But in people with psoriasis, the body makes far too many skin cells, producing them about five times faster than average, which causes the skin to get thick and scaly. Doctors aren’t sure what causes psoriasis, although it appears that the immune system may damage genetic material that tells skin cells how often to divide. [sidebar]

Peruse the Produce Aisle

There’s some evidence that eating more produce can help control psoriasis. In a study of more than 680 people, researchers at the University of Milan in Italy found that those who ate the most carrots, tomatoes, fresh fruits, and green vegetables were much less likely to get psoriasis than folks who ate less. In fact, eating just three or more servings of carrots a week reduced the risk of psoriasis by 40 percent. Those who ate seven or more servings of tomatoes a week reduced their risk by 60 percent, and those who had two servings a day of fresh fruits reduced their risk by 50 percent. Since carrots, tomatoes, and fruits are all important sources of beta-carotene and vitamins C and E, the researchers speculate that it’s the antioxidant and immune-stimulating effects of these foods that may make the difference to your skin cells. (To go organic or not to go organic? That question, answered.)

Why You Should Go Fish

For a long time, researchers have suspected that eating certain types of fish can help ease psoriasis. A British study, for example, found that people with psoriasis who ate 6 ounces of fish such as salmon, mackerel, and herring a day had a 15 percent improvement in symptoms in just 6 weeks. These and other cold-water fish contain omega-3 fatty acids, which appear to reduce the body’s production of prostaglandins and leukotrienes, compounds that can cause skin inflammation. While eating fish certainly won’t cure psoriasis, it may provide added relief when you’re already receiving other psoriasis treatments. Salmon is particularly high in omega-3s. (Bonus: omega-3s boost mood and brainpower, too.) More from Prevention: DIY Psoriasis Solutions