Throughout the world, bread is a staple food. In the UK, bread makes up about 10 per cent of the calories we eat, and around 20 per cent of our fibre intake1.
Bread is made using flour, water, salt and a raising agent like yeast. When producing sourdough bread, naturally occurring microbes (harmless bacteria) are used to help the dough rise.
What do we know about bread and psoriasis?
To date, there haven’t been any studies looking specifically at how bread intake affects psoriasis. Unlike some lifestyle factors (like alcohol, or being overweight), there isn’t any research to suggest that eating lots of bread increases psoriasis risk.
What we do know is that for some people with psoriasis, there seems to be a link between gluten (a protein found in wheat, rye and barley), and their skin condition2.
Scientists don’t fully understand why, but for these people, a gluten-free diet seems to improve psoriasis severity. Because bread usually is a source of gluten (from the flour), it is one of the foods excluded on a gluten-free diet.
It’s important to remember that not everyone with psoriasis reacts to gluten – or bread. For some people with psoriasis, a gluten free diet will make no difference to their condition.
What does the science say?
We don’t have any evidence that bread causes psoriasis. In fact, the Mediterranean diet (which traditionally includes bread) has been linked with a lower risk of psoriasis3.
However, scientists have found a link between psoriasis and gluten, a protein found in wheat, rye or barley – and also bread and other foods made from these grains.
People with psoriasis who have raised levels of ‘antibodies’ (a special type of immune cell) to gluten seem to have a more severe form of psoriasis.
In one study of psoriasis patients with raised levels of gluten antibodies4 (a special type of immune cell), a three-month gluten free diet significantly improved their skin. When the patients returned to their normal diet, most of the patients found that their skin deteriorated.
Other studies of healthy diets used to treat psoriasis have included bread with no adverse effects 5. It’s clear that not everyone with psoriasis will benefit from excluding gluten or bread.
Is one sort of bread better than the other?
In the UK, 75 per cent of the bread we buy is white bread1. White bread contains less fibre than wholegrain bread, because the outer husk (bran and the germ) is removed during the milling process.
Studies show that high fibre diets may protect against inflammation6,7. Because psoriasis is an inflammatory disease, experts think eating more anti-inflammatory foods may be helpful.
Wholegrain breads made with the ‘whole’ grain contain the most fibre. Brown bread is a mixture of white flour with added bran – it contains more fibre than white bread, but less than wholemeal or wholegrain.
Sourdough bread is traditional style bread that is made using with naturally occurring yeasts and bacteria. These bacteria are a source of probiotics, which play a role in regulating immune function. A small number of studies have suggested probiotics might be helpful in psoriasis, but more research is needed.
Should I stop eating bread?
At the moment, we don’t have any evidence to suggest that avoiding bread is helpful for people with psoriasis unless they have raised gluten antibodies.
If you want to trial a gluten free diet you will need to stop eating all foods containing gluten – and that includes bread from wheat, rye and barley. You can buy alternative breads that are gluten free, but these are more expensive, and have a different texture and taste to regular bread.
If you do include bread in your diet, choosing wholegrain is recommended, as it contains more fibre than white. In the U.K. and the U.S. dietary guidelines recommend that at least half the grains we choose should be wholegrain.
- Bread is made using flour, water, salt and a raising agent. In the UK, most of the bread we eat is made with wheat flour.
- A number of studies have found a link between gluten (a protein found in wheat, rye and barley) and psoriasis. In people who have raised antibodies to gluten, a gluten free diet seems to improve psoriasis severity.
- Wholegrain bread has more fibre than white bread. This is beneficial because fibre has anti-inflammatory benefits.
- Sourdough or traditionally made breads are a source of probiotics, which may be beneficial for the immune system.
- Flour Advisory Bureau. Facts about bread. 2016.
- 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;71(2):350-358. doi:10.1016/j.jaad.2014.03.017.
- 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.
- Michaëlsson G, Gerdén B, Hagforsen E, et al. Psoriasis patients with antibodies to gliadin can be improved by a gluten-free diet. Br. J. Dermatol. 2000;142(1):44-51. Available at: http://www.ncbi.nlm.nih.gov/pubmed/10651693.
- 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.
- North CJ, Venter CS, Jerling JC. The effects of dietary fibre on C-reactive protein, an inflammation marker predicting cardiovascular disease. Eur. J. Clin. Nutr. 2009;63(8):921-933. doi:10.1038/ejcn.2009.8.
- Krishnamurthy VMR, Wei G, Baird BC, et al. High dietary fiber intake is associated with decreased inflammation and all-cause mortality in patients with chronic kidney disease. Kidney Int. 2012;81(3):300-306. doi:10.1038/ki.2011.355.
- Holma R, Hongisto S-M, Saxelin M, Korpela R. Constipation is relieved more by rye bread than wheat bread or laxatives without increased adverse gastrointestinal effects. J. Nutr. 2010;140(3):534-541. doi:10.3945/jn.109.118570.