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“While many topical and systemic prescription options are available for the treatment of acne, some patients may be interested in natural and complementary therapies as either an adjunctive or an alternative to prescription medications,” researchers led by John S. Barbieri, MD, MBA, of the department of dermatology at Brigham and Women’s Hospital, Boston, wrote in their study, which was published online in JAMA Dermatology. The researchers defined nutraceuticals as products derived from food sources that provide both nutritional and medicinal benefits, such as vitamins, dietary supplements, and herbal products. “Although patients may be interested in nutraceuticals as a potential treatment option for acne, there is uncertainty regarding the efficacy and safety of these products,” they wrote.
For the systematic review, they searched the PubMed, Embase, Cochrane Central Register of Controlled Trials, and Web of Science databases from inception through January 30, 2023, to identify randomized clinical trials that evaluated oral nutraceutical interventions such as vitamins and minerals, botanical extracts, prebiotics, and probiotics in individuals with acne. They extracted clinician-reported outcomes, patient-reported outcomes, and adverse events from the included studies, and used the Cochrane Risk of Bias checklist tool to assess the quality of evidence in randomized clinical trials. Based on this tool, they used Agency for Healthcare Research and Quality standards to categorize the articles as good, fair, or poor quality.
The search yielded 42 unique studies with 3,346 participants. Of these 42 studies, 27 were considered poor quality, 11 were considered fair quality, and 4 were considered good quality. The good-quality studies separately evaluated four interventions: vitamin D, green tea extract, probiotics, and cheongsangbangpoong-tang, an herbal formula approved for use in acne by the Korea Food and Drug Administration.
The 11 fair-quality studies suggested potential effectiveness for pantothenic acid (vitamin B5), the fatty acids omega-3 (eicosapentaenoic acid [EPA] and/or docosahexaenoic acid [DHA]) and omega-6 (gamma-linoleic acid), and probiotics.
Zinc was the most studied nutraceutical identified in the review, but “there was substantial heterogeneity in the results, with only slightly greater than one-half of studies finding zinc to be efficacious,” the authors noted. “Studies using higher doses more often found zinc to be efficacious,” they said, adding that zinc “had the highest rate of adverse effect reporting of any nutraceuticals assessed in this review.”
Dr. Barbieri and colleagues acknowledged limitations of their analysis, including the fact that few of the nutraceuticals considered to have good or fair evidence for their use were evaluated in more than one study. “In addition, some studies had inconsistent results depending on the outcome measure assessed,” they wrote. “For instance, although green tea extract led to statistically significant improvements in lesion counts, it did not result in statistically significant improvements in quality of life, suggesting the observed lesion count differences may not be clinically meaningful to patients.”
And while probiotics had the most studies supporting their efficacy, they were generally of very small sample size.
Asked to comment on the study, Jonette Keri, MD, PhD, a dermatologist who directs the Acne and Rosacea Treatment Center at the University of Miami, who was not involved with the study, said that while the review was exhaustive, more research is needed to better determine the efficacy and side effects of the products studied. “The real strength of this wonderful review is now we have all of this information in one place, and this will serve as a great patient care resource,” she told this news organization.
Dr. Barbieri reported personal fees from Dexcel Pharma for consulting outside the submitted work. Dr. Keri disclosed that she is a consultant for L’Oréal.