This article is the first in our series of requested topics from our subscribers: Psoriasis and diet. A number of you requested an article about daily activities or approaches to life with skin disease. In this particular post, we will investigate dietary factors.
This article is the first in our series of requested topics from our subscribers: Psoriasis and diet. A
number of you requested an article about daily activities or approaches to life with skin disease. In this
particular post, we will investigate dietary factors. Many patients with skin conditions are concerned
that dietary factors are strongly correlated to their diseases. For example, some patients believe that
consuming sugar or milk can flare up acne. Others believe that eating products high in gluten such as
bread can also trigger a flare up of a scaly, itchy, and flaky rash. Today, we will focus on psoriasis and
specifically how diet, gluten sensitivity, and supplements play a role in the disease. We will try to answer
the following questions: Does diet does affect psoriasis? What should I be eating? What should I avoid
eating? Should I take any over-the-counter supplements?
Diet and Psoriasis
There is no doubt that your health is linked to dietary habits. For example, in the United States, we
typically consume what is described as a ?western diet? when compared to other cultures around the
world. The western diet typically contains high-calorie foods, added sugars, saturated fat, and red meat
which may cause weight gain if not balanced with exercise. Weight gain, we you will read in our next
section, can make psoriasis worse. So, if the a diet that causes weight gain should be avoided, which diet
is best? Well, a Mediterranean diet is a good place to begin. Generally speaking, this diet is mainly plant-
based, low in processed foods, low in sugar, high in whole foods, nuts, olive oil, and lean meats such as
fish. A diet made up of whole food including fruits, vegetables including tomatoes, carrots, green leafy
vegetables such as broccoli, spinach, and lean meat all contain antioxidants has been shown to be
protective against psoriasis. Specifically, individual small molecular components of these healthy foods
have been shown to improve the inflammation associated with psoriasis.1
Obesity and Psoriasis
Multiple studies have concluded that obesity plays a major role in psoriasis. Patients with a higher body
mass index (a measure a body fat) usually have more severe psoriasis. Also, being obese increases your
risk of psoriasis twice as much as someone with a normal weight.2,3 Additionally, once you have
psoriasis, it tends to be more difficult to treat and clear the skin. A higher drug dose is sometimes
needed for overweight patients as their psoriasis especially in patients who take biologic drugs.4,5 So,
does losing weight make your skin more easily treated? The answer is yes. Patients at a healthy normal
weight usually to respond better to treatment.6,7
Gluten is a common component of many foods and includes wheat, rye, and barley. It is a small particle
that is essentially tasteless and is difficult to completely avoid without a very strict diet. The most
common gluten-containing foods include bread, beer, cereals, gravy, salad dressings, soups, and beer.
Gluten is in so many different foods and even very small amounts can cause problems. Interestingly,
oats (although still a grain) are safe to eat as long are they are certified gluten-free and not
contaminated with trace amount of gluten during processing.
Gluten and Psoriasis: If I have psoriasis, should I avoid gluten?
The short answer is maybe. Celiac disease is an autoimmune disease triggered by exposure to gluten.
Because psoraisis is associated with other autoimmune diseases including Celiac disease, some scientists
have investigated whether patients with psoraisis may be at risk for Celiac disease. The risk of Celiac
disease in psoriasis patients is higher than the general population but overall extremely low at less than
0.5%. Additional studies have also shown that a small subset of psoriasis patients have the immune-
stimulating proteins (antibodies) to gluten similar to patients with Celiac disease.8 Although some
studies have not definitively shown that avoidance of gluten will improve the skin, others have
demonstrated improvement of psoriasis with a gluten free diet after 3 months of avoidance.9
Can fish oil improve psoriasis?
This is another common question we hear. What evidence, if any, exists to recommend patients take
fish oil supplements and can they help? Usually, patients are already using prescribed medications such
as topical steroids, phototherapy, or systemic medications, are not at their skin goals, and do not wish to
change their prescription treatment. The most common supplement for psoriasis is an omega-3 fatty
acid such as fish oil. Alternatively, a diet consisting of regular consumption of oily fish such a salmon can
be used instead of supplements. Does science support this recommendation? Well, it has been studied
extensively without clear benefit . To begin with, the typical dose of fish oil required is quite high since
three one gram capsules (a common dose of fish oil) is required. This is because most studies used an
average of three grams. This was quite variable and some studies used up to 12 grams.10 So, should
you take fish oil? A few of these smaller observational studies have shown improvement while many of
the well-done studies have not.11 Suffice it to say that the jury is still out on whether a diet heavy in fish
or omega-3 fatty acid supplements improve psoriasis.
Can any other dietary supplements improve psoriasis?
