Yes, according to the studies there are some foods that help to fight psoriasis. Using apple cider vinegar in diet can lead to significant improvements in the condition of the patients. Also adding it in the bath water or direct application with cotton balls can give some amount of relief. This is a natural treatment and has the healing effects.

Application of Capsaicin cream on the affected area can reduce redness and itching.  Capsaicin interrupts the actions of the molecule (substance P), which helps your brain to recognize pain and itching. Most of the over the counter creams available for psoriasis has this ingredient.
 
Oregano oil has antibacterial and antifungal properties. It has absolutely no side effects and can be ingested safely. It helps to control the infections associated with psoriasis.

Turmeric is also a useful natural remedy. It is must be added to the daily diet to spice the food. It helps to reduce inflammation due to psoriasis.

You can purchase milk thistle products which come in liquid or tablet form. They cause mild gastrointestinal disturbances at the start. But after some time you will get accustomed to it. This supplement is also beneficial in fighting psoriasis.