Evidence already suggests that obesity is a major risk factor for type 2 diabetes mellitus (T2DM), and that T2DM has been associated with a higher incidence of Alzheimer’s disease (AD). And, although high-fat diets are known to promote AD-like pathology in mice, it is not known whether consumption of excess sugar also affects the development of AD.
In a study published online ahead of print in the Journal of Biological Chemistry scientists from the University of Alabama at Birmingham studied the effect of a high-sugar diet on a genetic mouse model that develops AD-like symptoms in adulthood. Over a 25-week period, researchers supplemented the regular, balanced diet of half the animals with 10% sucrose-sweetened water. At the end of the trail period, they compared the metabolism, memory skills (by means of various mazes) and brain composition of the regular and sugar-fed mice.
Compared to the control mice with no sucrose added in the water, the sucrose group gained 17% more body weight and developed glucose intolerance, hyperinsulinemia and hypercholesterolemia. These metabolic changes were associated with the exacerbation of memory impairment and a two- to three-fold increase in insoluble amyloid-beta protein (Abeta) levels and deposition in the brain, an anatomical hallmark of AD.
Results underscore the potential role of dietary sugar in the pathogenesis of AD and suggest that controlling consumption of sugar may be an effective way to curtail the risk of developing AD.
