What is the truth about the human body changing approximately every seven years?

I had always heard it put something like this: Within a seven year period, every cell in your body will have been replaced.

That isn’t quite true as it turns out. Some neurons can last a lifetime.

I have heard the 7 year thing from people but never from doctors (not that doctors aren’t people but you know what I mean). I therefore, take it as a myth.

In my experience I really don’t remember how I was exactly 7 years ago. Change comes constantly and we can barely notice it, I’d say the body never stops changing.

It depends on what part of the body you ate talking about. Some things totally change every few days while others, mostly those dealing with the brain, never change.

Thanks all. The person who mentioned this was talking about hormonal changes that affected the body, and not cells or neurons. Examples are: hair, growth spurts, puberty, menopause, etc.

I agree with @fremen_warrior. We are changing all the time, little by little, without noticing it. Unless it’s something you can see and measure, like your fingernails and your hair. Think about it. Your hair changes color, texture, length. Your shoe size changes. Obviously, your weight changes. Even your eyes can change color.

@fremen_warrior and @Sunny2 That’s what I am wondering. Obviously these bodily changes don’t occur overnight.

Some seem to kick in at a certain age though. Is there a pattern? If so, is it caused by genetics or something else? It isn’t as if we all hit puberty or stop growing at a wide range of ages..

I hate to say this, but I never had allergies to anything… Now I can’t eat mustard or black pepper and have horrible hayfever. All are things that came about in the last 2 years and I am turning 29 this summer.

I too have wondered what in my body has changed. The doctor says that it is normal to develop allergies as you get older, but why….?

I think 7 years is the average. Some skin cells get replaced in short time spans. And most neurons live longer.