Punyani Supriya, Tosti Antonella, Hordinsky Maria, Yeomans Dawn, Schwartz James
The Procter & Gamble Company, Singapore, Singapore.
Department of Dermatology and Cutaneous Surgery, University of Miami, Miami, Florida, USA.
Skin Appendage Disord. 2021 Apr;7(3):183-193. doi: 10.1159/000512786. Epub 2021 Feb 15.
How frequently should the scalp and hair be cleansed? A dearth of objective data has led to confusion both among lay people and experts. Each extreme has potential detrimental effects: overcleaning may lead to surface damage while undercleaning may lead to buildup of harmful stimuli. This situation is complicated because both objective and subjective criteria are relevant to assess optimal cleaning.
The objective of this work was to combine epidemiological and treatment data with both objective and subjective end points to yield clear data to guide both the consumer and expert as to optimal scalp and hair cleaning practices.
Two studies were conducted with Asian populations without any specific scalp pathologies. An epidemiological study was conducted as a function of natural wash frequency. This was combined with a controlled wash frequency study. In both cases, objective measures of hair and scalp condition were assessed. These were combined with self-assessments of all participants.
In the epidemiological study, it was observed that overall satisfaction with hair and scalp condition was achieved when washing 5-6 times per week. This was consistent for both objective and subjective end points. Controlled treatment likewise showed that a daily wash regimen was superior to once per week cleansing for all end points. No objective detrimental effects to hair at this level of cleansing were observed.
Two different studies led to the same conclusion: higher wash frequency is both beneficial and more preferred to lower wash frequency among the Asian populations studied. Concerns related to "overcleaning" were unfounded both objectively and subjectively.
头皮和头发应该多久清洗一次？缺乏客观数据导致普通民众和专家都感到困惑。每种极端情况都可能有潜在的有害影响：过度清洁可能导致表面损伤，而清洁不足可能导致有害刺激物的堆积。这种情况很复杂，因为客观和主观标准都与评估最佳清洁效果相关。
这项工作的目的是将流行病学和治疗数据与客观和主观终点相结合，以产生明确的数据，指导消费者和专家了解最佳的头皮和头发清洁方法。
对没有任何特定头皮疾病的亚洲人群进行了两项研究。一项流行病学研究根据自然洗发频率进行。这与一项对照洗发频率研究相结合。在这两种情况下，都对头发和头皮状况进行了客观测量。这些测量结果与所有参与者的自我评估相结合。
在流行病学研究中，观察到每周洗发5-6次时，对头发和头皮状况的总体满意度较高。这在客观和主观终点上都是一致的。对照治疗同样表明，对于所有终点，每日洗发方案都优于每周一次的清洁。在这个清洁水平下，没有观察到对头发有客观的有害影响。
两项不同的研究得出了相同的结论：在研究的亚洲人群中，较高的洗发频率既有益又比低洗发频率更受青睐。与“过度清洁”相关的担忧在客观和主观上都是没有根据的。
