One thing I want to get into, and you mentioned early, very early on
in the introduction, I think we're getting there, is diet composition.
Well, there's good evidence, yes, eating vegetables and fruit is good for health.
And why is that?
And the emerging evidence that has kind of turned that "load up
on antioxidant" idea on its head.
And so, yeah, so during evolution, we're omnivores.
And the same would be true with other animals that are herbivores.
It is advantageous to be able to eat plant materials: fruits, nuts, roots,
leaves, because they have energy.
However, it's not necessarily advantageous to the plants that we eat them.
In fact, it's generally not.
And we know that in the case of insects, but it's also true
with herbivores and so on.
So, in most plants, the most vital parts of the plants, in terms of propagation
of the species, if you already eat those, they have a bitter taste.
So, for example, the skin of grapes or apples and, you know, broccoli, the
seed-producing part of the broccoli and so on, they have a bitter taste.
And so, the thinking is that it was to our advantage to be able to eat these
even though they have a bitter taste and have these naturally occurring pesticides.
It's what they are.
The plants are producing their own pesticides.
So, in fact, one of the reasons plants produce so many of the chemicals is
that many of those chemicals, their function is to dissuade insects and
other organisms from eating them.
That's their main function.
Okay.
So we co-evolved with these plants.
And as we co-evolved with them, we evolved several ways to protect ourselves
from overdosing on these pesticides that the plants normally produce.
So, one way is a bitter taste.
The second way is vomiting.
A third way, which is interesting from a human environmental health standpoint,
is we have evolved enzymes in our liver that rapidly remove these potentially
toxic chemicals when we eat them.
They're called cytochrome P450s.
Okay.
But the fourth way is that the individual cells in our body have evolved to
respond to some of these chemicals by, for example, enhancing their
antioxidant defenses or enhancing their ability to even extrude the chemicals.
So, I'll give you a few specific examples.
I mentioned broccoli.
Many of your viewers probably, if they're into health, they've
probably heard of sulforaphane, which is a chemical that's in broccoli.
And there's quite a bit of evidence that it can be good for health.
And one of the ways is it activates antioxidant defenses in our cells.
So, it's similar to exercise and fasting, which are stressors.
The stress of this chemical that's in the broccoli that we consume.
The stressor is the chemical.
It's activating antioxidant defenses.
Another example is curcumin, which is in turmeric root, which
in Indian food is very common.
And it also activates antioxidant defenses.
The most commonly consumed plant toxin by your viewers, very likely, is caffeine.
So, if you were to take powdered, if you were to take concentrated
caffeine and put it on your tongue, it has extremely bitter taste.
It's possible to overdose and die from caffeine.
And there have been some documented cases of actually people
essentially eating caffeine powder.
If you take tea leaves, coffee beans, you know, ground coffee beans, put them
on your kitchen table in the summer, assuming you don't have an ant-free
house, and there's ants crawling on the table, you'll notice that they
avoid the coffee and tea leaves.
And they're avoiding caffeine and other naturally occurring good toxins in them.
So, that contrasts with sugar or whatever, you know, a lot of other
highly palatable, addictive foods.
Yeah.
So, anyway, I was invited to write an article for "Scientific American" on
this general notion that the reason fruits and vegetables are good for
our health is not because they are free-radical-scavenging things like
vitamin E or C can help in certain ways, getting rid of free radicals.
That's not the answer.
The answer isn't that we want to swamp ourselves with things that sop
up free radicals because, actually, free radicals are important in our
cells for normal signaling and then our adaptive responses to stress.
Instead, the chemicals that are good for health seem to be acting
by triggering mild adaptive stress responses in our cells that overlap
quite a bit with exercise and fasting.
Yeah, these chemicals, again, they're concentrated in the exposed parts of
the fruit, like the skin of the fruits.
So, yeah.
Here's a really interesting thing.
Green tomatoes.
All right.
So, bugs usually don't eat tomatoes until they start to turn red in the garden.
Okay.
So, why is that?
The reason is they like the taste of the red ones better than the green ones.
So, it turns out, there's this chemical that's been called tomatidine that's
highly concentrated in the green tomatoes.
And then levels of tomatidine decline dramatically as the tomato turns red.
Okay.
By the time the tomato starts turning red, the seeds in the tomato that
have the potential to give rise to another tomato plant and propagate
the species, they're ready to go.
So, I guess, mainly this applies to birds.
So, birds won't eat green tomatoes either.
So, let's go with that.
So, the bird eats the red tomato and they may eat some of the seeds.
The seeds can resist going through their digestive system, then they poop
out the seeds, and the seeds can grow.
You know, and they might poop out the seeds, you know,
whatever, half a mile away.
So, now the tomato plants are...
You know, so these are all evolutionary mechanisms that give
advantages to one or both of the species during their co-evolution.
If a person is exercising regularly and also doing some form of intermittent
fasting and they're getting this activation of some of these stress
response pathways and the beneficial effects, you know, metabolic switching, is
there any need to also take in these plant phytochemicals that are also activating,
you know, perhaps the same or different or both, you know, stress response pathways?
In other words, like, can you just say, "Well, I don't need to eat the
plant compounds because I'm exercising and I'm doing intermittent fasting."?
I wouldn't do that or say that.
What hasn't been done though, Rhonda, is other...
And the reason is, it's expensive.
There haven't been studies where within a study, they do
all these various combinations.
You know, okay, we're gonna do this study with...well, some people intermittent
fast, we'll have some exercise, we'll have some do both, we'll have some,
whatever, taking sulforaphane, and then we'll have them do sulforaphane plus
intermittent fasting, and so on and so on.
And my view on diet composition is one that I think makes sense from data from
epidemiological studies, the Blue Zone, where, you know, certain places where
people have exceptional longevity.
And all of them have diets that are mostly plant based.
And then, the evidence that simple sugar is bad for health is overwhelming.
The saturated fat, I think, the evidence is pretty strong.
So, it's better to eat fish than red meat.
And so, complex carbohydrates are better than simple.
I think that, you now, people shouldn't say, "Well, I can just eat at McDonald's
every day if I exercise and do intermittent fasting because it's..."
They would be better off than having been intermittent fasting and exercising...
You know, if they're if they're going to eat at McDonald's and don't want
to give that up, then exercise and intermittent fasting will counteract that
somewhat, but it's still kind of stupid.
The way I also think about it is, you know, you have something like
sulforaphane, which we've talked quite a bit about in the podcast.
I've interviewed Jed Fahey.
Yeah, I know, him.
Jed, he's at Hopkins.
Yeah, he's a good friend of mine.
And so, you know, you have something like sulforaphane that's activating
the NRF2 pathway, which has, you know, you know, all these downstream effects
on phase II detoxification enzymes, you know, activating those, inhibiting
the phase I biotransformation enzymes, which are involved in potentially making
a procarcinogen an actual carcinogen.
You know, there's all these pathways that, you know, I don't know how
much exercise and/or intermittent fasting, you know, activates those
pathways, I'm sure to some degree.
But you know, it seems as though different types of stressors do
have a more robust effect on certain types of stress response pathways.
And so, why wouldn't you want to diversify?
Yeah, that makes sense.
Yep.
Although I should say that...
So, going back to sulforaphane and the NRF2-ARE pathway.
That is activated by exercise and fasting.
And so, I would say this.
These chemicals that are in the plants are more targeted in what they do.
Compared to exercise and fasting, those chemicals affect a more
limited number of pathways.
In other words, you can't just take sulforaphane and it's going to substitute
for exercise or intermittent fasting.