See: Oats (for allergy to the food), Cultivated Oat (for allergy to the pollen), and False Oat grass (Arrhenatherum elatius).

Oats are of uncertain origin, but probably originated in Europe from two species, Wild Oats (A. fatua L.) and Wild Red Oats (A. sterilis L.). Oats are now cultivated throughout the temperate zones of the world. The major growing areas are the USA, southern Canada, the USSR and Europe, particularly near the Mediterranean. Oats serve as food for humans, animal fodder and bedding, and - especially in the form of extracts - in a variety of industrial uses. There are many named varieties of this cultivated cereal, with new forms being developed each year.

Oats are an erect, tufted annual grass growing to 1.2m. The flowers are hermaphrodite (have both male and female organs). Flowering is between early spring and early summer, seed ripening between late summer and mid-autumn.

A carbohydrate-containing soluble fibre, shown to have a cholesterol-lowering effect. Oatmeal is a rich source of phytates (Sanders)

Castor bean and dehulled oats contain acid-stable lipase, which demonstrated significant lipolytic activity at pH 5.6 in this study (Tursi 1994 ref.1875 3)

Oats grow in cultivated beds, and in dry wasteland and meadows, especially on heavier soils.

Oats are by far the most nutritious of the cereal grasses. They are high in vitamin B-1 and contain vitamins B-2 and E. Used as a cereal, they are probably best known as the breakfast cereal porridge, but can also be used in many other ways. The seed can be sprouted and eaten in salads. The grain can also be ground into a flour and used in making biscuits, sourdough, etc. Oats are fairly low in gluten, and so not suitable for making bread. Oat flour inhibits rancidity and, as an additive, increases the length of shelf-stability of fatty foods such as vegetable oils. Oats are also one of the basic ingredients of whisky. The roasted seed is a coffee substitute. An edible oil is obtained from the seed and used in the manufacture of breakfast cereals. Oats are often a major ingredient in cosmetics, creams and skin cleansers. Available as whole oat grains when the husks are removed; oatmeal from cut or ground oats; and rolled oats when grains cut in slices then steamed and rolled. All produced from husked seed or grain of oat plant.

Oats are widely thought to have antispasmodic, diuretic, emollient, nervine, stimulant, anti-depressant, vulnerary and anti-tumor properties. When consumed regularly, oat germ reduces blood cholesterol levels. Oat straw and the grain are prescribed to treat general debility and a wide range of nervous conditions.

Among the conditions treated with Oats, both as a medical prescription and a folk remedy, are eczema, dyspepsia, gastroenteritis, gout, insomnia, neurosis, paralysis, parturition, psoriasis, and rheumatism.

Allergens/Function:

Allergens:

The 26, 38 and 69 kDa bands in wheat and the 46 and 66 kDa in oats could be classified as major IgE binding proteins of these cereals (> 50% of the sera were positive). (Varjonen 1995 ref.7564 4)

A 66 kDa protein in oats was found in 28 out of 33 sera (84%) from adult patients with atopic dermatitis, however, there was evident non-specific binding to this region and thus it may also represent lectin-like binding. (Varjonen 1994 ref.1330 1)

Three proteins, with an assessed molecular weight of 25, 27 and 32 kDa, have been identified by immunoblotting using coeliac sera, as the major coeliac serum IgA-binding components of oat endosperm. They correspond to alpha 2, gamma 4, and gamma 3 avenins, respectively. Another component shows weak alpha-amylase inhibitory activity and exhibits strong homology (60% identity) with the alpha-amylase inhibitor from ragi (Eleusine coracana). (Rocher 1992 ref.5625 6)

Adverse Reactions:

IGE AND IMMUNE:
Oats may be contaminated by wheat - it would be important to differentiate whether the allergic symptoms are attributable to wheat and not oats.

Oats uncommonly results in allergic reactions. Symptoms may include angioedema, urticaria, atopic dermatitis, asthma, rhinitis and gastrointestinal symptoms such as nausea, vomiting and abdominal pain.

