Psoriasis is a chronic and often relapsing inflammatory skin condition that affects up to 3.2% of adults in the United States alone. The most common type of psoriasis looks like silvery, pink scales that may be painful, itchy, and even bleed. We do not know exactly why people get psoriasis, but several components are known to play a prominent role including environmental factors such as diet, genetics, and immune system dysregulation. When it comes to diet, many people have questions about healthy psoriasis diets and if there are any food triggers that can cause psoriasis to worsen.
Diet Is an Environmental Factor That May Have a Role in Psoriasis
It has been reported that over 60% of patients with psoriasis look for alternative or complementary treatments to conventional medications. An abundance of dietary recommendations for psoriasis can be found in the media and popular literature, but there are no official dietary guidelines for psoriasis patients. However, there have been a few scientific studies showing that certain dietary habits may actually trigger psoriasis to worsen.
Which Nutritional Factors Could Trigger Psoriasis to Worsen?
Several studies since the 1980s have shown that it is common for people with psoriasis to have higher alcohol intake and a higher rate of alcohol abuse than the general population. In fact, research investigators have concluded that alcohol intake is actually considered a risk factor for getting psoriasis.[4-7] Furthermore, alcohol intake is associated with increased severity of symptoms and poor response to treatment.[8-11] It is thought that alcohol and its breakdown products may rev up the body’s inflammatory response and cause excessive cell turnover in the outermost layer of the skin. This could be one explanation for the strong association between alcohol intake and psoriasis.
There is some evidence to suggest an association between psoriasis and celiac disease, which is an autoimmune disease that causes intolerance to gluten (a protein found in many grains). It has been shown that psoriasis patients have almost a 3 time higher risk for celiac disease than people without psoriasis. However, this does not mean that everyone with psoriasis will benefit from a gluten-free diet. Current data suggests that in people with specific celiac antibodies (ex – IgA antigliadin antibodies), a gluten-free diet may improve their psoriasis.
There is a known link between red meat consumption and death from cardiovascular disease, as well as a known link between psoriasis and cardiovascular disease. Scientists have not yet directly looked at the impact of red meat consumption on psoriasis severity. However, there are reports of improvement in psoriasis symptoms in diet plans that included meat avoidance. In 5 patients who avoided meat and processed food while increasing the intake of fruits, vegetables, and legumes, there was a significant improvement in psoriasis severity after 6 months. In one case report, a patient was told to consume a diet rich in red meat and his psoriasis worsened! It is important to remember these studies did not look directly at the microscopic effect of meat on psoriasis in human cells, but it has been hypothesized that certain elevated fatty acids (ex – arachidonic acid) found in meat and other animal products can trigger an inflammatory cascade and worsen plaques in psoriasis.
Excessive Calorie Consumption Leading to Obesity
In people who are obese, there is a 2-fold increased risk of developing psoriasis than people who are a healthy weight. In fact, researchers have found that for each 1 unit increase in Body Mass Index (BMI) there was almost a 10% increased risk for developing psoriasis. Several other studies have also supported the notion that the higher the BMI or obesity, the greater the risk of developing psoriasis.[20,21] This trend has even been demonstrated in children. Not only does obesity increase your risk for psoriasis, but it can also hinder the ability of certain medications to effectively treat psoriasis symptoms.
Foods That May Help Psoriasis: Mediterranean Diet
A research study showed that patients with psoriasis are less likely to be following a Mediterranean diet compared to people without psoriasis. Specifically, people with psoriasis were found to consume significantly less extra virgin olive oil, fruit, seafood, and tree nuts while consuming more red meats and processed meats each day compared to people without psoriasis. The research team hypothesized that long-term use of extra virgin olive oil in cooking may lead to a reduction in inflammatory diseases like psoriasis. However, this is the only study looking at the association between psoriasis and a Mediterranean diet and future studies will yield more information on how dietary modifications could improve symptoms of psoriasis.
It is common for patients to ask their dermatologist if certain foods make psoriasis better or trigger psoriasis to worsen. While evidence supporting the negative impact of certain dietary factors such as alcohol and red meat is slowly emerging, future large clinical studies are still needed to establish clear nutritional guidelines for psoriasis.