Have you ever heard from your parents and grandparents that they were shrinking? You may think it's unbelievable, but it's VERY TRUE. But in the terms of shrinking, we are not talking about shrinking as in the movie "Honey, I Shrunk the Kids". Shrinking in this term means getting shorter by few inches as you age.
The cause of it is GRAVITY. Gravity is the force that keeps all things on Earth, including us. Gravity pulls down the parts of the spine: the vertebrae and the disks, and compacts it over time. In result, people get shorter as they get older.
There is another reason for shrinkage. OSTEOPOROSIS. Osteoporosis is when people's bones start breaking down, and getting weaker. That is why it's very important to drink calcium such as milk, to keep your bones strong. Anyways, when people have osteoporosis, the bones get weaker and smaller, resulting in people getting smaller. But do not assume, that everyone who shrunk has osteoporosis. They most likely just shrink due to mother nature . . . gravity.
To wrap it up, did you know that you shrink every day too? In the beginning of the day you're the tallest, then at night you're a little bit shorter. But that's natural! When you sleep, you get taller again, and the cycle repeats.
Author's Note: Source: kidshealth.org/kid/grownup/getting_older/shrink.html
I hope you enjoyed this article; I will be doing a few more science articles. I hope this article was easy for you to understand how people shrink!