This article was written by registered dietitian – Maeve Hanan
Psoriasis is an inflammatory skin condition that involves an overproduction of skin cells that leads to uncomfortable plaques and scales on the skin (1). Severity varies between people, but this condition can have a big impact on quality of life.
This is thought to be related to the immune system, may involve genetics and environmental factors, and tends to be linked with certain triggers. Managing psoriasis includes applying treatments like vitamin D and steroids to the skin, light therapy and in some cases immunosuppressive medication (1).
This article will cover whether nutritional factors impact psoriasis.
Are there any nutritional guidelines for psoriasis?
Although there are no official evidence-based dietary guidelines and no known nutritional cures, psoriasis charities like the National Psoriasis Foundation in the US and The Psoriasis and Psoriatic Arthritis Alliance (PAPAA) in the UK advise that eating a balanced diet is both good for overall health and may help with managing symptoms (2, 3).
This advice is based on the limited available evidence related to diet and psoriasis, as well as the role of inflammation in the condition and how diet may help to alleviate this. For example, as psoriasis has been found to share inflammatory pathways with other diseases such as heart disease, type 2 diabetes and Coeliac disease, so it’s thought that similar dietary principles may apply (4, 5).
The mediterranean diet
The Mediterranean diet is often recommended for those with psoriasis due to its anti-inflammatory effects (related to its high content of antioxidants and gut-healthy foods) and its benefits for related conditions like heart disease and type 2 diabetes.
This dietary pattern is based on fruit, vegetables, grains, nuts, olive oil and fish, with a small amount of wine every day.
A few studies have found following a Mediterranean diet may be linked with less severe psoriasis and vice versa (6, 7).
In 2019 another observational study found that following a Mediterranean diet was associated with a reduced risk of psoriasis and this was a stronger link than age, sex or BMI and psoriasis risk (8). Severity of psoriasis was also specifically linked with a lower intake of common foods on the mediterranean diet including fish, legumes and extra virgin olive oil.
These studies show an association rather than a ‘cause and effect’ link, but seem promising.
Research is ongoing inthis space. For example, a study called the APPLE (Asking People with Psoriasis about their Lifestyle and Eating) Study is currently underway in the UK (9). This will be examining the dietary patterns of people with psoriasis and comparing these with the UK control population as well as carrying out a small trial to compare response to both a Mediterranean-style diet and a time-restricted Mediterranean style diet (10).
It’s thought that antioxidants like vitamin E, vitamin C, Coenzyme Q10 and selenium may help with improving psoriasis due to reducing inflammation (11, 12). But results have been mixed and the evidence is limited overall.
There’s stronger evidence to support the role of fish oil supplements in reducing inflammation and severity of psoriasis. In 2020 a systematic review of randomised trials found that fish oil or omega-3 supplements combined with conventional psoriasis treatments significantly reduced symptom severity and inflammation; whereas no effect of the supplements alone was found (13). However there are some contrasting findings related to this so ongoing research is needed (14).
Vitamin D is a common treatment option for psoriasis in the form of ointments and medications that are applied on top of the skin to slow cell growth. Although there’s currently little evidence to support the benefits of consuming vitamin D for those with psoriasis, a study from 2021 found that supplementing with 5000 IU (125 micrograms) for 3 months led to a reduction in inflammation in those with psoriasis (15, 16). Most people in the UK are also advised to consider vitamin D supplementation to support bone, teeth and muscle health during winter regardless of whether they have this condition or not (17).
Folic acid supplementation is often recommended in those taking the immunosuppressant medication methotrexate as part of their psoriasis management (12, 18).
Vitamin B12 deficiency has also been associated with psoriasis, and some studies have found benefits associated with supplementing this vitamin, the evidence related to this is very limited overall (11).
Due to the role that gut health plays with inflammation and overall health, it’s thought that probiotics may help with managing psoriasis. A recent randomised controlled trial found that taking a daily multistrain probiotic for 2 months significantly improved the quality of life, psoriasis severity and inflammation (19). This is in line with previous studies, but more high quality studies are needed to investigate this (20).
If considering taking supplements as part of the management of psoriasis it’s important to speak with your healthcare team, as nutritional supplements aren’t without risks.
Gluten is a protein found in grains such as wheat, rye and barley.
A US survey of 1206 people with psoriasis from 2017 found that 36% followed a gluten-free diet in order to manage their psoriasis, and 53% of those avoiding gluten reported a reduction in their symptoms (5).
Coeliac disease is a condition where the body attacks its cells when gluten is eaten. Those with psoriasis have been found to be twice as likely to have coeliac disease (21). This may be due to shared genetic and inflammatory pathways between the two conditions (5).
Non-Coeliac gluten sensitivity is when similar symptoms of Coeliac disease occur but the immune system isn’t involved in the same way as it is with Coeliac disease. A few studies have found a positive impact of gluten free diets for those with psoriasis (22).
Overall, more research is needed to investigate the possible link between gluten and psoriasis. The most important thing if gluten is a suspected issue, is to be tested for Coeliac disease before cutting out gluten. And if trialling any exclusion diet, including a gluten free diet, it’s best to do this with support from a Registered Dietitian.
Although a moderate amount of alcohol may have anti-inflammatory benefits, a high or chronic intake is associated with increased inflammation (23, 24).
Population-based studies have found that drinking alcohol is associated with increased risk of psoriasis (25). This also goes in the opposite direction, as alcohol consumption has been seen to be higher in those with psoriasis (26).
