Sugar improves memory in older adults—and makes them more motivated to perform difficult tasks at full capacity—according to new research.
The study finds that increasing blood sugar levels not only improves memory and performance, but also makes older adults feel happier during a task.
“Over the years, studies have shown that actively engaging with difficult cognitive tasks is a prerequisite for the maintenance of cognitive health in older age. Therefore, the implications of uncovering the mechanisms that determine older adults’ levels of engagement cannot be understated,” says study leader Konstantinos Mantantzis, a PhD student from the psychology department at the University of Warwick.
The researchers gave younger (18-27) and older (65-82) participants a drink containing a small amount of glucose, and got them to perform various memory tasks. Other participants were given a placebo drink containing artificial sweetener.
The researchers measured participants’ levels of engagement with the task, their memory score, mood, and their own perception of effort.
They found that increasing energy through a glucose drink can help both young and older adults to try harder compared to those who had the artificial sweetener. For young adults, that’s where the effects ended, though: glucose did not improve either their mood or their memory performance.
However, older adults who had a glucose drink showed significantly better memory and more positive mood compared to older adults who consumed the artificial sweetener.
Moreover, although objective measures of task engagement showed that older adults in the glucose group put more effort into the task than those who consumed the artificial sweetener, their own self-reports showed that they did not feel as if they had tried any harder.
The authors conclude that short-term energy availability in the form of raised blood sugar levels could be an important factor in older adults’ motivation to perform a task at their highest capacity.
Heightened motivation, in turn, could explain the fact that increased blood sugar levels also increase older adults’ sense of self-confidence, decrease self-perceptions of effort, and improve mood. However, more research is needed to disentangle these factors in order to fully understand how energy availability affects cognitive engagement, and to develop clear dietary guidelines for older adults.
“Our results bring us a step closer to understanding what motivates older adults to exert effort and finding ways of increasing their willingness to try hard even if a task seems impossible to perform,” says coauthor Friederike Schlaghecken, also from the psychology department.
The paper is in press in Psychology and Aging.
Source: University of Warwick