Life-threatening, recurrent anaphylaxis or urticaria caused by allergy to gliadin (found in wheat, rye, barley and oats), triggered by exercise. (Varjonen 1997 ref.653 32) (Barley contains less gliadin than the other cereals)

No evidence of sensitization to topical oat and rice colloidal grain suspensions used for eczema in normal and atopic children in the group studied. (Pigatto 1997 ref.2146 3)

On oral provocation, 18 children with atopic dermatitis exhibited a positive response to wheat, three to rye, one to barley, and one to oats. Cereal-induced symptoms were dermatologic, gastrointestinal, or oropharyngeal, and their onset after provocation was immediate (eight cases), delayed (14 cases), or both immediate and delayed (one case). (Rasanen 1994 ref.1312 4)

It seems that the presence of IgA and IgG antibodies to different cereal antigens is a result of natural exposure and in atopic dermatitis displays little diagnostic significance, in contrast to antigliadin antibody response in dermatitis herpetiformis and celiac disease. (Varjonen 1996 ref.2147 6)

In a study with challenges to the common cereals, 80% reacted to only one grain. (Jones 1995 ref.2465 3)

In 34 children with atopic dermatitis, 33 were SPT positive with wheat and 18 with oats. Positive RAST to wheat and oats could be detected in 32 and 30 samples respectively. SPT with rice, corn, millet or buckwheat was positive in 16/34 patients. (Varjonen 1995 ref.7564 2)

Infantile food protein-induced enterocolitis syndrome (FPIES) is a severe, cell-mediated gastrointestinal food hypersensitivity typically provoked by cow's milk or soy. This study reports on other foods causing this syndrome: 14 infants with FPIES caused by grains (rice, oat, and barley), vegetables (sweet potato, squash, string beans, peas), or poultry (chicken and turkey) were identified. Symptoms of typical FPIES are delayed (median: 2 hours) and include the onset of vomiting, diarrhea, and lethargy/dehydration. Eleven infants (78%) reacted to >1 food protein, including 7 (50%) that reacted to >1 grain. Nine (64%) of all patients with solid food-FPIES also had cow's milk and/or soy-FPIES. Initial presentation was severe in 79% of the patients, prompting sepsis evaluations (57%) and hospitalization (64%) for dehydration or shock. None of the patients developed FPIES to maternally ingested foods while breastfeeding unless the causal food was fed directly to the infant. (Nowak-Wegrzyn 2003 ref.7791 5)

OCCUPATIONAL EXPOSURE:
Animal workers, food industry, baker & bakery, mill workers

Baker's asthma. (Block 1984 ref.239 34)

Cough, wheezing, shortness of breath, fever, stuffy nose, and skin itching/rash on exposure to grain dust. May also develop "grain fever". (Manfreda 1986 ref.1888 4) (This may not be an IgE reaction)

NON IMMUNE:
Without exception, in the most scientifically rigorous study on the safety of oats, no adverse effects associated with the regular consumption of moderate amounts of oats included in a gluten-free diet for Coeliac disease, could be found. However, there are concerns among some authorities on celiac disease that even if oats themselves are safe, they nonetheless may be contaminated with wheat, rye, or barley. (Thompson 2003 ref.7522 1) (See Gluten).

This study provides evidence of the long term safety of oats as part of a coeliac diet in adult patients with coeliac disease. (Janatuinen 2002 ref.7581 1)

Oats are safe and well tolerated by adults with coeliac disease and dermatitis herpetiformis, though the risk of wheat contamination of commercial oat products remains a cause of concern. (Hallert 1999 ref.7587 1)

Compared with controls, significantly elevated IgA antibody titers against gliadin, soy, HAV (salt extracted antigens of oat flour) and ovalbumin were found IgA nephropathy patients. (Kovacs 1996 ref.7593 3)

Antiendomysial antibodies (EMAs), which are highly sensitive and specific for celiac disease, are produced by intestinal mucosa. This study’s objective was to better define the controversial role of oats in celiac disease to determine whether oats can be safely included in a gluten-free diet. An in vitro model was used to test whether oats induce EMA production in supernatant fluid from cultured duodenal mucosa specimens collected from 13 treated celiac disease patients. The authors conclude that because the in vitro challenge with PT-avenin and its C fraction did not induce EMA production in treated celiac disease patients, it appears that oats have no harmful effect on celiac disease. Thus, oats can be safely included in a gluten-free diet. (Picarelli 2001 ref.4243 3)