How Does Adipose Grow?
Adipose tissue, or body fat, grows through two primary mechanisms: hyperplasia and hypertrophy.
Hyperplasia involves the creation of new fat cells (adipocytes). This is considered a healthier way for adipose tissue to expand (Vishvanath and Gupta, 2019). These new cells are initially small. Think of it like adding more, smaller containers to store lipids (fats).
Hypertrophy: An Increase in Fat Cell Size
Hypertrophy, on the other hand, refers to the enlargement of existing fat cells. As the body stores more lipids, individual fat cells swell up to accommodate the excess (Cleveland Clinic, 2022). This is what happens in obesity when the body has a limited supply of fat cells to store lipids. Existing cells have to grow larger to contain the excess lipid accumulation. Imagine filling up existing containers until they are overflowing.
The interplay of Hyperplasia and Hypertrophy
The relative contribution of hyperplasia and hypertrophy to adipose tissue growth depends on various factors, including genetics and diet (PubMed, 2009). In healthy adipose tissue expansion, hyperplasia plays a more significant role, while in obesity, hypertrophy dominates. Brown fat cells are smaller than white fat cells and their growth capacity is limited (Endotext, 2020).
Adipokines and Adipose Tissue Growth
Fat cells produce hormones called adipokines which can influence cell growth (NCI, 2022). Some adipokines stimulate growth, while others inhibit it, highlighting the complex regulation of adipose tissue expansion.
Other Factors Affecting Adipose Growth
- Temperature: Cool temperatures can increase brown fat levels (NIH, 2014).
- Lipomas: These benign fatty tumors grow slowly, comprised of mature adipose tissue with minimal connective tissue (StatPearls).
- Cancer: Cancer cells can utilize lipids from adipose tissue to fuel their growth and spread (MSKCC, 2018).
The capacity of adipose tissue to store lipids is increased either by enlarging existing fat cells (hypertrophy) or by increasing the number of fat cells (hyperplasia). Both processes play a role in adipose tissue growth but their relative contributions differ depending on factors including genetics and diet.
