by Dr. Shahrzad Alimohammadi, PhD Candidate, PharmD, Edited by Christopher M. Cirino, DO MPH

Introduction: Diet and the Skin

The skin is the body’s largest organ. The skin provides a physical barrier to the deeper structures of the body, but it is not a static structure. It plays a role in inflammation and immunity. Tiny blood vessels found within the dermis link the skin with the rest of the body. The skin is a window to the health and functioning of the body. It also reveals how the food that we put into our bodies can impact our entire system.

Long ago, scientists did not understand the link between skin disorders and dietary intake. However, recently, it has become clear that several skin manifestations, conditions, and systemic diseases are associated with nutrition. Dietary modifications may lead to improvements (Katta and Desai 2014). The body utilizes nutrients acquired in diet to maintain body organs, energy, and numerous metabolic processes. Nutritional balance is crucial for healthy skin maintenance, and cutaneous manifestations occur from vitamin, fatty acids, and mineral deficiencies.

Dietary intake correlates with many dermatological disorders. Some common examples include atopic eczema, dermatitis herpetiformis, psoriasis, hives, rosacea, acne, and gout (Sriharsha M and Krupa SN 2015). Food allergies, including dermatitis herpetiformis, caused by sensitivity to gluten, are related to specific dietary intake. Diet can influence the severity of certain skin disorders (e.g., acne, psoriasis) and can play a preventive role in skin cancer development and aging. Not only can a proper diet improve the outcome of skin disorders related to systemic diseases (e.g. gout), but it can improve chronic diseases (Katta and Desai 2014).

Skin Conditions Associated with Diet

Skin Changes of Aging

Saggy skin, or rhytides, and loss of elasticity come with aging, as changes occur to the collagen and elastic fibers of the skin. Dietary intake such as a high carbohydrate diet can accelerate these signs of aging as it improves collagen fibers cross-linking, a process known as glycation (Danby 2010). In the dermis, the lower layer of the skin, bonds are present between collagen and elastin fiber amino acids. Glucose and fructose facilitate the linkage of amino acids, driving advanced glycation end products (ADEs). Hyperglycemia from diabetes results in the accumulation of AGEs and leads to structural changes of the skin, for instance, increased stiffness and decreased elasticity. 

Some herbs, including spices, oregano, cloves, cinnamon, ginger, garlic, and some others containing lipoic acid, can block the production of AGEs (Katta and Desai 2014).

Skin Cancer

One of the most frequent cancers in the United States is nonmelanoma skin cancer (NMSC), and, aside from protection of injury of the skin from sunburns, following a diet rich in fruits and vegetables may aid in reducing the incidence of NMSC and skin cancer overall. Some laboratory studies have revealed that dietary intake of vitamin C, selenium, and green tea extract may contribute to skin tumor suppression. As carcinogenesis is a result of many mechanisms such as protein and lipids damage, cell proliferation, and inflammation, antioxidants are reported to enhance free-radical breakdown, neutralization, the elevation of neutralizing enzymes, expression of genes linked to DNA replication and repair (Katta and Desai 2014). In summary, although not commonly mentioned, a healthy diet may be beneficial to reduce the risk of cancer.

Acne Vulgaris (AV)

Acne is a common dermal disorder present in up to 90% of adolescents. Its presence can lead to psychological morbidity as well as stress, particularly in severe cases. Acne can manifest as a cystic or nodular, a condition that can lead to cosmetic disfigurement and scarring. Even though genetics play a role in the incidence of acne, nutrition may contribute to the pathogenesis of this skin disorder (Rezaković et al. 2014). In one study, a high glycemic load diet and dairy products correlated with acne formation. Milk contains growth hormones, anabolic steroids, and possibly higher insulin-like growth factor-1 (IGF-1) levels.

Aside from dairy products, carbohydrates with a higher glycemic index, including sugar, white rice, and white bread, are absorbed immediately, resulting in more elevated serum glucose and insulin levels. IGF-1 and insulin together lead to sebum production, adrenal androgen synthesis stimulation followed by androgen bioavailability elevation that results in the pathogenesis of acne.

As studies show, a lower glycemic diet benefits insulin sensitivity, decreases testosterone bioavailability, lowers adrenal androgens, and in the end, improves acne (Katta and Desai 2014)

Psoriasis

One of the most common and persistent relapsing immune-mediated skin diseases is psoriasis. Psoriasis occurs worldwide, and its prevalence is 3-4% of the global population (Afifi et al., 2017). It may result in psychosocial and psychological discomfort depending on the manifestations and severity (Ada et al., 2004; Rezaković et al., 2014). Besides being associated with genetics, certain medications, and infections (e.g., Strep), psoriasis can worsen with particular foods.

The high intake of simple sugars contributes to psoriasis. Mice fed a western diet, high in saturated fats and simple sugars, had a psoriaform skin condition, compared to mice that were fed a high-fat, low-sugar diet (Afifi et al., 2017)

Alcohol consumption is a possible trigger to psoriasis flare-ups, and lowering alcohol intake improves manifestations (Rezaković et al. 2014).

