Nutritional Approaches to Psoriasis

Your skin is itchy and burning, and you've got patches of scaly, inflamed and reddened areas on your knees, elbows and scalp. After weeks of trying to treat it yourself with various over-the-counter ointments (hardly ever a good idea!), you see a dermatologist who looks at your skin and says, "You've got psoriasis."

You've seen all those recent TV commercials for plaque psoriasis, but it never occurred to you that it might cause your problem, and you certainly never thought it was something that people could get when they're older. 

But, according to the American Academy of Dermatology, there are two peak incidences of the disease, with the majority of cases occurring between the ages of 20 and 30. However, the peak period for late-onset psoriasis is between 50 and 60 years of age, with most people developing it between 57-60. Women tend to develop it at a younger age than men.

Psoriasis is a chronic autoimmune disease affecting over 3% of the U.S. adult population. The immune system becomes overactive, leading to an abnormally rapid cycle of new skin cells being produced, dying and then piling up on the skin's surface. 

This causes scaly, dry and cracked skin that itches and bleeds, with lesions found most often on the scalp, elbows, knees, trunk, palms and soles of the feet. There may be thick, pitted fingernails.

Jessica Kaffenberger, M.D., an Associate Professor of Dermatology and Division Director of Medical Dermatology at Ohio State University Wexner Medical Center, says that "psoriasis is a systemic disease, in which inflammation exists throughout the body but is only visible on the skin."

She explains that 25-30% of people with the condition go on to develop psoriatic arthritis, usually about seven years after developing psoriasis itself, although a small percentage develop it before the skin manifestations, and adds that "psoriatic arthritis is characterized by swelling in the back of the leg, heel pain, inflammation of the fingers and toes, and morning stiffness that lessens during the day." 

It differs from osteoarthritis, a degenerative joint disease often associated with aging, frequently referred to as a "wear and tear" disorder.

The symptoms of psoriasis sometimes go through cycles, flaring for a few weeks or months, followed by periods when they lessen or even go into remission. Most cases are mild and can be managed with topical creams and ointments. However, more severe cases may require phototherapy or the administration of oral or biologic medications.

The treatment goals are to reduce the inflammation, discoloration of lesions, and amount of thickness and scaling. Results can be assessed by a change in the PASI (Psoriasis Severity Index), used to grade the severity of symptoms and to gauge the patient's response to treatment, and by the BSA (body surface area), which estimates the percentage of each body region affected.

According to the National Institute of Arthritis and Musculoskeletal and Skin Diseases, there are different types of psoriasis, with plaque psoriasis, marked by raised, red patches of skin covered by silvery-white scales, being the most common. Many people with psoriasis have other severe conditions, including:

• Cardiovascular disease, hypertension, high cholesterol levels
• Metabolic syndrome
• Mental health issues such as depression, anxiety, low self-esteem, social anxiety
• Celiac disease
• Inflammatory bowel disease

Because there is a high correlation between psoriasis and cardiometabolic disorders, improving one's diet (probably with resultant weight loss) will have a positive impact on co-existing conditions such as diabetes, cardiovascular disease, metabolic syndrome and fatty liver disease. 

The National Psoriasis Foundation recommends eating an anti-inflammatory diet rich in fruits and vegetables, lean protein, whole grains and healthy unsaturated fats, which describes many of the components of the Mediterranean diet.

"Several studies have been done over the years to determine the best foods or diet for managing psoriasis, as well as those which seem to be most detrimental. A high sugar diet, which is known to increase inflammation, has been found to have the most negative impact on psoriasis symptoms," says Kaffenberger. 

A diet that includes an excessive intake of simple sugars leads to dysbiosis (an imbalance of the organisms ordinarily present in the gut) with increased bacteria and inflammatory substances called cytokines.

A 2017 study reported in the journal Dermatology and Therapy surveyed more than 1200 psoriasis patients who were members of the National Psoriasis Foundation and found that about 43% of respondents were not certain if diet affected their psoriasis. 

Those who checked yes for dietary influence noted that their symptoms were exacerbated by sugar, alcohol, tomato, other nightshade vegetables such as eggplant and pepper, gluten and dairy. Excessive alcohol intake has been associated with the development of psoriasis, as well as increasing its severity. 

Less commonly reported triggers included meat, processed foods, soda, bread, eggs and spicy foods. The study also asked patients if there were foods that seemed to improve their symptoms. 35.1% of individuals reported that dietary supplements reduced skin irritation, while others endorsed vegetables, fruits and fish. 

Dietary supplements that were helpful included vitamins (especially vitamin D), probiotics, fish oil/omega-3, and turmeric capsules. Fruits and vegetables provide many antioxidants (such as carotenoids, flavonoids, vitamins and minerals), which have been inversely correlated with C-reactive protein (CRP), a measure of inflammation.

Several patients reported favorable results when following the Pagano, vegan, and Paleolithic diets, with others praising gluten-free, low-carbohydrate-high protein, Mediterranean and vegetarian diets. The Pagano diet was created by chiropractor John Pagano, who authored the 2008 book "Healing Psoriasis" and believed psoriasis was a manifestation of leaky gut syndrome, with the skin working overtime to release toxins.

Coffee, which contains antioxidant-rich polyphenols, has been shown to have an anti-inflammatory effect, suggesting that it could benefit psoriasis. Nevertheless, according to the Psoriasis and Psoriatic Arthritis Alliance, evidence concerning its usefulness must be more consistent. 

Some studies show that increased coffee intake is correlated with a rise in symptoms. In contrast, others show that coffee may enhance the effectiveness of some drugs to treat psoriasis. 

Research has suggested that its effect on psoriasis is dose-dependent, with moderate consumption (up to three cups per day) alleviating symptoms and decreasing inflammation and higher caffeine intake having an adverse effect.

"Because adipose (fat) tissue is a metabolically inflammatory substances, weight loss for those who are obese can be extremely helpful in psoriatic symptom reduction, as well as in reducing the comorbidities that often co-exist." says Kaffenberger, who adds that "intermittent fasting has been shown to decrease inflammation and to increase the lifespan, but many people find that adherence to the diet is difficult."

Now that you're uber-aware of the purported link between diet and psoriasis, you may want to make some modifications to increase your healthy eating habits (never a bad idea, whether you have the disorder or not.) These changes might include:

• Avoiding highly processed foods, foods that are high in saturated or trans fats, and foods high in added sugar or refined carbohydrates
• Increasing your consumption of plant-based and high-fiber foods such as vegetables, fruits, nuts, seeds and whole grains
• Eating lean protein and fatty fish, which is high in omega-3s; limiting your intake of red meat
• Using healthy unsaturated fats such as extra virgin olive oil and vegetable oils and eating healthy fats such as avocado or dark chocolate

Barbra Williams Cosentino RN, LCSW, is a psychotherapist in Queens, N.Y., and a freelance writer whose essays and articles on health, parenting and mental health have appeared in the New York Times, Medscape, BabyCenter and many other national and online publications. Read More