The microbial yeast Malassezia feeds on oils (sebum) that are secreted by our scalp, leading to the production of another oil called oleic acid. High levels of certain hormones such as testosterone and progesterone increase sebum production from skin glands in the scalp,[1] meaning more sebum for Malassezia to feed on and more oleic acid production. Some individuals who are highly sensitive to the presence of oleic acid may experience dandruff or dandruff-like symptoms. One study found that directly applying oleic acid to participant’s scalps caused dandruff-like flaking, [1] although the role of hormones was not investigated.
References
- ^DeAngelis YM, Gemmer CM, Kaczvinsky JR, Kenneally DC, Schwartz JR, Dawson TLThree etiologic facets of dandruff and seborrheic dermatitis: Malassezia fungi, sebaceous lipids, and individual sensitivity.J Investig Dermatol Symp Proc.(2005-Dec)