Not all body fat is the same. Scientists have identified the presence and significance of brown fat in adult humans. Shing Kajimura researches brown fat and how its presence curbs obesity and type 2 diabetes as well as other metabolic diseases.

Listen and learn

• What mechanisms cause brown fat to produce heat for our bodies and become a "metabolic sink" for glucose and lipids,
• How the amount of brown fat we have depends on age, climate, and time of year, and
• How researchers hope to use this to produce therapeutics for metabolic diseases like type 2 diabetes treatments.

Shingo Kajimura is with Harvard Medical School's Beth Israel Deaconess Medical Center and works in the endocrinology, diabetes, and metabolism division. He's interested in molecular bases by which we adapt to different environmental stresses like nutritional changes, dietary changes, and even temperature changes. Enter brown fat. Adult humans have brown fat around their neck, almost like an internal scarf, and in a few other areas. When we got cold and shivering can no longer do the trick to warm us, brown fat's thermogenesis steps in. He explains exactly how it undergoes a molecular process similar to how a light bulb emits energy, which in turns eats up glucose and lipids. Enter type 2 diabetes causes. 

This brown fat activity has associations with improved lipid and glucose handling. Because it eats up glucose and lipids, it is a significant "metabolic sink" for these molecules. It literally takes up glucose and combusts it in cells. Unfortunately, we can't just deposit brown fat in people as a type 2 diabetes cure. He explains how climate, which also implicates seasonality, and age connect to brown fat presence. There's a significant decrease in brown fat when we hit our forties and fifties.

Cold adaptation is also a factor, and the body starts making brown fat fairly quickly after cold exposure. All these factors make the issue a little more complicated and Dr. Kajimura explains how in very clear terms. There is hope that this research may benefit those of us that could benefit from more brown fat. He comments that researchers are looking at bio medics to make our fat cells feel cold without our brain actually thinking the same.

For more about his work, see his lab's web page: kajimuralab.org.

Available on Apple Podcasts: apple.co/2Os0myK