Delayed Food Allergies, or Food Sensitivities: What the Science Shows

Food sensitivities, also known as delayed food allergies have become much more mainstream since celiac was discovered to be a disease of gluten intolerance.

Now, it is suspected that a wide variety of otherwise inexplicable ailments may be caused by individual food sensitivities. In fact, there is quite a bit of research to support this suspicion.

Sufferers of chronic conditions have told their practitioners for years that certain foods seem to worsen their condition, but up until relatively recently there has not been much science on the subject.

Testing for delayed food allergies is often done by looking for the presence of IgG antibodies against specific foods.

While IgG testing for gluten - or gliadin, a fraction of the gluten molecule – is not an effective test for celiac, it may be useful in identifying other symptoms of food sensitivity, especially those that occur outside the gut (1).

Read more: Delayed Food Allergies: The Basics

Reviewing the Science

It would be great if researchers had looked at one ailment at a time, run a complete food sensitivity screen for dozens of foods, and followed through with stringent randomized, controlled elimination and challenge diets. Unfortunately, this is the case for very few studies, and even fewer ailments.

Eliminations diet refers to eliminating one or several foods for an extended period of time while monitoring health and symptoms. Challenge refers to reintroducing an offending food after it has been eliminated to monito the relapse of symptoms.

In lieu of the ideal complete and scientifically stringent data sets, we do have multiple studies that highlight the importance of delayed food allergies in very serious diseases, and the ability for patients to manage otherwise unmanageable conditions by altering their diet.

The reason that much of the data available is incomplete is because researchers looked at reactivity to only one food, or a handful of foods. Oftentimes studies did not follow-up with controlled and randomized elimination and challenge diets.

Despite these research design drawbacks, the research strongly suggests that delayed food allergies may be playing a much larger role in overall health and specific ailments than previously, or even currently known.

Gastrointestinal Disorders

It is well accepted by the scientific and medical community alike that celiac disease – a disease that leads to the destruction of the intestinal lining and subsequent pain and potential malnutrition – is caused by an immune response to gluten. Gluten is a small portion of a grain protein found in wheat, barley, and rye.

Researchers estimate that approximately 1% of the population is likely to have celiac disease, and approximately 6 times more are likely to have non-celiac gluten sensitivity – meaning 1 in approximately 16 people (2).

No estimates are available as to how many people suffer from sensitivities to other foods.

The fact is that gastrointestinal disorders are common in the general population, with annual prevalence figures ranging from 20% for irritable bowel syndrome to over 40% for dyspepsia (3). So understanding the underlying causes of gastrointestinal diseases are both medically, and socioeconomically important.

Crohn’s Disease - Patients were tested for IgG levels against certain foods. Subsequently, patients reported improvements in bowel function, reduced abdominal pain, and improved well-being after eliminating foods for which they had high IgG levels (4).

Irritable Bowel Syndrome (IBS) - 20 patients with IBS, who got no relief from conventional medical care showed nearly 100% improvement after 1 year of following an elimination and rotation diet based on IgG reactivity (5).

A rotation diet allows the subject to consume an offending food no more than once every third or fourth day, presumably to keep inflammation from reaching symptomatic levels.

In another controlled, randomized, blinded study, IBS patients reported an average 26% improvement in IBS symptoms (by ranking their symptoms) after 3 months on a diet that eliminated foods to which they had delayed food allergies. No improvement was seen on a restricted diet that included foods to which subjects had sensitivities (6).

Specific foods were found to provoke symptoms in 2 out of 3 irritable bowel syndrome patients (7).

Reflux - A study of infants under one year old showed that high levels of IgG antibodies against beta-lactoglobulin (a milk protein) were tightly associated with gastroesophageal reflux (GERD) and cows milk protein allergy (8).

Neurological Disorders – ADHD, Schizophrenia, Autism, and more

IgG antibodies against gliadin are believed to be a marker for gluten-sensitivity that lie outside the gut, and are particularly well-correlated different neurological disorders (1).

Gluten sensitivity is associated with certain forms of ataxia and peripheral neuropathy, headache, cognitive deficits, epilepsy, and even encephalopathy (1, 2).

