The effects of the solution of glucose molecules on the dynamics of solvent water have been studied by quasielastic neutron scattering (QENS) measurements on solutions of selectively deuterated glucose in natural water. The data are fitted to two Lorentzians ascribed to pure translational and mixed translational and rotational character, respectively. The addition of the glucose to the water causes a substantial slowing down, by a factor 10 for the translational diffusion and 3-4 for the rotational motion at the highest concentration studied, 1:11 C6H12O6:H2O. The values obtained for water diffusion constants are consistent with previous QENS and NMR experiments on monosaccharide solutions but an order of magnitude higher than those derived from a recent molecular dynamics simulation.