Introduction

-Diet is quite often a question the patient asks when seeing a skin doctor and it is important to acknowledge that frequently “natural” solutions are sought before any medical ones.

-Acne has been the classical target of this quest for simplicity and the results of studies over half a century have been contradicting and are still a matter of debate nowadays.

-This article is about evidence of influence of foods in skin conditions. The source is a presentation by the author of an article published in the Journal of the American Academy of Dermatology (JAAD) in 2014 (see Bibliography). The author does a review of the literature by classifying studies: from strong ones (Randomized-Control-Trial-RCT=level of evidence IA) to weaker ones (expert opinions=level of evidence IV).

 

Summary of Findings

I. Acne (Acne Vulgaris)

I.a. Sugar intake and “heavy meals”

-Basis: hyperinsulinemia leads to production Insulin Growth Factor IGF1 (IGF1) which acts on the epidermis.

-Evidence suggests that a high glycemic index and load (IB) can play a role.

-Recommendation: low sugar diets and reduced load for acne patients.

I.b. Milk

-Only level III evidence is available. Randomized-Control Trials (RCT’s) are still required.

-Recommendation: evidence not good enough. [Perhaps the use of skimmed milk can be recommended.]

[More facts on influence of the Diet in Acne: click HERE.]

 

II. Chronic urticaria (hives)

pseudoallergens could be involved (IB).

Gluten (III): only recommended to have a Gluten-free diet if celiac disease present.

Vitamin D supplementation is recommended. (IB)

 

III. Psoriasis

Weight loss (IB): recommend weight loss via diet and exercise.

-role for Alcohol ? (III): insufficient data.

PUFA supplementation (e.g. fish oil) (IB): not recommended. (PUFA: polyunsaturated fish acids)

-Gluten (IB): only recommended to have a Gluten-free diet if celiac disease present.

Folic Acid (IB): only recommended when taking Methotrexate. (systemic MTX)

Vitamin D supplementation: not recommended.

Selenium supplementation: not recommended.

Antioxidants: Beta-Carotene may be beneficial.

 

IV. Atopic Dermatitis

-Overall there are 11 RCT’s including 596 patients: poor evidence.

Vitamin D supplementation (IB): insufficient data.

Primerose and Borage (IB): not recommended.

Prebiotics (IA): recommended in infants.

Diet exclusion and food allergies (IA): Helpful if allergy proven but if the patient says that he is allergic and that there is no proof, it is not beneficial.

Maternal diet (IA): maternal diet avoidance not recommended.

Breastfeeding or hydrolyzed formula (IA): it is recommended in infantsexclusively if an allergy is present.

[More facts on Atopic Dermatitis Prevention through Diet: click HERE.]

 

V. Non-Melanoma Skin Cancer (NMSC=keratinocytic carcinoma)

Fat (IB): low fat diet not recommended.

Vitamin A (IB): Beta-carotene not recommended. Retinol can be moderately effective in preventing Squamous Cell Carcinoma (SCC). Isotretinoin and Acitretin are recommended in Xeroderma Pigmentosum (XP).

Vitamins C, D and E supplementation (III): no evidence. (insufficient Data)

Selenium supplementation (IB): good to AVOID as can increase the risk of SCC and NMSC.

 

VI. Melanoma

PUFA supplementation: not enough evidence.

Vitamins D and E: not recommended.

Selenium, Lycopene, Resveratrol and Green tea (III): no evidence. (no good studies)

 

Conclusion

Food probably has a significant influence on skin health. However apart from a few good RCT’s, scientific evidence still lags behind when it comes to answering questions that patients consider basic.

Further reading: Publications in the JAAD listed below. (Bibliography)

 

 

Bibliography

  1. Presentation by Rao B., MD. Diet in Dermatology. Dubaiderma 2017
  2. Diet in dermatology: Part I. Atopic dermatitis, acne, and nonmelanoma skin cancer. Bronsnick T, Murzaku EC, Rao BK. J Am Acad Dermatol. 2014 Dec;71(6):1039.e1-1039.e12. doi: 10.1016/j.jaad.2014.06.015. Epub 2014 Nov 15. Review. http://eblue.org/article/S0190-9622(14)01577-1/fulltext
  3. Diet in dermatology: Part II. Melanoma, chronic urticaria, and psoriasis. Murzaku EC, Bronsnick T, Rao BK. J Am Acad Dermatol. 2014 Dec;71(6):1053.e1-1053.e16. doi: 10.1016/j.jaad.2014.06.016. Epub 2014 Nov 15. Review. http://eblue.org/article/S0190-9622(14)01577-1/fulltext
  4. Corrections to the two aforementioned articles in Vol. 73, Issue 2, p353
  5. Diet and acne. Bowe WP, Joshi SS, Shalita AR. J Am Acad Dermatol. 2010 Jul;63(1):124-41.
  6. Prevention of Atopic Dermatitis – an Evidence-Based Review. Presentation by Lai D., MD. Atopic Dermatitis Symposium – Oct 2016 – Hong Kong