The European Food Safety Authority (EFSA) has issued guidance principles for conducting two-year whole food studies “to assess the risk of cancer and/or toxicity from the long-term consumption of such foods by humans.” Acting at the behest of the European Commission, EFSA relied on testing guidance (TG) 453 from the Organization for Economic Co-operation and Development in addition to considering the views of member state experts consulted through the Scientific Network for the Risk Assessment of GMOs. The agency has cautioned, however, that testing individual chemicals in animal models “may result in adverse effects caused by dietary imbalance rather than any potential toxicity of the whole food itself,” urging researchers to carefully design studies to avoid this outcome and to use a larger number of animals when conducting whole food studies.

“[I]t is essential that scientists implementing its guiding principles should define clear and specific objectives before starting a two-year feeding study for whole food. Identifying the exact nature of the risk that the study seeks to assess is key to this process if potential hazards have previously been identified which warrant further investigation,” noted EFSA in a July 31, 2013, news release. “The decision on the need for a two-year study should be based on an evaluation of all available information, such as results from previous analyses of the food’s composition and findings from earlier nutritional and toxicological studies.”