4.    Processed Foods

Processed foods are often loaded with fat and sugar, which can pack on the pounds. While extra weight is frustrating when jeans become tight, it also may worsen psoriasis.

According to the National Psoriasis Foundation, a relatively recent study found that obesity elevated the risk of psoriatic disease. In fact, researchers linked higher body mass index (BMI) with the risk of developing both psoriasis and psoriatic arthritis. Weight also played a factor in disease severity. Study author Dr. Wilson Liao said obesity may “provide the nudge that triggers psoriasis.”

That said, weight loss can help. Another study found that losing weight can decrease the severity of the condition. In this study, “dietary intervention” was stressed.

"There was a clear correlation between the amount of weight loss and the improvement of psoriasis," said Dr. Luigi Naldi, the study's lead author, as reported by the NPF. "Patients who lost more weight experienced a larger improvement in psoriasis.” However, smaller amounts of weight shed were also found to help.

5.    Refined Sugars

Diabetes is an inflammatory disease that affects more than 29 million Americans. And if you have psoriasis, your chance of developing the disease is higher.

According to WebMD, one study found that the risk of developing diabetes is twice as high in those with the most severe form of the condition. And other studies have linked a doubled risk of heart attack, stroke and even death to psoriasis.

“Our results underline the importance of considering patients with psoriasis as a high-risk population in terms of diabetes and [heart disease and stroke] risk. Screening for diabetes and cardiovascular disease risk factors in these patients is warranted," says researcher Ole Ahlehoff, M.D., Ph.D., as reported by WebMD.