Do adults retain significant brown adipose tissue, and how does age affect BAT?

Do adults retain significant brown adipose tissue, and how does age affect BAT?

• A. Adults have no detectable brown adipose tissue; it is present only in infancy.
• B. BAT activity remains constant from infancy through adulthood.
• C. BAT is present in adults at similar activity to infancy but becomes less efficient with age.
• D. Adults have detectable BAT, though less abundant than in infancy; BAT activity decreases with age and obesity.

Answer: (D)

Brown adipose tissue is the heat-generating tissue that uses UCP1 to convert energy into heat. It’s essential in infants for maintaining body temperature, but it doesn’t disappear in adults. In adults, BAT can still be detected, especially in areas like the neck and upper chest, but it is much less abundant than in infancy. Its activity is notable when stimulated by cold, which increases thermogenesis and energy expenditure. As people age, both the amount of BAT and its ability to burn energy decline. Obesity is also associated with reduced BAT activity and mass, making thermogenic responses less robust. Together, these trends explain why adults have detectable BAT, but less of it, and why its activity tends to decrease with age and higher adiposity.

Brown adipose tissue is the heat-generating tissue that uses UCP1 to convert energy into heat. It’s essential in infants for maintaining body temperature, but it doesn’t disappear in adults. In adults, BAT can still be detected, especially in areas like the neck and upper chest, but it is much less abundant than in infancy. Its activity is notable when stimulated by cold, which increases thermogenesis and energy expenditure.

As people age, both the amount of BAT and its ability to burn energy decline. Obesity is also associated with reduced BAT activity and mass, making thermogenic responses less robust. Together, these trends explain why adults have detectable BAT, but less of it, and why its activity tends to decrease with age and higher adiposity.