Brown Fat vs. White Fat: What You Need to Know

Adipose tissue has various functions, including temperature regulation, heat generation, insulation, and fat and fat-soluble vitamin storage. Adipose tissue comes in two main fat types with distinct functions brown and white. Read more to learn the difference between white and brown fat.

Key takeaways:

Brown fat vs. white fat: Is it different?

Adipose tissue is categorized into white and brown adipose tissue, and both have distinct functions:

  • Brown fat is known as good fat that generates heat to regulate body temperature.
  • White fat stores fat and fat-soluble vitamins and provides insulation.

Although they are different types of adipose tissue, it is possible to transform white adipose tissue into brown adipose tissue.

Characteristics and functions of brown fat

Brown adipose tissue (BAT), known as brown fat or good fat, is specialized in generating heat and regulating body temperature. It's distributed in the neck, just above the collarbone, near the shoulder and neck junction, and around the kidneys and chest area.

Brown fat is mitochondria rich

Brown fat is high in mitochondria, which are organelles responsible for energy production in cells. That's why the mitochondria are called the powerhouse of the cell. Brown fat's mitochondria-dense and vascularized (covered by many blood vessels) structure looks brown, which gives the name to the adipose tissue.

Brown fat regulates body temperature

Brown adipose tissue generates heat through non-shivering thermogenesis, which is critical to maintaining body temperature in newborns. In non-shivering thermogenesis, the body generates heat after exposure to cold temperatures without inducing shivering. Adults also have BAT depots that are activated during cold exposure, such as cold plunges and ice baths.

BAT cells contain a protein called uncoupling protein 1 (UCP1), which is located on the inner mitochondrial membrane. During non-shivering thermogenesis, UCP1 is expressed, which changes the mitochondrial pathway from generating ATP to heat.

Brown fat is positively correlated with resting metabolic rate

BAT is associated with resting metabolic rate, which shows the body's calorie burn at rest. Higher BAT was associated with a higher resting metabolic rate. Given the fact BAT activity has been shown to decrease in overweight and obese people, manipulation of BAT can be used as a therapeutic approach to treat obesity.

Characteristics and functions of white fat

White adipose tissue (WAT), also known as white fat, represents the majority of fat tissue in the body, accounting for 10 to 20% of weight in healthy people.

White fat provides insulation and protection

White adipose tissue is distributed throughout the body mostly as subcutaneous fat, which is the layer of fat that lies between the skin and the underlying muscles. It serves as a form of insulation, protection, and energy storage.

White fat stores energy and vitamins

The main function of white fat is to store triacylglycerols (TAG), also known as triglycerides, which are a type of lipid molecule that serve as a primary storage form of energy.

Triacylglycerols stored in WAT break down into fatty acids and glycerol when needed. These fatty acids are then released into the bloodstream and can be taken up by various tissues, including muscle and liver cells, to be used as an energy source.

White fat also stores fat-soluble vitamins such as A, D, E, and K.

White fat is the largest endocrine tissue

Adipose tissue produces many biologically active molecules, including adipocytokines, which are messenger molecules between adipose tissue and other organs.

Their effects can be both beneficial and detrimental, depending on their concentrations and the overall context of their actions. They have a major influence on metabolism and endocrine functions. One of the adipocytokines is leptin, which is known to influence energy expenditure and appetite regulation.

Health risks associated with excess white fat

Excess white adipose tissue is associated with a range of health risks and complications.

Obesity, characterized by the accumulation of excess body fat, particularly white adipose tissue, contributes to chronic diseases such as type 2 diabetes, metabolic syndrome, and cardiovascular diseases.

Is it possible to turn white fat into brown?

Scientists have been exploring the potential of turning white adipose tissue into brown adipose tissue to increase energy production, which can tackle obesity.

The transformation of white fat to brown fat is called '' browning'' or "beiging." Beige adipose tissue, also known as beige fat or brite (brown-in-white) fat, is a specialized type of fat tissue that shares some characteristics with both white adipose tissue (WAT) and brown adipose tissue (BAT).

Beige adipose tissue occurs due to white adipose tissue browning, which is a process of white fat adapting to brown fat functions as a response to increased energy expenditure, such as cold exposure and exercise.

Research highlights several ways to induce beiging of subcutaneous white adipose tissue:

  • Exercise. In animal studies, physical activity has been shown to increase markers of beige adipose tissue. Exercise also decreases the size of white adipose tissue and lipid content, reducing adiposity.
  • Cold. Cold exposure has been shown to contribute to browning of white adipose tissue.

In a study, browning and brown tissue activity markers were compared between 150 Siberian miners living in extreme cold and 29 people living in thermoneutral conditions. Results showed that Siberian miners had higher levels of beiging markers and lower body weight and body mass index (BMI).

Understanding the roles of brown and white fat in the body sheds light on their impact on metabolism, temperature regulation, and overall health. The possibility of converting white fat to brown fat can be a therapeutic approach to tackle obesity and related health concerns.



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