Bad diet has consequences on immune system, even before noticeable increase in body weight study reveals
Scientists from the Australian Research Council Centre of Excellence in Advanced Molecular Imaging, investigated the impact of a western-style high fat diet on the immune system.
This new research, published in the Journal of Immunology, found the structure and function of the immune to have been altered prior to weight gain and other clinical signs of obesity.
Lead author, Abigail Pollock, University of New South Wales, explains:
"Obesity is now a huge financial burden to the health systems of many Western countries.
"The World Health Organisation reported in 2014, that more than 1.9 billion adults were overweight, and of these over 600 million were obese.
"But what if immune dysfunction occurs before obesity?" Dr Pollock asks.
"Our research looked at whether bad diets have consequences before we notice an increase in body weight. And we found that the over consumption of saturated fats is a form of malnutrition: one that needs to be taken seriously."
The researchers examined how a diet rich in saturated fats impacts immune function, by examined the impact of dietary lipids on a class of immune cells - T lymphocytes, or T cells.
“We fed mice a western-style high fat diet for nine weeks to observe if this diet would impact the T cell response before the animal gains weight. Despite our hypothesis that the T cell response would be weakened we actually saw the opposite: the percentage of T cells multiplying increased,” added Pollock.
Overactive T cells may be an autoimmune disease, where the immune system begins attacking healthy parts of the body, suggested the study.
A second unexpected finding was that T cell responses were altered even in the absence of obesity and obesity induced inflammation.
“T cells are actually affected prior to the mice becoming overweight. Lipids in the diet change the abundance of lipids in the cell membrane, which in turn changes the structure of the cell altering the responsiveness of the T cells and changing the immune response,” added Pollock.
"The team set out to demonstrate that nutrition is able to directly impact immune function," she says.
However, further research has to be done to better understand which fats we should avoid, Professor Gaus, Deputy Director of the Imaging CoE, emphasizes.