from the National Psoriasis Foundation:
Biologically based practices include, but are not limited to, botanicals, animal-derived extracts, vitamins, minerals, proteins, prebiotics, probiotics, whole diets and functional foods.
Dietary supplements. These products include vitamins, minerals, herbs or other botanicals, amino acids, and substances such as enzymes. Supplements can be extracts or concentrates and can occur in many forms, such as tablets, capsules, softgels, gelcaps, liquids or powders.
A variety of supplements have been used by psoriasis patients to control their disease, including: evening primrose oil, milk thistle, and oregano oil. Turmeric has been used by a number of patients but recent studies have suggested that it is not effective in psoriasis treatment.
Herbal remedies are increasingly popular and mainstream.
It is important to carefully examine the herbal remedy you choose to use, as some cannot be used during pregnancy or when you have a pre-existing medical condition. If you are unsure of the potential side effects or possible interactions with medications, consult a health-care professional before starting to take an herbal remedy.
Functional Foods
Functional foods are a part of an average diet that may have biologically active components, such as fish oils, that may provide health benefits beyond basic nutrition. Examples of functional foods include soy, nuts, chocolate and cranberries.
Diet
People with psoriasis are individuals with different backgrounds, habits and medical histories, who respond to substances differently at different times. Moreover, people with psoriasis can have remissions that have nothing to do with changes in diets or treatments. These variables make it difficult to evaluate whether any specific dietary change is responsible for clearing or worsening psoriasis. The addition or elimination of one substance from the diet can be the remedy for one person and the culprit for another.
Some psoriasis patients believe that a wheat allergy triggers their psoriasis. Others have found success by eliminating red meat and fatty foods from their diet. The National Psoriasis Foundation message board is a good resource to learn about what diets have been successful for other psoriasis patients.