Psoriasis is chronic skin condition in which flaky or scaly patches of skin begin to form, usually on the scalp, elbows, knees, and trunk. It's thought to be caused by immune dysfunction. Millions of people around the world are thought to be affected by psoriasis. Two recent studies have revealed a link between diet and psoriasis severity.
The first study, reported in JAMA Dermatology, showed that people who consume higher levels of ultra-processed foods seem to have more severe psoriasis.
Ultraprocessed foods are usually made from stuff that has been isolated from whole foods, such as sugars and fats; and they often have additives like flavorings, preservatives, emulsifiers, coloring agents, and stabilizers. They can include foods such as cereals, packaged baked goods, frozen pizza, and deli meat.
The researchers assessed the health and habits of over 18,500 volunteers who were participating in a large French health database, and the data covered late 2021 to mid-2022. Along with health data, participants self-reported on various aspects of their lives, such as ultra-processed food intake. There were 1,825 psoriasis patients in this data, including 802 with active disease.
The work revealed that individuals with active psoriasis were 36 percent more likely to be among the highest third consumers of ultraprocessed foods on a daily basis, compared to people unaffected by psoriasis. This indicates a high association between the consumption of ultraprocessed foods and active psoriasis, the study suggested. While this research has not identified a cause-and-effect relationship, the researchers noted that they controlled for many other factors, and the findings still held true.
An unrelated study with fewer participants has also found associations between diet and psoriasis. This research, which was reported in the British Journal of Nutrition, determined that people who were less likely to consume plant-based diets were more likely to have severe psoriasis.
In this work, 257 adults self-reported on their psoriasis condition, and their adherence to certain diets, such as Dietary Approaches to Stop Hypertension (DASH), and the Healthy Plant-based Diet Index.
The DASH diet stresses the consumption of fruits, vegetables, whole grains, and foods low in fat, and sugar; it was deigned to to reduce blood pressure. The Plant-based Diet Index emphasizes diets that are made up of fruits, vegetables, whole grains, nuts, seeds, legumes, and lower levels of animal products, sugar, and refined starch. When people were less likely to consume foods based on these guidelines, and ate more sugary, fatty foods, they were also more likely to have more severe psoriasis symptoms.
"People with psoriasis often ask about how the food they eat affects their skin, and whether changing their diet helps; this research brings us closer to answering these important questions," noted a co-author of the British Journal of Nutrition study, Dr. Thivi Maruthappu, a consultant dermatologist at King's College London.
Sources: King's College London, British Journal of Nutrition, JAMA Dermatology
