The Potential Role of Lipids in Seborrheic Dermatitis

Lipids are an essential part of our diet. Without an adequate supply of lipids, various health conditions can arise and immune function instability is immanent. Luckily, obtaining an adequate amount of lipids from our diet is fairly easy and most individuals in the western world actually far exceed their bodies requirements.

However, not all lipids are created equally. Specific lipids such as omega 3 and omega 6 fatty acids are critical for stable immune function and inflammation. Without them, we would quickly experience a variety of ailments and this is why they are considered essential fatty acids (EFA).

Essential fatty acid balance in seborrheic dermatitis already came into discussion in the “Fatty Acid Metabolism & Synthesis” section of this chapter. In that section the potential issue with their metabolism in seborrheic dermatitis was discussed. This section, however, aims to discuss the dietary availability of essential fatty acids.

The Important Balance of Essential Fatty Acids

Essential fatty acids were first introduced in the “Balance of the Omegas” chapter of this book. In that chapter, their importance was thoroughly reviewed and the concept of maintaining an adequate balance of omega 3 to omega 6’s was introduced.

Some key takeaways from that chapter included:

• The ratio of omega 3s to omega 6s is a critical component of health [1]
• Innovations in food processing and dietary trends have caused a drastic shift in this ratio [2]
• A high omega 6 to omega 3 ratio has been attributed to a variety of chronic health conditions and immune system issues [3]

In summary, many modern diets result in unbalanced intake of essential fatty acids and some researchers believe this is major contributor to the rise in inflammatory disorders seen in the western world [4]

Omega 6 Fatty Acids and Skin Disease

For the most part, research on the subject of essential fatty acids and skin disease has focused on the role of omega 6 fatty acids. Some relevant findings include:

• Linoleic acid and its derivatives play a critical role in the structure and function of the natural skin barrier [5, 6]
• In the case of polyunsaturated fatty acid deficiency, oleic acid takes its place and this can result in an abnormal permeability and appearance [7, 8, 9]
• Polyunsaturated fatty acid deficiency results in increased transepidermal water loss, and induction of proliferative keratins and inflammation associated keratins [10]
• Studies have shown a reduced level of GLA and higher levels of LA in individuals affected by atopic dermatitis. Sadly, supplementation with evening primrose oil (high in GLA) appears to be of benefit in only a subset of affected individuals [11]

Clearly, omega 6 fatty acid are critical to skin health. However, the lack of consistent results from supplementation and low chance of deficiency from most modern diets leads to many unanswered questions.

Omega 3 Fatty Acids and Skin Disease

Omega 3s on the other hand, do not nearly have as much discussion in the case of skin maintenance and stability. For the most part, they are minimally mentioned for their vital role in the inflammatory response and modulation of the immune response [12]. There are, however, a few points that are extremely relevant in the case of skin health and stability.

First consider the following facts:

• Many skin’s defense mechanisms rely on inflammation and the majority of skin disease appears to have some sort of bacterial or fungal factor [13]
• Two specific omega 3 fatty acids (DHA and EPA) are essential for normal functioning of the immune response and controlling inflammation [4]
• If dietary sources do not provide enough DHA and EPA, the body must convert ALA (alpha-linolenic acid is common in many plant oils) [14]
• The process of ALA to DHA and EPA depends on the same metabolic mechanism (desaturase enzymes) as does the conversion of LA to ALA [15]

Now, consider a hypothetical situation in which there is an absence of dietary EPA and DHA plus a restricted amount of desaturase enzymes available. This means the body would have to allocate the available enzymes between omega 3 conversion and omega 6 conversion. In this situation, a deficiency in the amount of long chain omega 6 fatty acids may in part be due to a combination of both an exceedingly high demand for omega 3 conversion and diminished desaturase availability.

Accordingly, it’s easy to theorize that a dis-balanced ratio of essential fatty acids may play a significant role in various chronic inflammatory skin conditions. And though studies examining omega 3 supplementation have shown mixed results, overall it does appear that improving the omega 3 to omega 6 fatty acid ratio may have significant beneficial impact.

Fatty Acid Balance and Seborrheic Dermatitis

In the case of seborrheic dermatitis, the research in this area appears to be quite sparse. Some initial clues from the overall influence of fatty acid balance importance come from two studies which evaluate the importance of overall polyunsaturated acid availability:

• Evaluation of 30 children with infantile seborrheic dermatitis showed a clear difference in EFA (in the blood) levels when compared to healthy children. And normalization of EFA levels occurred in tandem with skin recovery [19]
• Comparison of 30 individuals affected by seborrheic dermatitis to 30 healthy subjects revealed lower levels of both EFAs and Vitamin E in the affected group [20]

Unfortunately, there doesn’t appear to be any studies examining the relationship between omega 3 balance and seborrheic dermatitis progression. However, since omega 3 fatty acids play such an integral role in immune function and stability, it remains unclear why such research is lacking. Especially considering the fact that seborrheic dermatitis appears to have both a microbial component and an altered inflammatory response.

And though there aren’t any specific studies for seborrheic dermatitis, there are some papers which discuss the role of omega 3s in several similar (often overlapping) skin conditions. Some key highlights from these papers include:

• Supplementation with omega 3s was shown to improve severity of atopic dermatitis at the age of 1 [21]
• Supplementation with omega 3 fatty acids (EPA, DHA and ALA) was shown to significantly improve both inflammatory and non-inflammatory acne lesions [22]
• Intravenous (direct into the blood) injections of omega 3 fatty acids showed significantly better results when compared to omega 6 fatty acids in the case of chronic plaque-type psoriasis [17]
• Daily supplementation with EPA resulted in an improved resistance to sunburn and reduced other markers of cellular damage due to ultraviolet radiation [23]

Clearly, there is some evidence that increasing omega 3s may hold significant potential in correcting various chronic inflammatory skin conditions. Perhaps their potential role in seborrheic dermatitis may be evaluated by other researchers in the near future.

Essential Fatty Acid Deficiencies, Oleic Acid and Seborrheic Dermatitis

Another important area to consider is what happens in the case of essential fatty acid deficiency and how it may be connected to seborrheic dermatitis. Specifically, consider the following points:

• Whenever our bodies are deficient in linolenic and alpha linolenic acids, it attempts to replace their presence (in the sebum) with palmitoleic and oleic acids [24]
• At high enough concentrations, oleic acid has been shown to cause alterations in the skin barrier [25]
• Oleic free fatty acids released by malassezia have been shown to be the exact cause of seborrheic dermatitis symptoms [26]

Accordingly, a relative deficiency of omega 6 fatty acids (due to metabolism issues) may result in a high concentration of oleic acid in the sebum. This high concentration of oleic acid weakens the skin barrier, increases the presence of irritating oleic free acids and prevents the skin from healing. And perhaps this is essentially the cause of seborrheic dermatitis.

Section Summary

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