Does genetic engineering impact to human health?
Maybe. Or maybe not. Genetically modified products are new, with new proteins that have never before eaten. We never ate proteins of bacteria in corn or fish proteins in tomato or vrusi proteins in potatoes. Our organisms have no experience with these proteins and there is no way to predict whether they will cause allergies or other chronic diseases after 5 or 10 years.
Genetic engineering technology is not accurate: there is no way to insert a gene to a particular place in the cell. Genes subject to random places. But they do not act in isolation but interact with other genes. New genes can disrupt the activity of other genes may affect the neighboring genes and disrupt important relationships between them. Most likely the market will not appear highly toxic food, but nobody can provide long-term harmful effects of genetically modified foods. Some of them are:
Allergic reactions and immune responses to new substances in genetically modified foods.
Genes which confer resistance to antibiotics can pass that resistance to humans and can no longer be treated the same disease with the same antibiotics.
New genes can affect the manifestation of other genes with unexpected secondary effects.