Although there is a complex genetic component to psoriasis, environmental factors are also at play. Stress, infection, certain medications, smoking and alcohol use have all been shown to be potential triggers for flare-ups.
The results of that research we mentioned make it increasingly clear that inflammation is a factor in many chronic and degenerative diseases, including heart disease, diabetes and many cancers. Since inflammation plays a significant role in psoriasis, a lot of attention is now being paid to your question of whether diet may affect the disease.
Due to the way psoriasis behaves, drawing conclusions can be difficult. Flare-ups are followed by periods of dormancy, which give way again to subsequent flare-ups. Since the nature of the disease is to fluctuate, connecting the dots between a specific dietary or behavioral change, and the absence or presence of flare-ups, is a challenge.
Still, scientists are beginning to find answers. In studies of psoriasis patients whose diets included fish oil supplements to add omega-3 polyunsaturated fatty acids, a measurable number of participants reported fewer and less severe flare-ups. When they stopped following the diet, the benefits also waned.
Gluten sensitivity may also play a role. In a study of individuals with antibodies to gliadin, one of the proteins that are present in wheat, following a gluten-free diet lessened psoriasis symptoms. When gluten was reintroduced to the diet, flare-ups became more frequent.