The research you reference was addressed by the Royal Society, which is a fellowship of the world's most eminent scientists and is the oldest scientific academy in continuous existence. The Royal Society convened a panel of scientific experts to review the research and found “no convincing evidence of adverse effects from GM potatoes,” due in part to a number of flaws in study design, execution and analysis. You can find the highlights and full repor,t conducted in 1999, here.
The panel also pointed out that this research was conducted on “one particular species of animal, when fed with one particular product, modified by the insertion of one particular gene by one particular method.” It would be very difficult to base conclusions about the overall impact of GM foods and health on the results from this study or any other single study.
In contrast, there have been thousands of studies done on GM crops and their impact on human food safety, animal food safety and the environment. The overwhelming body of evidence has shown the safety of GM crops and food produced from them. For example, the Biofortified website includes a database of peer-reviewed reports in the scientific literature which document the general safety and nutritional wholesomeness of GM foods and feeds. Visit the database here for more details.