I will be adding to this post.
This research article, dated 2012 is an easy read, very well referenced and contains some surprising to me, information. Aside from vegetable oils feeding yeasts, See this blog post, their degradation once on skin can be a potentially serious issue. This information makes cosmetic mineral oil use for hair and skin even more of a better choice and again, its moisturization properties are highlighted.
While the thrust of the article concerns infants, there is information that olive oil for example can and has been reported to cause contact dermatitis. I am constantly reading about and hearing from people with scalp issues. The causes of some of those problems may in fact be the results of products used, they may not have connected to the problems. For any dandruff or suspected dandruff or other scalp conditions that cause severe symptoms, like extreme itching or worse, consulting a doctor or dermatologist is best. I do not give advice when medical intervention is required, except to recommend that if you are unhappy with your doctor or dermatologist, seek another medically qualified opinion. I like the fact that a number of the article reference abstracts are linked and can be easily viewed.
Highlights From The Above Linked Research Article Text
"Not all vegetable oils are appropriate for use on skin [118]. Vegetable oils can vary in composition ... the ratio of linoleic to oleic acid. Some vegetable oils, including certain olive, soybean, and mustard oils, can be detrimental to the integrity of the skin barrier [119]. Some unsaturated free fatty acids can act as permeation enhancers [120], an effect that may cause contact dermatitis in adults [121–124].
In addition, many vegetable oils are unstable and degrade by hydrolysis and oxidation. Degradation can increase the likelihood of microbial growth and spoilage, especially in hot, humid environments. Cutaneous Propionibacterium acnes and Propionibacterium granulosum secrete lipases, enzymes that hydrolyze sebum triglycerides to free fatty acids [125]. By extension, Propionibacterium acnes, Propionibacterium granulosum, and possibly other cutaneous bacteria may hydrolyze vegetable oils present in topicals into free fatty acids, accelerating the degradation of vegetable oils on the skin surface. ...
Emollients that contain inert, stable ingredients such as mineral oil are preferable for use on the maturing infant skin. Mineral oil, a semiocclusive ingredient that penetrates the upper layers of the SC [126] ... is noncomedogenic [127], has a long record of safe use [128] ... unlikely to go rancid even in hot, humid climates. Mineral oil helps to enhance the skin barrier as shown by a reduction in TEWL following topical application of the oil [126]."
Properly preserved cosmetics are crucial to skin and scalp health.
"Several studies have found very high concentrations ... of microbial contaminants in consumer products that are poorly preserved or preservative-free [135, 136]."
"Eczema (Atopic Dermatitis)Treatment Skin Care at Home", 2016, bolding added by me, @NIAIDNews
http://www.niaid.nih.gov/topics/eczema/Pages/treatment.aspx
"Lubricate or moisturize the skin two to three times a day using ointments such as petroleum jelly. Moisturizers should be free of alcohol, scents, dyes, fragrances, and other skin-irritating chemicals. A humidifier in the home also can help."
"Patient information: Atopic dermatitis (eczema) (Beyond the Basics)"
Keep the skin hydrated", 2016, bolding added by me
https://shar.es/129nJY via @sharethis
"Systematic review ... What are the effects of different models of delivery for improving maternal and infant health outcomes for poor people in urban areas in low income and lower middle income countries?", 2012 color and bolding added by me
http://r4d.dfid.gov.uk/PDF/Outputs/SystematicReviews/Health_outcomes_2012Coast_report.pdf
"the use of sunflower seed oil (albeit not as effective as Aquaphor) is likely to be more sustainable as treatments costs are at a level that is much more affordable to people in Bangladesh paying out of pocket for medicine – $1.55 per month compared with $29 per month for Aquaphor (the average monthly salary is $39). There is a strong case, however, for public funding of Aquaphor, given the highly favourable cost-effectiveness ratio."
World Health Organization International Bulletin 2010, bolding added by me
"The 26% reduction in mortality with SSO ... translated to 19 deaths averted per 100 neonates" SSO is "sunflower seed oil" ... "Aquaphor reduced mortality by 32% ... 23 deaths averted ... per 100 neonates"
See Also
“Vegetable Oils and Animal Fats | Emergency Response | US EPA", 2016, @EPA
http://www2.epa.gov/emergency-resp
"Like petroleum oils, vegetable oils and animal fats and their constituents can:
Cause devastating physical effects, such as coating animals and plants with oil and suffocating them by oxygen depletion; Be toxic and form toxic products; ... Form products that linger in the environment for many years."
And this blog post
"The 26% reduction in mortality with SSO ... translated to 19 deaths averted per 100 neonates" SSO is "sunflower seed oil" ... "Aquaphor reduced mortality by 32% ... 23 deaths averted ... per 100 neonates"
See Also
“Vegetable Oils and Animal Fats | Emergency Response | US EPA", 2016, @EPA
http://www2.epa.gov/emergency-resp
"Like petroleum oils, vegetable oils and animal fats and their constituents can:
Cause devastating physical effects, such as coating animals and plants with oil and suffocating them by oxygen depletion; Be toxic and form toxic products; ... Form products that linger in the environment for many years."
And this blog post