Have there been any unexpected changes in the nutrient content of Golden Rice?

The compositional evaluation of crops intentionally modified to express altered nutritional properties, such as GR2E Golden Rice, is intended to determine whether the composition differs significantly from its traditional counterpart aside from the intended change, and to assess the safety of the intended change and any unintended changes. Golden Rice is intended to produce provitamin A in the grains, unlike white rice, but otherwise its composition is intended to be equivalent to conventional rice.

The composition of key nutrients and anti-nutrients was determined in samples of GR2E rice grain (paddy), straw, and derived bran and compared to corresponding values from samples of conventional white rice. The choice of compositional parameters was based on the OECD consensus document on compositional considerations for new rice varieties, which for rice paddy included proximates, fibre, polysaccharides, fatty acids, amino acids, minerals, vitamins, and anti-nutrients. Straw and bran samples were analyzed for proximates and minerals.

The only biologically meaningful difference between GR2E Golden Rice and control rice was in levels of beta-carotene and other provitamin A carotenoids in the grain. Except for beta-carotene and related carotenoids, the compositional parameters measured in GR2E rice were within or similar to the range of natural variability of those components in conventional rice varieties with a history of safe consumption.

Other than the intended production of provitamin A in the grains, GR2E Golden Rice was found to be compositionally equivalent to conventional rice and there were no observed unintended, unexpected, changes in nutrient composition as a result of the genetic modification process.