A high-fat, high-sugar diet can cause skin inflammation, lead to psoriasis

A Western diet high in fat and sugar may be linked to inflammatory skin conditions such as psoriasis, a study conducted by researchers at UC Davis Health has found.

Published in the Journal of Investigative Dermatology, the study suggests that dietary factors rather than obesity itself may be responsible for skin inflammation and the onset of psoriasis.

Psoriasis is a chronic skin condition that causes red patches and scales that can be irritating and painful.

Previous research has identified obesity as a risk factor for psoriasis, and the Western diet, which is high in saturated fats and sugar and low in fibre, has been linked to the increasing prevalence of obesity worldwide.

"In our study, we found that short-term exposure to Western diet is able to induce psoriasis before significant body weight gain," said Sam T. Hwang, professor, and chair of dermatology at UC Davis and senior author on the study.

A high-fat and high-sugar diet like the Western diet was found to be necessary for inducing observable skin inflammation, according to findings from a mouse model.

The study also showed that mice on a Western diet had significant ear swelling and visible dermatitis within just four weeks, compared to those fed a controlled diet and those on a high-fat diet alone.

"Eating an unhealthy diet does not affect your waistline alone, but your skin immunity too," said Zhenrui Shi, visiting assistant researcher in UC Davis Department of Dermatology and lead author on the study.

The mechanisms underlying the inflammatory effects of a Western diet were further explained in the study.

Specifically, the researchers identified bile acids as critical signalling molecules in the regulation of skin immunity.

These bile acids are produced in the liver from cholesterol and then broken down by gut microbiota in the intestine. They are essential for dietary lipid absorption and cholesterol balance in the blood.

According to the study, cholestyramine, a medication used to lower cholesterol by attaching to bile acids in the intestine, can help lower the risk of skin inflammation. This discovery indicates that bile acids play a role in the development of psoriasis.

By binding to bile acids in the gut and releasing them through the stool, cholestyramine can reduce skin inflammation.

(ANI)