Overweight People at Greater Risk of Stress-Related Diseases

Overweight or obese people are at a higher risk of developing cancer, type-2 diabetes and other stress-related diseases, a study has revealed.

It is a well-documented fact that psychological stress leads to a biological response that is similar to the effect of illness or injury including inflammation. Normal inflammation is crucial part of the body's healing response; on the other hand, runaway inflammation triggers chronic and life-threatening diseases.

In the recent study, researchers at the Brandeis University focused on a group of overweight and obese individuals that had higher levels of stress-induced inflammation as compared to those falling within the range of healthy weight. They noticed that there existed a significant association between weight and stress-induced inflammation.

"We've known that overweight and obese individuals already have chronic, low grade inflammation," said psychology professor Nicolas Rohleder, the study's principal investigator. "Now, it seems that when you add stress to the mix, it's a double hit."

To prove the hypothesis, the researchers measured the levels of interleukin (IL-6) - an inflammatory agent tied to stress. Using these measurements, they evaluated the levels of inflammation in both normal-weight and overweight individuals over the course of two psychological stress tests. Subjects' weights were further classified into several factors that include body mass index (BMI), body fat percentage. Those with BMI of 25 or higher were classified as overweight.

On day one of testing, a similar reaction to stress was seen from both lean and overweight individuals, irrespective of the higher starting levels of IL-6 in overweight subjects. On day two of testing, there was two-fold increase in the IL-6 levels among overweight subjects, whereas the IL-6 levels in the lean participants remained the same.

According to the researchers, a linear association existed between BMI and IL-6 levels.  Higher the BMI, higher were the levels of IL-6. The same applied for the lean individuals as well.

"It seems that every percentage point of body fat makes your more susceptible to inflammation," said graduate student Christine McInnis.

The finding was documented in Brain, Behavior and Immunity.