What to Eat, What To Avoid
The right diet can help prevent psoriasis flare- ups. Try these nutritionist-approved tips for giving your daily food a healthy makeover.
The body’s immune system is made up of an intricate network of cells, glands, natural chemicals, and so much more. It’s spread throughout the body—and the skin—and it’s constantly working to keep us healthy. Just as with every other system in the body, this critical system needs energy to fuel it. The right diet and the right nutrients can help feed the immune system, helping it to function optimally.
“There is no one food or nutrient that is a magic bullet for optimal immune function,” explains Healthful Living Nutritionist Tina Marinaccio, MS, RD, CPT, “but generally, a nutrient-dense diet supports a healthy immune response. Conversely, a diet that’s low in nutrients (e.g., processed foods that are high in sugar and fat) impairs immune function.” This impaired response can trigger chronic systemic inflammation in the body (see more, p. 20), which is an immune response that can no longer turn on and off as it should.
The Role of the Gut
More than seventy percent of immune cells are found in the gut. This means that if the gut is out of balance through foods eaten or lifestyle (i.e., drinking too much alcohol or being chronically stressed), the immune system isn’t able to do its job right.
“When someone gets sick all the time with any passing virus and/or starts to develop symptoms of chronic inflammation, the first place to look is the diet and the foods that are being fed to the gut,” explains Tina Marinaccio, MS, RD, CPT, a registered dietitian based in Morristown, New Jersey. Symptoms of chronic inflammation include body pain, chronic fatigue, insomnia, mood disorders, gastrointestinal complications, and unexplained weight gain or loss.
Research tells us that the foods we eat over time can affect the balance of the gut, which is a synergistic mix of bacteria, fungi, and even parasites. These all work together to keep us healthy, provided good bacteria outweigh the bad. An unhealthy diet and lifestyle can upset the delicate balance of the gut, as can taking antibiotics regularly (which kill all bacteria in the body, both good and bad).
Enter probiotics and prebiotics. Probiotics are live organisms (i.e., specific good strains of bacteria) that can be consumed through fermented or cultured foods or supplements. However, for those with psoriasis, supplements are often best as some foods like yogurt or kefir may trigger flares. Look for supplements with at least 25 to 50 billion CFUs, or colony-forming units. This is a measure of the healthy bacteria in a supplement.
Prebiotics are plant fiber that, when ingested, act as food for the growth of these healthy bacteria. Good sources of prebiotics include asparagus, beans, onions, and leeks. Both probiotics and prebiotics are necessary for the health of the gut, which in turn helps to reduce inflammation and potential flare-ups in the case of those with psoriasis.
Nutrient-Rich Foods for Your Skin
A Western diet has been implicated as a culprit in triggering systemic chronic inflammation. This is a diet, commonly followed in the U.S., that’s high in sugar and unhealthy fats (found in processed and fried foods) and low in nutrients. A Mediterranean diet, on the other hand, is a diet rich in nutrient- dense vegetables, fruit, nuts, legumes, fish, and healthy fats like olive oil. Research has shown that following this type of diet reduces the risk of chronic inflammatory diseases like cardiovascular disease and Alzheimer’s, as well as psoriasis. It does so by reducing systemic inflammation in the body.
“If an overall diet is nutrient dense, a few indulgences here and there are probably okay for most people,” says Marinaccio. “Some people may find they have a threshold of certain foods they can tolerate before having a reaction. For example, simple sugars can exacerbate psoriasis. Little bits of sugar here and there may be tolerated, but in large amounts may worsen skin.”
It takes about three weeks of dietary changes for the immune system to begin to quiet down, but it may take up to three months to build up enough nutrients for the body to draw upon to fight inflammation. The following foods, says Marinaccio, are particularly good for those with psoriasis.
Avocados are a good source of healthy fats, fiber, and zinc, a critical nutrient for optimal immune function and health of the skin. Zinc helps regulate the normal division of cells in the body, including skin cells and immune cells. Even a mild deficiency in zinc has been shown to impair immune response. Other plant- based sources of zinc include pomegranates, kiwifruit, and berries. Zinc can also be found in beef, oysters, and eggs.
Berries are rich in phytonutrients called flavonoids that are good for the overall health of the skin and for reducing inflammation in the body. Research shows that flavonoids help improve blood flow to the skin and increase skin hydration, reducing roughness and scaling.
“We now know of more than 25,000 phytonutrients in plants, and they work synergistically to decrease inflammation,” says Marinaccio. “The best advice is to eat an abundance of plants, and a variety of color, instead of focusing on a few foods. Ideally, work up to consuming about nine servings of plants daily with a balance of fruits, non-starchy vegetables, and whole grains.” Avoid citrus fruits, however, as they’ve been shown to trigger flare-ups in some patients.
Broccoli is rich in so many good- for-you nutrients, making it a top choice for those with psoriasis. Broccoli is rich in sulforaphane, an antioxidant that reduces inflammation. It’s also high in fiber, which is essential for gut health and helps to reduce inflammation in the body.
What’s more, broccoli is a non-citrus source of vitamin C, a nutrient that helps boost immune function and reduce something called oxidative stress in the skin. Oxidative stress occurs when there are too many damaging unstable molecules called free radicals in the skin and not enough good-for-you antioxidants
to counteract them, explains Marinaccio. (Phytonutrients are high in antioxidants.) The result is cell and tissue damage.
Clams are high in vitamin B12, a deficiency of which has been found to play a role in psoriasis. Vitamin B12 is also a key nutrient in liver and eggs, as well as in fortified foods like breakfast cereals. (Opt for low-sugar ones.)
Lentils are an excellent source of selenium, a trace element that’s important for optimal immune function. Patients with psoriasis tend to have low selenium levels in their blood. Other foods high in selenium include salmon and sardines, whole-grain breads, and fortified foods like breakfast cereals.
Red Cabbage is rich in an amino acid called glutamine. It’s this amino acid that serves as an energy source for cells, including immune cells. Other sources of glutamine include seafood and eggs.
Salmon supplies vitamin D, a key nutrient for optimal immune system function. The body cannot produce vitamin D; it must either come from food or exposure to sunlight. (Vitamin D is created by the body when exposed to the sun’s UV rays.) “Vitamin D is not abundant in the food supply, but can be found in salmon as well as in enriched plant-based milks and egg yolks,” says Marinaccio, who adds: “A supplement may be needed to achieve a therapeutic dose of vitamin D. A blood test can be performed to check for deficiencies, and a qualified healthcare professional can recommend the proper dose if a supplement is needed.”
Salmon is also high in omega-3 fatty acids, types of critical fats that help reduce inflammation in the body. “Wild-caught salmon is better than farmed for reducing inflammation,” explains Marinaccio, who adds that other good sources of omega-3 fatty acids include mackerel and sardines. Plant sources include flax seeds and walnuts.
Sweet Potatoes are rich in vitamin A, a nutrient that stimulates the production and activity of immune cells. Vitamin A is a nutrient that’s also crucial for the health of the skin. Other foods high in vitamin A include red peppers, carrots, spinach, pumpkin, and winter squash.
What Not to Eat & Drink
These foods and beverages have been shown to cause inflammation in the body. “Occasional indulgences are likely okay if the base of the overall diet is nutrient dense,” explains Marinaccio. “The key is that it is occasional and not every day.”