It's a beautiful idea, when you think about it: You can leave the old you behind and become a completely new person every seven years. Unfortunately, it's just not true. Chances are you can't actually remember where you heard this, but the truth is that the seven-year myth isn't even a rough average of every cell's lifespan.
The Birth of a Cell
To understand how often your cells replace themselves, you need to understand how cells come into being in the first place. Your body can make new cells in a couple of ways. First, existing cells can divide via a fairly simple process called mitosis. During mitosis, a parent cell splits into two new cells. These new cells, called daughter cells, are basically copies of the original cells.
The second way that cells are created is from stem cells. These are special cells found throughout the body, although in lower numbers. They're able to….
image credit: agawa288 / iStock / Getty Images Plus