- Diet is the behavior that's been studied the most
in terms of trying to affect things
like aging and longevity-
and what scientists end up leaning on
is what we call 'epidemiological' or observational data.
They compare the diets that different people eat,
and then they look at the features of those people
using things like biological aging
or disease risk or life expectancy.
Do certain diets tend to correlate with certain outcomes?
There are really three components of diet
that seem to be impacting aging:
So the first is how much we eat,
the second is what we eat, and the third is when we eat.
So in terms of how much we eat,
a lot of science went into this idea of caloric restriction.
Caloric restriction isn't starvation.
It's usually just about a 20% reduction
in the overall calorie intake.
In a lot of different animal models,
so anything from a worm, fly, mouse,
people have seen that when animals are caloric restricted,
they tend to live longer.
When trying to figure out if something
like caloric restriction is actually beneficial
to the aging process in terms of slowing aging,
one caveat is that humans today are not at baseline;
we're actually more prone to overeating.
So some researchers have figured out
that it might not be the caloric restriction
that's actually the beneficial thing.
So even if you can't restrict your calories,
just moving away from overeating
is probably gonna have a beneficial effect for most people.
The other thing that's been studied
is this concept of what we eat.
A lot of research has gone into
whether things like a plant-based diet
are actually beneficial to aging and longevity.
And there seems to be some evidence
that eating less animal products, more fruits and veggies,
more whole foods is gonna be better overall;
and also minimizing things like refined sugars,
and the things that we know are bad for our health.
The third comes down to when we eat,
and this is really a new field
in aging and longevity science.
So again, most people aren't gonna be able
to calorically restrict,
but what scientists found is actually fasting can mimic
some of the benefits
that we've seen with caloric restriction.
So if people can perhaps minimize
their eating to a small window,
we think that this can actually recapitulate
a lot of the benefits that we're seeing
in the caloric restriction studies.
The idea of why things like caloric restriction
or fasting might actually improve our aging process
is because we think this evokes this idea
of 'hormesis' in our bodies.
What hormesis refers to is a mild stressor
that actually makes our bodies more resilient
and robust to stress over time.
So having these short-term mild stressors,
whether it be fasting
or whether it be a small caloric deficit,
actually makes our bodies more resilient against
a lot of the changes we see that increase with aging.
It's not that easy to figure out what the optimal
or ideal diet is for each of us,
and we don't know exactly how things, like genetics,
are going to predispose people to different diets,
but one way to do this is to keep track of things
like our biological age measures
to see how our diet is affecting us.
So if you were to completely change your diet
or introduce something like intermittent fasting,
do you see that reflected in your measures?
The other things are just, functionally, how you're feeling.
So people who are older
and more prone to things like muscle loss or weakness
might actually need more protein
than people who are younger, where science has shown
that a low protein diet might be beneficial.
So it's important to keep in mind
that these things aren't set in stone,
and really need to be considered on a personalized basis.
As we move forward in the science
and develop more of these biomarkers of aging,
I think this will really start to accelerate
our understanding of how diet impacts the aging process.
Our lifestyle and our behaviors
are actually gonna be the biggest contributors
to how fast we're aging.
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