In fact, it is estimated that approximately 57% of people who suffer from neurological disorders with no known origin suffer from gluten sensitivity (2).

In addition to those already listed, researchers have correlated gluten sensitivity with schizophrenia, anxiety disorders – specifically social phobia and panic disorders - depression, ADHD, autism, multiple sclerosis, myasthenia gravis, myopathy and neuronal degeneration (2).

Headache and Migraine - IgG testing successfully identified foods that, when eliminated, significantly reduced migraines in a study of 56 patients (9).

ADHD - In children diagnosed with ADHD, one study showed that an elimination diet based on delayed food allergies was successful in significantly reducing ADHD scores in a subpopulation of children. When eliminated foods were reintroduced, regardless of new IgG levels, 63% of those children showed a relapse to their previous ADHD rankings (10).

ADHD has been specifically linked to gluten sensitivity, and in one study, 74% of ADHD patients who tried a gluten-free diet chose to remain on the diet citing significant improvements (2).

Schizophrenia - Schizophrenia and gluten sensitivity have a robust relationship dating back several decades. In the most dramatic case study, one woman diagnosed with schizophrenia, suffering from hallucinations, and altered EEG measurements, recovered after 6 months on a gluten-free diet with no continued symptoms, and she discontinued use of antipsychotic drugs. The patient remained symptom-free at a one year follow-up (2).

Other less dramatic studies have also shown significant improvements in larger groups of psychotic patients. In multiple studies, approximately 25% of schizophrenia patients showed increased antibodies against gliadin (gluten), without a significant amount of celiac-indicating antibodies (2).

Autism - Autism spectrum disorders are more common in children with a family history of celiac disease, irritable bowel syndrome, rheumatoid arthritis, and abnormal intestinal permeability: disorders that are also associated with delayed food allergies (2).

In studies, a subset of people suffering from autism spectrum disorders had positive responses to a gluten- and casein-free diet (2) (Casein is a protein found in many dairy products and as an additive in non-dairy products). Given a disorder with a whole spectrum of symptoms and possible causes, dietary changes may be one of the simplest autism treatments for some.

Obesity and Heart Disease

Delayed food allergies contribute to a low-level of chronic inflammation when foods are consumed. Imagine the body mounting an attack against an ingested food, which it perceives as a health threat.

Systemic low-grade inflammation has been shown to contribute to the development of obesity, insulin resistance, Type II Diabetes, and atherosclerosis (vascular disease) (11).

In fact, one study showed that obese children were more likely to have positive IgG reactivity to foods, increased inflammatory markers and thickened arteries (11). Yes, thickened arteries in children!

Arthritis

Rheumatoid Arthritis - Rheumatoid arthritis patients were more likely to have increased IgG levels against food compared to healthy people (12).

In another study, a subset of rheumatoid arthritis patients reported improvements in pain following elimination of dairy and/or yellow dyes (13).

Very early estimates suggest that 5% of patients with rheumatoid-like arthritis may have symptoms due to delayed food allergies (14).

Juvenile Arthritis - In one study, 33.9% of children with juvenile arthritis tested positive for anti-gluten antibodies without increased intestinal permeability or celiac disease (15).

Psoriasis

Psoriasis sufferers who tested positive for gluten sensitivity showed improved symptoms by following a gluten-free diet (16).

Other

Inflammation of the kidneys is associated in some people with milk and/or soy sensitivities (17).

As you can see, gluten sensitivity has dominated the latest scientific research on delayed food allergies. However, the body can raise an IgG response against any food. This fact alone, demands future research with a broad assay of delayed food allergies. The handful of studies that have confirmed a connection between foods other than gluten, and chronic ailments highlight this fact.

As we learn more about delayed food allergies, their causes, and their effects, it will be interesting to see what science shows in future studies designed with a broader scope.

The most personally compelling evidence still seems to come from individuals who have experienced dramatic health improvements after identifying specific food sensitivities.

Do you have an experience with delayed food allergies or food sensitivities? Please share below.

