A glass of sugar water boosted older adults’ memory without increasing exertion, according to results recently published in Psychology and Aging.
“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,” Konstantinos Mantantzis, a PhD student in the department of psychology at the University of Warwick in the United Kingdom, said in a press release.
Researchers randomly assigned 112 participants — 54 were aged 18 to 27 years; 58 were aged 65 to 82 years — to receive either a drink containing 25 g of glucose or aspartame. Both sweeteners were dissolved in 300 mL of water and 25 mL of sugar-free orange-flavored cordial to improve palatability. Participants performed a memory-search task, then rated 10 abstract expressionist paintings, and had their heart rate measured throughout the session.
“In older but not in young adults, glucose ... improved cognitive performance and increased positive affect,” the researchers wrote. “Subjective effort, in contrast, did not differ between the older-glucose and older-placebo groups. These results suggest that in older adults, glucose improves cognitive performance by promoting higher cognitive engagement while mitigating the subjective costs of effortful exertion.”
Mantantzis and colleagues found that older adults who consumed the sugar drink used more of their memory on the required task (P = .048); took longer to rate each painting (P < .001) and had higher heart rates (P = .001) vs. the young 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,” Friederike Schlaghecken, MA, PhD, DSc, of the department of psychology at the University of Warwick, said in the release. – by Janel Miller
Healio Family Medicine was unable to determine the authors’ relevant financial disclosures prior to publication.