So then, what supplement is best for psoriasis? Well, one supplement that is essential, as most
members of the modern world are deficient, is vitamin D. The recommended daily amount of vitamin D
is 400 international units (IU) for children up to age 12 months, 600 IU for ages 1 to 70 years, and 800 IU
for people over 70 years. In general, patients with psoriasis are more likely to be vitamin D deficient
when compared to the general population so supplementation is generally recommended when treating
psoriasis and scalp psoriasis. Taking additional vitamin D at higher doses has not yet been shown to
improve psoriasis.13 Extensive exposure to the sun, although can improve psoriasis, is typically not
recommended since it can increase the risk of skin cancer. Additionally, only about 50% of people that
live in sunny locations such as Hawaii do create enough their own vitamin D even with regular sun
exposure.14 Therefore, dietary intake is essential. Furthermore, many internet sources reference
supplements that could help psoriasis which is possible but not founded upon scientific research. Just a
few vitamins, cobalamin (also known as vitamin B12) and selenium, have been studied and not been
shown to improve psoriasis.
Diet and psoriasis symptoms are linked in ways as we outlined above. Whether these interventions
translate into improvement of scalp psoriasis, sebopsoriasis, dandruff, or a dry, flaky, itchy scalp is
unknown as these conditions were not studied exclusively. That being said, why not try them and see if
it works for you? A healthy diet which includes lean meats and is rich in fruits and vegetables, regular
exercise, and vitamin D supplementation is recommended to maintain a healthy body. You can take
steps on your own to potentially improve your skin that does not require a prescription or visit to a
1 Naldi L, Parazzini F, Peli L et al. Dietary factors and the risk of psoriasis. Results of an Italian case–
control study. Br J Dermatol 1996; 134:101–6
2 Wolk K, Mallbris L, Larsson P, Rosenblad A, Vingård E, Ståhle M. Excessive body weight and smoking
associates with a high risk of onset of plaque psoriasis. Acta Derm Venereol. 2009; 89:492–7.
3 Kumar S, Han J, Li T, Qureshi AA. Obesity, waist circumference, weight change and the risk of
psoriasis in US women. J Eur Acad Dermatol Venereol. 2011
4 Papp KA, Langley RG, Lebwohl M, Krueger GG, Szapary P, Yeilding N, et al. Efficacy and safety of
ustekinumab, a human interleukin-12/23 monoclonal antibody, in patients with psoriasis: 52- week
results from a randomised, double-blind, placebo-controlled trial (PHOENIX 4. Lancet. 2008; 371:1675–
5 Lebwohl M, Yeilding N, Szapary P, Wang Y, Li S, Zhu Y, et al. Impact of weight on the efficacy and
safety of ustekinumab in patients with moderate to severe psoriasis: rationale
6 Menter A, Gordon KB, Leonardi CL, Gu Y, Goldblum OM. Efficacy and safety of adalimumab across
subgroups of patients with moderate to severe psoriasis. J Am Acad Dermatol. 2010; 63:448–56.
7 Naldi L, Addis A, Chimenti S, Giannetti A, Picardo M, Tomino C, et al. Impact of body mass index and
obesity on clinical response to systemic treatment for psoriasis. Evidence from the Psocare project.
Dermatology. 2008; 217:365–73.
8 Bhatia BK, Millsop JW, Debbaneh M, Koo J, Linos E, Liao W. Diet and psoriasis, part II: celiac disease
and role of a gluten-free diet. J Am Acad Dermatol. 2014 Aug;71(2):350-8. doi:
10.1016/j.jaad.2014.03.017. Epub 2014 Apr 26. Review
9 Michaëlsson G, Gerdén B, Hagforsen E, Nilsson B, Pihl-Lundin I, Kraaz W, et al. Psoriasis patients with
antibodies to gliadin can be improved by a gluten-free diet. Br J Dermatol. 2000; 142:44–51.
10 Collier PM, Ursell A, Zaremba K et al. Effect of regular consumption of oily fish compared with white
fish on chronic plaque psoriasis. Eur J Clin Nutr 1993; 47:251
11 Soyland E, Funk J, Rajka G et al. Effect of dietary supplementation with very-long-chain n-3 fatty
acids in patients with psoriasis. N Engl J Med 1993; 328:1812–16.
12 Fairris GM, Lloyd B, Hinks L et al. The effect of supplementation with selenium and vitamin E in
psoriasis. Ann Clin Biochem 1989; 26:83–8.
13 Jarrett P, Camargo CA Jr, Coomarasamy C, Scragg R. A randomized, double-blind, placebo-
controlled trial of the effect of monthly vitamin D supplementation in mild psoriasis. J Dermatolog Treat.
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14 Binkley N, Novotny R, Krueger D, Kawahara T, Daida YG, Lensmeyer G, Hollis BW, Drezner MK. Low
vitamin D status despite abundant sun exposure. J Clin Endocrinol Metab. 2007 Jun;92(6):2130-5. Epub
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