Food Allergy & Intolerance

Food allergy is an adverse reaction to a normal food by the body's immune system. The response leads to the production of increased amounts of specific IgE or IgG antibodies, which can be detected in the blood.

There are two types of food allergies:

1. Classic food allergy. This is a rapid and potentially severe allergic reaction, which produces IgE antibodies. This is the one we shall look at here.
2. Food intolerance or hidden food allergy. This is a slow and usually mild allergic reaction which produces IgG antibodies. It is fully discussed in the section on food intolerance and hidden food allergy

Classic food allergies are usually rapid, and symptoms appear within minutes or a few hours of eating the food you are allergic to. Sensitive people can have this reaction triggered by the minutest trace of the problem food. Severe reactions are a medical emergency, and can result in death.

Fortunately few foods produce this type of allergy, and then only in sensitised people. Well known examples of these foods include nuts, fish, wheat, milk and eggs. The problem food can usually be easily identified because the reaction to it is so quick. Living With Food Allergy looks at the five fold increase in food allergies over the last ten years, including raw fruits and vegetables, and how to live with this problem.

Peanut and other nut allergies are increasing in the UK as more of these nuts are being eaten. These reactions can be fatal, and unfortunately if the allergy starts in childhood it does not normally get any less when the child reaches adulthood. Living with Nut Allergies explains the background to this and how to cope with nut allergies in everyday life.

Wheat allergy is caused by the gluten contained in the wheat and leads to coeliac disease, where the lining of the gut suffers an allergic inflammatory reaction and is damaged to the extent that food is not properly absorbed into the body.

Food allergies are tested using the RAST test to measure IgE levels to specific allergens in the blood.

Food intolerance is not generally accepted by most doctors, so don't expect your doctor to take this too seriously, however it is accepted by nutritionists as being a common problem at the root of many accepted diseases, and also the cause of many general health problems where patients know that they are not really well, but neither they or their doctor can put a label on what is actually wrong with them.

Food intolerance is difficult to diagnose, because the body's reaction to the food does not happen straight away as in a classic allergy. The delay between eating the food and the body's reaction can be between a few hours and a few days. The offending foods are usually those which are eaten regularly and for some people dependence on and craving for them may develop.

Symptoms and health problems can vary from mild uncomfortable symptoms to chronic diseases. Here are some of the commonest symptoms:

• Nose - Hay fever, runny or blocked nose, catarrh, recurrent sinusitis
• Eyes - dark circles around the eyes (allergic shiners), swelling, wrinkles or puffiness under the eyes, blurred vision and watery eyes, horizontal creases in the lower eyelid, itchy eyes
• Ears - ear infections, tinnitus (ringing, buzzing or popping in ears), itching ears, throat and eyes
• Neck & Throat - sore throat and chronic cough, tonsillitis and hoarseness
• Lungs - Asthma, irregular heartbeat and increased heart rate, congestion, breathlessness and wheezing
• Bowels - Chronic candida infection, inflammatory bowel disease (Ulcerative colitis and Crohn’s disease), undigested food in the stool, abdominal pains and cramps and anal itching or irritation, diarrhoea, constipation, irritable bowel syndrome or IBS, bloating, flatulence, belching, gastritis
• Nervous system - Headaches and migraines, insomnia and disturbed sleep, excessive drowsiness after eating, nausea and vomiting, binge eating and food and other cravings, depression, anxiety, low energy and chronic fatigue syndrome, slurred speech, stuttering and clumsiness, emotional disturbances, mental deficiency and learning disability, inability to concentrate, confusion, feeling stressed, irritability, anger, aggressive behaviour, tearfulness, phobias and panic attacks, hyperactivity and attention deficit disorder in children and adults
• Body - Chronic fluid retention (oedema), chronic swollen glands, weight problems and obesity, hypoglycaemia and other blood sugar imbalances, menstrual disorders, hypoglycaemia (low blood sugar), arthritis, fibromyalgia, dizziness, faintness, nutrient deficiencies and imbalances, skin problems – rashes, eczema, psoriasis, hives and acne,dry skin, brittle dry hair and nails, ulcers, body pains and aches, growing pains and failure to thrive in infants, bed wetting in children, teenagers and adults,canker sores.
  Hidden food allergies are mainly due to an unhealthy gut due to the typical unhealthy western diet and lifestyle. The health of the gut is vitally important to health, and is greatly under rated in our modern society. Poor gut health stems from poor nutrition, poor health and poor digestion. The gut bacteria swing out of balance, with unhealthy bacteria growing at the expense of the good bacteria, and fungal overgrowth or candida often occurring.

The intestinal lining protective factor (IgA) is reduced when the gut is in poor health. Stress also reduces the protection given to the gut lining, and this is why stress can make some conditions worse. Leaky gut syndrome occurs when the gut walls become inflamed, and no longer provide an effective barrier to stop partially digested food elements entering the blood stream. These can be attacked by the body's immune system to produce an allergic reaction, and this type of reaction releases IgG antibodies to specific food elements, causing food intolerance.

Food intolerance can happen to anyone who is exposed to any of the following risk factors:

• Excessive regular consumption of a limited number of foods
• Regular consumption of allergy triggering foods
• Early weaning and early introduction of solid foods
• Improper weaning – early introduction of dairy products and solid food
• High intake of preservatives, stabilizers, artificial colourings and flavouring
• Long term use of some drugs and medications
• Adrenal exhaustion (fatigue) and chronic stress
• Inherited predisposition to allergies
• Nutrient deficiencies and imbalances
• Consumption of alcohol, coffee, tea, junk food and carbonated drinks
• Cigarette smoking and passive smoking
• Hypoglycaemia and other blood sugar imbalances
• Reduced gastric and pancreatic secretion
• Chronic candidiasis (intestinal yeast overgrowth)
• Leaky gut syndrome
• Presence of inhalant sensitivity
• Under-functioning liver with poor detoxification capacity
• Disturbed immune function
• Severe viral infections
• Heavy metal poisoning (excess)
• Chemical exposure and free radical oxidative damage  .

There are two common types of tests. The classic food allergy test and also the slowly acting food allergy, often referred to as food intolerance or hidden food allergy.

Food allergy tests measure IgE antibodies in the body, which are produced in response to an immediate allergy.

Other food allergies your doctor will test for include nut allergies, and coeliac disease caused by allergy to gluten.

Food intolerance tests measure IgG antibodies in the body, which are slowly produced in response to foods that are upsetting your system, but which can be very difficult to pin down, because it takes the body some time to react to them, which can be hours or even days after eating them. These reactions are the sort of thing that make you feel unwell, but neither you or your doctor can seem to fathom out why, and these reactions are not investigated on the NHS, so it is up to you to find out yourself, or in conjunction with a nutritionist.