Psoriasis; how to support the condition through nutrition
Psoriasis affects 1.8 million people in the UK.
Living with the skin condition can bring huge demands on daily life; it can affect an individual’s appearance, confidence, social interactions and relationships. From getting a haircut to swimming, these experiences can be unpleasant and stressful for individuals. Psoriasis may flair up in response to lifestyle and environmental changes.
What is Psoriasis?
Psoriasis is an immune stimulated condition where skin cells develop rapidly and is highly inflammatory. Normally, skin cells are replaced after 21-28 days, however in psoriatic individuals this can be as quickly as 4-7 days. The build up of skin cells create raised sections of skin called plaques, that can occur on any body part and appear flaky, scaly and red on fair skin, or as dark patches on darker skin tones, with intense itching. Furthermore, psoriasis is defined into 6 subtypes; Plaque, Guttate, Scalp, Pustular, Sensitive Area and Nail.
Conventional treatments include immunosuppressant and anti-depressant medications besides topical preparations.
The good news is that dietary modification can really make a difference. Conditions that involve inflammation often respond well to the removal of inflammatory foods from the diet. The main suspects are processed foods with additives, sugar laden foods, gluten and for some; dairy. These foods promote the cycle of inflammation and so, by removing them and replacing them with seasonal wholefoods, lean proteins, a rainbow of fruits and veggies, alongside healthy fats from nuts, seeds, avocado and oily fish, the inflammatory cycle can be interrupted.
Such dietary recommendations are supported by an encouraging Italian explorative study that reported a significant inverse relationship between the psoriasis symptom severity and the intake of carrots, tomatoes and fresh fruit. The same study revealed a positive association between psoriasis and body mass index (BMI); subsequently those with a greater BMI also showed greater symptom severity.
Diets rich in fruits and vegetables have unequivocally demonstrated an increase in blood anti-oxidant levels, suggested to be an essential mechanism in countering the oxidative damage associated with psoriasis. Furthermore, blood glucose spikes caused by refined carbohydrates, typically from processed foods, have been shown to stimulate insulin secretion and contribute to the inflammatory signalling cascade that results in the increased severity of psoriatic symptoms. Therefore, adopting a wholefoods approach will regulate blood glucose and dampen down the associated insulin and inflammatory signalling.
What the research shows
A random controlled nutritional investigation evaluated the administration of 50mg Coenzyme Q10, 50mcg Vitamin Eand 48mcg Selenium daily on Psoriatic patients using the Psoriasis Area and Severity Index (PASI). The study ran for 50 weeks and it was observed that the Coenzyme Q10, Vitamin E and Selenium group experienced a significant improvement in clinical biomarkers of psoriasis and a faster normalisation of oxidative stress markers compared to the placebo group. The authors concluded that the treatment combination could be feasible for the management of psoriasis.
It is known that Vitamin D has important immunomodulatory effects on psoriasis. Subsequently a noteworthy study investigated vitamin D intake in 104 patients with and without psoriasis living in the Mediterranean. The aim was to measure vitamin D intake and evaluate for an association to psoriatic clinical outcomes. An insufficient intake of both, vitamin D2 and D3 was observed overall, while patients with psoriasis were observed to be at a greater risk of cardiovascular occurrences characterised by elevated cholesterol, metabolic syndrome and elevated blood pressure. This raises important questions regarding the ability of affected skin to synthesis vitamin D from UV rays and whether psoriatic patients have a greater vitamin D intake requirement.
A conventional treatment for psoriasis is synthetic retinoids (vitamin A treatment), however, their use is occasionally limited by adverse effects, such as; disruption of mucous linings and tissues. The carotenoid family is a group of orange pigmented compounds found in fruits and vegetables, that undergo a rate-controlled transformation into vitamin A once consumed. Therefore, a thought provoking study sought to investigate the use of a carotene-rich algae on 34 adult psoriasis patients. Patients received either capsules of the alga Dunaliella bardawil or starch powder capsules (placebo) for 12 weeks. It was reported that at 6 weeks the reduction in the average PASI score was significantly greater in the Dunaliella group than in the placebo group. Furthermore, no significant changes were observed in the liver function tests or in the lipid profile, thus signifying a lack of adverse effects for the treatment.
