The hidden intolerances in a vegan diet

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Climate concerns, animal welfare, health and wellbeing. Whatever the reason, more and more of us are adopting a vegan diet, or at least looking to cut down on the amount of animal products on our plates.

While maintaining a healthy, balanced diet free from meat and other animal derived produce is completely possible, a radical shift in eating habits can have an unexpected impact on health and how we feel day to day.

Even the healthiest swaps can trigger unwanted side effects and getting to the root cause can be frustrating when you’re trying to make meaningful changes to your eating habits.

So, what should we be looking out for when it comes to food intolerances and a vegan or free-from diet?

The rise of veganism and free from foods

In recent years, the free from market has exploded. Meat free alternatives and substitutes for animal produce, such as dairy, has never been so widely available or affordable. This has made it easier for more people to adopt a vegan diet or to reduce the amount of animal derived products in their diets – something which has become increasingly important for both health-conscious consumers and those concerned with sustainability.

While all this variety provides greater freedom of choice, it’s worth thinking about the changes that they introduce into the diet. Free from alternatives can be made from ingredients which may not have featured heavily in your diet previously. You might notice that, as you start to consume them more often, you experience a few unwanted side effects, such as bloating, irritable bowel syndrome (IBS), headaches or even skin complaints like acne or eczema.

Let’s look at some of the common vegan substitutes and what they contain which could be causing you problems.  


Seitan is a common meat substitute. Made from gluten, it replicates the texture of meat while also taking on the flavour of the other ingredients it’s cooked with. Seitan, also known as wheat meat or wheat protein, is a popular meat substitute because of its versatility.

But if you find that you’re experiencing unwanted issues, such as bloating, it might be the case that this additional consumption of gluten, on top of more conventional sources of wheat, such as breads and pastas, is causing you to feel unwell. 


Soya is a common stand in for all sorts of dairy products. Replacing in the cows’ milk in yoghurt, cheese and as a replacement milk, soya features heavily in many vegan diets. Soya also forms the basis of two popular meat replacements used in a wide range of vegan and vegetarian dishes.

Tofu – a soft white substance made from mashed soya beans is a versatile ingredient used in many dishes, from a replacement protein that can mimic meat to a thickener in decadent deserts.

Tempeh – a cake-like substance made from cooked and slightly fermented soybeans – is another common staple in vegan diets. The fermentation process helps to break down the phytic acid in soybeans, making the starches in tempeh easier to digest. After fermentation, the soybeans are formed either into a patty, similar to a firm veggie burger or a block which can be sliced.

While these substitutes are healthy and provide good nutritional value in a vegan diet, too much soya, through meat and dairy alternatives, could cause problems.

Nut milks

Almond, coconut, hazelnut, or cashews. The range of plant-based milks is ever-growing, providing greater variety for those looking to avoid animal based dairy products. But if you’re not someone who commonly consumes nuts in their diet, you might find that this switch leads to a few unwanted side effects.

What are the signs of a food intolerance?

Food intolerances, which can occur when your body’s immune system mistakes a food protein as a threat, releasing antibodies to fight it, can cause a host of inflammation.

Headaches, brain fog, IBS, bloating, low mood, and joint pain are all reactions that can result from a food intolerance, as well as skin complaints like eczema or acne.

Are vegans more prone to food intolerance?

Adopting a vegan diet means moving to alternative sources of protein. This can potentially lead to over consumption of alternatives like soy, which can be found in meet substitutes such as seitan, tofu and tempeh and dairy alternatives like milks, yoghurt, and cheese.

This over-exposure could lead you to develop sensitivities over time. However, this isn’t exclusively a potential problem for vegans. Anyone with a limited diet could be more likely to experience intolerances, due to a lack of variety in the foods they eat. If you find that you’re living with some of the common symptoms of a food intolerance, it might be worth considering whether your diet could be contributing.  

Take control of your diet

Getting to the bottom of a food intolerance can be frustrating. A common recommendation is the elimination diet, where you remove one food at a time for a few weeks to see how you feel. But this process can take a long time. And, although many of us commonly react to a few different ingredients, the elimination diet is often abandoned when the first trigger food is found, leaving an incomplete picture of what’s causing the problem.

Get answers faster with Smartblood

When it comes to food intolerance testing, it’s important to do your research and choose a reputable laboratory testing company.

At Smartblood, we offer a comprehensive test to help you take control of your diet quickly and discover your own trigger foods. 

Our home-to-laboratory service gives you fast, accurate results that pinpoint exactly which foods you are reacting to. Tests are completed in our accredited laboratory by trained experts, with clear, easy to understand results sent to you via email within three days. 

Dedicated nutritional support

Our full food intolerance test includes a telephone consultation with our BANT registered Nutritional Therapist. This important additional support is there to help you understand your results and put a plan together to make safe, sustainable changes to optimise your diet. 

If you’re making changes to your diet to reduce or eliminate animal products, our Nutritional Therapist can make helpful suggestions to make sure you get the right information to help you maintain a healthy, balanced diet.

Could you have a food intolerance?

If you think that food intolerance may be responsible for your symptoms then we believe that our easy-to-complete tests could help you. Find all your food intolerances at once with a full Smartblood test.

Around 10% of our customers exhibit no IgG reactions to the 134 foods whatsoever – we provide non-reactive customers with a 100% REFUND so they can continue their investigations through other testing.

Find out today with Smartblood.

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