Serious discussions between spouses shouldn't take place on an empty stomach, a study suggests.
Husbands and wives reported being most unhappy with their spouses when their blood-sugar levels were lowest, usually at night, according to research released this week in the Proceedings of the National Academy of Sciences. Missing a meal, dieting or just being hungry may be the reason, researchers said.
Sugar, or glucose, is used by the brain as fuel to help regulate self-control. Without the fuel, it is more difficult for people to control emotions like anger and aggression, researchers said. The findings are among the first to show how low sugar levels in the body may play a part in marital arguments, confrontations and even domestic violence, said Brad Bushman, the lead study author.
"Self-control comes in part from the fuel we give our brains. This is one of the few physiological aspects we can control," said Bushman, a professor of communication and psychology at Ohio State University in Columbus, in a telephone interview. "People who are hungry are often very cranky."
Researchers in the study included 107 married couples who for 21 days had to test their blood-sugar levels before breakfast in the morning and before bed in evening. They were also given voodoo dolls representing their spouses and told to insert as many as 51 pins daily depending on how angry they were with their partner. The researchers were testing aggressive impulses.
Those with the lowest nighttime blood-sugar levels inserted the most pins, while those with the highest glucose levels inserted the least, the study found. Women tended to stick more pins into their husband voodoo doll, but the finding wasn't significant. The authors only found the association for nighttime blood glucose levels as the amount of sugar in the body drops throughout the day, Bushman said.