Vegan Diet and Inflammatory Bowel Disease
Its January and ‘Veganuary’ so I have been asked a lot this month about vegan diets with Crohn’s and Colitis.
I know that vegan diets can be a controversial topic, but I wanted to share the evidence we have about vegan diets and IBD. I will only be discussing the nutrition and health side of vegan diets in IBD in this blog, rather than the environmental side.
What is a vegan diet?
A vegan diet contains only plants (such as vegetables, grains, nuts and fruits) and foods made from plants.
Vegan diets avoid all foods that come from animals including meat, fish, dairy products and eggs.
The terms vegan and plant-based are often interchanged at the moment and I think its important to distinguish between the two before we continue – vegan diets exclude all animal products, but plant-based diets are just that, based on/around plants but do not completely remove animal products. The amount of animal products included in a plant-based diet will vary from person to person depending on preference.
Can going vegan help Crohn’s or Ulcerative Colitis?
Currently, there are no clinical trials that have been conducted that look at completely vegan diets and their impact on IBD.
The research we have into plant-based diets for IBD is in semi-vegetarian diets.
Can following a plant-based diet help Crohns and Colitis?
There is some evidence that a semi-vegetarian or plant-based diet may help to maintain remission in Crohn’s disease. The diet trialled was a lacto-ovo vegetarian diet, in which eggs and milk were allowed (yoghurt daily) with fish included weekly and small portions of meat offered once every two weeks. This diet was shown to maintain a longer clinical remission in patients with CD compared with an omnivorous diet. The remission rate at 2 years was 94% in the lacto-ovo vegetarian diet versus 33% in the omnivorous diet (1).
Wider research into the microbiome and gut health has demonstrated the important role of plant fibres in our diets which feed the microbes living within us that help to keep us and our gut healthy. We know that an imbalance in our microbes is a factor in IBD so supporting the balance of these is important and recent studies have demonstrated that a diet high in fibre is beneficial to both patients with UC and CD (2, 3) and this may be one of the reasons why more plant based diets could show benefit in IBD (NB: there are certain circumstances where a lower fibre diet is appropriate for some people with strictures and stomas).
Are meat and animal products bad for Crohns and Colitis?
Epidemiological studies (big population studies) have suggested that a western diet, high in fat and protein content and low in fruits and vegetables might help explain the increase incidence of IBD globally (4).
Several large longitudinal studies (following population groups for a long period of time) have shown an association between a reduced risk of developing IBD and a diet rich in fruits and vegetables, whereas consuming high amounts of animal fats and refined sugar is associated with an increased IBD risk (5).
When we look at meat on risk of flares in IBD there is some evidence that increased meat consumption, particularly processed meats, are associated with a higher risk of relapse in patients with UC (6). But when researchers looked at Crohn’s Disease this didn’t seem to be the case (7) which is confusing given the positive impact of the semi vegetarian diet in the study discussed above.
On the other hand, there is some evidence to show including omega 3 rich oily fish may help reduce UC symptoms (8) and we know that omega 3 fatty acids help to reduce inflammation (9).
It has also been shown that including yoghurt which contains probiotics and kefir, a fermented yoghurt, is beneficial for gut health and may be beneficial in IBD (10).
Potential benefits of vegan diets in IBD
Vegan diets are high in fibre which promotes overall gut health and feeds the healthy bacteria in our gut which may be beneficial in IBD.
Reducing saturated fat intake from animal products may have a positive impact on UC (6)
A whole food vegan diet encourages intakes of a wide range of fruit, vegetables and whole plant foods like legumes which we know are good for our health.
A whole food vegan diet eliminated ultra-processed foods and processed meats which may have a negative impact on IBD (11).
Potential drawbacks of vegan diets in IBD
Excluding whole food groups and following an unbalanced vegan diet increases nutrient deficiency risk, something that is already high in IBD, particularly Crohn’s Disease that affects the small intestine.
Animal products, although not essential in our diets are a great source of vitamins that are harder to obtain from a vegan diet like protein, omega-3 fat, B-vitamins (including B12), iodine, calcium, iron, zinc and selenium, many of which are frequently found to be low in IBD.
Vegan junk and processed foods often contain lots of additives which may have a negative impact on our gut health and IBD (12).
A whole food vegan diet that is high in fibre may not be well tolerated by many with IBD who find certain fruit, vegetables and vegan sources of protein like legumes cause symptoms.
For those with strictures and stomas, a whole food vegan diet containing lots of high fibre foods could increase risk of bowel obstruction.
Take Away
For now, there is simply not enough evidence to be recommending completely vegan diets for IBD. There may be risks associated with following any diet that excludes large food groups as this restricts important nutrients and can put us at risk of nutrient deficiency – something that is already a concern with IBD.