Alcohol intake may also impact effectiveness and compliance with psoriasis treatment and immune factors that impact the skin (27).
So for both overall health and the management of psoriasis, it is wise to stick to the low risk alcohol guidelines of no more than 14 units per week, without binge drinking and including several drink-free days each week.
Weight loss diets
There seems to be a link between psoriasis and a higher fat mass that may go in both directions and involve inflammatory pathways, but this isn’t entirely understood.
Weight loss following changes to diet and exercise have been associated with a reduction in psoriasis risk and symptoms (28, 29). However, it’s difficult to say whether the weight loss specifically was the reason for improvement, or whether it was the changes to diet and movement, or a combination of both.
A few studies have also found that very-low calorie diets may lead to improvements in psoriasis (30, 31). But these studies were quite small and only lasted a few weeks. Very low calorie diets are also an extreme approach that can involve eating as little as 800 calories per day, so this approach comes with risks and considerations and isn’t suitable for everyone.
Similarly, weight loss diets in general aren’t helpful or suitable for many people.
Although a higher weight or fat mass may be a risk factor for psoriasis, both psoriasis and weight are complex and impacted by many different factors. Trying to lose weight may be helpful for some people with psoriasis. Whereas for others a more helpful focus may be to focus on the quality of their diet – like the Mediterranean diet as discussed above.
There’s an overall lack of evidence related to psoriasis and diet, which is why there is currently no specific evidence-based guidance on diet for those who have this condition.
Eating patterns linked with reducing inflammation currently seem like the most sensible approach when it comes to nutrition and psoriasis, as well as being beneficial for overall health. This includes the Mediterranean diet and other similar eating patterns that are based on plenty of fruit, vegetables, grains, nuts, olive oil and oily fish and not too much alcohol. Fish supplements may also play a role in reducing inflammation and severity of psoriasis, but ongoing studies are needed.
Although there’s a possible link between gluten and psoriasis, again, this isn’t entirely clear. But it’s really important to be properly tested for Coeliac disease by a doctor before cutting out gluten. If making any big changes to your diet it’s always best to get support from a registered dietitian.
- NHS Website (2022) “Psoriasis” [accessed August 2022 via: https://www.nhs.uk/conditions/psoriasis/]
- National Psoriasis Foundation (2020) “Dietary Modifications” [accessed August 2022 via: https://www.psoriasis.org/dietary-modifications/]
- The Psoriasis and Psoriatic Arthritis Alliance “Diet and Lifestyle” [accessed August 2022 via: https://www.papaa.org/learn-about-psoriasis-and-psoriatic-arthritis/diet-and-lifestyle/]
- Takeshita, J., Grewal, S., Langan, S. M., Mehta, N. N., Ogdie, A., Van Voorhees, A. S., & Gelfand, J. M. (2017). Psoriasis and comorbid diseases: epidemiology. Journal of the American Academy of Dermatology, 76(3), 377-390. [accessed August 2022 via: https://pubmed.ncbi.nlm.nih.gov/28212759/]
- Bhatia, B. K., Millsop, J. W., Debbaneh, M., Koo, J., Linos, E., & Liao, W. (2014). Diet and psoriasis, part II: celiac disease and role of a gluten-free diet. Journal of the American Academy of Dermatology, 71(2), 350-358. [accessed August 2022 via: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4104239/]
- Phan C, Touvier M, Kesse-Guyot E, Adjibade M, Hercberg S, Wolkenstein P, Chosidow O, Ezzedine K, Sbidian E. Association Between Mediterranean Antiinflammatory Dietary Profile and Severity of Psoriasis: Results From the NutriNet-Sant Cohort. JAMA Dermatol. 2018 Sep 1;154(9):1017-1024 [accessed August 2022 via: https://pubmed.ncbi.nlm.nih.gov/30046840/]
- Caso, F., Navarini, L., Carubbi, F., Picchianti-Diamanti, A., Chimenti, M. S., Tasso, M., … & Costa, L. (2020). Mediterranean diet and Psoriatic Arthritis activity: a multicenter cross-sectional study. Rheumatology International, 40(6), 951-958. [accessed August 2022 via: https://pubmed.ncbi.nlm.nih.gov/31605152/]
- Korovesi, A., Dalamaga, M., Kotopouli, M., & Papadavid, E. (2019). Adherence to the Mediterranean diet is independently associated with psoriasis risk, severity, and quality of life: a cross‐sectional observational study. International Journal of Dermatology, 58(9), e164-e165. [accessed August 2022 via: https://pubmed.ncbi.nlm.nih.gov/31168780]
- KCL “The APPLE Study (Asking People with Psoriasis about their Lifestyle and Eating): examining associations between diet and psoriasis severity” [accessed August 2022 via: https://www.kcl.ac.uk/study-legacy/funding/the-apple-study-asking-people-with-psoriasis-about-their-lifestyle-and-eating-examining-associations-between-diet-and-psoriasis-severity]
- BDA (2022) “Nutrition and the skin” [accessed August 2022 via: https://www.bda.uk.com/resource/nutrition-and-the-skin.html]
- Millsop, J. W., Bhatia, B. K., Debbaneh, M., Koo, J., & Liao, W. (2014). Diet and psoriasis, part III: role of nutritional supplements. Journal of the American Academy of Dermatology, 71(3), 561-569. [accessed August 2022 via: https://pubmed.ncbi.nlm.nih.gov/24780177/]
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Nutrition and Psoriasis was last modified: August 11th, 2022 by