- [Voiceover] When something increases the
chance that you'll develop a certain disease
we call it a risk factor, right?
Because essentially it increases
your risk or puts you at a higher risk
for developing that disease.
By far, the most common risk factor
for Alzheimer's disease, vascular dementia,
and other types of dementia is age.
Dementia is very rare in people under the age
of 65 years old but becomes very common after age 80.
Unfortunately for us, the fact that we age over time
is a risk factor that's completely out of our control,right?
Even more unfortunately, the reason as to why
this risk of developing dementia
increases as we get older is mostly unknown.
And another risk factor that tends
to be mostly out of our control is family history.
So here's you. Here are your parents.
Here are your brother and your sister and here's your child.
If any of your family here has developed dementia,
let's say Alzheimer's disease because that's
the most common, then you're gonna be at a
higher risk for developing the disease yourself.
So say someone else in your family
also has developed Alzheimer's,
then the risk of you developing Alzheimer's
grows even more and this can be the result
of environmental factors like how or in what setting
you were raised since it's probably going
to be a similar setting for your immediate family, right?
And with Alzheimer's in particular,
scientists are well aware that specific genes
are involved even further Alzheimer's disease
has both what we call risk genes
and deterministic genes.
Now risk genes are defined just like a risk factor.
If you have this specific risk gene,
then you're going to be more likely
to develop a certain disease but you're not
necessarily going to develop it, you're just
gonna be at higher risk.
So the risk gene that scientists have found
that have the strongest association
with developing Alzheimer's disease
is called Apolipoprotein E-E4 and
a lot of times you see it shortened to APOE-E4.
This APOE gene helps us make molecules
called lipoproteins which help carry fats
and cholesterols through the bloodstream.
Maintaining normal levels of cholesterol
is very important for helping
to prevent a variety of disorders.
Now there are three slightly different versions
to this gene also called alleles.
You have E2, E3 and E4 and it's the E4 type
that increases your risk of Alzheimer's.
So if you were to inherit one copy of this allele
you'll be at a greater risk for developing Alzheimer's
and if you inherit two copies,
you'll be at even greater risk.
It's been suggested that this gene
is a factor in about 20-25% of all Alzheimer's cases.
So that's the major risk gene, right?
Deterministic genes, on the other hand,
directly cause a particular disease.
In other words, it determines that
the disease will be present and
essentially guarantees that anyone
that inherits it will develop the disorder.
As applied to Alzheimer's disease,
this is called familial Alzheimer's or
sometimes early onset Alzheimer's
as it can often happen before age 65.
Now scientists have discovered that this
can be caused by a mutation in at least one of three genes.
You can have a mutation in amyloid precursor protein
or APP, Presenilin-1 or PS-1,
or Presenilin-2 or PS-2.
When any of these genes are mutated or altered
large amounts of amyloid plaques tend to build up
and these are a major component
of Alzheimer's disease, right?
Fortunately though, familial or early onset Alzheimer's
resulting from a deterministic gene is very rare.
And there is always some evidence to suggest
that those with Down Syndrome have
an increased risk for developing
Alzheimer's disease because Down Syndrome
occurs when someone has an extra copy
of chromosome 21 in every cell
which means that many of the genes
in their cells have three copies instead of the usual two
and that includes the amyloid precursor protein gene.
Although that's still fully understood,
it's thought that this extra gene might account
for an increased production of amyloid plaques
and therefore, increase the risk for Alzheimer's disease.
Now some of the risk factors for dementia
and Alzheimer's, however, are, in fact, in your control.
Many experts are starting to reveal trends
includes that, start to hint at, other lifestyle
and wellness choices that can have
a significant influence on your risk of developing dementia.
And one big, big risk is head trauma
and there is a very strong link that exists
between head injury and dementia
later on in life, especially when the trauma
is repeated like in high-impact sports like football
or soccer or when loss of consciousness is involved.
With that said, protect your brain! It's really important!
And another risk factor is actually heart trauma.
Scientists and health professionals are continuing
to see links between brain health and heart health.
Many of the risk factors that lead to heart disease
also apply to dementia but why is that?
Well, most types of heart disease,
your heart gets less efficient at pumping blood, right?
Well, if less blood's getting to brain,
it's gonna have an increased risk of damaging your
brain cells and developing some sort of dementia.
So things like poor diet and obseity, diabetes,
smoking and heavy alcohol use will
increase your risk of both heart diseases and dementia.
And if there is some sort of heart conditions
that already exist like atherosclerosis
or high blood pressure, your risk
for dementia increases as well.
That being said, protect your heart!
It's also important.