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Throughout your life, the cells in your body are in a constant cycle of replacing themselves. What’s particularly interesting is the vastly different lengths of time that it takes for various cells to renew. Some, such as muscle and fat cells, linger for decades, while others replace themselves every few days (like those in the stomach walls and intestines). And the neurons in the brain’s cerebral cortex, responsible for processes like memory and language, are never replaced.
You may have heard the factoid that you become a “new person” every 7 years because of your cells regenerating. This figure comes from the average length of time it takes for the body’s cells to regenerate (7 to 10 years), though this rate differs drastically by cell type.
Skin cells are no exception – like the rest of your body, they are in a constant state of flux. As the keratin-producing cells located in the upper layer of the epidermis mature, they eventually die and fall away, and are replaced by new cells that form in the deeper levels of the epidermis.
Yet this skin regeneration happens at different rates depending on your age. It happens as quickly as every two weeks for babies and children, and averages around 28 to 42 days by the time you reach adulthood. The slowdown continues and the skin regeneration cycle can take as long as 84 days for people over age 50, which means more dead cells on the skin’s outermost layer. Following a healthy lifestyle involving plenty of exercise, a good diet, and regular hydration can promote skin regeneration. Exfoliating products can also help remove unwanted dead skin cells.
Cells, cells, everywhere:
- There are roughly 30 trillion cells in the human body. Every day, around 1% of your cells are replaced (that’s approximately 330 billion cells).
- The skin is the largest and heaviest organ in the human body and is equivalent to up to one-seventh of your body weight.
- The thickness of the epidermis varies significantly depending on its location. At its thickest point (on the soles of your feet or palms of your hands) it can be up to 4 millimeters thick, whereas it is just 0.3 mm thick on your elbows and behind your knees.