Benefits and risks of GM crops

Genetically modified (GM) crops have had their genes modified to give them desired characteristics. These characteristics can help farmers reduce crop losses or improve the quantity and quality of the food produced.

Benefits of GM crops

A GM crop may be made resistant to disease or insect attack. If fewer plants are damaged or lost, more of the crop can be harvested. A crop may also be made resistant to a herbicide, allowing the herbicide to be used against unwanted plants without damaging the crop.

Other modifications can produce larger or better-quality fruits. By reducing losses or improving production, GM crops generally give increased yields: more crop is harvested from the same area of land.

Risks and concerns about GM crops

Changes in how a GM crop is grown can affect organisms beyond the crop itself. For example, herbicide use may reduce wild flower populations in and around fields. Insects that depend on those plants for food or habitat may then also be affected.

Some people also question whether the effects of eating GM crops on human health have been fully explored. A concern about a possible effect, however, does not by itself establish that harm occurs.

Medical applications of genetic engineering

Genetic engineering can give cells a gene that provides instructions for making a useful substance. A gene can be cut out of the chromosomes of one organism and transferred into cells of another organism. The receiving cells can then use the gene to make the substance.

Producing human insulin

A human gene for insulin can be introduced into bacterial cells. The bacteria use the gene’s instructions to produce human insulin, which can be collected and used to treat diabetes. This allows a medicine needed by patients to be produced using genetically modified organisms.

Medicines made this way must be assessed for safety and purity before use. For example, the insulin preparation must be checked for harmful contaminants as well as whether it is safe for patients.

Investigating inherited disorders

An inherited disorder can result from a gene that does not provide functional instructions for making a protein. Researchers are investigating whether introducing a functional gene into affected cells could allow those cells to make the protein. This could address an underlying genetic cause of a disorder, rather than only treating its effects.

Changing human cells can have unintended effects, and the long-term outcomes may be uncertain. Some people also have ethical objections to modifying human cells. These risks and concerns must be considered alongside the potential benefits.

Genetic modification for inherited disorders

Some inherited disorders are caused by a faulty gene that prevents cells from making a functional protein. Genetic modification is being explored as a treatment for some of these disorders by introducing a working copy of the gene into affected cells.

If the introduced gene works in those cells, it can provide the instructions for making the functional protein. This may reduce the effects of the disorder. The treatment aims to address the effects of the faulty gene; it does not necessarily remove or repair that gene.

Limitations and risks of genetic modification

A working gene must reach enough of the relevant cells to make a useful difference. Even if it does, its effect may not last. A delivery vector is used to carry the gene into cells, but the body may react to the vector, causing an immune reaction. Genetic modification can also cause unintended changes to DNA.

Genetic modification of embryos

Some people object to modifying embryos because the changes could be inherited by future generations. Those generations would also be affected by consequences that may be uncertain in the long term.