There is considerable misinformation – “Fake News” in the popular press and on some websites written by people who don’t know the difference between a fatty acid & an amino-acid – in other words, scientifically ignorant – about harmful effects of Genetically Modified organisms in general & soya beans in particular – e.g. “soya is both GM, soaked in chemicals…” This statement is palpably untrue – it’s UTTER RUBBISH! G.m. soya will contain minute traces of such chemicals as are applied to control weeds, pests & pathogens such as fungi. This also applies to non-g.m. soya – some of the chemicals will be different. Agrochemicals are also applied to the majority of crops produced throughout the world – e.g. linseed; cereals such as wheat, barley & oats; legumes such as peas & beans; potatoes & sugarbeet; palm trees; fruit of all kinds.
One chemical which has been singled out for criticism is glyphosate (Round-up). A manufacturer’s trial showed this to have low mammalian toxicity (albeit a small trial). The author used it himself for several years, when farming, without any adverse effects, and still uses it in his garden. The agrochemical industry has occasionally made mistakes e.g. with organophosphorus insecticides, as have drug companies with e.g. Thalidomide. Modern crop production & monitoring techniques have been set up to try & ensure that any chemical residues are below safety thresholds.
It is inevitable that there will be a few individual horses, or people, or other species who will be particularly sensitive to particular chemical residues and food ingredients; this has to be balanced against the ever-increasing demand for food from the growing world population. If suspected elimination trials can be carried out to identify the source of the sensitivity & so avoid it in future.
There are a considerable number of potentially toxic factors in the environment – some natural, e.g. poisonous weeds, venomous snakes & insects, & many man-made. Mankind is steadily poisoning the environment with a variety of pollutants including nitrate fertilisers, nitrous oxides, carbon dioxide (reversing the billions of years of locking-up by nature), waste plastic, etc etc.
The author has known of horses whose itching problem has stopped when moved some miles to a new home, & recurred when moved back, suggesting some local environmental trigger. It is therefore illogical to blame soya alone when sensitivity problems arise; to identify them owners have to either: remove one item at a time from the diet, or make 1 management change; or go to a very basic diet such as unmolassed oat chaff, cooked linseed or soya (not both) and a mineral & vitamin supplement, then add ingredients to that to test for a sensitivity reaction.
Some websites remark that when GM soya was created, besides the genes for glyphosate resistance, others for a protein synthesising gene were included. In the gut there are powerful protein- digesting enzymes which will break down any such material.
Modern precision genetic engineering techniques developed by Jennifer Doudna and Emmanuelle Charpentier have enabled scientists such as Sir Gregory Winter et.al. to develop drugs for treating breast cancer, rheumatoid arthritis (e.g. Humira 2018 global sales US$14BILLION) multiple sclerosis etc. All 3 are Nobel Prize-winners.
The author of this website is privileged to have been taught animal nutrition & physiology, agricultural botany & crop production; & genetics at Cambridge University. He is a member of the same college as Sir Gregory (Trinity.) He has also consumed ale in the same hostelry in which Watson & Crick announced their discovery of the structure of DNA!
Global annual production of soya is currently around 350 million tonnes; any significant problems with its use should have become apparent years ago. It's environmental effect is a controversial topic, which will not be considered here