London, Jul 20 (IANS): For older adults (over 60), increase in sugar levels can improve memory and make them more motivated to perform difficult tasks at full capacity, according to new research.

The findings showed that high blood sugar levels not only improves their memory and performance, but also makes older adults feel happier during a task.

"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," said Friederike Schlaghecken, from Britain's University of Warwick.

For the study, reported in the journal Psychology and Aging, the team gave young (aged 18-27) and older (aged 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 - a drink containing an artificial sweetener.

Older adults who had a glucose drink showed significantly better memory and more positive mood compared to older adults who consumed the artificial sweetener.

But, in young adults, the glucose did not improve either the mood or the memory performance.

The researchers noted 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, the researchers said.