Are rapeseed oil crops (known as oilseed rape) highly allergenic?
A Registered Dietitian has searched the science for you regarding allergy/allergic reactions and the crop used to make rapeseed oil. Oilseed rape has been cultivated for centuries and there’s no clear evidence that it has an adverse effect on our health. There are a few studies that have shown that pollen from oilseed rape is allergenic, but data is highly conflicting.
Oilseed rape pollen is heavy so, unlike other pollens, is not widely disseminated by the wind. It is therefore usually localised in its distribution. It is also an insect-pollinated crop, whereas hay fever is usually caused by wind-pollinated plants like grass and birch, which are the top two pollens that provoke hay fever. Studies on the dispersal of oilseed rape pollen generally conclude that very little airborne pollen is transported over long distances. Oilseed rape pollen does not generally contribute greatly to the total amount of pollen present in the general environment at the time oilseed rape flowers.
A school of thought is that symptoms attributed to oilseed rape are in fact caused by other allergens but are incorrectly associated with oilseed rape because it is so visible with its bright yellow flowers. Although it may be possible that exposure to oilseed rape may increase symptoms in some people, there is as yet no evidence to suggest that these symptoms would be any different from, or more intense than those caused from other allergens (such as grass and birch).
As is normal with plants, oilseed rape produces natural chemicals. Perhaps these may trigger a reaction similar to that caused by pollen in many people (e.g. watering eyes, irritated airways etc.) but we do not know if these compounds in nature ever reach concentrations high enough to cause physical effects.