Recently, a patient asked, “What is brown fat and will liposuction get rid of all my brown fat?” Well, I got to thinking and realized that I have never really removed brown fat either with liposuction or by surgical excision. Please let me explain. Basically, in our bodies, there are two types of fat: brown and white fat. First, let's look at their primary difference, namely color.
What Does Brown Fat Look Like? Why is Brown Fat Brown?
Brown fat is unique in that brown fat has a high number of mitochondria. Mitochondria are highly specialized cells that convert sugar into energy and heat. Also, brown fat has a high number of capillaries to distribute heat created by the mitochondria. To further spread and dissipate heat, brown fat has many small droplets of fat called lipids. Because brown fat has so many capillaries and its mitochondria has so much iron, this is why brown fat is tinged brown.
What Does White Fat Look Like?
In contrast to brown fat, white fat has a low number of mitochondria, a small number of capillaries, and has only a single fat droplet. Since white fat has fewer mitochondria and capillaries than brown fat, white fat is white instead of brown.
What is Beige Fat?
To make things slightly more confusing, there is also beige fat. Technically, beige fat is a type of brown fat. Think of beige fat as brown fat on its way to becoming white fat. Since beige fat has fewer mitochondria than classic brown fat, beige fat is lighter in appearance. Beige fat is dispersed throughout your body in the fat tissue. Beige fat is regulated by your adrenal glands.
Well, Why Do We Have Brown Fat?
Think of babies and bears here. Brown fat is most common in babies and hibernating mammals. Brown fat’s primary function is to generate heat. On average, brown fat makes up about 5% of an infant’s body mass. Keeping warm by heat production from brown fat is critical for an infant's survival. Think of all the blankets and heat lamps in the hospital. This is why brown fat is so essential. Heat generated from brown fat is very different from the heat that is made from shivering.
What Happens to the Brown Fat As We Age?
As we age, most of the mitochondria in brown fat disappears and, thus, the percentage of brown fat in our bodies decreases. Most brown fat becomes similar in function and appearance to white fat. Perhaps this is why older patients are more sensitive to the cold.
Where is Brown Fat Located?
In infants, brown fat is located around the shoulder blades (scapula), neck, clavicle, back and deep inside your body around the kidneys, heart, and pancreas. In adults, brown fat is found around the clavicle, spine, heart, and kidneys.
How Do You Turn Brown Fat On? How is Brown Fat Activated?
As you can probably guess, brown fat is activated by cold.
What Exactly Happens When Brown Fat is Activated?
Many things happen after brown fat activation. This is an exciting new field of study with almost limitless boundaries. After cold exposure, brown fat activation leads to an increase in several proteins and hormones. There are four primary molecules which are increased by brown fat activation. First, adiponectin levels are increased. Adiponectin leads to lower levels of C-reactive protein and E-selectin. Adiponectin has been linked to a longer lifespan. Second, Fibroblast Growth Factor 21 levels are increased. Fibroblast Growth Factor 21 improves insulin sensitivity and glucose stability. Fibroblast Growth Factor 21 has also been linked to a longer lifespan. Third, irisin concentrations are increased. Irisin enhances insulin sensitivity and glucose stability. Irisin also increases bone health and helps to build lean muscle mass. Somehow, irisin also increases the conversion white fat to brown fat and, thus, reduces obesity. Irisin may also be linked to a longer lifespan. Fourth, sirtuin levels are increased. Sirtuin improves insulin sensitivity and glucose stability. Sirtuin also triggers the conversation of white fat into beneficial brown fat.
How is Brown Fat Beneficial?
Activated brown fat has been shown to: Decrease triglyceride levels Decrease cholesterol levels Decrease atherosclerosis development Improve insulin sensitivity Improves bone density Improves bone health Stabilize glucose levels You see, brown fat is a useful type of fat to have. Brown fat has many “good" qualities. Fortunately, brown fat is hidden deep in our bodies and is protected from the liposuction cannula. So go and have your white fat removed, but leave your brown fat behind. If you have any more questions about brown fat, beige fat, white fat, or VASER liposuction, please call my office at (310) 859-7770 to schedule an appointment. I have offices in Beverly Hills, CA and Las Vegas, NV.