Scientific Studies

Last Updated: 10th November 2022 · Written by Kate Young

Atkinson, Sheldon, Shaath, et al (2003) – Food elimination based on IgG antibodies in irritable bowel syndrome: a randomised controlled trial

Introduction – A total of 150 outpatients with IBS were randomised to receive, for three months, either a diet excluding all foods to which they had raised IgG antibodies (enzyme linked immunosorbant assay test) or a sham diet excluding the same number of foods but not those to which they had antibodies.

Summary – A clinically significant improvement in IBS symptomatology was observed in patients eliminating foods to which they were found to exhibit sensitivity, as identified by an ELISA test for the presence of IgG antibodies to these foods.

Lewis et al., (2012) – Eliminating Immunologically-Reactive Foods from the Diet and its Effect on Body Composition and Quality of Life in Overweight Persons

Introduction – 120 subjects over the age of 18 took part in a study, involving elimination of their IgG reactive foods for 90 days.

Summary – Those who eliminated their IgG reactive foods from their diet experienced reductions in weight, BMI, waist & hip circumference. Subjects also saw improvements in all quality of life measures after 90 days.

Dixon HS. (2000) – Treatment of delayed food reactions based on specific immunoglobulin G testing

Introduction – Conducted by Hamilton Dixon MD in 2000, this study focused on patients that had a history of suffering from a variety of symptoms, including Fatigue (and fatigue after meals, Diarrhoea, Migraines and Itchy Skin. All patients had been unable to find the route of their problem/s using conventional methods.

Summary – 114 patients in total were tested for food sensitivities using a food specific IgG antibody test. Of the 114 initial subjects, 80 completed the study by following an elimination diet based on their IgG reactive foods. Upon elimination of reactive foods, subjects showed significant improvements in their previously reported symptoms. In subjects who reported having symptoms, the following improvements were observed, 71% of subjects realised a 75% or greater improvement in their condition/s, half of the study group realised 90% or more relief from their symptoms and perhaps most importantly, the 15 patients that did NOT eliminate their reactive foods, experienced no relief in their symptoms.

Zar, S. e.a. (2005) – Food-Specific serum IgG4 and IgE titels to common food antigens in irritable bowel syndrome.

Introduction – Food hypersensitivity is a common perception among irritable bowel syndrome (IBS) patients. Data from dietary elimination and food challenge studies support an etiopathological role of diet in IBS, but there are no well-established tests to identify food hypersensitivity. The aim is to compare IgG4 and IgE titers to common food antigens in IBS and controls.

Summary – IBS had significantly higher IgG4 titers (µg/L) to wheat (395 IQR ± 1,011 vs 0 IQR ± 285, p < 0.001), beef (1,079 IQR ± 930 vs 617 IQR ± 435, p < 0.001), pork (481 IQR ± 379 vs 258 IQR ± 496, p < 0.001), and lamb (241 IQR ± 460 vs 167 IQR ± 232, p = 0.009) compared to controls. These differences were maintained across all three subgroups. The antibody titers to potatoes, rice, fish, chicken, yeast, tomato, and shrimps were not significantly different. No significant difference in IgE titers was observed between IBS and controls. SPT was positive for only a single antigen in 5 of 56 patients tested with the same panel of foods. No correlation was seen between the pattern of elevated IgG4 antibody titers and patients’ symptoms.

Serum IgG4 antibodies to common foods like wheat, beef, pork, and lamb are elevated in IBS patients. In keeping with the observation in other atopic conditions, this finding suggests the possibility of a similar pathophysiological role for IgG4 antibodies in IBS.

Bentz et al. (2010) – Clinical relevance of IgG antibodies against food antigens in Crohn’s disease: a double-blind cross-over diet intervention study

Introduction – In this pilot study, 79 Crohn’s Disease patients and 20 healthy controls were examined for food specific immunoglobulin G (IgG). Thereafter, the clinical relevance of these food IgG antibodies was assessed in a double-blind cross-over study with 40 patients. Based on the IgG antibodies, a nutritional intervention was planned.

Summary – A nutritional intervention based on circulating IgG antibodies against food antigens showed effects with respect to stool frequency. Significant improvement in Crohn’s disease sufferers who followed diet removing food they showed sensitivity to (food sensitivity highlighted though IgG test). A clinically significant improvement in IBD symptoms was observed in patients eliminating foods to which they were found to exhibit sensitivity.

Bentz, S., Hausmann, M., Piberger, H., Kellermeier, S., Paul, S., Held, L., Falk, W., Obermeier, F., Fried, M., Schölmerich, J. and Rogler, G., 2010. Clinical relevance of IgG antibodies against food antigens in Crohn’s disease: a double-blind cross-over diet intervention study. Digestion, 81(4), pp.252-264.

Virdee et al., (2015) – Food-specific IgG Antibody—guided Elimination Diets Followed by Resolution of Asthma Symptoms and Reduction in Pharmacological Interventions in Two Patients: A Case Report:

Introduction – A pilot study looked at two case studies of individuals with Asthma. The two subjects were put on an elimination diet after taking an IgG food intolerance test.

Summary – Both patients demonstrated substantial relief in symptoms of Asthma after following a IgG antibody guided elimination diet.

Rees et al. (2005) – A prospective audit of food intolerance among migraine patients in primary care clinical practice

Introduction – This prospective audit was set up to investigate whether migraine sufferers have evidence of IgG-based food intolerances and whether their condition can be improved by the withdrawal from the diet of specific foods identified by intolerance testing. Migraine patients were recruited from primary care practices and a blood sample was taken. Enzyme-linked immunosorbent assays (ELISA) were conducted on the blood samples to detect food-specific IgG in the serum. Patients identified with food intolerances were encouraged to alter their diets to eliminate appropriate foods and were followed up for a 2-month period

Summary – This investigation demonstrated that food intolerances mediated via IgG may be associated with migraine and that changing the diet to eradicate specific foods may be a potentially effective treatment for migraine. Elimination of food that caused high IgG response lead to 30% of subjects reporting benefit to migraine symptoms after 1 month and 40% after 2 months. 60% subjects who reintroduced their reactive foods suffered onset of migraine symptoms.

Lee and Lee (2017) – Alterations of Food-specific Serum IgG4 Titers to Common Food Antigens in Patients with Irritable Bowel Syndrome:

Introduction – 32 Patients diagnosed with IBS and 32 health controls were tested using and IgG antibody test.

Summary – Patient with IBS had significantly higher IgG antibody reactions than the control group.

Serum antibody levels to common foods are abnormally elevated in IBS patients.