Randomized Assessor-Blinded Controlled Trial on the Efficacy and Safety of Virgin Coconut Oil versus Mineral Oil as a Therapeutic Moisturizer for Senile Xerosis
Authors: Escuadro-Chin Mariecon O. , Maaño Michael Marc C. , Dofitas Belen L. 
Published: January 2021

Background. Xerosis is one of the most common dermatologic complaints in the elderly. People in the tropics, including the Philippines, have effectively used coconut oil as a traditional moisturizer for centuries. Its film-forming qualities allow it to act as a skin moisturizer and as a protectant against moisture loss. To date, only one randomized clinical trial has proven the efficacy and safety of coconut oil as a skin moisturizer for xerosis. With the increasing number of VCO products in the market, this study aimed to validate the use of an indigenous agricultural product, virgin coconut oil, for senile xerosis. With its moisturizing, antioxidant, and antiseptic effects, VCO may be superior and more cost-effective compared to the frequently used synthetic mineral oil.

Objective. This study aimed to determine the efficacy and safety of virgin coconut oil compared to mineral oil for the treatment of senile xerosis.Methods. This was a community-based assessor-blinded, randomized controlled trial, which included elderly patients with mild to moderate senile xerosis of the legs. Participants were instructed to apply the test oil twice daily to the legs for 2 weeks. The following primary outcomes were measured at baseline and 2-weeks post treatment: skin dryness (over-all dry skin score, ODSS), skin hydration (corneometer readings), skin lipid content (sebumeter readings), and quality of life (Dermatology Life Quality Index). Secondary outcomes like patient-assessed clinical efficacy and adverse effects were also measured.

Results. A total of 148 participants (59 males, 89 females) with mean age of 68 years (SD 6.02) were included in the study. Eighty-one (81) were assigned under the VCO group and 67 under the mineral oil group. There was a total of 25 dropouts, 7 in the virgin coconut oil group, and 18 in the mineral oil group. The distribution of the patients’ ODSS after treatment with VCO and mineral oil showed a trend towards improvement: 43% in the VCO group had no visible signs of leg xerosis versus 22.4% in the mineral oil group. The proportion of participants with>1 point decrease in ODSS, was statistically greater in the VCO group at 74% (60/81) compared to the mineral oil group, 34% (23/67) (p<0.0001). VCO showed significantly greater skin hydration at 74% (60/81) as compared to 46% (31/67) in the mineral oil group (p<0.0010). Improvement in the skin lipid content using the sebumeter showed 82.7% (67/81) in the VCO group compared to 61.2% (41/67) in the mineral oil group (p=0.6591). Moreover, the patients’ perceived efficacy of the oil applied on their skin was 29.6% (24/81) in the VCO group compared to 5.9% (4/67) in the mineral oil group (p=0.0030). Baseline DLQI scores showed no significant difference in the assessed quality of life of the patients between the two treatments (p=0.0161).Over all, the VCO group showed 32.1% (26/81) treatment success compared to 8.9% (6/67) in the mineral oil group (p=0.004614). Adverse events in the 2 groups were all mild and transient with 8% (6/74) patients in the VCO group and 26.5% (13/49) in the mineral oil group (p=0.089).

Conclusion. Among elderly patients with mild to moderate xerosis, 2-week topical application of VCO was superior to mineral oil in the immediate improvement of leg xerosis based on primary outcome measures of the Over-all Dry Skin Score (ODSS), corneometer, sebumeter readings, and the Dermatology Life Quality Index.