Vegan Diet: Friend Or Foe For Ibs?

Irritable bowel syndrome (IBS) is a common condition that affects between 7-15% of the population. It is more common among women and is usually diagnosed before the age of 50. IBS is characterised by symptoms such as abdominal pain, diarrhoea, constipation, bloating, excessive gas, and distension.

A vegan diet is a plant-based diet that avoids all animal-based products. While veganism has many health benefits, it is not a clear solution for those with IBS. This is because many plant-based foods can irritate the gastrointestinal (GI) system and cause or worsen IBS symptoms.

However, it is possible to follow a vegan diet while managing IBS. A low FODMAP diet has been found to reduce IBS symptoms in up to 70-86% of people with IBS. FODMAP is an acronym for Fermentable Oligo- Di- Mono-saccharides and Polyols, which are tiny carbohydrates that are poorly absorbed in the intestines and can lead to bloating and discomfort.

A low FODMAP vegan diet can be challenging as many vegan staples are high in FODMAPs. However, with careful planning and the support of a dietitian, it is possible to ensure that the diet is nutritionally balanced.

A plant-based diet may not reduce IBS symptoms

The low FODMAP diet

The low FODMAP diet has been found to reduce IBS symptoms in 70-86% of people with the condition. FODMAP stands for fermentable oligo-, di-, mono-saccharides and polyols. These are short-chain carbohydrates and sugar alcohols that may irritate the GI system. The low FODMAP diet involves three phases: a FODMAP reduction phase lasting 4-8 weeks, a re-introduction phase to identify trigger foods, and a long-term modified diet that avoids the trigger foods.

Plant-based low FODMAP diet

It is possible to follow a plant-based low FODMAP diet, but it can be challenging. It requires planning and guidance from a registered dietitian. During the elimination phase, it is important to focus on getting enough of the following five nutrients: calcium, iron, protein, vitamin B12, and zinc.

Vegan low FODMAP diet

A vegan low FODMAP diet can be restrictive and may lead to nutritional deficiencies. However, it is possible to follow one safely with the right support and advice. A dietitian can help ensure that the diet is nutritionally balanced.

Other considerations

It is important to note that the low FODMAP diet is not meant to be a long-term dietary strategy. The idea is to give your body a break from fermentable carbohydrates, allow your gut to calm down, and then reintroduce them in smaller amounts later on.

Additionally, other factors outside of diet can influence IBS symptoms, including stress, anxiety, menstruation, physical activity, and other lifestyle factors. It is recommended to consult a healthcare professional for proper diagnosis and guidance on dietary options to help manage IBS symptoms.

Vegan diets can be low in protein, iron, calcium, B12, vitamin D and omega-3 oils

Vegan Diets and IBS

A vegan diet is a plant-based diet that avoids all animal-based products. It can include vegetarian diets, and focuses on eating and enjoying plenty of vegetables, nuts, seeds, legumes, whole grains, and fruits.

Irritable bowel syndrome (IBS) is a common disorder that affects the bowel and digestive tract. It is characterised by symptoms such as abdominal pain, bloating, diarrhoea and/or constipation, and excessive gas. It is usually diagnosed by a medical doctor, and other conditions must be ruled out before a diagnosis of IBS is confirmed.

While a vegan diet has many well-known health benefits, there is no evidence that it will decrease IBS symptoms. In fact, it could make them worse, as it may increase the intake of fermentable carbohydrates (FODMAPs). However, increasing your intake of plant-based foods can promote good bacteria in your gut, so if you can tolerate an increase of these foods, it could be beneficial.

The low FODMAP diet

The low FODMAP diet has been found to reduce IBS symptoms in up to 70-86% of people with IBS. It is a complex dietary strategy that has been shown to be successful with the help and guidance of a registered dietitian. It involves three phases: a FODMAP reduction phase, a re-introduction phase, and a long-term modified diet.

It is possible to follow a vegan low FODMAP diet, but it can be restrictive and lead to social restrictions and nutritional deficiencies. It is important to seek advice from a dietitian to ensure it is done in a nutritionally balanced way.

The following plant-based, low FODMAP foods can be enjoyed daily to maximise nutrient intake and optimise gut health:

• Fortified plant beverages: almond, rice, soy, quinoa, hemp, macadamia
• Tofu, firm, plain, with calcium
• Tempeh, plain, with calcium
• Oatmeal: instant, fortified
• Quinoa: grain, flakes, pasta
• Nuts: almonds, hazelnuts, peanuts, brazil nuts, pine nuts, walnuts
• Seeds: chia, poppy, pumpkin, sesame, sunflower
• Nut and seed butter: peanut, almond, pumpkin, sunflower
• 100% pea protein isolate
• Soy beverage (made from soy protein, no inulin)
• Fortified nutritional yeast
• Nuts: pine, peanuts, almonds

The low-FODMAP diet is not meant to be a long-term dietary strategy

The low-FODMAP diet is a short-term strategy to help people with irritable bowel syndrome (IBS) identify which foods are causing their symptoms. It is not intended as a long-term solution.

The low-FODMAP diet is a three-phase process. In the first phase, all high-FODMAP foods are eliminated from the diet for an extended period, typically four to six weeks. FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols—certain types of carbohydrates that are difficult for some people to digest. These include wheat, beans, garlic, onions, dairy products, and some fruits and vegetables.

