It is estimated that up to 45% of the population suffers from food hypersensitivity(1). Typically a wide range of symptoms from fatigue, headaches, migraine, low mood and skin problems, to bloating, stomach pain, diarrhoea, IBS, weight gain, joint pains, catarrh and runny nose.
What’s the difference between food allergy and intolerance?
IgE-mediated Food Allergy is an inappropriate and harmful response of the immune system as it mistakes perfectly normal substances and treats them as invaders. Allergic symptoms can range from relatively minor rashes through to generalised swelling or collapse as a potentially fatal anaphylactic shock occurs. An allergic reaction can occur quite rapidly, often within minutes but generally within a maximum of twotwo hours. Food Intolerance is quite different, it is not life threatening although it can and does make the sufferer feel unwell. It is very difficult to identify the food that is causing the problem as symptoms can appear up to 72 hours after the food is eaten. There is much confusion, particularly in the media, about different types of food hypersensitivity and how they manifest themselves. Frequently we find that a food allergy and food intolerance are confused with each other. This is not surprising when you look at the raft of different mechanisms involved.
What causes most food reactions?
There are several mechanisms by which an individual may have an adverse reaction to food and these include:-
• IgE allergy – the most commonly known, immediate and potentially fatal response to foods (such as peanuts).
• Coeliac disease – blood tests for coeliac disease look for specific antibodies; tissue transglutaminase and eendomysial antibodies.
• Delayed onset food allergy, now called a food intolerance – Measurement of food-specific IgG antibodies is used as an effective strategy to identify foods to which an individual may be sensitive. Validated programmes such as the YorkTests,’ Food&DrinkScan Food Intolerance Programme are not diagnostic of any condition, but are used by those with chronic conditions, and include nutritional therapist support that can help you devise the perfect diet for you. This IgG-guided elimination diet is now considered mainstream.
• Enzyme deficiencies – foods requires enzymes to be digested. For example, if a person lacks sufficient glucoamylase they may struggle digesting greens. If they lack alpha-galactosidase they may struggle to digest beans. Many people who think they are dairy intolerant actually lack enough of the enzyme lactase which digests the milk sugar lactose. That is why a wise first step is to take a comprehensive digestive enzyme supplement containing all these, and take a double dose with each meal for three days. If that relieves symptoms then enzyme deficiency may be the cause.
• Chemical sensitivity – some people are sensitive to certain chemicals but the reaction may not be ‘allergic’ as such. Examples are sensitivity to sulphites in wine or chemical food additives like tartrazine (E102) and sunset yellow (E110).
What evidence is there that IgG-guided elimination diet is effective?
There is evidence across many trials that diet adjusted to food-specific IgG levels to foods can lead to symptom improvement. These include those within IBS (2-9), inflammatory bowel disease (IBD; 10, 11), migraine (12, 13, 14), weight gain (15, 16), rheumatoid arthritis 17 , mental health (18, 19), and looking at overall quality of life measures (15). In addition, IgG-guided elimination diet has been mainstream in veterinary practice for many years.
Doesn’t everyone produce IgG antibodies to the food they eat?
This is not the case. Using technically validated tests such as the YorkTest Food&DrinkScan, the average number of positive foods is only between 4 and 5 (for those who have positive reactions) out of the ~160 food and drink ingredients tested. Reactions to large numbers of foods is unusual, results are personalised, and differ widely from individual to individual despite similar diets. Individuals can eat large quantities of foods, and a wide range of foods, and not have an IgG reaction to them. Not everyone produces IgG antibodies to the foods that they eat.
In addition, there are an increasing number of studies that demonstrate significantly higher levels of food-specific IgG in certain patient groups. Examples include those within IBS (20), eczema and asthma (21), rheumatoid arthritis (17) and IBD (22). Obese children have significantly higher food-specific IgG antibody values directed against foods than normal weight children and these food-specific IgG antibodies are “tightly associated with low grade systemic inflammation”. (23).
How do you know that a food-specific IgG test is reliable?
It is acknowledged that there is an absence of international reference standards available for each of the different types of food-specific IgG antibodies that are being measured by these types of tests; this means that clinical studies and scientific validation are needed to prove tests are effective. In order to show that the YorkTest food-specific IgG tests are effective survey data hasve been collected since the launch of the service in 1998, and still are to this day. A wide range of parameters, including the reasons why the YorkTest customer wanted to change their diet, how well the customer was able to respond to the dietary advice, how much benefit, if any, that they felt and how quickly they felt any benefit. In the largest survey of its kind, data wasere collated from 5286 individuals who had taken a YorkTest programme and independently audited by the Department of Health Sciences at the University of York. Thisese data wasere subsequently published (24). The YorkTest food-specific IgG ELISA (the hospital standard enzyme linked immunosorbent assay) tests have also been used in other independent studies (2, 12, 14).
In terms of reproducibility, YorkTest have extensive data sets supporting test reproducibility of >98%. This is achieved by using consistent and controlled manufacturing processes and operating procedures. Reproducibility performance is supported with regular routine quality control checks. The other relevant parameter is sample stability. Stability, including transport studies, has been validated and samples are only tested if they have been collected less than 28 days previously. YorkTest set quality specifications and requirements for their products that must be met before results are released to the customer. Tests are only carried out by trained, qualified scientists at the YorkTest laboratory.
