Adverse reactions to food are relatively common, but they are often misrepresented due to a certain degree of confusion surrounding the terms food allergy and food intolerance. While these terms are commonly used as synonyms, medical experts agree that allergies and intolerance are completely different issues, with food allergies being much rarer as compared to food intolerances. While the symptoms can be misleadingly similar, there are important differences that help distinguish food allergies from intolerances.
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What are food allergies?
An allergic reaction to certain type of food will manifest if the body’s immune system misidentifies the food as a threat, in a way it would perceive a bacterial or fungal infection. In response, the immune system will trigger several reactions so it could fight the perceived threat.
The first thing that will happen is the release of immunoglobulin E (usually abbreviated to IgE) antibodies that will in turn trigger a release of histamine. Histamine is a naturally synthesised compound that is responsible for the majority of characteristic symptoms of an allergic reaction including breathing difficulties, swelling, diarrhoea and vomiting.
However, the immune system can also react with less severity and usually with a slight delay – in those cases, IgE release will be absent and instead a type of white blood cells called T-cell will be released, leading to a different array of issues, including eczema, skin problems and problems with the digestive tract.
However, the most severe food allergies will instead result in anaphylaxis which can be a life-threating condition that will require immediate treatment in order to avoid potentially lethal outcome.
What is food intolerance?
As opposed to food allergies, food intolerances are marked by an inability of organism to process a specific type of food which will in turn cause an irritation of the digestive system and the characteristic symptoms. So, unlike allergies, food intolerance does not include an immune response, and the food causing the problem is not viewed by the body as an infection – the body will simply fail to process it properly and this will cause a number of other issues.
While the symptoms don’t necessarily appear immediately, they can be rather long-lasting, from several hours to as much as several days. The nature of the symptoms can be very varied, ranging from bowel and skin problems to general malaise, fatigue, headaches or bloating.
Why some people have food intolerances?
While the exact causes of food intolerances are still largely debated and any significant consensus on the issue is still lacking. However, certain risk factors have been identified:
- Enzyme deficiencies
- Irregular food intake
- Diet rich in refined foods and saturated fats
- Lack of fibre in the diet
- Poor nutritional choices
Coping with food intolerance is often misrepresented, leading to slightly distorted expectations among those affected. Being intolerant to a certain type of food doesn’t mean you will experience an adverse reaction every time you consume it – in most cases, you will have to consume a certain amount before noticing any symptoms. However, despite this, altering your diet might be a good idea, of course, in accordance with your doctor’s tips that should help you ensure you are not missing out on any vital nutrients.
Diagnosing food intolerance
Unlike allergies which can be relatively easily diagnosed with proper tests, food intolerances are much more elusive. In fact, in many cases, the subjective experience and record of different symptoms is the only thing that can help a medical expert make a diagnosis, as the body will usually produce little to no medical abnormalities when examined.
Lactose intolerance
Certainly the most common type of food intolerance, lactose intolerance occurs when the body has a deficiency of a specific enzyme that is used to break down the naturally occurring sugars in dairy products. Consequentially, lactose won’t get absorbed in the bloodstream and will instead remain in the large intestine where it will ferment. As this process progresses, the person affected will experience a number of symptoms including abdominal pain, nausea, diarrhoea and flatulence.
While there are some indications that lactose intolerance might be hereditary, the medical experts agree that one can be both born with lactase deficiency and develop it at some later stage in life, meaning that there are no guarantees, and that even if genetic factors do play a role, it is not especially prominent.
The severity of this condition can also vary significantly between individuals. So, while some might completely avoid uncomfortable symptoms by limiting their lactose intake, others might experience severe reactions to even trace amounts of the compound. However, due to significant prevalence of this condition, lactose-free products can be easily obtained in majority of supermarkets, making living with condition much easier than one might initially assume.
Coeliac disease
Coeliac disease is a medical condition that is marked by the inability of the person affected to digest gluten. While this substance is relatively common as it is found in wheat, barley and rye, roughly one out of every hundred people in the world will experience an adverse reaction to it. These people are usually diagnosed with coeliac disease or alternatively non-coeliac gluten sensitivity.
However, it is worth mentioning that coeliac disease is neither intolerance nor an allergy – on the contrary, it is classified as an autoimmune disease. When people affected by this condition consume food containing gluten, the substance will cause the body to react by attacking itself, potentially damaging the lining of the small intestine, thus altering the structure of this part of the digestive system and making it unable to absorb nutrient efficiently.
On the other hand, non-coeliac gluten sensitivity will produce the tell-tale symptoms, but will not contribute to damage to the intestines.
If you are diagnosed with this condition, the only way to successfully manage it is to adhere to a gluten-free diet.
Reactions to food additives
Food additives include various substances such as preservatives sweeteners and colours that are commonly added to different foods and that can cause adverse reactions in a number of people. The majority of those reacting to food additives are more likely to get diagnosed with intolerance than an allergy. However, confirming the diagnosis can be rather tricky since, as of now, no specific tests for this type of food intolerance have been developed.
Adverse reaction to medications – allergy or intolerance?
There are situations when an individual is not able to take certain drug due to underlying health conditions – usually called contraindications. Alternatively, potential for adverse interactions with other medicines might make certain drug unsafe in a specific situation. In these instances, your doctor will assess the risks and have a final say in whether you should use the given medication.
However, neither contraindications nor interactions can be classified as either allergies or intolerances and the same is true for side effects. However, it is not impossible to experience an allergic reaction to certain medicines, with penicillin and contrast injections for x-ray scans being the most common culprits.
Alcohol and allergies
While alcohol reactions can occur, they are rather rare and the most commonly experienced relation between alcohol and allergies is rooted in the fact that many alcoholic beverages contain trace amounts of histamines, sulphites, additives and yeast which can all cause an adverse reaction by the body. Still, alcohol is much more likely to exacerbate symptoms of pre-existing problems than cause an allergic reaction on its own.
