Nutritional factors linked to psoriasis risk
medwireNews: Psoriasis is significantly linked to increased serum vitamin A and alpha-carotene levels, as well as reduced sugar intake, say US scientists.
"This study provides preliminary data for future research examining the differences in nutritional factors between patients with and without psoriasis," comment April Armstrong, from the University of California Davis Health System in Sacramento, and colleagues.
"Future research in this area needs to control for psoriasis treatments or monitor longitudinal intake of nutrition in psoriasis patients to elucidate the role of nutritional factors in psoriasis pathogenesis and progression."
The team examined data from the US National Health and Nutrition Examination Survey (NHANES) for 2003-2006, identifying 6260 participants who responded to a question on a provider-given diagnosis of psoriasis.
Of the participants who responded to the psoriasis question, 2.49% had the condition. There were no significant differences between participants with and without psoriasis on univariate analysis in variables including systolic blood pressure; intake of calories, protein, carbohydrates, and fat; and serum levels of a range of vitamins, cholesterol, albumin, and calcium.
Significant differences between those with and without psoriasis were observed, however, for race, family poverty income ratio, education, marital status, age, body mass index (BMI), history of arthritis, diastolic blood pressure, sugar intake, and serum vitamin A, vitamin E, and alpha-carotene levels.
Multivariate analysis of these variables indicated that non-Hispanic Black and Hispanic people were significantly less likely to have psoriasis than non-Hispanic Whites, at odds ratios of 0.56 and 0.37, respectively, the team reports in the Journal of the European Academy of Dermatology and Venereology.
Higher BMI was associated with an increased likelihood for psoriasis, while the presence of arthritis more than doubled the risk. A family poverty income ratio below 1.3 was also linked to a significantly increased risk for psoriasis, at an odds ratio of 1.68 versus a ratio of 1.3-3.5.
Increased vitamin A and alpha-carotene levels were significantly associated with psoriasis. Mean vitamin A levels were 62.28 µg/dL in psoriasis patients, compared with 58.31 µg/dL in individuals without psoriasis. For alpha-carotene, the corresponding levels were 4.97 and 4.26 µg/dL, respectively. Higher sugar intake, however, was significantly associated a reduced risk for psoriasis.
"Our observation of reduced sugar intake among psoriasis patients is curious given the current literature's support of an association between psoriasis and type 2 diabetes," say the researchers. They speculate that psoriasis patients could have deranged insulin metabolism pathways.
By Liam Davenport, medwireNews Reporter