The signs and symptoms of food intolerance
It’s estimated that up to 20% of the world’s population may have a food intolerance - and many of these individuals may be totally unaware certain foods are causing them to feel unwell.
Gut health expert, doctor Megan Rossi joins us to discuss the symptoms to look out for, ways to test and how to manage the uncomfortable effects of triggering foods.
What is a food intolerance?
A food intolerance is when you have difficulty digesting certain foods or ingredients in food. Eating the food you're intolerant to can make you feel unwell.
Is a food intolerance different to an allergy?
Unlike a food allergy, an intolerance is not caused by your immune system reacting to certain types of foods. The difference is that your digestive system struggles to break down the nutrients, rather than your immune system triggering a defensive response - and allergic reaction.
What are the differences between the two?
Food allergies involve the immune system, where the body mistakenly tags specific food proteins as harmful. In turn, this triggers the body's defence system. Food allergies are less common, affecting around 1 to 2 percent of adults.
Food intolerances typically occur when you don't have enough of the right enzymes or other chemicals to digest a nutrient. For example: lactose intolerance, where your body lacks the enzyme (called lactase) that is needed to digest the milk sugar lactose. This gets malabsorbed and can lead to symptoms like bloating and altered poo.
How can we tell the difference?
Instead of visible allergic reactions such as itchy skin, wheezing or swelling of the eyes, face and lips, the following symptoms could indicate a food intolerance:
Diarrhoea
Bloating
Flatulence
Tummy pain
Heartburn
Vomiting
Could it be IBS? How does that differ?
With the growing awareness of gut disorders like IBS, it's increasingly common for people to jump to the conclusion that their problem must be IBS, without considering whether their symptoms are the result of a food intolerance.
What are the most common food intolerances?
The most common food intolerance is that of lactose, when your body struggles to digest a certain type of sugar found in milk and dairy products. Other types of intolerances, albeit much less common include:
Gluten (Wheat, rye and barley) - in breads and pastas
Histamines - a chemical in your immune system that triggers reactions found in wine and cheese
Caffeine - in coffee, tea and energy drinks
Alcohol (including sulphites) - in cider, beer and wine
Salicylates - in fruits, vegetables, herbs and spices
What food intolerances are available to buy and are they reliable?
There are tests that are marketed to test for food intolerances, if you are willing to pay a fee. These include:
IgG Blood Test - Looking for IgG4 (an immune marker) for many food groups in the blood. If a result is positive, it is advised that you remove that food from the diet.
Applied Kinesiology - Is supposed to show how the muscles in your body respond when a vial of allergens such as food, are held to the body.
Hair Analysis - You send off a sample of your hair which has also been used to identify things like heavy metal poisoning or drug use.
Leukocytosis - This test is where white cells in the blood are mixed with different food groups. If the cells swell up, then you are told you are intolerant to that food group.
Vega (Electrodermal) Test - Measuring the electric current when the body is exposed to a food item.
Clinics will diagnosis a food intolerance by going through a three step process:
Step 1: Record symptoms and food diary
Step 2: (if you identify culprit e.g. lactose) Restrict for 7-14 days
Step 3: Reintroduce - needed to reproduce symptoms.
How can I tell if it's something more serious like Crohn's disease?
Crohn's disease is a chronic inflammatory bowel disease that causes inflammation in the intestine, and is often mistaken for an intolerance to lactose. Both share similar symptoms: Diarrhoea, bloating, and flatulence. But there are key differences that we should be aware of, which, including: + Loss of appetite
Weight loss
Fever
Fatigue
Stomach aches and cramps
Anaemia
Blood in your poo
At what point should we call our GP?Intolerances are not considered serious, as opposed to allergies or an autoimmune disease like Crohn's.
Regardless of this, you should still visit your GP if you or your child have recurring symptoms.
Unintended weight-loss (more than 5 percent of your body weight in six months)
Blood in your poop
Low blood iron levels
Fever
Family history of cervical or colon cancer, inflammatory bowel disease (IBD) or coeliac disease
New onset of symptoms after 50 years of age