Psoriasis is a chronic dermatological disease often linked with systemic conditions such as cardiovascular disease, obesity, and type 2 diabetes(1). Unlike many other systemic diseases, psoriasis lacks specific dietary recommendations for its management(2). To develop evidence-based dietary advice, profiling dietary intakes in this population group is paramount. As part of the Asking People with Psoriasis about Lifestyle and Eating (APPLE) study, we aimed to quantify macronutrient intakes and their food group sources and assess associations with psoriasis severity.
The APPLE study is a web-based cross-sectional survey recruiting UK-based adult volunteers with psoriasis (King’s College London Research Ethics Committee LRS/DP-21/22-29257; NCT05448352). Recruitment was between June 2022 and January 2024 through social media. Participants self-reported age, weight, height, and alcohol use, depression or anxiety diagnosis, as well as psoriasis severity by responding to the self-assessed Simplified Psoriasis Index (possible score range 0-70 points). Diet was self-reported with a validated 147-item food frequency questionnaire. Nutritional composition was determined using the Composition of Food Integrated Dataset(3).Linear models tested associations between food groups sources and psoriasis severity.
The final sample (n=270) primarily constituted mid-life (median (IQR) 40 (20) years), White-British (85%), female participants (82%) with psoriasis, of which 51% were living with overweight or obesity. Protein intake from animal sources (processed meat, poultry, and red meat) was significantly positively associated with psoriasis severity, adjusted for age, gender, smoking, alcohol use, energy intake, and diagnosed depression/anxiety (β between 0.133 and 0.225, P<0.05). Plant-based (excluding tree nuts) and tree nut sources of protein were inversely associated with psoriasis severity (adjusted β between -0.145 and -0.131, P<0.05). Protein from red meat and plant-based protein remained significantly associated with psoriasis when adjusting for BMI. Poultry and processed meat sources of n-6 polyunsaturated fatty acids were also positively associated with psoriasis severity (β between 0.125 and 0.133, P<0.05), whilst tree-nut sources were inversely associated with disease severity (β= -0.144, P<0.05), but associations were no longer significant when adjusting for BMI.
Our findings highlight that associations between psoriasis severity and protein and n-6 polyunsaturated fatty acids intakes depend on their source, suggesting that healthy plant-based diets warrant further investigation by randomised controlled trials for the dietary management of psoriasis.
The authors are grateful to the volunteers who took participated in the study and to the Psoriasis Association for funding the study.
References:
Takeshita J, Grewal S, Langan et al. (2017) J Am Acad Dermatol 76,377-390.
National Institute for Health and Care Excellence (NICE) (2017) Psoriasis: assessment and management [Available at: https://www.nice.org.uk/guidance/cg153/resources/psoriasis-assessment-and-management-pdf-35109629621701]
Public Health England (PHE) (2021) Composition of foods integrated dataset (CoFID) [Available at: https://www.gov.uk/government/publications/composition-of-foods-integrated-dataset-cofid]

Psoriasis is a chronic dermatological disease often linked with systemic conditions such as cardiovascular disease, obesity, and type 2 diabetes(1). Unlike many other systemic diseases, psoriasis lacks specific dietary recommendations for its management(2). To develop evidence-based dietary advice, profiling dietary intakes in this population group is paramount. As part of the Asking People with Psoriasis about Lifestyle and Eating (APPLE) study, we aimed to quantify macronutrient intakes and their food group sources and assess associations with psoriasis severity.
The APPLE study is a web-based cross-sectional survey recruiting UK-based adult volunteers with psoriasis (King’s College London Research Ethics Committee LRS/DP-21/22-29257; NCT05448352). Recruitment was between June 2022 and January 2024 through social media. Participants self-reported age, weight, height, and alcohol use, depression or anxiety diagnosis, as well as psoriasis severity by responding to the self-assessed Simplified Psoriasis Index (possible score range 0-70 points). Diet was self-reported with a validated 147-item food frequency questionnaire. Nutritional composition was determined using the Composition of Food Integrated Dataset(3).Linear models tested associations between food groups sources and psoriasis severity.
The final sample (n=270) primarily constituted mid-life (median (IQR) 40 (20) years), White-British (85%), female participants (82%) with psoriasis, of which 51% were living with overweight or obesity. Protein intake from animal sources (processed meat, poultry, and red meat) was significantly positively associated with psoriasis severity, adjusted for age, gender, smoking, alcohol use, energy intake, and diagnosed depression/anxiety _(β_ between _0.133_ and _0.225, P<0.05)._ Plant-based (excluding tree nuts) and tree nut sources of protein were inversely associated with psoriasis severity _(_adjusted _β_ between _-0.145_ and _-0.131, P<0.05)_. Protein from red meat and plant-based protein remained significantly associated with psoriasis when adjusting for BMI. Poultry and processed meat sources of _n_-6 polyunsaturated fatty acids were also positively associated with psoriasis severity _(β_ between _0.125_ and _0.133, P<0.05),_ whilst tree-nut sources were inversely associated with disease severity (_β= -0.144, P<0.05_), but associations were no longer significant when adjusting for BMI.
Our findings highlight that associations between psoriasis severity and protein and _n_-6 polyunsaturated fatty acids intakes depend on their source, suggesting that healthy plant-based diets warrant further investigation by randomised controlled trials for the dietary management of psoriasis.
The authors are grateful to the volunteers who took participated in the study and to the Psoriasis Association for funding the study.
References:
1. Takeshita J, Grewal S, Langan et al. (2017) _J Am Acad Dermatol_ 76,377-390.
2. National Institute for Health and Care Excellence (NICE) (2017) _Psoriasis: assessment and management_ [Available at: [https://www.nice.org.uk/guidance/cg153/resources/psoriasis-assessment-and-management-pdf-35109629621701]](https://www.nice.org.uk/guidance/cg153/resources/psoriasis-assessment-and-management-pdf-35109629621701])
3. Public Health England (PHE) (2021) _Composition of foods integrated dataset (CoFID)_ [Available at: https://www.gov.uk/government/publications/composition-of-foods-integrated-dataset-cofid]

OC162 - Associations between macronutrient sources and psoriasis severity in a UK-based population: results from the Asking People with Psoriasis about Lifestyle and Eating study. 

Unique to the new Congress (previously the Summer Conference) is that you will have greater opportunity to engage with more nutrition science than ever before. In 2024 the core programme will be delivered by the Irish Section of The Nutrition Society, supported by the Science Committee. The theme of these symposia will be ‘new data – focused approaches and challenges’. Outside of the core programme you will have the chance to hear the latest research from the Society’s partner organisations, universities, the private sector and more, on a diverse range of research.