells in a dynamic niche. Nature, 616(7958), 774-782. In mice, live imaging, single-cell RNA sequencing and lineage tracing showed that most melanocyte stem cells move between the hair follicle stem cell and transit-amplifying compartments and reversibly change differentiation state under local cues such as WNT; the system is maintained by reverted cells rather than a reserve exempt from change. During ageing, stranded stem cells accumulate that no longer contribute melanocyte progeny. The authors suggest modulating stem-cell mobility as a possible approach to preventing greying; nothing was tested in people. 10.1038/s41586-023-05960-6
6. Wood, J. M., Decker, H., Hartmann, H., Chavan, B., Rokos, H., Spencer, J. D., Hasse, S., Thornton, M. J., Shalbaf, M., Paus, R., & Schallreuter, K. U. (2009). Senile hair graying: H2O2-mediated oxidative stress affects human hair color by blunting methionine sulfoxide repair. FASEB Journal, 23(7), 2065-2075. Human gray/white scalp hair shafts accumulate hydrogen peroxide in millimolar concentrations (FT-Raman in vivo); catalase and methionine sulfoxide reductase A and B protein are almost absent in the gray hair follicle; oxidation of methionine residues, including Met 374 in the active site of tyrosinase, limits the enzyme and leads to gradual loss of hair color. The authors frame this as support for a long-voiced but insufficiently proven concept; L-methionine prevented the oxidation only in vitro, and no treatment was tested in people. 10.1096/fj.08-125435
7. Zhang, B., Ma, S., Rachmin, I., He, M., Baral, P., Choi, S., Gonçalves, W. A., Shwartz, Y., Fast, E. M., Su, Y., Zon, L. I., Regev, A., Buenrostro, J. D., Cunha, T. M., Chiu, I. M., Fisher, D. E., & Hsu, Y.-C. (2020). Hyperactivation of sympathetic nerves drives depletion of melanocyte stem cells. Nature, 577(7792), 676-681. In mice, restraint stress, chronic unpredictable stress and pain induced by resiniferatoxin all produced white hairs. The stress-induced loss of melanocyte stem cells was independent of immune attack or adrenal stress hormones: sympathetic nerves innervating the niche release a burst of noradrenaline that drives quiescent melanocyte stem cells to proliferate rapidly, then differentiate, migrate and be permanently depleted. After resiniferatoxin many follicles lost their stem cells within 5 days while the existing coat stayed black; transient suppression of stem-cell proliferation prevented greying. Mouse study; noradrenaline also switched on proliferation and differentiation genes in cultured human melanocytes, but greying in people was not studied. 10.1038/s41586-020-1935-3
8. Adhikari, K., Fontanil, T., Cal, S., Mendoza-Revilla, J., Fuentes-Guajardo, M., Chacón-Duque, J. C., et al. (2016). A genome-wide association scan in admixed Latin Americans identifies loci influencing facial and scalp hair features. Nature Communications, 7, 10815. Genome-wide association scan in over 6,000 Latin Americans; reported the first locus for hair greying, SNP rs12203592 in IRF4, a gene that works with MITF in switching on tyrosinase, the key enzyme of melanin synthesis; age was the trait most correlated with greying (r = 0.56). An association study: it finds one locus, and does not say how much of greying is genetic. 10.1038/ncomms10815
9. National Institute of Diabetes and Digestive and Kidney Diseases. (2020). Polygonum multiflorum. In LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. Bethesda, MD: NIDDK. Likelihood score A; latency a few days to ~6 months; ~10% of clinically apparent cases were fatal or required urgent liver transplantation. www.ncbi.nlm.nih.gov/books/NBK548795
10. NHS. (2025). Hair dye reactions. Many permanent and some semi-permanent hair dyes contain PPD (paraphenylenediamine), which can irritate the skin or cause an allergic reaction; for a mild reaction stop using the dye and wash it off, and a pharmacist or GP can help. Call 999 if your lips, mouth, throat or tongue suddenly become swollen, you are breathing very fast or struggling to breathe, your throat feels tight or you are struggling to swallow, or your skin, tongue or lips turn blue, grey or pale (page last reviewed 29 December 2025). www.nhs.uk/conditions/hair-dye-reactions
11. NHS. (2023). Vitamin B12 or folate deficiency anaemia: symptoms. Symptoms usually develop gradually and include feeling weak or tired, shortness of breath, headaches, palpitations, a sore or red tongue sometimes with mouth ulcers, and problems with memory; vitamin B12 deficiency can also cause neurological symptoms including numbness, pins and needles, muscle weakness, and problems with balance and coordination. See a GP if you have these symptoms; diagnosis and treatment as soon as possible matters, because some problems can be irreversible if left untreated. www.nhs.uk/conditions/vitamin-b12-or-folate-deficiency-anaemia/symptoms
12. NHS. (2025). Underactive thyroid (hypothyroidism): symptoms. Symptoms may be mild and hard to notice; common symptoms include extreme tiredness, feeling cold more than usual, weight gain, constipation, difficulty concentrating, low mood. www.nhs.uk/conditions/underactive-thyroid-hypothyroidism/symptoms