How is psoriasis associated with food? The mechanisms are multifactorial. Researchers have identified both immunological (e.g. IL-17A production after certain foods) and genetic associations. Studies show T-lymphocyte activation in the skin, vitamin A and D responses, and intrinsic abnormalities of keratinocytes (Ada et al., 2004).

Some studies correlate changes in gut microbiome from a high sugar diet, including the overgrowth of certain strains of bacteria, production of short-chain fatty acids, and problems with bile acid production. All of these factors promote inflammation, making psoriasis worse (Kanda et al., 2020).

Psoriasis is a systemic inflammatory disease. Several research studies show a higher risk of cardiovascular diseases (CVD) in patients who have psoriasis. According to the data of several studies, the greater severity and longer duration there is with psoriasis, the higher the CVD incidence.

A particular dietary routine that includes anti-inflammatory food can be highly beneficial (Katta and Desai 2014). According to a study, the Mediterranean diet, replete with fruits, beans, grains, olive oil, seeds, and lowered meat and dairy products intake, can benefit psoriasis. These foods improve the function of the endothelium and reduce cytokines and proteins such as interleukin 18 (IL-18) and C-reactive protein (CRP), respectively (Katta and Desai 2014; Rezaković et al. 2014).

Another study reveals that this diet can result in weight loss, reduction in insulin sensitivity together with inflammatory response reduction, all of which improve psoriasis (Prussick 2019; Afifi L, et al. 2017). Additionally, a diet rich in vegetables, fruits, fish oils, selenium, oral vitamin D3, whole grains, and omega-3 fatty acids can improve vascular inflammation markers (Katta and Desai 2014; Rezaković et al. 2014).

Conclusion

Diet is a critical player in the treatment and prevention of many diseases, including dermatological disorders. Acne, skin cancer (e.g., NMSC), skin aging, and psoriasis are examples of skin diseases that might benefit from a rich and healthy diet (Rezaković et al., 2014). If you have a skin disorder, it is a good idea to take a closer look at your diet and determine which foods may be playing a role. Lifestyle and dietary modifications can help improve many skin disorders manifestations and severity, namely acne, skin cancer, psoriasis, and even the aging process of the skin (Katta and Desai 2014).

Inflammatory skin diseases such as atopic dermatitis (AD), acne vulgaris (AV), and psoriasis can benefit from a healthy and nutrient-rich diet to decrease skin findings and reduce inflammation. The goal is to follow a lower glycemic index (GI) by avoiding bread, rice, pasta, and cereal and using acids such as lemon juice or vinegar to lower AGEs to 50% (Prussick 2019). To conclude, diet and food intake are involved in preventing several diseases such as systemic and dermatological disorders and have a high impact on one’s health. Here are a few Your Health Forum article links for more information on healthier carbohydrate options or dietary suggestions.

Shahrzad Alimohammadi is a Pharm.D. and currently a junior research fellow at the Department
of Immunology, University of Debrecen. She is a Ph.D. candidate, and her research mainly
focuses on the skin’s immune cells, including Langerhans cells and dendritic cells and their
possible roles in the skin!

Pharmaceutical technology, as well as dermatology, are her favorite topics when it comes to
research. In the dermatological field, Shahrzad is interested in inflammatory and immune-related
skin diseases and cosmetic dermatology.

References

Ada LS, Anna A, Vincenzo G. Foods, Diet, and Skin Diseases. SKINmed: Dermatology for the Clinician. 2004;3(2):83–91 Available from: https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1540-9740.2004.02363.x

Afifi L, Danesh M, Lee K, Beroukhim K, Farahnik B, Ahn R, Yan D, Singh R, Nakamura M, Koo J, Liao W. Dietary Behaviors in Psoriasis: Patient-Reported Outcomes from a US National Survey. Dermatology and Therapy. 2017. 7, 227-242.

Danby W. Nutrition and aging skin: sugar and glycation. Clin Dermatol. 2010; 28(4): 409-11. DOI: 10.1016/j.clindermatol.2010.03.018

Kanda N, Hoashi T, Saeki H. Nutrition and Psoriasis. 2020. Int J Mol Sci. 21(15): 5405. https://dx.doi.org/10.3390%2Fijms21155405

Katta R, Desai SP. Diet and Dermatology. J Clin Aesthet Dermatol. 2014;7(7):46–51 Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4106357/

Prussick R. Diet and Inflammation in Dermatology [Internet]. Practical Dermatology. Bryn Mawr Communications; 2019 [cited 2021 May 24]. Available from: https://practicaldermatology.com/articles/2019-may/diet-and-inflammation-in-dermatology

Rezaković S, Pavlić M, Navratil M, Počanić L, Žužul K, Kostović K. The Impact of Diet on Common Skin Disorders. J. Nutr. Ther. 2014;3(3):149–55 Available from: http://www.lifescienceglobal.com/journals/journal-of-nutritional-therapeutics/volume-3-number-3/87-abstract/jnt/1135-abstract-the-impact-of-diet-on-common-skin-disorders

Sriharsha M DS, Krupa SN NR. Role of Diet in Dermatological Conditions. J Nutr Food Sci. 2015;05(05) Available from: https://www.omicsonline.org/open-access/role-of-diet-in-dermatological-conditions-2155-9600-1000400.php?aid=60091