In phase two, restricted foods are systematically reintroduced to identify which ones trigger symptoms. In the final phase, a long-term, personalised diet is established, in which trigger foods are avoided, and all other foods can be enjoyed without worry.

The low-FODMAP diet is very restrictive, and it can be challenging to ensure proper nutrition during the first phase. It is not intended to be followed long-term, and it is important to work with a doctor or dietitian when undertaking this diet. The goal is to identify trigger foods and then reintroduce as many foods as possible.

The low-FODMAP diet is not the only dietary strategy for managing IBS. Traditional IBS dietary advice focuses on reducing caffeine, fat, insoluble fibre, and gas-producing foods, and this approach can be effective for some people. It is recommended to try this before starting the more restrictive low-FODMAP diet.

Additionally, there are some concerns about potential negative effects associated with long-term restriction of high-FODMAP foods. These foods are important energy sources for beneficial gut bacteria, and their absence may negatively impact intestinal health and worsen digestive issues over time.

A vegan low-FODMAP diet is possible but requires careful planning

A vegan diet can increase the number of IBS symptoms due to the higher percentage of fermentable carbohydrates in the diet. The low-FODMAP diet is not meant to be a long-term dietary strategy. The idea behind the diet is to give your body a break from these fermentable carbohydrates, allow your gut to calm down, and then reintroduce them in smaller amounts later on.

A vegan low-FODMAP diet can be restrictive and lead to nutritional deficiencies. It is important to know that the elimination part of the diet is short-term (2-8 weeks), and there will be more options to choose from after that. The five nutrients to focus on getting enough of are calcium, iron, protein, vitamin B12, and zinc.

• Canned pulses may be better than those you have to soak for hours. Drain off the liquor (aquafaba) and rinse before use.
• Avoid adding aquafaba to dishes if you have experienced symptoms previously. Use commercial egg replacer, linseed/chia seed, or egg-free xanthan gum to provide texture in recipes instead.
• Avoid well-known bloat-causing vegetables such as dark green cabbage, cauliflower, and Brussels sprouts.
• A great aquafaba alternative is linseed – make sure you drink a mug of fluid with the linseed. Linseed can also help with bloating and is a plant-based omega-3 source.
• Avoid adding wheat bran to meals.
• Avoid foods containing sorbitol, xylitol, and mannitol found in sugar-free chewing gum and sweets.
• Reduce fruit intake to no more than three 80g portions and split these portions throughout the day.
• Reduce caffeine intake slowly to no more than two mugs of coffee per day.
• Avoid meals containing very large amounts of onion and garlic.
• For milk alternatives, nut and hemp milks are a good choice and ensure they are fortified with vitamin D, calcium, and B12 (plus iodine, if possible).
• If choosing soy milk, the better option is one made from soy protein rather than soy beans – although this is not generally available in the UK.

Vegan low-FODMAP foods include:

• Fortified plant beverages: almond, rice, soy, quinoa, hemp, macadamia
• Tofu, firm, plain, with calcium
• Tempeh, plain, with calcium
• Oatmeal: instant, fortified
• Quinoa: grain, flakes, pasta
• Nuts: almonds, hazelnuts, peanuts, Brazil nuts, pine nuts, walnuts
• Seeds: chia, poppy, pumpkin, sesame, sunflower
• Nut and seed butter: peanut, almond, pumpkin, sunflower
• 100% pea protein isolate
• Soy beverage (made from soy protein, no inulin)
• Fortified nutritional yeast
• Nuts: pine, peanuts, almonds

IBS symptoms can be managed faster with the help of a FODMAP nutritionist

Irritable Bowel Syndrome (IBS) is a common gastrointestinal disorder that affects around 12% of the population. While a vegan diet may be a good choice for those who want to focus on their health, animal rights, or the environment, it is not a clear solution for those with IBS. In fact, many plant-based foods can irritate the gastrointestinal (GI) system and cause or worsen IBS symptoms such as bloating, constipation, or diarrhea.

One way to manage IBS symptoms is to adopt a diet that eliminates foods that are difficult to digest, such as the low FODMAP diet. FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols—short-chain carbohydrates and sugar alcohols that may irritate the GI system. Research has shown that the low FODMAP diet can reduce IBS symptoms in up to 70-86% of people.

The low FODMAP diet is a three-step process: elimination, reintroduction, and personalization. During the elimination phase, all high FODMAP foods are eliminated from the diet for several weeks. In the reintroduction phase, FODMAPs are slowly reintroduced one at a time to identify which foods are triggers. Finally, in the personalization phase, the diet is modified to increase variety while still limiting trigger foods.

Because the low FODMAP diet can be challenging and restrictive, it is important to work with a doctor or registered dietitian/nutritionist to ensure it is followed correctly and to maintain proper nutrition. They can help you identify your trigger foods and plan well-rounded, nutritionally balanced meals that are safe for you to eat. This is especially important if you are underweight, as the low FODMAP diet can lead to weight loss due to the restricted number of foods allowed.

In conclusion, while a vegan diet may be beneficial for some, it is not a cure-all for IBS. If you are experiencing IBS symptoms, it is important to see a health professional for a proper diagnosis and to ask for a referral to a dietitian/nutritionist for advice on dietary options to help manage your symptoms.

Frequently asked questions