Obesity is a well-established risk factor for a whole host of diseases, including diabetes, heart disease, and even cancer. Yet, not everyone who is obese will go on to develop these conditions, and are in fact "metabolically healthy." And now, a new study may explain why: inflammation.
Researchers from University College Cork in Ireland found that lower levels of inflammation are associated with being metabolically healthy, whether you're obese or not.
"From a public health standpoint, we need better methods for identifying which obese people face the greatest risk of diabetes and heart disease," study researcher Catherine Phillips, B.Sc., Ph.D., said in a statement. "Inflammatory markers offer a potential strategy for pinpointing people who could benefit most from medical interventions."
The new research, published in the Journal of Clinical Endocrinology & Metabolism, is based on data from 2,040 people between the ages of 50 and 69 who were part of the Cork and Kerry Diabetes and Heart Disease Study, Phase II., between 2010 and 2011. All the study participants were interviewed on their lifestyle habits, and also underwent testing on their body mass indexes, inflammatory markers and metabolic profiles.
Researchers found an association between inflammatory markers and metabolic health of the study participants, no matter their weight. Being metabolically healthy was indicated by having low levels of white blood cells and acute-phase response proteins (which grow in number during inflammation), as well as higher levels of the anti-inflammatory hormone adiponectin.
Inflammation is a natural body process -- it means your immune system has sensed a threat, and is mobilizing to respond to it -- but too much of it can be bad for health. This blog post from Eating Well summarizes the dangers of chronic inflammation well:
Chronic or systemic inflammation is when the "protect me" signal misfires (which is not a good thing). "Essentially, white blood cells inappropriately move into tissues, causing destruction," explains Floyd Chilton, Ph.D., director of the NIH-sponsored Center for Botanical Lipids and Inflammatory Disease Prevention at Wake Forest Baptist Health School of Medicine in North Carolina. This reaction can happen anywhere in your body. "If [it] happens in the heart, you wind up with heart disease; if it happens in the joint, it's arthritis; in the brain, it might be dementia," Chilton says.