High levels of negative emotions, such as anger, sadness and anxiety, are common among people living with obesity, diabetes or prediabetes. In a new study, researchers from Iowa State University (ISU) suggest these negative feelings may stem from problems regulating blood sugar levels that influence emotional responses in the brain.
The researchers found that people with Type 2 diabetes and prediabetes were more likely to focus on and have a strong emotional response to threats and negative things; these reactions can significantly impact one’s quality of life and increase the risk for depression.
The new findings are published in the journal Psychosomatic Medicine.
For the study, the research team from ISU and colleagues at the University of Wisconsin-Madison analyzed data on startle response, brain activity, cortisol levels and cognitive assessment. Data for the study came from Midlife in the U.S. (MIDUS), a national study of health and well-being.
According to the researchers, gauging the startle response would allow them to measure central nervous system activity through tiny electrodes placed below the eye. Study participants viewed a series of negative, positive and neutral images designed to elicit an emotional response. The electrodes captured the rate of flinch or startle — a reflex we cannot control — associated with each image.
“People with higher levels of insulin resistance were more startled by negative pictures. By extension, they may be more reactive to negative things in life,” said Dr. Auriel Willette, an ISU assistant professor of food science and human nutrition.
“It is one piece of evidence to suggest that these metabolic problems are related to issues with how we perceive and deal with things that stress all of us out.”
The evidence is even more compelling when combined with the results of EEG tests recording activity when the brain is at rest. Participants with prediabetes and Type 2 diabetes showed more activity on the right side of the brain, which is connected to depression and negative emotions.
If someone is predisposed to focusing on negative things, it may become a barrier for losing weight and reversing health issues, said Tovah Wolf, lead author and a graduate student working with Willette on this project.
People with prediabetes and diabetes also showed reduced cortisol levels — a potential indicator of chronic stress — and cognitive test scores, providing additional support for the findings.
Wolf, a registered dietitian, says her experience working with patients suffering from chronic diseases led her to investigate these topics further. She would notice differences in how her patients responded to stress and wanted to know how it affected their motivation to live a healthy life.
Understanding the impact of these biological factors is a vital step in helping improve the quality of life for the one-third of Americans who are obese.
“For people with blood sugar problems, being more stressed and reactive can cause blood sugar to spike. If people with prediabetes and diabetes are trying to reverse or treat the disease, stressful events may hinder their goals,” Wolf said. “Frequent negative reactions to stressful events can lead to a lower quality of life and create a vicious cycle that makes it difficult to be healthy.”
Source: Iowa State University