Your Daily Blood Glucose Levels
May Affect Your Decision Making
A new American study suggests that fluctuating blood glucose levels
may affect decision-making
Psychological scientists X.T. Wang and Robert D. Dvorak from
the University of South Dakota looked into how blood glucose levels
affect our thinking about present and future rewards.
Participants in the study answered a series of questions asking
if they would prefer to receive a certain amount of money tomorrow
or a larger amount of money at a later date. The subjects answered
seven of these questions before and after drinking either a regular
soda that contained containing sugar or a diet soda, which contained
the artificial sweetener aspartame. Blood glucose levels were
measured at the beginning of the experiment and after the participants
drank the soda.
It was seen that blood glucose levels might influence peoples
preferences for current versus later rewards. The volunteers who
drank the regular sodas and thus had higher blood glucose levels
were more likely to select receiving more money at a later date,
while those who had diet sodas and had lower blood glucose levels
were likely to opt for receiving smaller sums of money immediately.
These findings suggest an adaptive mechanism linking decision
making to metabolic cues, like blood sugar levels.
The results show that when we have more energy available (higher
blood glucose levels), we are likely to be more future-oriented.
The authors of the study write, "The future is more abstract
than the present and thus may require more energy to process.
Blood glucose as brain fuel would strengthen effortful cognitive
processing for future events."
On the other hand, having low energy (low blood glucose levels)
may make an individual focus more on the present. It can also
be said that artificial sweeteners may alarm the body of imminent
caloric crisis, causing increased impulsivity.
The authors conclude that if controlling blood glucose levels
may influence our decisions for later versus current rewards,
then "reducing the degree of fluctuation in blood glucose
may offer a possible means for the treatment and intervention
of some impulsive disorders, anorexia, drug addiction, and gambling
The findings of the study have appeared in Psychological Science
, a journal of the Association for Psychological Science.
January 27, 2010