According to a study carried out at SUNY Downstate Medical Center and other institutions, being overweight appears to be related to reduced levels of a key molecule that reflects brain cell health in the hippocampus - a part of the brain involved in memory, learning and emotions and likely also involved in appetite control.
A multicenter team worked together to visualize the molecule - known as N-acetyl-aspartate (NAA) - using magnetic resonance spectroscopy, a non-invasive magnetic resonance imaging (MRI) application.
This study included subjects with a body-mass index (BMI) equal to or greater than 25, where normal weight is defined as a BMI of 18.5-24.9, being overweight falls between 25 and 29.9 and obesity is at a BMI of 30 or greater.
Levels of NAA are associated with brain cell health. Overweight study participants had lower levels of NAA in the hippocampus when compared to normal weight subjects. This effect was independent of age, sex and psychiatric diagnoses.
Health experts have long been aware of the significance of the brain area known as the hippocampus for the formation and preservation of memory and emotional control. However, its role in appetite control is less well known.
This study - the first human research examining the relationship between NAA and body weight - shows that being overweight is associated with specific changes in the hippocampus and may affect memory formation and emotions, along with probably appetite as well.
Whether low NAA levels arise as a consequence of being overweight or whether NAA levels are responsible for being overweight or if a combination of both these situations is ultimately responsible still remains to be determined. Future studies are planned to understand if weight loss leads to an increase in NAA.
Study researchers also found that high worry also produced low levels of NAA in the hippocampus, but was not associated with a high BMI.
Overall, this study adds to the already massive body of evidence that being overweight or obese is unhealthy for your mind and body on many different levels.