SKIN

September 2018 Volume 2 Issue 5

ORIGINAL RESEARCH

Pilot Study on the Effects of Natural Oils on Skin Barrier Function in Xerotic
Skin

Alexandra R. Vaughn MDa,b, Mimi Nguyen BSa, Melody Maarouf MHSc, Melissa R. Van Skiver
BAd, Khiem A. Tran PhDc, Iryna Rybaka, Raja K. Sivamani MD MS APa,e,f, Vivian Y. Shi MDd

aDepartment of Dermatology, University of California – Davis, Sacramento, CA
bDrexel University College of Medicine, Philadelphia, PA
cUniversity of Arizona College of Medicine, Tucson, AZ
dDepartment of Medicine, Division of Dermatology, University of Arizona, Tucson, AZ
eDepartment of Biological Sciences, California State University, Sacramento, CA
fPacific Skin Institute, Sacramento, CA

Xerosis is associated with disrupted stratum
corneum (SC) integrity and skin barrier
function (SBF), leading to decreased
hydration and transepidermal water loss
(TEWL).1 There is a growing trend towards

using alternative natural moisturizers, as
barrier repair emollients are expensive and
often contain potential irritants and allergens.
White petrolatum (WP) is a commonly
recommended moisturizer, but compliance is
often limited by its greasiness.

INTRODUCTION

Objective: To compare the effect of natural oils and white petrolatum on skin barrier function
in patients with xerosis.
Design, Setting, and Participants: Randomized, open label, comparison pilot study
(NCT03093597).
Interventions: Participants were randomized to apply 1 of 4 moisturizers to assigned
treatment areas twice daily for 2 weeks. Clinical dry skin score, stratum corneum hydration,
and transepidermal water loss (TEWL) were assessed at baseline, 1 week, and 2 weeks.
Results: Thirty-two participants completed the study. Neither TEWL nor hydration were
statistically different among the moisturizers at each visit. All four moisturizers led to
significant initial increase in TEWL at week 1 (p < 0.05) with an associated increase in
hydration for coconut oil, jojoba oil, and white petrolatum. All four moisturizers led to significant
increase in hydration by week 2 (p < 0.01). The preferred moisturizers were almond oil and
coconut oil, which were most “liked” by 38% and 31% of the participants, respectively. The
least preferred moisturizer was white petrolatum.
Conclusions: Almond oil, jojoba oil, and coconut oil significantly increased hydration after 2
weeks, and are as effective as white petrolatum as daily moisturizers for xerosis. The
participants preferred natural oils to white petrolatum, implying that these moisturizer options
may improve patient compliance.

ABSTRACT

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September 2018 Volume 2 Issue 5

The fatty acid composition of natural oils
contributes to their unique characteristics and
effects on the skin; for instance olive oil is
higher in oleic acid and appears to disrupt the
skin barrier, while oils higher in linoleic acid
appear to improve the skin barrier.2 Coconut
oil (CO) is comparable to mineral oil at
improving hydration without altering TEWL
and has anti-microbial properties.3 Jojoba oil
(JO) can decrease TEWL and enhance SC
moisturization.4 Almond oil (AO) is rich in
antioxidants such as omega and linoleic fatty
acids and vitamin E and has occlusive
properties comparable to mineral oil.5

There is no head-to-head comparison
between natural oils and WP for
moisturization. This randomized, open label,
comparison pilot study aims to compare the
ability of natural oils (AO, CO, and JO) and
WP to improve xerosis and SBF. This clinical
trial was registered on clinicaltrials.gov
(NCT03093597) prior to participant
enrollment.

Nineteen subjects from University of
California, Davis (UCD) in Sacramento and
eighteen subjects from University of Arizona
(AZ) in Tucson participated in this study
(mean age 59.5 years old, range 24-85
years). The study was approved by the
Institutional Review Board at both sites, and
time period for recruitment and follow-up was
January 18, 2017 through July 31, 2017.
Baseline TEWL and hydration were not
significantly different.

