There is not one universal diet that has been shown to make psoriasis predictably better or worse. However, many individuals report that a link exists for them between psoriasis severity and diet. Many people will try different diets and, over time, find one that works well for them. Psoriasis sufferers have reported the associations listed in Table 2 and many others probably exist.
Of the supplements listed in Table 2, several studies on fish oil have been formally reported. Some small studies have shown improvement when fish oil was given orally or by vein. One study showed that oral fish oil worked better than olive oil when given with light therapy. Another study from the same group showed that fish oil was not better than olive oil when used in combination with topical steroids.
A much larger study, published in 1993, showed fish oil was no better than corn oil. Although associations between these supplements and skin improvement have been reported, for some, no response or even an opposite response may be seen. It is useful to discover what works best for your psoriasis through trial and error.
If a person is interested in making a diet change, making one change at a time will help to identify exacerbating or helpful diet changes. When making a diet change, make sure to give it at least 2 to 4 weeks before coming to a conclusion. Psoriasis may wax and wane over time independently of diet as well. Knowing that other external factors, such as stress and sunlight (see Question 93), may affect psoriasis, it is worth considering possible effects of these changes when evaluating a diet or any new therapy.
Because of a possible association of psoriasis and celiac disease (sensitivity to wheat gluten), many people with psoriasis have tried a gluten-free diet. Gluten is the insoluble component of grains such as wheat, barley, and rye, and people with celiac disease have an immunologic reaction to gluten. However, this diet is a very challenging one and a trial of weeks to months is often recommended. If a person has gastrointestinal symptoms like bloating, diarrhea, or abdominal pain, evaluation with a physician including possible blood tests for celiac disease could be considered.
One excellent resource to learn about people’s individual experiences is a feature from the National Psoriasis Foundation’s bimonthly magazine called “It Works For Me.” Previous submissions are archived on their Web site (more information is in the Appendix). In these testimonials, people with psoriasis and psoriatic arthritis share treatments they have found effective, from medicines to foods to exercise regimens and more