AGING MEASURES - BIOMARKERS
Biomarkers for Aging
We need biomarkers for aging: ways of measuring the
progression of the aging process in our bodies.
Early studies on biomarkers reveal that even though
effective markers can be established, using them to
measure how effective an antiaging measure is, is still
in the early stages of development.
Of course, this will take time, and probably more than
a few 30-year studies. Until these studies have validated
these “biomarkers” and measurement criteria,
there will be no mainstream acceptance of anti-aging
treatments.
Much of the current debate over biomarkers is in the
naming convention rather than disagreement as to what
constitutes a valid marker. So, whilst this debate continues,
we can reasonably make fair assumptions as to what these
markers are.
We must also consider that benchmarks will change.
What was previously considered an effective result,
such as having a 5 year impact, will no longer be acceptable,
when new products and treatments are promising a 10
year impact.
But we need to start somewhere. The accepted first
step to establishing biological markers to aging is
still to establish scientific consensus on those factors
that cause aging. As yet, there is not full consensus
in the scientific community.
So firstly, let’s accept well known biomedical
gerontologist, Dr Aubrey de Grey's findings that there
are seven major types of damage that accrue to the passing
of time. If we could fix them all, we simply wouldn’t
age.
Dr De Greys list includes:
- Cell loss - older cells harbor fewer progenitor
cells, tissue-specific or adult stem cells, capable
of dividing to replace damaged or lost cells.
- Mutations in our chromosomes
- Mitochondrial mutations
- Excess cells of unneeded types [senescent cells,
fat cells]
- Extra-cellular cross linking [reaction between
sugars in the blood stream and long lived proteins
that causes, among other problems, hardening of the
arteries]
- Extra cellular junk, garbage that needs to be brought
into the cell to be broken down by the cellular lysosomes
- Junk within the cells that the lysosomes are not
adapted to break down.
Other researchers have added:
- Cell replication rate - cells stop dividing as fast
as they used to; resulting in fewer immune system
cells, weakening the body's defenses, few bone cells
leading to decreased bone mass and ultimately osteoporosis
and reduced skin cells showing as wrinkles appear.
- Changes in cells, hormones, genes, and even behaviors
- Shrinkage of the brain as the brain cells become
smaller and reduce in volume
- Menopause - suggests ovarian function is related
to the overall aging process
- Changes in the immune system - subsets of T cells
[a type of lymphocyte or white blood cell patrol for
foreign substances, such as bacteria and viruses].
Changes may reflect the age-induced senescence or
death of some organ or tissue important in regulating
the immune system.
Secondly, effective tests must be developed for each
of these seven factors. Examples of such test might
include:
- A scan of the brain and heart to measure cell loss
- Using fat DEXA to measure body fat percentage to
determine the level of excessive fat cells and the
loss of lean muscle mass.
- Blood tests to identify chromosome and mitochondrial
mutations.
- Blood tests can also me used to determine the level
of Senescent cells, extra-cellular cross linking,
and junk inside and outside the cells.
- Biopsies to confirm degeneration or level of mutation
of tissues in certain cases.
Thirdly, an effective measuring or scoring system
such that adding up all of the results for a complete
body of tests could produce a “biological age”.
One can only imagine how complex the weighting of each
of these factors could be in agreeing a “simple
age index”
Such tests must :
- Predict a person's physiological, cognitive, and
physical function and the future onset of age-related
conditions and diseases, and do so independent of
chronological age.
- Be able to be tested repeatedly without harming
the person.
Work in laboratory animals as well as humans. This
is so that it can be tested in lab animals before
being validated in humans.- Be simple and inexpensive to use.
- Cause little or no pain and stress.
- Measure aging accurately.
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