With clinical trials and scientific validation, the YorkTest is the only food-specific IgG food intolerance test that has been independently proven.
Reversing your food intolerances
Some types of food sensitivity, for example enzyme deficiencies and coeliac disease, are for life. Others, such as those identified using food-specific IgG testing, can, with avoidance of the culprit foods, resolve itself in time. Removing the cause of the inflammation, and giving the gut time to heal is key.
The association between reduced IgG levels for excluded foods and symptomatic improvement is consistent with the hypothesis that the food-specific IgG plays a direct role in symptom initiation or exacerbation. The likely reason for this is that IgG antibodies circulating in your bloodstream live for about 12 weeks. So, if you strictly avoid a food for at least 12 weeks it is likely that all the IgG antibodies you had that had become sensitised to attack a particular food protein will have disappeared. . With a reduction in inflammation and gut healing, food proteins large enough to stimulate an antibody reaction will no longer pass through into the blood stream.
Reducing your food sensitivity
I believe that most intolerances happen partly because the gut is compromised. The wafer thin layer of cells that make up the gut wall is only one quarter of a sheet of paper thick, and replaced every four days. These cells, which feed off the amino acid glutamine to regenerate, are very easily damaged by alcohol, antibiotics, painkillers, infections and become inflamed if you eat something you’re intolerant to. Excessive bloating puts on a further load.
Having a healthy gut microbiome further protects the gut wall which, if it becomes more permeable, let’s through perhaps only partially digested food proteins to which the immune system reacts. The two main protective types of gut bacteria are Lactobacillus acidophilus and Bifidobacterium. By re-inoculating your gut with these, or supplementing them almost every day, the gut wall becomes further protected.
Therefore, my first line of advice for anyone with gut sensitivities or suspect food intolerances is to supplement:
• Digestive enzymes
• Probiotics (Lactobacillus acidophilus and Bifidobacterium)
• L-glutamine These are available in combination formulas, best taken with each meal. There are other nutrients that are known to reduce gut inflammatory reactions and thus calm down the gut, making you less likely to react. These include:
Vitamin C is a powerful promoter of a strong immune system, immediately calms down allergic reactions and is also anti-inflammatory. Blood levels of vitamin C have been shown to be low both in people with treated and untreated asthma. It’s really recommended for everyone at an absolute minimum of 1,000mg (1g) a day, although 2,000mg (2g) or more is optimum for most people, whether or not you have intolerances. If you are suffering from allergic symptoms, you might want to take twice this amount on a regular basis. Since vitamin C is in and out of the body within six hours, it’s best taken in divided doses, either 1g in the morning and 1g at lunch or, if you’re taking larger amounts, 1g four times a day.
You can also increase your vitamin C intake through food by eating plenty of fresh fruit and vegetables, although you would have to eat an enormous amount to get up to 2g. For example, 100g of peppers contains about 100mg of vitamin C, 100g of broccoli contains 110mg and 100g of strawberries 60mg, and that’s assuming they are fresh. Foods that contain vitamin C typically also contain antioxidant bioflavonoids such as hesperidin, rutin and quercetin, and these bioflavonoids may actually help the body absorb vitamin C – another good reason to eat vitamin-C-rich foods.
Quercetin is another bioflavonoid and is a potent antioxidant that promotes a healthy inflammatory response. Animal studies also show that quercetin regulates histamine production. One study found that of all the flavonoids, quercetin was the most effective at inhibiting histamine. Another study showed a reduction in inflammatory markers and improvement in airway inflammation. (25)
The best food sources of quercetin are red onions, apples and berries, but you’ll be hard pushed to eat more than 20mg a day. So supplementing therapeutic amounts is also necessary if you’re suffering with allergies. Take 500mg three times a day if your symptoms are severe, then drop down to 500mg once a day, whenonce your reaction is under control. This maintenance dose is also effective for reducing allergic potential. The best results are achieved by supplementing 250mg twice a day, with some bromelain (a digestive enzyme from pineapple) and vitamin C.
MSM has so many benefits for food intolerance sufferers that it’s hard to know where to start. In one study, 55 volunteers diagnosed with seasonal allergies were given 1,300mg of MSM twice daily for 30 days. A significant reduction in symptoms of both the upper respiratory tract (including nasal congestion) and lower respiratory tract (including cough) was seen. As long as you’re still suffering from any allergic symptoms, or are in pain, it’s well worth supplementing MSM on a daily basis. While therapeutic intakes go up to 6,000mg a day, I recommend you start with 1,000mg, or half of this if in combination with the other anti-allergy nutrients.
