Introduction

Food is a material consumed by living organisms, including animals, humans, and plants, for nourishment and growth. It contains the essential components required to sustain life, namely carbohydrates, lipids, fats, proteins, minerals, vitamins, nutrients, and fibre. Food is one of the fundamental substances of life; however, it can sometimes cause inconvenience in the gastrointestinal tract (GIT), resulting in reactions such as food allergy, food intolerance, and food poisoning, among others. Food may be ingested in raw, processed, or cooked form, after which the body metabolises it to produce energy.

The source of food may vary among organisms depending on their habitat, but its purpose remains the same: to provide energy.

Food Intolerance or Food Sensitivity

Food intolerance refers to an unpleasant reaction after consuming certain foods that cannot be adequately digested or metabolised by the enzymes present in the gut. While food intolerance is not a serious condition, consuming foods that trigger sensitivity can cause an individual to feel unwell.

Food Intolerance vs Food Allergy

Functional Effects of Food Intolerance

Symptoms of the Digestive System

• Loose motions (diarrhoea): Passing of watery stools
• Bloating: A feeling of fullness or overstretching of the abdomen
• Abdominal pain: A sense of congestion or tightness in the belly
• Flatulence: Commonly known as gas, which causes pain in the abdomen

These symptoms may collectively lead to headaches, muscle and joint pain, sluggishness, and general weakness.

Emotional Impact of Food Intolerance

• Fluctuating mood: Discomfort caused by food intolerance can make a person moody, impulsive, and irritable
• Low mood or sluggishness: Constant abdominal pain may give rise to depressive thoughts, making an individual inactive
• Nervousness and stress: Continuously managing or coping with symptoms can result in anxious and stressed behaviour
• Impact on self-confidence: Symptoms such as bloating, increased abdominal distension, burping, and flatulence may lower confidence levels
• Social stigma: Bloating and burping can contribute to social embarrassment due to the unusual sounds produced by the digestive tract

Impact on Routine Life

Elimination Diet or Exclusion Diet

People with food intolerance may adopt an elimination diet as part of their daily routine. An elimination diet involves removing foods or food groups that contain certain ingredients or allergens that trigger gastrointestinal issues such as gas, burping, and bloating. The most commonly eliminated foods include milk and milk products, fish, eggs, and seafood.

An elimination diet has both advantages and disadvantages. Challenges include:

• Difficulty in selecting appropriate foods
• Social challenges at gatherings, parties, or functions due to selective dietary preferences
• Economic burden, as nutritional supplements may not be affordable for everyone

Impact on Lifestyle, Well-being, and Living Conditions

• Physical health: Selective food choices may fail to provide adequate nutrients and energy, leading to sluggishness and reduced physical health
• Secondary conditions: Long-term consumption of foods that are poorly tolerated may lead to secondary conditions such as gastritis, irritable bowel syndrome (IBS), headache, migraine, depression, social anxiety, and diarrhoea

Common Types of Food Intolerance

Lactose Malabsorption or Alactasia

Lactose intolerance is the most common form of food intolerance. Lactose, commonly known as milk sugar and found in milk and milk products, is a disaccharide that cannot be digested by the small intestine when there is insufficient production of the digestive enzyme lactase, which is responsible for breaking down lactose for absorption. Symptoms include bloating, gas, and abdominal cramps. Lactose intolerance can be diagnosed through hydrogen breath tests and blood tests.

FODMAP Sensitivity

FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. It refers to an intolerance to certain carbohydrates. A low-FODMAP diet is commonly prescribed for patients with irritable bowel syndrome (IBS).

Caffeine Intolerance

Intolerance to caffeine may lead to symptoms such as headache, shakiness, palpitations, and low mood.

Management

Treatment and management of food intolerance are relatively straightforward:

• Identify and stop consuming the food that triggers sensitivity
• Find an alternative or substitute for the offending food (for example, taking lactase supplements for lactose intolerance)
• Slowly reintroduce the food into the diet to monitor for symptoms
• Antacids may be prescribed for symptoms such as gas and bloating
• Antidiarrhoeal drugs are advised for diarrhoea
• An elimination or exclusion diet is incorporated into the individual's routine
• Introducing more fruits and vegetables into the diet can help address nutritional deficiencies

FAQs

What is food intolerance?

Food intolerance is a chemical reaction towards certain foods or food components, making them difficult to digest.

What causes food intolerance?

The exact cause is not always known; however, it is often attributed to a lack of digestive enzymes in the gut required to break down complex food into simpler components.

What are the symptoms of food intolerance?

The most common symptoms are gas, bloating, indigestion, burping, belching, flatulence, headache, fatigue, muscle weakness, and tiredness.

What are the types of food intolerance?

Common types include lactose intolerance, histamine intolerance, caffeine intolerance, and sensitivity to wheat, soy, fish, and FODMAPs.

What is a food allergy?

Food allergy is distinct from food intolerance. It is an allergic or anaphylactic reaction to certain foods or allergens, with symptoms that include rashes, skin itching, swelling, redness, and fever.

How is food intolerance diagnosed?

Diagnosis can be carried out through tests such as blood tests and hydrogen breath tests.

How is food intolerance treated?

Treatment involves eliminating the trigger food from the diet. Antacids and antidiarrhoeal drugs may be used for symptomatic relief.

Summary

Food is a substance that provides energy to the body for carrying out routine functions. However, certain foods or food components can cause inconvenience in the gut, resulting in food intolerance. Food intolerance is a reaction to specific food materials that causes symptoms such as gas, flatulence, bloating, and indigestion, primarily due to deficient or absent digestive enzymes in the small intestine. The most common forms include lactose, histamine, caffeine, soy, wheat, fish, and seafood intolerance. Management involves eliminating the offending foods from the diet and taking appropriate nutritional supplements.