Most experts believe human beings are how old when they start to shrink?

As men and women get older, their body slows down. They appear to get shorter with age. Each year after the age of 30, men and women lose approximately one heartbeat per minute off their maximum attainable heart rate. This will decrease blood flow and circulation. ‌They also start to shrink since their bones have started to weaken.

With age, the chemical composition of the human body changes. In between the bones of humans, there is a cushion that keeps the bones from rubbing together. Over time this cushion retains less water and deteriorates. Bone mass is also affected.

As the bones of men and women settle in together, they lose a few millimeters at a time. It is normal for people to then shrink by about one inch as they age. If an individual shrinks more than an inch, a more serious health condition may be the cause.