Food allergies, intolerances, and sensitivities explained

Food Allergies

According to The European Academy of Allergy and Clinical Immunology (EAACI), the number of people living with allergies in the UK is rising by 5% every year. The ‘first wave’ of allergic disease occurred some 50 years ago with a huge surge in asthma and hay fever. We are now experiencing a ‘second wave’ of allergic disease, which has presented itself with a sharp increase in people suffering from life-threatening food allergies.

Figures suggest at least 1 in 40 children in the UK are suffering from at least one serious allergy. Today, more children than ever are being diagnosed with food allergies, as are an increasing number of adults, to foods that were previously safe for them to eat.

Figures suggest at least 1 in 40 children in the UK are suffering from at least one serious allergy

Why are so many more people allergic or intolerant to foods now?

There are several primary factors thought to contribute to this rise in allergy incidence:

  • Timing of introduction of foods – Delaying the introduction to young children of highly allergenic foods, such as peanuts and eggs, has likely contributed to the rise in food allergies.
  • Hygiene hypothesis – We’re cleaner than ever now, using antibacterial soaps and hand sanitisers. However, the more we are exposed to microbes, the more our immune system is able to recognise friend or foe.  Do you remember making mud pies in the garden as a child?  How many children are allowed to do this nowadays due to parents who are afraid to allow their kids to get dirty?
  • Climate change – The way crops grow due to shifts in temperatures may make them more immunogenic and provoke the immune system, leading to the development of food allergies.
  • Dietary patterns – People around the world eat more processed foods and less fruit and vegetables, which affects our gut microbiome.
  • Genes and environment – This includes not only genetic make-up but in utero maternal exposures to allergens, including prenatal maternal diet, pollution, and chemicals.
  • Early antibiotic use – This may also have an influence on the gut; changes in the bacterial flora impacts the likelihood of allergic diseases.

Breaking down the difference between allergies, intolerances, and sensitivities

Food allergies and intolerances are unwanted reactions to food that some people experience, but they are not the same, and happen for different reasons. The symptoms of a food intolerance and a food allergy can be similar, and therefore people can get confused between the two. The difference between the two is that food allergies create a response from the immune system, which can be life-threatening.

A food allergy happens when the body’s immune system, which normally fights infections, sees the food as an invader. This leads to an allergic reaction – an immune system response in which chemicals like histamine are released in the body. The reaction can cause symptoms such as hives, vomiting, belly pain, throat tightness, hoarseness, coughing, breathing problems, or a drop in blood pressure.

Even if previous reactions have been mild, someone with a food allergy is always at risk for the next reaction being life-threatening. Eating a microscopic amount of the food could lead to anaphylaxis. So, anyone with a food allergy must avoid the problem food(s) entirely and always carry emergency injectable epinephrine.

A food intolerance creates unpleasant symptoms, which can be uncomfortable, but they aren’t life-threatening. A food intolerance means either the body can’t properly digest the food that is eaten, or that a particular food might irritate the digestive system. Symptoms of food intolerance can include nausea, gas, cramps, belly pain, diarrhoea, irritability, or headaches.

After eating certain foods, a large part of the population experiences symptoms that are not related to food intolerances or food allergies. These are referred to as food sensitivities. Though there is controversy around what exactly happens in the body of someone with a food sensitivity, it appears that exposure to specific foods may create an immune reaction that generates a multitude of symptoms. The symptoms are not life-threatening, but they can be quite disruptive and include joint pain, stomach pain, fatigue, rashes, and brain fog. Gluten is probably the best-known trigger of food sensitivities.

The role of antibodies

Food allergies involve the production of antibodies called immunoglobin E (IgE), which are specific to a particular food. Each time the food is eaten (think gluten in coeliac disease, for example), the immune system will remember and mount a similar attack. Essentially, it’s an error on the part of the immune system. Allergies can be genetic and run in families. A person doesn’t usually inherit a specific allergy, just the likelihood of having allergies. There are also environmental influences to consider, such as lack of exposure to bacteria in infancy, overuse of antibiotics, and a lack of friendly bacteria in the gut.

Approx 70% of the immune system is located in your gut and this is where immune cells learn what to attack and what is a normal part of our environment.

Although nearly any food can trigger an allergic reaction, there are nine foods that cause the majority of reactions:

  • milk
  • eggs
  • peanuts
  • soya
  • wheat
  • tree nuts
  • shellfish
  • fish
  • sesame

When the allergen enters the body, the immune system starts its protective response by making the IgE antibodies against the allergen. These antibodies then trigger certain types of immune cell to release inflammatory chemicals into the bloodstream. One of these is histamine, which then acts on the eyes, nose, throat, airways, skin, or digestive system to trigger the allergic symptoms.

