Psoriasis and diet - are they linked?

A number of factors are thought to contribute to the autoimmune condition psoriasis. Researchers have found that risk factors for the condition can be split into two categories; intrinsic and extrinsic. Intrinsic factors can include stress, diabetes, hypertension, obesity and metabolic syndrome, while extrinsic factors can include pollution, medication, infection and smoking. But what about diet?

There is some evidence which suggests that certain food groups may trigger the condition to flare up. However the research is conflicting and, as with other chronic conditions, general medical advice is to follow a healthy, balanced diet.


Red meat and dairy

Both of these food groups contain arachidonic acid, which is a type of fatty acid. Some researchers believe that the byproducts which are created when arachidonic acid is broken down may play a role in psoriasis.



Nightshade vegetables come from plants containing solanine, a compound which has been known to affect the digestive system and cause inflammation. Tomatoes, potatoes, aubergines and peppers are all considered to be nightshades. Some people have reported reduced symptoms of psoriasis when avoiding this food group, although the research is not conclusive.


Studies in Sweden found that around 16% of people with psoriasis also have antibodies which are associated with gluten sensitivity. For these people, adopting a gluten-free diet may help to improve the symptoms of psoriasis. During one study in 2018, all participants who were known to have an antibody associated with gluten sensitivity, known as anti-gliadin, saw improvements in their condition after following a strict gluten-free diet over a two year period.



There are several ways alcohol can interact with psoriasis. It can trigger symptoms to flare up, inhibit treatment plans and aggravate the side effects of medication. Alcohol is also known to alter the immune system. This can in turn increase the risk of infection, which is sometimes a trigger in itself. Reducing or eliminating your alcohol intake may help to reduce the severity of your symptoms, but speak to a healthcare professional for more information if you have any concerns.


Processed foods

There hasn’t been substantial research into the impact of processed foods on psoriasis. However, some guidance suggests a reduction in processed foods may be beneficial. This is because psoriasis is an inflammatory condition and processed foods are believed to aggravate inflammation. Diets that are high in processed foods have also been connected with health conditions, such as obesity and metabolic syndrome, which are classed as intrinsic risk factors for psoriasis.



Some people have also reported that condiments and spices,  like tabasco sauce, vinegar and paprika, have had an impact on their symptoms. All of these contain substances which have been linked to inflammation. 

Psoriasis triggers can vary from person to person, so it’s important to understand what your own triggers are in order to manage them. While some people might find that cutting out certain foods, or introducing others, helps to alleviate their symptoms, this may not be the case for everyone. Medical treatments, such as topical applications and phototherapy remain the most effective method of treating and managing psoriasis.


If you are experiencing scalp psoriasis, you may find a medicated shampoo like Polytar Scalp Shampoo can help to reduce itching, flaking and inflammation.