| |
| Date: 07-29-2016 | HC# 011622-549 |
Boucetta KQ, Charrouf Z, Derouiche A, Rahali Y, Bensouda Y. Skin hydration in postmenopausal women: argan oil benefit with oral and/or topical use. Prz Menopauzalny. October 2014;13(5):280-288.
Lipids are an important component of skin and allow the skin to maintain high hydration levels. Dry skin is common in postmenopausal women, with a decrease in skin hydration related to the decrease in estrogen that occurs during menopause. Hormone replacement therapy (HRT) often restores skin moisture levels and reduces dry skin, which can also be relieved with topical application and ingestion of oils. Argan (Argania spinosa, Sapotaceae) oil is used both medicinally and as a food ingredient in North Africa. In this open-label, randomized, controlled study, the effect of argan oil on skin moisture was measured in postmenopausal women.
One hundred postmenopausal women were recruited for the study, which was conducted in Rabat, Morocco. Of these, 60 met study criteria. Subjects were included if they were postmenopausal and did not have any type of skin disease. Subjects were excluded if they were taking HRT or dietary supplements or using moisturizing products.
The study was divided into 2 phases. During the first phase, subjects consumed 25 mg of butter (source not listed) daily for 2 weeks in order to standardize lipid profiles. During the second phase, subjects were randomly assigned to either a control or treatment group for 60 days. The control group consumed 25 mg of olive (Olea europaea, Oleaceae) oil (source not listed) daily, whereas the treatment group consumed 25 mg of argan oil (Targante Cooperative; Chtouka Aït Baha, Morocco). In addition, subjects in both groups placed 10 drops (approximately 240 mg) of argan oil on the left volar forearm each day. The right volar forearm was left untreated. Subjects were asked to adjust their diets to the Moroccan food table diet in order to limit the effect of the dietary fat content. Compliance was measured by collecting used bottles of oil. Transepidermal water loss (TEWL) and water content of the epidermis (WCE) were measured on the right and left forearm at baseline and 30 and 60 days. At each visit, subjects stabilized for 15 minutes to adjust to climate-controlled room conditions. Data were analyzed with one-way analysis of variance, Bonferroni post hoc comparisons, and Student's t-test. Differences were considered to be statistically significant at P < 0.05.
When the untreated (right) forearm was measured, TEWL decreased significantly and WCE increased significantly with argan oil consumption over the course of the study, i.e., the difference between at least 2 test days (P = 0.023 and 0.001, respectively), with a slightly higher P value by the end of the study (P = 0.043, TEWL and P = 0.002, WCE). TEWL and WCE did not change significantly with olive oil consumption in the untreated forearm. By the study's end, TEWL was significantly lower and WCE was significantly higher on the untreated forearm in the group that consumed argan oil vs. the group that consumed olive oil (P = 0.046 and 0.047, respectively).
When the left forearm treated with argan oil was measured considering the difference between at least 2 test days, TEWL decreased significantly in both the argan oil consumption group and the olive oil consumption group (P = 0.01 and 0.009, respectively), with a slightly higher P value by the end of the study (P = 0.012, argan and P = 0. 016, olive oil). WCE increased significantly on the left forearm in both groups for all parameters (P < 0.001). There was no significant difference between groups in TEWL or WCE of the treated forearm at the end of the study.
No significant difference was found between the left and right forearms within the argan oil consumption group. In the olive oil consumption group, however, the left forearm treated with argan oil had a significantly lower TEWL and significantly higher WCE than did the untreated forearm (P = 0.012 and 0.023, respectively).
Skin hydration was improved with both topical application and consumption of argan oil in postmenopausal women. Either argan oil consumption or topical application seems to increase skin hydration to the same extent. The consumption of argan oil may have additional health benefits and may be the preferred means of increasing skin hydration. The choice of topical application or consumption may also be based on the difference in cost between these treatments. In contrast, olive oil consumption did not affect skin hydration.
Argan oil is much higher in linoleic acid and tocopherols than olive oil. The authors note that linoleic acid is important in the matrix of the epidermis and that this may be one of the mechanisms whereby argan oil improves skin hydration. It is also likely that the difference between argan oil and olive oil is due to a synergy between particular components of unsaponifiable fractions. No adverse effects were reported with argan oil consumption or application. The study provides evidence that argan oil increases skin hydration in postmenopausal women, and there would be value in repeating the study in a larger sample size of subjects.
Argan oil is much higher in linoleic acid and tocopherols than olive oil. The authors note that linoleic acid is important in the matrix of the epidermis and that this may be one of the mechanisms whereby argan oil improves skin hydration. It is also likely that the difference between argan oil and olive oil is due to a synergy between particular components of unsaponifiable fractions. No adverse effects were reported with argan oil consumption or application. The study provides evidence that argan oil increases skin hydration in postmenopausal women, and there would be value in repeating the study in a larger sample size of subjects.
The Hassan II Academy of Science and Technology (Rabat, Morocco) funded the study and the Ibn Al Baytar Association (Rabat, Morocco), which trains women's groups to set up cooperatives for the production of argan oil and works to conserve the argan tree, was involved in its management.
—Cheryl McCutchan, PhD