A Military Medical Doctor published a series of case studies on individual care for patients with extensive psoriasis. The reports confirm the gradual improvement of the skin, culminating in full remission by daily use of Wild ChagaExtract. Further anecdotal evidence was reported by the same Doctor who treated 50 individuals with gastrointestinal upset and psoriasis, each group member commenced with Wild Chaga Extract and it was reported that 76% experienced complete remission for psoriasis, 16% saw improvements and only 8% stating no effect; while no patients reported an aggravation of symptoms. In those that experienced improvement and full remission, the Doctor reported that noticeable effects occurred after 9-12 weeks continuous consumption of the Wild Chaga Extract.
When fish oil administration was assessed for its effect on cell structure and subsequent skin appearance; a study that administered 30g daily of fish oil for two months reported notable improvements. It is acknowledged that psoriasis is often characterised by a large proportion of omega 6 essential fatty acids (EFA) incorporated in the cell membrane. The knock-on effect is rigid cell membranes that are difficult for nutrients to enter and waste to leave, consequently this situation can promote oxidative damage.
At the end of the two months it was reported that the cellular lipid pattern had changed; eicosapentaenoic and docosahexaenoic acids (omega 3 EFA EPA and DHA) substituted the arachidonate (omega 6) in the membrane and the markers of oxidative damage were reduced. The significant improvement of the psoriatic lesions reported suggests that the mediators of inflammation generated from the omega 6 dominant cell structure had been remarkably reduced, confirming the inhibition of this pathway and the usefulness of fish oil in the treatment of psoriasis. The research on fish oil consumption in relation to psoriasis severity is inconclusive, this is suggested to be due to the variation of inflammatory states unique to each sufferer.
Black seed has been quoted to ‘cure all except death’ and has long term use in Eastern traditional medicine. To investigate the effect of Black Seed (Nigella sativa) on skin cell production rate in psoriasis; an experimental study was undertaken using a Nigella sativa seed tincture. The results found that the outer layer of skin thickened and utilised the additional skin cell production and improved the overall skin appearance. A further investigation assessed the dosage forms of Nigella sativa and concluded that the best anti-psoriatic activity occurred when Nigella sativa was administered both internally and topically.
Oregon grape (Mahonia aquifolium) is an evergreen shrub, rich in the bioactive; berberine, reported to exert anti-inflammatory and anti-bacterial properties. There have been several studies showing the beneficial effect of this compound in patients with psoriasis. 200 patients with mild to moderate psoriasis were treated at 6 sites in the United States and Canada with a topical administration of Mahonia aquifolium or placebo. There was a significant decrease in the PASI score among the Mahonia aquifolium treated patients when compared with placebo at 12 weeks. A similar study on 82 patients with moderate to severe psoriasis saw improved self-assessed ratings score after a 4-week topical administration of Mahonia aquifolium extract.
The Coeliac Connection?
Previously studies have demonstrated that some psoriatic patients produce antibodies; an immune response, to gluten containing foods. Consequently, a study set out to investigate the effect of a gluten-free diet on psoriasis severity. After 3 months, the patients saw a reduction in antibody production and a highly significant reduction in PASI score. When the ordinary diet resumed, the psoriasis symptomology deteriorated in 60% of the patients.
Beyond the Skin
Beyond the skin, psoriasis is associated with a systemic inflammatory state that has been linked to obesity, type 2 diabetes and cardiovascular diseases. Although a relationship between obesity and psoriasis has been established, the mechanistic link between these conditions is unclear, yet the conditions bear excessive inflammation as a commonality.
Overall, increasing the nutrient density of the diet provides the body with a greater pool of nutrients to support essential processes. In the case of psoriasis, specific nutrients have shown to improve symptomology and skin appearance. While food supplements can provide a useful option when therapeutic quantities of those nutrients are necessary to trigger improvements.
Author: Jenny Hall is a Nutritional Practitioner and Technical Advisor at Viridian Nutrition. She holds a BSc honours degree in Nutritional Science.