Angry at Your Spouse? Blame Low Blood Sugar, Perhaps

Low blood sugar levels are enough to make anyone grouchy. Yet a recent study shows how just the right levels could help prevent bickering among married couples.

Based on the findings of a 21-day study, researchers found that levels of blood glucose in married people measured each night predicted how angry they would be with their spouse that evening.

At the end of the 21 days, people who had generally lower levels of glucose were more likely to get in arguments with their spouses.

According to lead study author Brad Bushman, professor of communication and psychology at The Ohio State University, these and future findings on the topic may carry important implications regarding how to help marital arguments and even some cases of domestic violence.

"People can relate to this idea that when they get hungry, they get cranky," Bushman said, via a press release. (He uses "hangry" as a slang term to describe hungry + angry.) "We found that being hangry can affect our behavior in a bad way, even in our most intimate relationships."

For the study, researchers looked at 107 married couples. They study started with the couples completing a relationship satisfaction measure that asked each spouse how much they agreed with statements like "I feel satisfied with our relationship."

All participants were given a voodoo doll in order to represent their spouse, along with 51 pins. At the end of the day over a 21-consecutive-day-period, each participant inserted 0 to 51 pins in the doll, depending on how angry they were with their spouse. They did this alone without their spouses being present and recorded the number of pins stuck in the doll.

A blood glucose measure was also used to measure glucose levels before breakfast and every evening before bed throughout the period.

Findings showed that the lower the participants' evening blood glucose levels, the more pins they stuck in the doll

"When they had lower blood glucose, they felt angrier and took it out on the dolls representing their spouse," Bushman said, via the release. "Even those who reported they had good relationships with their spouses were more likely to express anger if their blood glucose levels were lower."

Yet there's more to the experiment. After the 21 days, the couples came into the laboratory to take part in an experimental task that they were told to complete with their spouse to see who could press a button faster when a target square turned red on the computer. The winner on each trial could blast his or her spouse with loud noise through the headphones.

Though the participants were playing against a computer and not their spouse, each time they won, participants were allowed to decide how loud a noise they would deliver to their spouse would be and for how long it would last.

Nonetheless, just as lower glucose levels translated to more pins stuck in the doll, longer, more intense noise settings also resulted with lower glucose levels.

"Results suggest that interventions designed to provide individuals with metabolic energy might foster more harmonious couple interactions," the authors concluded, via the release. "Food could be a potential tool for curbing aggression by bolstering resources for effective self-control. This intervention might be especially important in stressful settings in which aggression might erupt, such as in prisons, psychiatric hospitals and schools." 

More information regarding the findings can be seen via the Proceedings of the National Academy of Sciences.