Consuming sugar early in life paves way for poor learning and memory

Eating and drinking high-sugar foods early in life may pave the way for learning and memory issues later in adulthood, according to a new study from the University of Southern California. The findings are particularly concerning in light of how many food products marketed at youth contain high levels of corn syrup and other sugars.

A number of studies have revealed that various foods have different effects on the 'good' bacteria found in the gut; diets high in fat and sugar and low in fiber, for example, are linked to multiple health problems. This latest study focused on sugar and its potential impact on adulthood cognitive function.

The research involved young rats that were given unlimited access to a sugary beverage similar to the sodas and other sweetened drinks teens often drink. Two methods were used to test the rats' memories when they reached adulthood, including one that tested perirhinal cortex-controlled memory and one that tested hippocampus-controlled memory.

When compared to rats that were given ordinary un-sweetened water, the rats that were given unlimited access to the sugary drink were found to struggle with hippocampus-controlled memory function, but not function related to the perirhinal cortex.

The scientists likewise found differences in gut bacteria between the two rat groups, with the sugary drink group featuring greater numbers of two particular gut bacteria species called Parabacteroides distasonis and Parabacteroides johnsonii.

Rats that were given water who received transplants of the Parabacteroides bacteria experienced similar memory issues as the rats who drank the sugary beverage — and they went on to develop issues with perirhinal cortex-controlled memory, too.

The findings directly link gut bacteria changes induced by diet to cognitive function, highlighting the importance of limiting sugar consumption, particularly in youth who are often drawn to sweet drinks and treats.