Metabolic and cognitive improvement from switching to saccharin or water following chronic consumption by female rats of 10% sucrose solution

High consumption of sugar-sweetened beverages (SSBs) is a risk factor for weight gain and metabolic disease. Whether this risk is reduced by switching to 'diet' beverages containing low-calorie sweeteners (LCS) is controversial. Two experiments modeled whether a switch from SSB to LCS beverages produced positive outcomes on behavioral and metabolic measures. Both experiments consisted of a Stage 1, in which adult female rats received unrestricted access to 10% sucrose solution in addition to chow and water for 4 (Experiment 1) or 8 weeks (Experiment 2). In Stage 2 rats were switched to either saccharin (Suc-Sacch) or water (Suc-Water) or remained on 10% sucrose (Suc-Suc) for a further 4 (Experiment 1) or 7 weeks (Experiment 2). Experiment 2 contained a fourth group that was maintained on water throughout (Water-Water). In both experiments energy intake and weight gain in Stage 2 was reduced for Suc-Sacch and Suc-Water groups relative to the Suc-Suc groups and at cull the Suc-Suc groups showed poorer insulin sensitivity and greater g/kg fat than Suc-Water and Suc-Sacch groups. In Experiment 2 short-term place recognition memory was impaired at the end of Stage 1 but recovered to a similar extent in the Suc-Water and Suc-Sacch groups; when the latter groups were compared with the Water-Water group, recovery was found to be essentially complete. A higher saccharin concentration in Experiment 2 than in Experiment 1 increased absolute amounts of saccharin ingested but intake solution volumes remained low. These results show that switching from sucrose to either water or saccharin produces equivalent improvements on both metabolic and cognitive measures.