Most psoriasis sufferers will tell you that their psoriasis is affected by the foods they eat. Some foods will cause the condition to worsen whilst other foods seem to improve their symptoms.
To date there is no proof to confirm this. There is no definite list of foods that makes up the psoriasis diet. This means the evidence is purely anecdotal.
Which foods help or aggravate the condition may well vary from person to person. I expect that a lack of concrete proof will do little to sway the belief of so many psoriasis sufferers.