The connections between psoriasis and lifestyle are interesting. There are many links between stress and depression, and we know that depression can make psoriasis worse. Additionally, there is interest in examining whether certain diets can improve psoriasis, including a hypocaloric diet in patients who are overweight and obese, a ketogenic diet, a gluten-free diet, and supplementation with vitamin D. 

It can be difficult to know the true impact of these lifestyle interventions when studies do not account for changes in patient adherence. Studies will report that patients have experienced improvement with lifestyle interventions alone, without any changes to their psoriasis treatment. In such trials, we do not know that the patient’s adherence to treatment remained the same. Patients may be on topical or systemic therapies but not taking them well before the study, and the study intervention might regiment their lifestyle, providing the structure for them to go on a diet. Or the intervention might address stress in their lives and might help with stress reduction. These measures might change how adherent patients are to their ongoing treatment, and even small changes in adherence to topical therapy can make a big difference in outcomes. Stress and depression are thought to worsen psoriasis. This, too, could be related to adherence because, when an individual is under a lot of stress or is struggling with low energy and depression, they might reduce the application of topical therapies or the use of other treatments. Implementing interventions that change a patient’s lifestyle to promote health and to provide structure may set patients up for better use of their medications.

All that being said, I would not dismiss the benefits of healthy living and stress reduction. There is some evidence that weight loss will help in psoriasis, and I will encourage patients to achieve a weight loss goal that they want and need to achieve anyway. Additionally, encouraging patients to stop smoking and to exercise regularly are reasonable approaches, although the latter may be difficult for some individuals because of psoriatic arthritis. Still, in the case of diet, for instance, I do not know that you are going to be successful in treating psoriasis through diet alone. And this is consistent with the 2018 National Psoriasis Foundation publication by Ford and colleagues, which recommends that dietary interventions should always be used in conjunction with standard medical therapies for psoriasis and psoriatic arthritis.