Red meat includes beef, lamb, pork, duck and game, and any foods prepared from these meats, for example sausages, minced beef and burgers.
Red meat is often listed as a food to avoid if you have psoriasis, but why?
What do we know about red meat and psoriasis?
Red meat is a source of arachidonic acid (AA), a fat which is part of the omega-6 family. Like omega-3, omega-6 fats are used to make locally acting hormones which play a role in regulating inflammation in the body.
Studies show hormones formed from omega-6 (and particularly from arachidonic acid), tend to be pro-inflammatory, while those produced from omega-3 tend to be anti-inflammatory 1.
We also know that when arachidonic acid is metabolised, it produces a compound which triggers inflammation 2, and may stimulate the growth of skin cells3.
What does the science say?
To date, there are no studies which have looked directly at the effects that increasing or decreasing intake of red meat might have on psoriasis. This means we have to rely on research which look at associations between red meat consumption and psoriasis or inflammation.
In a recent study looking at dietary patterns of patients with psoriasis, both psoriasis severity and levels of inflammatory markers were positively correlated with meat consumption (meaning as one increases, so does the other).
Patients with psoriasis also reported eating more red meat than the people who did not have psoriasis (the control group) 9. However, it’s not clear if the link is down to the red meat, or if people eating more red meat also ate more or less of other foods (such as fish) which could play a role.
However, some small studies do suggest reducing meat intake may be helpful as part of an overall dietary strategy. In one small trial of five patients with plaque psoriasis, a 6-month programme which excluded red meat, processed foods, alcohol and refined carbohydrates significantly reduced psoriasis severity 10.
During the study patients were encouraged to eat a diet high in fresh fruits and vegetables, small amounts of protein from fish and poultry, plus olive oil, and herbal teas. On average, psoriasis severity scores (which represent severity of symptoms and area of coverage) dropped from 18.2 to 8.7.
Some studies that have supplemented with omega-3 have also limited red meat 11,12, and it’s possible that a combination of the two changes may have an additive effect.
Outside of psoriasis studies have found a link between red meat intake and the risk of arthritis, a condition which shares similar inflammatory pathways to psoriasis 13,14,15,16. In one study, researchers found that a combination of fish oil plus a diet low in arachidonic acid was beneficial in rheumatoid arthritis 17
How much is too much?
Because we can’t confirm the effects of red meat on psoriasis, it’s not clear how much may increase psoriasis risk or severity, if indeed there is a link.
The advice in the UK is to consume no more than 500 grams of cooked red meat per week, with as little as possible being processed meat. This is due to associations between high processed meat intakes and cancer 18. To put this into perspective, a medium portion of roast beef is around 100 grams and a medium cooked steak is around 150 grams.
- Red meat is a source of arachidonic acid, an omega-6 fat that has been linked to the inflammatory process in psoriasis
- Some studies show people with psoriasis tend to eat more red meat than control groups, but there is still no clear evidence that it increases risk
- Some studies have found reducing red meat intake as part of an overall dietary strategy can reduce psoriasis severity
- Changing the ratio of omega-3 to omega-6 in the diet by eating less red meat and more oily fish or using omega-3 supplements appears helpful
- Wolters, M. Diet and psoriasis: experimental data and clinical evidence. Br. J. Dermatol. 153, 706–714 (2005).
- Crooks, S. W. & Stockley, R. a. Leukotriene B4. Int. J. Biochem. Cell Biol. 30, 173–178 (1998).
- Iversen L, Kragballe K, Z. V. Significance of leukotriene-A4 hydrolase in the pathogenesis of psoriasis. Ski. Pharmacol. 10, 169–77 (1997).
- O., A. Dietary fatty acids and immune reactions in synovial tissue. European journal of medical research 8, 381–387 (2003).
- Brain, S., Camp, R., Dowd, P., Black, a K. & Greaves, M. The release of leukotriene B4-like material in biologically active amounts from the lesional skin of patients with psoriasis. The Journal of investigative dermatology 83, 70–73 (1984).
- Corrocher, R., Ferrari, S. & Gironcoli, M. de. Effect of fish oil supplementation on erythrocyte lipid pattern, malondialdehyde production and glutathione-peroxidase activity in psoriasis. Clin. Chim. Acta 179, 121–131 (1989).
- Schena, D. et al. Increased erythrocyte membrane arachidonate and platelet malondialdehyde (MDA) production in psoriasis: normalization after fish-oil. Acta Derm. Venereol. Suppl. (Stockh). 146, 42–44 (1989).
- Ricketts, J. R., Rothe, M. J. & Grant-Kels, J. M. Nutrition and psoriasis. Clin. Dermatol. 28, 615–626 (2010).
- Barrea, L. et al. Nutrition and psoriasis: is there any association between the severity of the disease and adherence to the Mediterranean diet? J. Transl. Med. 13, 18 (2015).
- Brown, A. C. et al. Medical nutrition therapy as a potential complementary treatment for psoriasis–five case reports. Altern. Med. Rev. 9, 297–307 (2004).
- Kragballe, K. & Fogh, K. A low-fat diet supplemented with dietary fish oil (Max-EPA) results in improvement of psoriasis and in formation of leukotriene B5. Acta Derm. Venereol. 69, 23–8 (1989).
- Ziboh, V. A. et al. Effects of dietary supplementation of fish oil on neutrophil and epidermal fatty acids. Modulation of clinical course of psoriatic subjects. Arch. Dermatol. 122, 1277–1282 (1986).
- Christophers, E. Comorbidities in psoriasis. Clin. Dermatol. 25, 529–34 (2007).
- Grant, W. B. The role of meat in the expression of rheumatoid arthritis. Br. J. Nutr. 84, 589–595 (2000).
- Choi, H. K. Diet and rheumatoid arthritis: red meat and beyond. Arthritis Rheum. 50, 3745–3747 (2004).
- Pattison, D. J. et al. Dietary risk factors for the development of inflammatory polyarthritis: evidence for a role of high level of red meat consumption. Arthritis Rheum 50, 3804–3812 (2004).
- Adam, O. et al. Anti-inflammatory effects of a low arachidonic acid diet and fish oil in patients with rheumatoid arthritis. Rheumatol. Int. 23, 27–36 (2003).
- CRUK. Processed meat and cancer – what you need to know. (2015). at <http://scienceblog.cancerresearchuk.org/2015/10/26/processed-meat-and-cancer-what-you-need-to-know/>
- Sinclair, A., Johnson, L., O’Dea, K. & Holman, R. Diets rich in lean beef increase arachidonic acid and long-chain omega 3 polyunsaturated fatty acid levels in plasma phospholipids. Lipids 29, 337–43 (1994).
- Mayser, P. et al. Omega-3 fatty acid-based lipid infusion in patients with chronic plaque psoriasis: results of a double-blind, randomized, placebo-controlled, multicenter trial. Journal of the American Academy of Dermatology 38, 539–547 (1998).
- Li, D., Ng, A., Mann, N. J. & Sinclair, A. J. Contribution of meat fat to dietary arachidonic acid. Lipids 33, 437–440 (1998).
- Daley, CA, Abbott, A, Doyle, PS, Nader, GA, Larson, S. A review of fatty acid profiles and antioxidant content in grass-fed and grain fed beef. Nutr. J. 9, 10–21 (2010).