Speaking at the Institute of Food Technologists (IFT) Annual Meeting & Expo in the USA Professor Dye presented research linking impaired glucose tolerance in pre-diabetics to reduced cognitive performances – warning that these early signs of diabetes and reduced brain functioning are ‘like a ticking time bomb’ that needs to be reversed.
Dye, who is professor of nutrition and behaviour at the University of Leeds, UK, presented a recent review of 31 previous studies on cognitive performance under various dietary conditions in which she found that those with impaired glucose tolerance group showed difficulties in 12 of 27 cognitive test outcomes - including word recognition, visual verbal learning test, visual spatial learning test, psychomotor test and Corsi block-tapping.
The impaired glucose tolerance group was made up of all middle-aged women who appeared to be in general good health.
"There was significant impairment in those women who were impaired glucose tolerant," said Dye. "To me, that feels like a ticking time bomb.”
Industry action
The UK-based researcher noted while people with impaired glucose tolerance often also show signs of impaired cognitive function, such conditions have the potential to be alleviated through a diet designed specifically for their condition.
Dye called on the food industry to continue researching and developing the best products for consumers with glucose tolerance issues, such as those foods with increased fibre and those with limited glycaemic impact.
“We need to use food – the diet and food industry – to help us shift these people back from impaired glucose tolerance,” she warned. “By the time they get to Type 2 diabetes, the impairments are much more evident."
Also speaking at the IFT session, Dr Nicolas Bordenave, associate principal scientist in the analytical department of PepsiCo Global R&D, added that a key aspect to consider in glucose management is satiety.
Two proven avenues for doing that are a shift toward slowly digestible starch and resistant starch in foods and enhanced viscosity of food through digestion, he said.
However, Bordenave noted that a challenge for food manufacturers is to create foods with these characteristics that taste appealing to consumers. While the translation of new discoveries and findings on the mechanisms of satiety in to food products also remains a challenge, he added.
"From the consumer standpoint there is still a lot to understand," he said. "Right now, people think of glucose management in terms of satiety. They are not aware yet of the effect of glucose delivery on their mental performance, for example, and of all the possible ways to achieve proper glucose management."
“It's really about consumer education."
Cognitive improvement
Dye pointed to a 2009 Japanese study of 129 people in their 80s, 55 of whom had impaired glucose tolerance or Type 2 diabetes. She noted that all the subjects in the study consumed more than 30 grams of dietary fibre per day and exercised two to four times per week over a two-year period.
Within that timeframe, 36 of the people with impaired glucose tolerance showed improvements in delayed recall and block design tests, while those with type 2 diabetes group showed improvement in dementia, delayed recall and their mental state.
"That tells us something about how improving glucose regulation through dietary fibre and exercise could improve cognitive functions," she added.