Nuts have been part of our diets for thousands of years, even before we started farming1. People who regularly eat nuts are less likely to develop heart diseases 2, but how do nuts affect psoriasis?
What do we know about nuts and psoriasis?
Nutrition scientists have been interested in the health benefits of nuts since finding that they have anti-inflammatory benefits.
For example, some studies have found that regularly eating nuts can help lower CRP (C-reactive protein) 3, a marker of inflammation.
In people with psoriasis, CRP levels are linked with psoriasis severity 4. This means symptoms tend to get worse as CRP levels increase. Because of this link, eating more foods that lower inflammation may be helpful.
Nuts are also high in antioxidants 5, which help to protect the skin from oxidative stress. Oxidative stress is a process where unstable molecules damage cells. Because high levels of oxidative stress have been linked with psoriasis progression, some experts think antioxidant rich foods might be beneficial 6,7.
What does the science say?
To date there haven’t been any scientific studies looking directly at the relationship between nut intake and psoriasis risk or severity. However we can find some clues about the links between nuts and psoriasis from studies looking at overall dietary patterns.
In a 2015 study from Italy, people with psoriasis eating a Mediterranean style diet (including a regular intake of nuts) had lower psoriasis severity scores than those who ate a more western style diet 8. In the same study, psoriasis severity and levels of inflammation were lower in people who ate more nuts.
Another case study which encouraged eating nuts as part of a psoriasis dietary plan (together with more fruit, vegetables and olive oil, and less red meat and sugar) 10 reported improvements in psoriasis severity in all five patients. This doesn’t mean nuts alone improve psoriasis, but it does show they might help as part of an overall change to diet.
On the other hand, some people with psoriasis have reported that nuts seem to aggravate itching11. Until there are more studies, it’s difficult to draw any conclusions.
Are there any risks associated with eating nuts?
In some people nuts can trigger food allergy, but this is quite rare, affecting around 1 in 100 people 2. Nut allergies mostly affect young children, but people who have other allergic conditions (like asthma, eczema) may be more likely to develop nut allergies.
How many nuts should I be eating?
We don’t know how many nuts are needed to lower inflammation, but studies have found that eating nuts several times a week can protect against heart disease and diabetes.
This is important, because people with psoriasis are more likely to develop these conditions.
After reviewing the evidence, the FDA (Food and Drug Administration) decided that eating about 1.5 ounces of nuts per day could protect heart health. 1.5 ounces is equal to around 40 grams – roughly a handful of nuts.
- Nuts are linked to lower levels of CRP, a marker of inflammation which is found in high levels in psoriasis
- The antioxidants in nuts can protect skin from oxidative stress, a process which is involved in psoriasis progression
- A small amount of research has found that disease severity is lower in psoriasis sufferers who regularly eat nuts
- Eaton SB, Konner M. Paleolithic nutrition. A consideration of its nature and current implications. N. Engl. J. Med. 1985;312:283-289. doi:The general mismatch hypothesis…
- Ros E. Health benefits of nut consumption. Nutrients 2010;2(7):652-682. doi:10.3390/nu2070652.
- Salas-Salvad?? J, Casas-Agustench P, Murphy MM, L??pez-Uriarte P, Bull?? M. The effect of nuts on inflammation. Asia Pac. J. Clin. Nutr. 2008;17(SUPPL. 1):333-336.
- Reich K. The concept of psoriasis as a systemic inflammation: Implications for disease management. J. Eur. Acad. Dermatology Venereol. 2012;26(SUPPL. 2):3-11. doi:10.1111/j.1468-3083.2011.04410.x.
- Vinson JA, Cai Y. Nuts, especially walnuts, have both antioxidant quantity and efficacy and exhibit significant potential health benefits. Food Funct. 2012;3(2):134-40. doi:10.1039/c2fo10152a.
- Zhou Q, Mrowietz U, Rostami-Yazdi M. Oxidative stress in the pathogenesis of psoriasis. Free Radic. Biol. Med. 2009;47(7):891-905. doi:10.1016/j.freeradbiomed.2009.06.033.
- Lin XHT. Oxidative stress in psoriasis and potential therapeutic use of antioxidants. Free Radic. Res. 2016;21:1-11.
- Barrea L, Balato N, Di Somma C, et al. Nutrition and psoriasis: is there any association between the severity of the disease and adherence to the Mediterranean diet? J. Transl. Med. 2015;13(1):18. doi:10.1186/s12967-014-0372-1.
- Mena M-P, Sacanella E, Vazquez-Agell M, et al. Inhibition of circulating immune cell activation: a molecular antiinflammatory effect of the Mediterranean diet. Am. J. Clin. Nutr. 2009;89(1):248-56. doi:10.3945/ajcn.2008.26094.
- Brown AC, Hairfield M, Richards DG, McMillin DL, Mein E a, Nelson CD. Medical nutrition therapy as a potential complementary treatment for psoriasis–five case reports. Altern. Med. Rev. 2004;9(3):297-307. Available at: http://www.altmedrev.com/publications/9/3/297.pdf.
- Prignano F, Ricceri F, Pescitelli L, Lotti T. Itch in psoriasis : epidemiology , clinical aspects and treatment options. 2009:9-14.
- Blomhoff R, Carlsen MH, Andersen LF, Jacobs DR. Health benefits of nuts: potential role of antioxidants. Br. J. Nutr. 2006;96(S2):S52-S60. doi:10.1017/BJN20061864.