New research highlights the role of diet in combating vitiligo

In a recently published review Journal of Cosmetic Dermatology, The researchers compiled existing literature investigating the effects of diet and nutritional interventions against vitiligo. The datasets consisted of 14 publications from three online scientific databases. The review findings highlight that vitiligo, a relatively rare autoimmune skin disease, potentially develops in response to increased somatic reactive oxygen species (ROS) concentrations. Although some heavy metals (Cd, Hg, and Pb) play a role in the development of this condition, the effects of trace minerals such as Zn and Cu remain unclear and contradictory.

Study: Investigating the impact of diet and nutrition on vitiligo: A systematic review of dietary factors and nutritional interventions. Image Credit: Master1305 / Shutterstock

In general, diets and nutritional interventions rich in ROS-depleting molecules (such as vitamin C, B12, and vitamin D, polyunsaturated fatty acids (PUFAs), and antioxidants) have been shown to trigger beneficial vitiligo outcomes and reduce the burden of metabolism, cellular degradation, and ROS. caused by oxidative stress. Although unlikely to replace pharmacological and phototherapy interventions against vitiligo, dietary interventions offer an important step forward in reducing our dependence on these potentially adverse clinical interventions. However, large-scale clinical studies are needed. Before these interventions became commonplace.

What is vitiligo and what do we know about its pathology?

Vitiligo is a rare autoimmune disease characterized by loss of skin pigmentation in patches or spots, usually around the mouth, hair, and eyes. It is estimated to affect 0.004% to 2.28% of the global population, and although phototherapy and pharmacological interventions can reduce the visibility of symptoms, there is currently no treatment for this condition. Although the mechanisms that support the development and progression of vitiligo have not yet been elucidated, it is hypothesized that this condition is caused by a combination of hormonal and genetic factors, particularly cellular degradation (melanocytes), metabolic imbalances, and oxidative stress.

Increased concentrations of reactive oxygen species (ROS) combined with reduced effectiveness of the body’s normal antioxidant mechanisms are hypothesized to significantly exacerbate the disease; studies have found significant differences in the volumes of ROS production per erythrocyte between patients with (much higher) and without. Vitiligo A growing body of literature reveals that although vitiligo is physically harmless, it is associated with more serious comorbidities such as alopecia areata, atopic dermatitis, and psoriasis.

As with other chronic conditions characterized by altered ROS metabolism (some cancers and neurodegenerative conditions), diets are being investigated for their potential antioxidant properties. Studies in several fields, including vitiligo research, support that dietary interventions are natural, relatively inexpensive, and generally side-effect-free alternatives to traditional clinical interventions (corticosteroids and calcineurin inhibitors), which are often costly and prone to side effects. Unfortunately, these studies are so recent and seemingly disconnected that a synthesis and holistic assessment of the subject has been lacking until now.

About the study

In the current review (PROSPERO registration number CRD42023464740), researchers discuss current results from studies and publications investigating the relationship between diet and vitiligo. Two independent reviewers retrieved articles from three online scholarly repositories, PubMed, European PMC, and Google Scholar, using archival-optimized search strategies for publication acquisition and screening. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) guidelines were followed in the methodological design and presentation of the review.

Of the 214 records initially found in keyword searches, 19 were found to be duplicates and were excluded. 173 records were not included in the title and abstract screening; these records were further narrowed down to the final set of publications (n ​​= 14) following full-text screening. The Rayyan platform was used to scan the included publications. Elicit and PDF Gear platforms were then used to extract data with critical variables such as study description details, methodological characteristics, outcome measures, and a brief study summary.

“…studies without complete or accessible full-text articles were excluded to preserve the robustness of our ability to comprehensively evaluate and synthesize findings.”

The Critical Appraisal Skills Program (CASP) tool was used to assess the quality of included publications and risk of bias. Data synthesis involved classifying and combining results and then visual representation of them as pie charts or bar diagrams.

Study findings

This review highlights the critical role of ROS and the body’s antioxidant mechanisms in the development and progression of vitiligo. ROS-producing heavy metals such as Cadmium (Cd), Mercury (Hg) and lead (Pb) are thought to be disease-causing agents. In contrast, the roles and effects of micronutrients are not fully understood; Studies provide confusing and often conflicting results.

Vitamin supplements, especially C, D, and B12, have been hypothesized as potential anti-vitiligo interventions due to their high antioxidant activity.

“A pilot study investigated the effectiveness of high-dose oral vitamin D supplementation on vitiligo repigmentation in 16 people with vitamin D deficiency vitiligo. More than half of the patients experienced 26-75% repigmentation after consuming 35,000 IU per day. 29 Supplementation is recommended but dosing strategies have not been established. “

Recently, researchers have begun to explore fatty acids such as saturated fatty acids (SFAs) and polyunsaturated fatty acids (PUFAs) for their beneficial effects on vitiligo patients. PUFAs in particular have been shown to exert a strong immunosuppressive effect on disease. Narrow band (NB) ultraviolet B (UVB) light as well as Alpha Lipoic acid (ALA) have been shown to reduce and even reverse vitiligo symptoms compared to placebo.

While this review highlights the current dearth of vitiligo-diet relationship research (only 14 publications met the criteria for inclusion in the review), significant ongoing research will soon supplement our current knowledge in this area. Although corticosteroids and calcineurin inhibitors are unlikely to be dethroned as primary clinical interventions against vitiligo progression, studies have shown that the effectiveness of both interventions is impressively supported by some dietary components, suggesting their role as adjuncts in the future.

“Larger-scale clinical studies are needed to establish strong evidence and protocols and may also help reduce reliance on pharmacological methods, which come with their own adverse effect profiles.”