Does an exclusively plant-based diet make sense if you have a gut condition?

The number of people adopting vegan and vegetarian diets has been steadily increasing in recent years. A survey by Ipsos Mori, commissioned by The Vegan Society (UK) in 2019 found that the number of vegans in Great Britain quadrupled between 2014 and 2019 and the numbers continued to rise in 2020.

We certainly understand the environmental and ethical reasons behind adopting these diets but we have real concerns when it comes to vegan diets for those who have a gut condition as they can be problematic. If you have other digestive conditions such as Crohn’s disease, Ulcerative colitis or coeliac disease then a vegan diet isn’t recommended at all as, as well as increasing the fibre intake, it also increases the risk of significant nutritional deficiencies.

Evidence shows that vegan diets are not superior to a Mediterranean style diet (that contains fish and meat, along with fruit, vegetables and vegetable oils) in terms of overall health. We’re advocates of the Mediterranean style diet because we believe that it is optimum for gut and total body health.

Plant-based foods (cereals, legumes, vegetables and fruit) have many, many well-researched and proven health benefits – “eat the rainbow” we say. But you don’t need to follow an exclusively vegan, or even a vegetarian diet to enjoy the benefits of these foods, just incorporate a lot of them into your diet.

Why are plant based foods important?

  • Excellent source of fibre, which is good for digestive function
  • Act as a prebiotic, which means that they stimulate the growth of ‘good bacteria’ in our gut, and increase the diversity of the gut bacteria
  • Help lower cholesterol and hence reduce risk of heart disease and stroke
  • Low in saturated fats (the main type of fat in meat), which lowers the risk of various cancers
  • Low in calories and fat and so help with weight control

What are the drawbacks of plant-based foods?

Low in some essential vitamins and minerals:

  • B12 (essential for production of blood and for the health of our nerve cells)
  • Iron (some vegetables are relatively high in iron, but it is not easily absorbed)
  • Calcium and vitamin D (dairy produce are a great source of these vitamins)

Most Plant-based foods lack essential amino acids (AAs):

  • AAs are the building blocks of every protein in our body. There are 20 AAs needed for healthy bodily function – we can make 11 of them ourselves (non-essential AAs), but the other nine we have to get from our diet (essential AAs). Animal proteins (meat, fish, eggs and dairy) are ‘complete’ proteins, meaning that they contain all 20 AAs.
  • Most plant-based proteins are ‘incomplete’ meaning that they lack the essential AAs. Notable exceptions are hemp, buckwheat, chia seeds and quinoa – these are complete proteins

High in fibre:

  • While this is a benefit on the one hand, it can also be a problem if you have a digestive condition such as IBS or Inflammatory Bowel Disease (IBD – either Crohn’s disease or Ulcerative Colitis)

High in other ‘fermentable’ food contents:

  • Tend to cause bloating and can worsen IBS symptoms

We’re seeing more and more patients in our clinics who are adopting vegan diets and find that much to their surprise, their gut symptoms are worsening. This is because exclusively plant-based diets often worsen IBS symptoms. As you’ll learn in our Dietary section, people who suffer with IBS need to pay particular attention to how much they eat of certain foods, as too much of some of these can bring on unpleasant and sometimes debilitating symptoms like bloating, stomach cramps, diarrhoea or constipation.

Why does this happen?

Because these particular foods are ‘fermented’ by the gut bacteria and this causes gas production and a number of other unpleasant effects. This happens in everyone’s gut but if you have a condition like IBS it is more evident and can become very uncomfortable and can result in excessive wind, bloating, pain and more. These foods are called ‘fermentable foods’ for a reason.

The main fermentable foods that are problematic for those with IBS are fibre, fruit sugar (called fructose), the allium family (garlic and onions), certain vegetables and also a food constituent called polyol, which is found in relatively large amounts in mushrooms, avocados and cauliflower – there’s a reason you may not feel so wonderful after those lovely mushrooms and avocado on toast you had for breakfast.

Wheat, lentils and beans contain additional factors that can also cause bloating – that’s why that delicious but healthy hummus and caramelised onion toastie can wreak havoc.

If we look at all of these foods, they are all plant-based foods. In contrast to this, animal protein based foods, such as fish, chicken, hard cheeses (which contain virtually no lactose) and red meat cause little or no bloating.

In order to meet your daily nutritional requirements as a vegan or vegetarian you generally have to eat a lot of plant-based food and this results in consumption of large amounts of fibre and other fermentable foods.

In our experience exclusively plant-based diets are problematic for those with gut conditions and hopefully you can now see why. Of course if you choose to follow one, please take professional dietary advice to ensure you can find the best possible nutritious options for you.

Visit The Gut Experts Kitchen for some gut friendly recipes.  

©The Gut Experts 2021


Share on email
Share on facebook
Share on twitter

Related Articles

What is Omega-3? Omega-3 fatty acids (omega-3s) are polyunsaturated fats that perform important functions in...

Sign up for our newsletter

to get the latest gut health insights,

our top tips, recipes and more.