Subjects were supplied with pre-measured
certified organic CO (Nature’s Bounty®), JO
(The Jojoba Company), AO (Mountain Rose
Herbs), and WP. Each of the four
moisturizers was pre-randomized in blinded
envelopes to one of four application areas on
the right and left forearms prior to

recruitment. The subjects applied 0.1ml of
each moisturizer twice daily to the assigned
area for two weeks. TEWL and hydration
were measured at baseline, 1 week and 2
weeks using Vapometer and
MoistureMeterSC (Delfin Technologies),
respectively. Xerosis was graded using the
Dry Skin Scale (DSS)6, and UCD participants
were asked to complete a survey regarding
moisturizer preferences at the final visit.
Intra- and intergroup evaluations were
performed using paired t-test and a
Bonferroni correction was implemented to
reduce type I error when comparing
moisturizers.

Four subjects were lost to follow-up after the
baseline visit, one subject dropped out after
week 1 due to scheduling conflicts, and thirty-
two subjects completed the week 2 study
visit. Outcome measurements are displayed
in Figure 1. Neither the TEWL nor the
hydration were statistically different among
moisturizers at each visit. All moisturizers
significantly increased TEWL at week 1 (p <
0.05) compared to baseline, and only JO and
CO persisted to have a significant increase in
TEWL at week 2 (p < 0.05).

All four moisturizers significantly increased in
hydration by week 2 (p < 0.01). There were
no significant differences in outcome
measurements when data was analyzed
separately for each study site. Thirteen
participants at the UCD study site completed
a survey, and AO was most “liked” (38%),
followed by CO (31%). WP was “least liked”
(62%). No adverse events were reported.

METHODS

RESULTS

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Figure 1. Changes in skin barrier biophysical
properties with moisturizer use. Transepidermal water
loss (A) and hydration (B) values at week 1 and week
2 visits are normalized to the measurements at the
baseline visit. Error bars represent SEM. n=32. * =
p<0.01.

AO, JO, and CO can be as effective as WP in
improving SBF in patients with xerosis.
Limitations of this study include:
assessments localized to forearms, short
study period, and relatively low baseline DSS
in study subjects. Natural oils can be
comparable alternatives to commercially
available emollients and are preferred over
WP, which may improve patient compliance.
Antimicrobial, antioxidant, and anti-
inflammatory properties are additional
benefits of natural oils. Larger randomized
trails that evaluate the benefit of additional
natural oils are needed, especially in
inflammatory dermatoses associated with
barrier defects, such as atopic dermatitis and
psoriasis.

Conflict of Interest Disclosures: RKS serves as a
scientific advisor to Dermveda and serves as a
consultant to Dermala and Burt’s Bees. VYS has
stock options in Dermveda, serves as a consultant for
Menlo Therapeutics, Sanofi Genzyme, Burt’s Bees,
and the National Eczema Association, and has
received research funding from Skin Actives
Scientific.

Funding: ARV received a medical student research
grant from Banyan Botanicals. The funding source had
no role in data analysis or the decision for publication.

Corresponding Author:
Vivian Y. Shi, MD
Department of Medicine, Dermatology Division
University of Arizona
vshi@email.arizona.edu

References:

1. Kezic S, Novak N, Jakasa I, Jungersted
JM, Simon M, Brandner JM, et al. Skin
barrier in atopic dermatitis. Frontiers
in bioscience (Landmark edition).
2014;19:542-56.

2. Vaughn AR, Clark AK, Sivamani RK, Shi
VY. Natural Oils for Skin-Barrier Repair:
Ancient Compounds Now Backed by
Modern Science. Am J Clin Dermatol.
2018;19(1):103-17.

3. Agero AL, Verallo-Rowell VM. A
randomized double-blind controlled
trial comparing extra virgin coconut oil
with mineral oil as a moisturizer for
mild to moderate xerosis. Dermatitis :
contact, atopic, occupational, drug.
2004;15(3):109-16.

4. Meyer J, Marshall B, Gacula M, Jr.,
Rheins L. Evaluation of additive effects
of hydrolyzed jojoba (Simmondsia
chinensis) esters and glycerol: a
preliminary study. Journal of cosmetic
dermatology. 2008;7(4):268-74.

5. Ranzato E, Martinotti S, Burlando B.
Wound healing properties of jojoba
liquid wax: an in vitro study. Journal of

DISCUSSION

mailto:vshi@email.arizona.edu

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September 2018 Volume 2 Issue 5

ethnopharmacology. 2011;134(2):443-
9.

6. Serup J. EEMCO guidance for the
assessment of dry skin (xerosis) and
ichthyosis: clinical scoring systems.
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