Do our bodies turn over every 7 years?

[Gvac]

Hey buddy -

Is it true that your body chemistry changes every seven years? I've heard this on several occasions and in my own life I've "outgrown" allergies and my hair has changed from very straight and fine to very curly to very thick and coarse.

Thanks!

[Dr Steve]

Hey buddy -

Is it true that your body chemistry changes every seven years? I've heard this on several occasions and in my own life I've "outgrown" allergies and my hair has changed from very straight and fine to very curly to very thick and coarse.

Thanks!

I think this comes from the idea that the ATOMS in your body turn over approximately every seven years. Outgrowing allergies is more a function of being desensitized to allergens over time.

This study in its entirety reported that most human cells are much younger than the human host itself:

Cell. 2005 Jul 15;122(1):133-43.

Comment in:
Cell. 2005 Jul 15;122(1):4-6.

Retrospective birth dating of cells in humans.

Spalding KL, Bhardwaj RD, Buchholz BA, Druid H, Frisén J.

Department of Cell and Molecular Biology, Medical Nobel Institute, Karolinska
Institute, SE-171 77 Stockholm, Sweden.

The generation of cells in the human body has been difficult to study, and our
understanding of cell turnover is limited. Testing of nuclear weapons resulted in
a dramatic global increase in the levels of the isotope 14C in the atmosphere,
followed by an exponential decrease after 1963. We show that the level of 14C in
genomic DNA closely parallels atmospheric levels and can be used to establish the
time point when the DNA was synthesized and cells were born. We use this strategy
to determine the age of cells in the cortex of the adult human brain and show
that whereas nonneuronal cells are exchanged, occipital neurons are as old as the
individual, supporting the view that postnatal neurogenesis does not take place
in this region. Retrospective birth dating is a generally applicable strategy
that can be used to measure cell turnover in man under physiological and
pathological conditions.


So how can we have cells that are 14 years old, but we are 53 years old (or whatever) and still be "us"? and if this crap is true, why do we have to get old and die? What do you get when you cross an elephant and a rhinoceros? "ElePhino!"

[jauble]

I got allergies after I hit 23, bullshit I tell you.

[Radioguy]

That made me wonder how people get LSD flashbacks after so many years. If the remaining acid is in the brain, and bonded to some cells or something, how can it remain once the cells are replaced? (assuming they are)

[Fez4PrezN2008]

Sooo... you're saying Gvac has the brain cells of a 7 year old. OK, all makes sense now.