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Testing for Allergies and Intolerances

The following are some of the options available for allergy and intolerance testing at Greenfields. The most suitable method will be advised according to individual circumstances and medical history during a consultation. More detailed information on each test is available on request, please contact us for details.

Classical allergy (immediate hypersensitivity) is an immunoglobulin E (IgE) antibody response provoked by allergens such as foods, pollens, dust mites, feathers, animal hair and moulds. This usually results in symptoms such as asthma, swelling, or sneezing, minutes to hours after contact. IgE may last for years. Individual allergens can be tested, as well as combinations such as grass mix, which contains the pollens of several local grasses that typically cause allergic response.

Food intolerance (delayed immune response) involves different mechanisms to that of IgE: immunoglobulin G (IgG) response either causes local tissue damage or deposit of immune complexes. Symptoms related to IgG food intolerance can be wide-ranging, such as irritable bowel syndrome, fatigue, urticaria, Crohn’s disease, infant colic and glue ear. The cause may not be obvious, as symptoms can last for many hours to days after the food was eaten. IgG levels may decline with avoidance over 3 to 12 months, depending on the strength of the initial reaction. IgG food intolerance is normally tested in a panel of many individual foods. Greenfields uses a laboratory which tests reaction against organic foods to avoid cross-reactivity with chemicals such as pesticides, fungicides and herbicides. Intolerance to Candida and aspergillus niger is also tested for cross-reactivity purposes.

Testing for total antibody levels of IgE and IgG is a way of assessing whether a problem is due to antibody-antigen reaction before determining specific allergies/intolerance with a full screening test of individual allergens. Total IgE and total IgG will give some indication of the level of overall reactivity, but will not reveal which allergens are causing the problem.

Gluten intolerance can be caused by coeliac disease, which can be found with a coeliac screen blood test. Gluten sensitivity can also be identified by specific gluten testing.

Histamine is a protein made in the body that is involved in local immune responses to allergens, causing enlargement of blood vessels and an inflammation. Release of histamine in the lungs causes the symptoms of asthma. Some people have naturally high or low levels of histamine in their blood. Certain foods are also high in histamine. A measurement of histamine levels in both blood and stool can help to determine whether a histamine problem is being caused by being unable to break down histamine from foods.

Candida albicans is a type of yeast that is normally present in the intestines of many people. This and other yeasts can grow out of control under circumstances such as low immunity, and may cause an abnormal response to eating certain foods. Yeast infection is often present with changes in intestinal permeability. As with other sensitivities, antibodies to Candida may be present in the blood for some time after the levels in the stool have reduced to acceptable limits.

Gut fermentation in the small intestine can be estimated by measuring changes in fasting blood alcohol concentrations after taking glucose. In the gut glucose ferments to alcohol, which then passes into the bloodstream. This may be due to bacterial overgrowth in the gut or malabsorption. Overgrowth of bacteria in the small intestine can be measured using lactulose, a non-digestible sugar. Fasting levels of breath hydrogen is measured, followed by four further measurements after taking lactulose. If bacteria are present they will metabolise the lactulose, and hydrogen is given off as a byproduct, which appears in the breath.

Lactose intolerance can also be measured from breath hydrogen in response to lactose ingestion. If the lactose is not digested in the intestinal tract it gets metabolised by bacteria and produces hydrogen in the breath.

Intestinal permeability may be present with food allergy/intolerance: undigested proteins enter the bloodstream through an intestinal lining that has become more permeable than usual. This may be caused by intestinal infection, radiation, chemotherapy or long-term use of antibiotics or anti-inflammatories. Zonulin is a byproduct of intestinal permeability, and can be tested in the stool to assess the level of permeability. 

Genetic Testing

Blood group can be an important aspect relative to allergy or intolerance symptoms, as people of certain blood groups may be more or less able to digest and metabolise particular foods. The major blood groups are A, B, AB and O. The antigens for these blood groups are present on red blood cells. Blood group is inherited from both parents.

Secretor status is useful in addition to blood group, as this determines whether a person secretes their blood group antigens that are on their red blood cells into their saliva and digestive secretions. Non-secretors may be more prone to intestinal permeability, allergy and Candida or yeast infection.

Genomic Polymorphisms are additional inherited factors that can make a person more or less susceptible to allergies. These include the following: IL-1RN (marker of chronic inflammation); TNF-α (viral infection and cancer); and three TH-2 cytokines (Allergy, Asthma and Atopy). Interleukin 1ß and Interleukin-4 may also be evaluated when possible.

A genomic test can be carried out simply using a saliva sample, and can be analysed by Greenfields for susceptibility to allergens. Genomic testing will also find out blood group, secretor status and lactose intolerance, as well as other factors. Using the following link to 23andMe will prioritise your sample handling and you will receive £20 discount off the cost of the cost of the testing: www.23andme.com/drgreenfieldUK (www.23andme.com/drgreenfieldUS in the US for a $20 discount).

Contact Greenfields reception on 01227 454 848 to book an appointment with one of our naturopaths.

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