by Fleur Borrelli (Nutritionist at The Putney Clinic of Physical Therapy)
The skin and the brain are intricately linked. Both produce the same hormones and neurotransmitter substances. In the skin, serotonin should be converted to melatonin which acts as a natural antibiotic and anti-inflammatory. It is no wonder, therefore, that the skin condition psoriasis is linked to both depression and anxiety disorders(1). A lack of nutritional cofactors such as vitamins B6 and B12 may prevent this conversion in a biochemical process known as methylation.
Geographical latitude may also influence incidence of psoriasis as beneficial sunlight is also needed to produce melatonin(2). Overuse of sunscreens and lack of exposure to the sun will also inhibit the production of vitamin D, vitally important for the integrity of the barriers of the body which include the intestinal lining, the blood brain barrier, the synovial lining and of course the skin(3). The function of the barriers is to protect us against pathogens such as viruses and bacteria. They are lined, therefore, with immune cells including B memory cells which remain in communication with each other all over the body. It makes perfect sense, therefore, when treating the skin to also support the gut with probiotic therapy(4).
Another tool in the nutritional medicine toolbox to alleviate psoriasis is the use of adaptogenic herbs. Herbs such as ginseng and rhodiola can be very effective in reducing the detrimental effects of the stress axis. Chronic activation of this axis can be a factor in the over-triggering of the part of the immune system that deals with cellular immunity with the result being the higher cell proliferation that characterises psoriasis(5). As one of a spectrum of autoimmune diseases, it develops when the immune system mistakes a normal skin cell for a pathogen and sends out faulty signals that cause the overproduction of skin cells. An epidemiological link has been found between the consumption of beer and the incidence of psoriasis(6). Beer is made from the gluten-grain barley and other anti-nutrients such as saponins and lectins that can damage the gut and have been linked to autoimmunity(7).
Nutritional medicine offers a multi-system approach to tackling psoriasis. It aims to reduce the damaging effects of stress hormones whilst supporting barrier function and the immune system. Methotrexate is a pharmaceutical drug used in the treatment of autoimmune disease. It inhibits the metabolism of folic acid and so folic acid is often prescribed alongside. Folic acid, routinely used in fortified foods such as bread and supplements, is the synthetic version of the naturally occurring folate. Many of us have a genetic enzyme deficiency that prevents us from being able to convert folic acid into the folate. The result of this is that un-metabolised synthetic folic acid may remain in the bloodstream with undesirable consequences. Nutritional medicine can come to the fore by offering foods forms of folate. Folate is vital for cell division, DNA repair, immune function and cognitive health.
References for 'Looking at psoriasis the nutritional medicine way':
- Gunasti S, Marakii SS et al. Clinical and histopathological findings or psoriatic neurodermatitis and of typical lichen simplex chronicus. J Eur Acad Dermatol Venereal 2007. July 21 (6): 811-7.
- Reiter R.J. The melatonin rhythm: both a clock and a calendar. Experientia 15.8. 1993, Vol 49, Issue 8, pp 654-664.
- Kong J. et al. Novel role of vitamin D receptor in maintaining the integrity of the intestinal mucosal barrier. American Journal of Physiology. 1 January 2008 Vol. 294.
- Ouwehand AC, Tiihonen K, Lahtinen. The Potential of Probiotics and Prebiotics for Skin Health. Textbook of Aging Sin 2010, pp 799-809
- Lowes MA, Kikuchi T et al. Psoriasis Vulgaris Lesions Contains Discrete Populations of Th1 and Th17 T Cells. Journal of Investigative Dermatology (2008) 128, 1207-1211.
- Schafer T. Epidemiology of psoriasis. Dermatology Vol 212, No. 4, 2006.
- Rook G. Hygiene Hypothesis and Autoimmune Diseases. Clinical Reviews in Allergy and Immunology, February 2012, Volume 42, Issue 1, pp 5- 15.
For appointments with Fleur at The Putney Clinic of Physical Therapy, call 020 8789 3881 or send an email to firstname.lastname@example.org.
Fleur Borrelli (Nutritionist)
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