Is There a Diet for Psoriasis? 5 Foods That May Be Beneficial and 5 That Probably Aren't
If you're a psoriasis sufferer, then you're already well aware that those red, itchy, and sometimes painful patches of scaly skin can be triggered by just about anything.
Skin injuries, cigarette smoking, illness, or changes in the weather are just a few things that are thought to provoke attacks, but what about food? Does your diet play a part in psoriasis flare-ups? And maybe more important—can changing it help prevent them?
The answer is: maybe.
"It depends a lot on the patient and their history," Ashley Wentworth, MD, adult and pediatric dermatologist at Mayo Clinic in Jacksonville, Florida, tells Health. Everyone has different dietary requirements based on their own personal needs, she says. "But we do know that eating a healthy diet makes people feel better and reduces stress, and that can impact their psoriasis."
Can what you eat improve or worsen your psoriasis symptoms?
Overall, the jury is still out on whether eating certain foods, or avoiding others, can have a significant impact on the frequency or severity of psoriasis.
A review of studies published in JAMA Dermatology examined whether dietary changes might make different in people with psoriasis or psoriatic arthritis. The findings suggests that people who are overweight or obese may be able to reduce the severity of their psoriasis symptoms by adopting a low-calorie diet.
"We do know that psoriasis has been linked to obesity," says Dr. Wentworth. "We often encourage weight loss for patients who are not at the weight that has been established as a goal for them with the assistance of their primary care provider."
Per the JAMA Dermatology review, psoriasis patients with celiac disease may find that avoiding foods containing gluten may be helpful in managing their symptoms. "We have done studies to show that if someone has celiac disease antibodies, a gluten-free diet could potentially benefit their psoriasis," says Dr. Wentworth.
But while there may not be one, cure-all, psoriasis treatment diet, evaluating what you eat is still a critical step in managing the disease says Victoria Yunez Behm, CNS, LDN, manager of nutrition science for the American Nutrition Association.
"Many descriptions of psoriasis focus on causes and conditions that are genetic or environmental in nature but gloss over nutrition or only mention the possibility of foods as triggers," Behm explains. "However, nutrition determines so much of our internal environment and the health of the barriers that protect us, like the lining of the gastrointestinal tract."
What to limit or avoid if you've got psoriasis
Because psoriasis is an immune-mediated disease, it's not just limited to the skin; it's systemic. So, Behm explains, it makes sense to choose foods that support your overall heath and avoid those that don't.
Here are a few to consider limiting in your diet:
Often loaded with sugar, sodium, and other additives, ultra-processed foods are high in saturated and trans fats, and should be avoided says Bridget Shields, MD, assistant professor, Department of Dermatology, University of Wisconsin-Madison.
"Unhealthy fats are found in partially hydrogenated oils or excessively processed foods," Dr. Shields tells Health. "These are important foods for patients with psoriasis to avoid when possible."
According to a 2018 review in Current Obesity Reports, examples of ultra-processed foods include:
- pastries, cookies, and crackers
- ice cream
- processed meat
- breakfast cereal
- soft drinks
- prepared meals
Red meat and dairy
According to Dr. Shields, certain animal products, like red and processed meats and dairy, can be pro-inflammatory because they're high in trans and omega-6 fats and may be converted to an unsaturated fatty acid called "arachidonic acid."
"It is important to highlight that not all fats are created equal," she explains. "Omega-3 fatty acids, as found in mackerel, salmon, sea bass, hemp seeds, and chia seeds, are thought to be anti-inflammatory and omega-6 fatty acids may also have some beneficial systemic effects as well. The safest way to consume omega-6 fats is probably from whole foods, such as walnuts, sunflower seeds, and pumpkin seeds."
High-glycemic index foods
The glycemic index measures how quickly a certain food raises the glucose (or sugar) levels in your blood. As you might expect, foods ranking high on the glycemic index (GI) tend to increase blood sugar levels, and maintaining a diet of high-GI foods can lead to a variety of health issues, including increased risk of cardiovascular disease.
Certain high-glycemic foods may also "worsen psoriatic disease when eaten in large quantities for extended periods of time," says Dr. Shields ,and because of that, people with psoriasis may be better off avoiding them. Some examples of high-glycemic foods are:
- white bread
- white rice
- fruit juices (that don't contain fiber)
"Nightshades are a class of vegetables that some people can react to," Julie Zumpano, RD, a registered dietitian with the Department of Preventive Cardiology at Cleveland Clinic, tells Health. "Specifically for psoriatic arthritis, nightshades can be a trigger."
Nightshades contain alkaloids, a class of compounds primarily found in plants that can lead to psoriasis flare-ups, per Cleveland Clinic.