There will be some people with IBD who follow a vegan diet and it works well for them but as we know, everyone with IBD is different – we are all at different stages of our journey, whether in a flare or in remission, we all have different foods we can or cannot tolerate, and that we do and do not like, and we all have different lifestyles - so there is no one diet that will work for everyone.
Following a more plant-based diet may have a positive impact on maintaining remission IBD, specifically Crohn’s Disease. Including more plant-based foods is good for our health – it helps to increase some nutrients and fibre which is beneficial for (most) people with Crohn’s and Colitis. Including some animal foods within a healthy balance diet with IBD can help to provide important nutrients like protein, omega-3 fat, B-vitamins (including B12), iodine, calcium, iron, zinc and selenium, and there is some evidence that some animal foods may have a positive impact in IBD, such as oily fish. If you are going to make any large changes to your diet please speak to your consultant or a nutritionist before doing so.
I have written a free e-book to help you find a way forward for your everyday life with Inflammatory Bowel Disease. Whether you are right at the beginning of your journey with IBD or have been living with your condition for years and feel like you have tried almost everything, there are things you can do everyday, beyond the medication you are taking, to help you take back control and feel better.
Disclaimer: All content found on the nalmclinic.com website, including: text, video, or other formats have been created for informational purposes only. The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your doctor, consultant or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
We are all wonderfully unique and what works for one person may not work for another so please seek help and advice before changing your diet to work out the right way forward for you.
References
Chiba, M., Abe, T., Tsuda, H., Sugawara, T., Tsuda, S., Tozawa, H., Fujiwara, K., & Imai, H. (2010). Lifestyle-related disease in Crohn's disease: relapse prevention by a semi-vegetarian diet. World journal of gastroenterology, 16(20), 2484–2495. https://doi.org/10.3748/wjg.v16.i20.2484
Ananthakrishnan, AN, Khalili, H, Konijeti, GG, et al. A prospective study of long-term intake of dietary fiber and risk of Crohn’s disease and ulcerative colitis. Gastroenterology 2013; 145: 970–977.
Brotherton, CS, Taylor, AG. Dietary fiber information for individuals with Crohn disease: reports of gastrointestinal effects. Gastroenterol Nurs 2013; 36: 320–327.
Amre, DK, D’Souza, S, Morgan, K, et al. Imbalances in dietary consumption of fatty acids, vegetables, and fruits are associated with risk for Crohn’s disease in children. Am J Gastroenterol 2007; 102: 2016–2025.
Hou, JK, Abraham, B, El-Serag, H. Dietary intake and risk of developing inflammatory bowel disease: a systematic review of the literature. Am J Gastroenterol 2011; 106: 563–573.
Jowett, SL, Seal, CJ, Pearce, MS, et al. Influence of dietary factors on the clinical course of ulcerative colitis: a prospective cohort study. Gut 2004; 53: 1479–1484.
Albenberg, L, Brensinger, CM, Wu, Q, et al. A diet low in red and processed meat does not reduce rate of crohn’s disease flares. Gastroenterology 2019; 157: 128–136, e5.
Grimstad T, Berge RK, Bohov P, Skorve J, Gøransson L, Omdal R, Aasprong OG, Haugen M, Meltzer HM, Hausken T (2011) Salmon diet in patients with active ulcerative colitis reduced the simple clinical colitis activity index and increased the anti-inflammatory fatty acid index--a pilot study. Scand J Clin Lab Invest 71:68–73. [PubMed: 21142420]
Barbalho, S. M., Goulart, R., Quesada, K., Bechara, M. D., & de Carvalho, A. (2016). Inflammatory bowel disease: can omega-3 fatty acids really help?. Annals of gastroenterology, 29(1), 37–43.
Yılmaz İ, Dolar ME, Özpınar H. Effect of administering kefir on the changes in fecal microbiota and symptoms of inflammatory bowel disease: A randomized controlled trial. Turk J Gastroenterol. 2019 Mar;30(3):242-253. doi: 10.5152/tjg.2018.18227. PMID: 30662004; PMCID: PMC6428516.
Pigneur B, Ruemmele FM. Nutritional interventions for the treatment of IBD: current evidence and controversies. Therapeutic Advances in Gastroenterology. January 2019. doi:10.1177/1756284819890534
Marion-Letellier, R., Amamou, A., Savoye, G., & Ghosh, S. (2019). Inflammatory Bowel Diseases and Food Additives: To Add Fuel on the Flames!. Nutrients, 11(5), 1111. https://doi.org/10.3390/nu11051111