Public concern about allergy symptoms from oilseed rape has increased dramatically over the last five years as information filters through to the public via the national newspapers and television , suggesting a possible link with the dramatic increase in hay fever and asthma sufferers over the last decade, even horses  appear to suffer from oilseed allergy. However, in March 1993, Professor Seaton of Aberdeen University issued a public statement based on his interim results and advised that oilseed rape’s reputation was a media creation with no scientific basis .
Are there any restrictions controlling the planting of oilseed rape in close proximity to residential areas and roadways?
This question was put to the European Commission in 1991 by a Scottish MEP., the Commissions response was as follows : The Commission has not instituted any guidelines, nor does it intend to in the foreseeable future, which would prevent the sowing of oilseed rape (OSR) crops in close proximity to residential areas and roadways as it is not aware of any conclusive evidence to date indicating that the growing of such seed is harmful to human health. The Commission itself has not carried out any research on potential human health risks associated with exposure to oilseed rape. The only research of which the Commission is aware concerns a three year project on the human health effects of the growing of oilseed rape in progress at Aberdeen University, which was commissioned by the Scottish Office. The Commission awaits the results of this research with interest.
What aspects of oilseed rape can cause allergy?
The brassica family, which includes oilseed rape, mustard, cabbage and cauliflower, broccoli, brussel sprouts and radish.., is well documented for causing both antibody-mediated allergy and cell-mediated allergy .
Brassica’s are characterized by a yield of volatile chemicals called isothiocyanates (ITCs) which are derived from biochemicals contained in the plant tissue and released by the plant’s natural enzyme myrosinase during degradation of the plant materials .
ITCs have been well documented for causing allergic symptoms in patients who have had skin contact with or have ingested brassica derivatives . In France 1987, Dr Gervais reported that patients who had developed occupational asthma due to exposure to isocyanates (organic chemical extensively used by the paint and plastic industries, and it is chemically related to ITC) also developed asthma after eating brassica condiments. This study confirmed that ITCs could also induce asthma . In 1988, Dr Tollsten reported that ITC was one of many volatile substances found in the air space above brassica crops, including oilseed rape .
Scientists have reported that oilseed rape pollen (biological allergens) can be transported by wind and may travel in excess of 1km from the source . Furthermore, it is suspected that the airborne pollen may also carry traces of ITCs .
Fungal spores thrive on oilseed rape (OSR) and they also can be transported large distances by the wind. Spores from field fungi are well documented for causing allergy and are particularly hazardous to asthmatics .
What are the results of previous oilseed rape allergy studies?
The first person to be diagnosed with oilseed rape allergy was a farmer aged 30, from Sweden. The patient was diagnosed by Dr Colldahl in 1954, and was found to be suffering severe rhinitis, conjunctivitis and bronchial asthma when oilseed rape was grown in close proximity to his house. He had no family history of allergy .
In Scandinavia 1978, Dr Bucur reported that for several years he had found a large and increasing number of patients who reacted to oilseed rape skin tests. A number of his patients described severe rhinitis, conjunctivitis and asthma when passing by or staying near fields of oilseed rape. Dr Bucur advised that it seemed obvious that sensitisation would occur, and concluded that patients suffering from similar symptoms in oilseed rape regions, should be examined for oilseed rape allergy .
In North America 1979, Dr Lewis reported that 283 atopic patients were skin tested positive when tested with brassica pollen. Though oilseed rape pollen was not specifically mentioned, Dr Lewis qualified this by stating that pollen from the brassica family is all very similar .
In Scotland between 1988 and 1993, Dr Parratt led a team of scientists who conducted numerous oilseed rape (OSR) allergy studies in Tayside region over a period of five years. After a clinical study involving RAST testing (blood testing) of patients in 1989, Dr Parratt reported that his findings supported the general public concern that oilseed rape is a potent source of sensitisation .
In Scotland 1990, Prof Ninan reported after skin testing atopic children suspected of having oilseed rape allergy, that his results supported the view that oilseed rape pollen was not a potent allergen. He advised that the chemicals given off from the crops were the likely cause of oilseed rape allergy, and a further study would be required to ascertain their effects on human health .
In England 1991, Dr Fell reported that his findings indicated a low prevalence of allergy to oilseed rape pollen unless the subjects were occupationally exposed. Like Prof. Ninan, he too reported that research into the effects of the airborne volatiles was required .
In Scotland March 1993, Prof. Seaton reported interim results of his three year study of 2,000 people living in oilseed rape and non-oilseed rape areas. He advised that the results indicated no increase in symptoms in people living in oilseed rape areas in comparison to those living in non-oilseed rape areas. Prof. Seaton concluded that oilseed rape’s reputation was a media creation with no scientific basis .
It is interesting to note that Prof. Seaton’s interim report was based on the results of a questionnaire  and had not in fact carried out clinical tests on any of the 2,000 interviewees.
Conclusions and recommendations
There is no doubt that oilseed rape (OSR) pollen will cause allergic symptoms in established allergy sufferers who live, travel or work in close proximity to rape fields .
Introducing “new” allergens into the environment also creates a window of opportunity in people who have no past history of allergy . The main determining factors in the development of allergy are the concentration of allergen, mode of contact, distance from source, immunocompetence and the total immune stress load .
As long as orthodox scientists continue to study and explain oilseed rape allergy using reductionist science, i.e. cause and effect , the health of the nation will suffer as scientists fail to identify the causation. Modern science requires modern “lateral thinking” which takes into account all variable interactions (and immune stressors) and their cumulative effects. This is called the precautionary approach , which is advocated by the European Commission .
The precautionary approach is not new to allergy, clinical ecologists have been studying cell-mediated allergy caused by environmental factors for decades  but it is only now that their efforts are coming to fruition, though the “old boy network” of orthodox scientists continue to ignore precautionary science and clinical ecology .
It is perhaps noteworthy that the precautionary approach shifts the burden of proof from the clinical ecologist, who previously had to prove that a threat existed, to the accused, who must prove using the same approach that a threat does not exist. When scientists wake up to this “new” way of thinking, the world will become a healthier place for most allergy sufferers .
Perhaps a starting point should be Government recognition that oilseed rape may indeed be a hazard to human health and it therefore should be taking precautions to protect public health by introducing exclusion zones around residential areas, until at least oilseed rape allergy has been studied using the precautionary philosophy.
Future attempts to exonerate oilseed rape from causing widespread allergy should not be undertaken until both sides of allergy (antibody-mediated and cell-mediated) have been properly addressed by research scientists.
Author: Derek Armitage, February 1994
Presented and circulated widely to the UK medical, environmental & scientific communities February 1994.
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10d. Item 11a. above, p164.
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11c. Item 18. below, p504.
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27c. Item 3a. above.
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27e. Item 25. above.
27f. Item 26a above, p217.
28a. Not all in the mind., Mackarness R., 1976, p38,39,76.
28b. Item 26a. above, 221,222.
28c. Item 26b. above, p25.
Author - Armitage; copyright 2007
key words: sensitisation, immunogenic, asthmagenic, haptenic, haptens, synergism, tvoc, rhinitis, headache, asthma, rapeseed, canola, GMOs, immunocompromised, OSR, volatiles, volatile organic compounds, terpenes, attractants, alternaria, irritants, reactive airways dysfunction syndrome, chemical sensitivity, eczema, ozone, yellow peril, pungent, biodiesel, biofuel, rme, cap, set-aside, double low, allergy, armitage