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References

1. Hadjivassiliou, M, DS Sanders, RA Grunewald, N Woodroofe, S Boscolo, D Aeschlimann. “Gluten sensitivity: from gut to brain.” Lancet. 2010; 9(3).

2. Jackson JR, WW Eaton, NG Cascella, A Fasano, DL Kelly. “Neurologic and psychiatric manifestations of celiac disease and gluten sensitivity.” Psychiatr Q. 2011 Aug 30

3. Jones, RH. “Clinical economics review: gastrointestinal disease in primary care.” Aliment Pharmacol Ther. 1996;10(3):233-9.

4. Bentz S, Hausmann M, Piberger H, Kellermeier S, Paul S, Held L, Falk W, Obermeier F, Fried M, Schölmerich J, Rogler G. “Clinical relevance of IgG antibodies against food antigens in Crohn’s disease: a double-blind cross-over diet intervention study.” Digestion. 2010;81(4):252-64.

5. Drisko J, Bischoff B, Hall M, McCallum R. “Treating irritable bowel syndrome with a food elimination diet followed by food challenge and probiotics.” J Am Coll Nutr. 2006; 25(6):514-22.

6. Atkinson W, Sheldon TA, Shaath N, Whorwell PJ. “Food elimination based on IgG antibodies in irritable bowel syndrome: a randomized controlled trial. Gut. 2004; 53(10):1459-64.

7. Jones VA, McLaughlan P, Shorthouse M, Workman E, Hunter JO. “Food intolerance: a major factor in the pathogenesis of irritable bowel syndrome.” Lancet. 1982; 2(8308):1115-7.

8. Cavataio F, Iacono G, Montalto G, Soresi M, Tumminello M, Campagna P, Notarbartolo A, Carroccio A. “Gastroesophageal reflux associated with cow’s milk allergy in infants: which diagnostic examinations are useful?” Am J Gastroenterol. 1996; 91(6):1215-20.

9. Arroyave Hernández CM, Echavarría Pinto M, Hernández Montiel HL. “Food allergy mediated by IgG antibodies associated with migraine in adults.” Rev Alerg Mex. 2007; 54(5):162-8.

10. Pelsser LM, Frankena K, Toorman J, Savelkoul HF, Dubois AE, Pereira RR, Haagen TA, Rommelse NN, Buitelaar JK. “Effects of a restricted elimination diet on the behaviour of children with attention-deficit hyperactivity disorder (INCA study): a randomized controlled trial.” Lancet. 2011; 377(9764):494-503.

11. Wilders-Truschnig M, Mangge H, Lieners C, Gruber H, Mayer C, März W. “IgG antibodies against food antigens are correlated with inflammation and intima media thickness in obese juveniles.” Exp Clin Endocrinol Diabetes. 2008; 116(4):241-5.

12. Hvatum M, Kanerud L, Hällgren R, Brandtzaeg P. “The gut-joint axis: crossreactive food antibodies in rheumatoid arthritis.” Gut. 2006; 55(9):1240-7.

13. van de Laar MA, van der Korst JK. “Food intolerance in rheumatoid arthritis. I. A double-blind, controlled trial of the clinical effects of elimination of milk allergens and azo dyes.” Ann Rheum Dis. 1992; 51(3):298-302.

14. Panush RS. “Food induced (“allergic”) arthritis: clinical and serologic studies.” J Rheumatol. 1990; 17(3):291-4.

15. Lepore L, Pennesi M, Ventura A, Torre G, Falcini F, Lucchesi A, Perticarari S. “Anti-alpha-gliadin antibodies are not predictive of celiac disease in juvenile chronic arthritis.” Acta Paediatr. 1993; 82(6-7):569-73.

16. Wolters M. “Diet and psoriasis: experimental data and clinical evidence.” Br J Dermatol. 2005; 153(4):706-14.

17. Kloster Smerud H, Fellström B, Hällgren R, Osagie S, Venge P, Kristjánsson G. “Gastrointestinal sensitivity to soy and milk proteins in patients with IgA nephropathy.” Clin Nephrol. 2010;74(5):364-71.