These include:

  • Sneezing
  • Runny or blocked nose
  • Itchy, red, watery eyes
  • An itchy, red skin rash
  • Swollen lips, tongue, eyes, or face
  • Swelling in the airways causing difficulty breathing
  • Digestive discomfort, such as cramps, feeling sick, vomiting, or diarrhoea

Signs of a food intolerance

Food intolerances don’t involve the immune system but occur when the body reacts to food because it’s unable to digest or break it down effectively. We may lack the enzymes to break down a particular protein, which is what happens in the case of lactose intolerance, or we may be sensitive to certain chemicals naturally present in food such as salicylates, histamine, or sulphites.  

The effects of food intolerances can be delayed from a few hours to a few days. The severity of the reaction may depend on the quantity of the food eaten or what other foods are eaten in the same meal. This means intolerances can be difficult to identify.

Common culprits causing food intolerances include dairy, grains and eggs – but practically any food can potentially be a problem.

Signs of food sensitivities

When the immune system mounts a reaction to a food without IgE antibodies being involved, this is known as a food sensitivity, and involves a different type of antibody known as IgG. Often this occurs because food particles which have not been completely digested are absorbed through a permeable intestinal lining (leaky gut). They are unfamiliar to the immune system in that form, so it mounts an attack. People can be sensitive to one or more additives used in food processing such as MSG, artificial sweeteners, etc.

Reactions from food sensitivities can be delayed and symptoms can be diverse, affecting almost any part of the body.

Treatment options

Because food allergy reactions aren’t likely to alter over the course of a lifetime, the only effective way of managing them is to avoid the problem food. They’re readily diagnosed by blood or skin-prick tests.

There are 3 main types of medication that can be used to relive the symptoms of an allergic reaction to foods.

  • Antihistamine and decongestant medication to reduce allergy symptoms such as itchy eyes and a streaming or blocked nose.
  • Steroid medications may be recommended to suppress the immune system. These can be inhalers for respiratory symptoms or creams for skin reactions.
  • For severe allergies, sufferers will be required to carry an epi-pen containing injectable adrenaline. This will mitigate the symptoms of anaphylaxis – a life-threatening allergic response where the airways close off and blood pressure can drop dangerously low.

In the case of food sensitivities and intolerances, avoiding the offending food does not address the reason the problem developed in the first place.

Unless the health of the digestive system is restored, further sensitivities and intolerances will tend to develop. If the remaining food choices become limited, problems can occur because eating the same foods day in, day out is highly likely to bring about trouble tolerating previously ‘safe’ foods.


If someone is over the age of 50, and most definitely if they are taking a daily PPI, they are going to struggle with digesting food, especially proteins, so I always recommend they start out with the supplements in my Perfect Balance Kit for 30 days, then move to a maintenance protocol of Live Bacteria probiotics and Digestive Enzymes. This is when they can try incorporating small amounts of previously ‘banned’ foods and monitor the results. 

Incidentally, whether a person has a food allergy, intolerance or sensitivity or not, I would recommend to anyone taking a daily PPI like omeprazole or lansoprazole that they take Digestive Enzymes and Live Bacteria to mitigate the side effects of these drugs and to help support proper digestion of food and absorption of nutrients from their food. 

Elimination diet

It is recommended to complete this under the guidance of a practitioner to make sure you complete the re-introduction stages appropriately. During this process, it is important to establish and rectify any underlying root causes of your food intolerance/ sensitivity, such as leaky gut, lack of digestive enzymes/ stomach acid, gut dysbiosis, SIBO, candida or parasite infections.

Often it is not the food that is the enemy in the case of a food sensitivity, but what is happening to the food after you eat it. For example, if you have SIBO, you may bloat after eating certain foods. This is likely down to the bacteria fermenting the food and producing gases. Therefore, once the SIBO has been treated, you should be able to eat those foods again. Similarly, a lack of digestive enzymes could mean you do not break down food well, causing bloating and gas, but restoring the enzymes would mean you could eat those foods again. Working with an experienced practitioner will help you to establish any of these underlying root causes.

Many food intolerances and food sensitivities can be traced back to a lack of stomach acid and/or a deficiency in friendly gut bacteria.  Stomach acid and friendly bacteria are needed to properly digest food and absorb nutrients.  Therefore, anything that interferes with the production of stomach acid like strong PPI antacid medication and antibiotics that destroy billions of friendly gut bacteria can precipitate food intolerances/sensitivities.  It is worth trying a month’s course of Live Bacteria probiotics (one capsule before breakfast and one before bed) and Digestive Enzymes (one tablet just before lunch and one just before dinner) to put this theory to the test.  If your symptoms dramatically reduce, then you know that it’s because you didn’t have enough stomach acid/gut bacteria to properly digest all the different food groups – fats, carbohydrates, and proteins.