Glutamine is an essential part of any regime designed to quickly restore healthy mucous membranes and reduce food intolerance potential. It is also a powerful nutrient for supporting proper immune function and protecting the liver. For this reason, I not only recommend it as part of healing a leaky gut – thereby reducing your allergic potential – but also for anyone experiencing food reactions. As part of a daily anti-allergy regime take 500mg. Or if you suspect you have a leaky gut (which usually goes hand in hand with intolerances), increase this dose to 8g a day for three weeks. If you use glutamine powder, stir it into cold water – a heaped teaspoon is about 4g. For best results, drink this solution on an empty stomach first or last thing.
Bromelain is a collection of proteolytic (literally meaning protein breakdown) enzymes found in pineapple stems that have considerable anti-inflammatory and anti-swelling properties. In a double-blind clinical trial, participants given 160mg of Bromelain daily experienced significant improvements in nasal drainage, swelling and restored free breathing, compared to those on dummy treatment. Take up to 300mg daily if you are having an allergic reaction or 100mg daily to reduce your allergic potential.
Combinations of these nutrients are available from HOLFORDirect.com.
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1. Allergy UK Report (2007), “Stolen Lives 3, The Food Allergy and Food Intolerance Report”.
2. Atkinson et al (2004) Food elimination based on IgG antibodies in irritable bowel syndrome: a randomised controlled trial. Gut 53:1459-1464
3. Zar et al (2005) Food-specific IgG4 antibody guided exclusion diet improves symptoms and rectal compliance in IBS. Scand J Gastroenterol 40:800-7
4. Drisko et al (2006) Treating IBS with a food elimination diet, followed by food challenge and probiotics. J Am Coll Nutr 25:514-22
5. Yang and Li (2007) The therapeutic effects of eliminating allergic foods according to food-specific IgG antibodies in irritable bowel syndrome. Zhonghua Nei Ke Za Zhi 46:641-3
6. Guo, Jiang, and Wang (2012) The Value of Eliminating Foods According to Food-specific Immunoglobulin G Antibodies in Irritable Bowel Syndrome with Diarrhoea. The Journal of International Medical Research 40:204-10
7. Aydinlar et al (2013) IgG-based elimination diet in migraine plus IBS. Headache 53:514-25
8. Hart (2016) Food-specific IgG guided elimination diet; role in Irritable Bowel Syndrome?
9. Kim-Lee et al (2015) GI disease in Sjogren’s syndrome: related to food hypersensitivities. SpringerPlus 4:766
10. Gunasekeera et al (2016) Treatment of Crohn’s Disease with an IgG4-Guided Exclusion Diet: A Randomized Controlled Trial. Digestive Diseases and Sciences 61:1148-57
11. Bentz et al (2010) Clinical relevance of IgG antibodies against food antigens in Crohn's disease: a double-blind cross-over diet intervention study. Digestion 81:252-64
12. Rees et al, 2005: A prospective audit of food intolerance among migraine consumers in primary care clinical practice. Headache Care 2:11-4
13. Alpay et al (2010) Diet restriction in migraine, based on IgG against foods: a clinical double-blind, randomised, cross-over trial. Cephalalgia 30:829-37.
14. Mitchell et al (2011): Randomised controlled trial of food elimination diet based on IgG antibodies for the prevention of migraine like headaches. Nutrition Journal 10, 85.
15. Lewis et al (2012) Eliminating Immunologically-Reactive Foods from the Diet and its Effect on Body Composition and Quality of Life in Overweight Persons’. J Obes Weig los Ther 2:1.
16. Hart (2016) Food-specific IgG guided Elimination Diet; a Strategy for Weight Loss?
17. Hvatum et al (2006) The gut-joint axis: cross reactive food antibodies in rheumatoid arthritis. Gut 55:1240-7.
18. Karakuła-Juchnowicz et al (2017) The role of IgG hypersensitivity in the pathogenesis and therapy of depressive disorders. Nutr Neurosci 20:110-8.
19. Hart (2017) Food-specific IgG guided elimination diet; a role in mental health? BAOJ Nutrition 3:1.
20. Zar, Benson, and Kumar (2005) Food-specific serum IgG4 and IgE titers to common food antigens in irritable bowel syndrome. American Journal of Gastroenterology 100: 1550-7.
21. Shakib, F., Brown, H.M., Phelps, A. et al (1986) Study of IgG sub-class antibodies in patients with milk intolerance. Clinical Allergy, Vol. 16, pp. 451-8.
22. Inns, S.J., Emmanuel, A.V., Hurel, S. and Bloom, S.L. (2007), “Prevalence of IgG food-specific antibodies in IBD: a case-control study”, Gastroenterology, Vol. 132, Suppl. 2, A-655.
23. Wilders-Truschnig, M. et al, (2008), “IgG Antibodies against food antigens are correlated with inflammation and intima media thickness in obese juveniles”. Exp Clin Endocrinol Diabetes Vol. 116, pp. 241-245.
24. Hardman and Hart, 2007: Dietary advice based on food-specific IgG results. Nutrition and Food Science 37:16-23.
25. Caglayan Sozmen, S et al. (2016) “Effects of Quercetin Treatment on Epithelium-derived Cytokines and Epithelial Cell Apoptosis in Allergic Airway Inflammation Mice Model.” Iran J Allergy Asthma Immunol. 15(6):487-497.