According to a small, national survey of psoriasis patients' dietary habits described in the journal Dermatology and Therapy, more than half of respondents reported skin improvements after reducing their intake of nightshade veggies.
Examples of nightshades include:
- potatoes (excluding sweet potatoes)
- peppers (hot and sweet)
- certain spices made from peppers (cayenne, paprika)
Alcohol technically isn't a food, but it still makes the list because of its link to both initial onset of psoriasis, as well as possibly contributing to flare-ups. "We may not have all the science to explain it, but we do see some people can flare with psoriasis if they do have a heavy alcohol intake on a daily basis," says Dr. Wentworth. "That can cause flaring or could potentially be an initial trigger."
It can also render certain psoriasis treatment medications less effective, she says, since the liver must do double duty: metabolizing alcohol and systemic medicines people take to manage psoriasis. "If you are having a heavy alcohol intake, that's going to put a strain on the liver and then it may make have more side effects with these medications."
What to eat if you have psoriasis
While there's no single, "best" diet for psoriasis, a Mediterranean diet is not a bad choice.
Dr. Shields cites large trials demonstrating a wealth of benefits for people following a Mediterranean diet, including reductions in markers of inflammation, decreased body weight, and lower insulin production. "All factors that should, in theory, benefit patients with psoriasis," she says.
Zumpano says that the Mediterranean diet is a good diet to try, but like anything, suggests giving it a month or two to see how you respond. "There's trial and error," she says. "So, if you're going to try a diet to 'cure your psoriasis,' I would do a very whole foods, heavily-plant-based, clean diet, then I would track your flare-ups and see if there was anything in your diet that may have stimulated it."
Here are some foods to include in your diet:
Omega-3 fatty acids
According to the Cleveland Clinic, omega-3 fatty acids are an essential fat that the body doesn't produce on its own. When added as part of a healthy diet, omega-3 fatty acids can help improve cardiovascular health, raise "good" cholesterol, and help lower pressure, among other benefits.
The upside for people with psoriasis? Behm says numerous clinical studies confirm the benefits of omega-3s for reducing inflammation that accompanies immune-mediated inflammatory diseases like psoriasis.
Foods's high in omega-3s include:
- flax seed
- chia seeds
Fruits and vegetables
"Vegetables are excellent anti-inflammatory foods, as are many fruits, especially those that are on the lower glycemic index and have higher fiber content," says Dr. Shields.
Behm recommends getting creative and eating a "rainbow of fresh plant foods each day," especially the colorful ones, which contain phytonutrients, or compounds that have anti-inflammatory and antioxidant properties. Examples include:
- dark, leafy greens
- yellow beets
- pumpkin, and other winter squashes
- purple carrots
RELATED: 13 Foods That Fight Inflammation
"It's important to note that as we are learning more and more about psoriasis, we are learning it can be linked to things like diabetes, high blood pressure, high lipids, or fats in the blood," says Dr. Wentworth.
Dietary fat is essential to your health. What matters is where you get it from. Saturated fat, found in things like baked and fried foods, can lead to increased "bad" cholesterol, while unsaturated fat can help improve cholesterol levels and decrease your risk of heart attack and stroke.
"There are many wonderful foods to embrace if you've got psoriasis," says Behm, and healthy fats are among them. According to Behm, examples of healthy fats include:
- coconut oil
- cold-pressed extra virgin olive oil
- low-mercury, wild-caught fish like wild Alaskan salmon
Psoriatic disease is associated with inflammation, and eating foods to help reduce it can be beneficial in managing psoriasis, according to the National Psoriasis Foundation, which says that a healthy eating regimen that includes proteins like fish and beans may help reduce the impact of symptoms or how often they occur.
When it comes to those proteins, Behm suggests opting for "high-quality" sources, whether they're animal or plant-based. Examples of proteins include:
- cage-free eggs
- wild fish
- nuts (almonds and walnuts)
- fatty fish, like salmon, mackerel, and tuna
Vitamin D is the main ingredient in two, topical prescription medications for psoriasis, and according to Dr. Shields, they work well in helping treat the skin. Based on that, it seems logical that taking vitamin D as an oral supplement could also benefit sufferers. Unfortunately, there's not a lot of research to back the theory.
"If you look at the data [for] vitamin D supplementation in psoriatic patients, we really don't have good evidence that high-dose vitamin D supplementation is helpful," says Dr. Shields.
That said, however, it may be beneficial to add it to your diet naturally and according to the National Psoriasis Foundation, the safest way to do that is through food. Good sources of vitamin D include:
- cod liver oil
- tuna fish (canned, in water)
- orange juice (fortified with vitamin D)
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