Psoriasis may be reduced by vigorous physical activity, according to a new study carried out amongst nurses in the US. Working together, the Brigham and Women’s Hospital and Harvard Medical School, Boston, studied data from more than 85,000 female nurses in the US who had enrolled in the Nurses’ Health Study II.
This longitudinal study has amassed a huge amount of data on lifestyle habits, diseases, and conditions such as psoriasis and this latest article adds weight to increasing evidence of an association between physical activity and inflammatory disorders. Exercise could be a way to naturally healthy skin, at least when it comes to psoriasis.
Psoriasis and Systemic Inflammation
Dr. Frankel and colleagues published this latest research in the May edition of Archives of Dermatology, noting that other disorders related to systemic inflammation have a reduced incidence in association with increased physical activity. Such inflammatory disorders include diabetes mellitus, colon cancer, coronary artery disease, and breast cancer and the hypothesis is that vigorous activity reduces the risk of psoriasis by modulating systemic inflammatory mediators such as cytokines.
Diet and other factors can also influence inflammation and some psoriasis sufferers find that an anti-inflammatory diet can help reduce symptoms of the skin condition.
Reducing Psoriasis Risk
In this analysis the psoriasis researchers found that active women had a much lower risk (adjusted for age) than the least active women. The active women did more than 31.9 hrs of vigorous activity a week and had a risk ratio of 0.71 compared to the least active women. Even after adjusting for age, smoking, and alcohol intake, all risk factors in psoriasis, the risk ratio remained at 0.72.
Women doing more than 20.9 hrs of vigorous activity a week had a psoriasis risk ratio of 0.66 compared to those that did no activity, and this reduction in psoriasis risk remained even after adjustment for other factors.
Half the Risk of Psoriasis with Vigorous Exercise
Unfortunately, walking did not significantly reduce the risk of psoriasis, the effect only being observed for those women engaging in vigorous physical activity. The data included women with self-reported psoriasis and so the researchers looked at a subset of 500 women with confirmed psoriasis using the Psoriasis Screening Tool questionnaire.
Again, adjusting for age, alcohol intake, and smoking, the women with the highest levels of total physical activity had a risk ratio of just 0.62, with those engaged in vigorous physical activity enjoying almost a 50% reduction in risk of psoriasis compared to the inactive women.
Limitations of the Study
The dependence on self-reported symptoms in the study, rather than dermatologists’ assessment, limits the credibility of the research, as does the lack of randomisation, lack of control for some confounding factors, and the inability to distinguish between indoor and outdoor activity. The latter is relevant due to the potential influence of ultraviolet light exposure on psoriasis.
However, the results do suggest a dose-dependent gradient supporting a causal association between psoriasis risk and physical activity. Those at high risk of developing psoriasis can add a reduction in this risk to the other benefits of exercise. More research is warranted to determine exactly why exercise has benefits for psoriasis risk reduction, and how genetics and exercise combine to alter the risk profile for any given patient.
Hillary C. Frankel, AB; Jiali Han, PhD; Tricia Li, MD, MS; Abrar A. Qureshi, MD, MPH, The Association Between Physical Activity and the Risk of Incident Psoriasis, Arch Dermatol. 2012;():1-7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4102422/