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Gut Expert: Eating these 3 foods could improve your mental health | Tim Spector: Full Interview
Gut Expert: Eating these 3 foods could improve your mental health | Tim Spector: Full Interview
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1:13:04 · Jun 19, 2026
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My
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Tim
Spector.
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/1330
0:00
My name is Tim Spector.
0:01
I'm an MD.
0:02
I'm a professor of epidemiology at King's College in London
0:07
and I'm also co-founder of the nutrition
0:10
and gut health company,
0:12
ZOE.
0:13
Today on Big Think,
0:14
I'm going to talk about the connection between what's going on in your gut
0:18
and your gut microbes
0:20
and how that affects your brain
0:21
and your mental health.
0:23
I'll also be giving you tips about how you can improve your gut health
0:27
to improve your overall health.
0:35
Chapter one, how the gut microbiome works.
0:38
The gut microbiome I like to think of
0:41
as as it's like a virtual organ in our bodies
0:44
that we've only recently discovered.
0:47
Something like discovering we had a liver.
0:49
And essentially, it's made up of trillions of little tiny microbes
0:55
that you need a microscope to see. bacteria,
0:58
fungi, parasites, viruses, and other things we still don't exactly know about.
1:04
This collection forms a community mainly inside the lower part of our colon,
1:11
the large intestine.
1:13
They essentially need to be thought of as mini pharmacies.
1:18
They convert the food that we eat into chemicals,
1:22
into hundreds and thousands of different chemicals.
1:25
And those chemicals have this amazing impact on our body
1:29
that we're only just beginning to realize.
1:31
This collection of microbes has something like 200 times more genes than we have
1:36
in our own human cells.
1:38
That means they're much more versatile.
1:40
They're more flexible in what they can produce in terms of chemicals
1:44
and they're actually more numerous than our uh human cells.
1:49
This is important because we evolved from these bacteria
1:54
and the very first mammals
1:57
and then humans were built
2:00
because they contained these colonies of microbes
2:04
that could interact with them
2:05
and without these microbes we really wouldn't function
2:09
and particularly our brains don't develop normally.
2:13
So, one way to think about our gut microbiome is either
2:17
as a the environment of a jungle
2:19
or an amazing natural zoo where you've got these thousands of different species of
2:26
microbes that have taken over a little niche inside our gut
2:31
that is very specialized to them.
2:33
They're not all fighting for the same food.
2:35
They've evolved just like animals have to get have very specific tastes.
2:41
The example I like comes from our own research where we found there is
2:47
one bug that only really eats
2:51
or drinks coffee.
2:52
It is so fussy it hangs around maybe for years just waiting for
2:57
that first cup of coffee before it will replicate
3:00
and really start to be noticeable.
3:03
If we start thinking of coffee as a great example,
3:05
then you think about all the other bugs
3:08
that we might have lying dormant in our guts
3:11
that are waiting for us to eat something unusual,
3:14
say a bit of baobob
3:15
or some beetroot or um some particular type of of nut
3:21
or herb or spice.
3:23
And so that's a really important concept
3:26
because we now know
3:27
that the more diverse your gut microbes are,
3:30
the healthier you are.
3:32
So that's why uh we need to be thinking how can I best feed
3:38
these very different gut microbes.
3:41
Some of which might like coffee,
3:43
others will only like uh the leaf of a bit of cabbage,
3:48
others uh might like seeds
3:50
or nuts and others will like the leftovers from what the other microbes have
3:54
eaten.
3:55
And this is also a really interesting concept because they they're working together.
3:59
They make sure there's no waste. they are these perfect ecological beings.
4:05
So that the concept of waste doesn't really exist.
4:07
And what they've shown in some mouse studies is
4:11
that um if you uh have a really strong colony of gut microbes
4:18
that are very diverse,
4:20
then you eat your standard diet, you have no waste left over.
4:23
But if you only have a few microbes, rather poor uh colony,
4:28
they're not very well diversified, you get leftovers.
4:31
And when you get the leftovers,
4:33
then you get what we call the bad bugs will eat those uh
4:36
because they've got something to eat.
4:38
So a really good healthy colony of microbes, like a zoo,
4:43
is one where all the animals have a role, they've got something to eat.
4:47
Uh there's no real waste, and everything is used up.
4:51
It's really a marvelous model that we all love, a sustainable gut society.
4:56
Although we all have thousands of species of these trillions of bugs inside our
5:02
guts,
5:03
we're actually really different one to another.
5:09
And this is because as as kids uh when we're born, we're born sterile.
5:13
So, it's slightly random which microbes end up colonizing our own uh colons.
5:21
And it turns out
5:21
that the average person only shares about 20% of their gut microbes with another.
5:29
And even in identical twins, they don't share many more than that.
5:33
So it's a process that's part random uh part uh designed
5:40
that way and not very genetic.
5:43
This means that we all have a different set of microbes producing slightly different
5:47
functions.
5:48
Until recently, we didn't really know how good bugs and bad bugs were interacting.
5:56
And it turns out they're fighting for resources.
6:00
The good bugs, these are ones that eat your, for example,
6:03
plants and change those plants into healthy chemicals that your body can then use.
6:10
And that has a a health effect.
6:12
If they do well, they leave no food left over for the bad bugs,
6:18
by which we mean bugs that increase when you have a bad, you know,
6:23
an average American diet with fast foods and burgers, etc., lots of fat,
6:28
those ones will increase and cause bad outcomes.
6:32
So, it turns out
6:33
that if you're only having a a a good diverse diet,
6:37
there's very little waste to supply the bad bugs.
6:41
This concept has changed quite recently
6:43
because we used to be thinking okay how do we get rid of the
6:45
bad bugs that are causing inflammation irritation in there
6:50
but now we know it's focusing on on the good it's increasing uh those
6:56
guys as much as possible essentially giving them a greater diversity of food
7:01
so that everybody gets something to eat
7:04
and we can really use the full armory of all those good microbes to
7:09
produce the biggest possible possible array of chemicals
7:12
that the body can
7:12
then use in the best way.
7:17
Chapter two, an unhealthy gut leads to an unhealthy brain.
7:21
When I started this research,
7:22
we thought that the gut microbiome was really just involved in things like obesity
7:28
and metabolism.
7:30
And it's only recently we've realized that it does so much more.
7:34
I like to think of it really interacting in sort of three key parts
7:39
of the body.
7:40
Yes, it does influence metabolism, energy levels.
7:45
It uh sends signals to the brain about appetite
7:49
and body weight and distribution etc.
7:52
and is probably important in things like type 2 diabetes.
7:56
But one of its key roles is acting on the immune system.
8:00
Our immune system is pretty crucial for virtually every common disease
8:05
that we're encountering at the moment.
8:06
From autoimmune diseases, food allergies to things like preventing cancer by these our immune
8:14
cells killing off early cancers
8:16
and the aging process itself.
8:18
So the immune system is a huge part of what the gut microbiome does.
8:23
And without a really good microbiome, you can't have a good immune system.
8:27
The third key thing that the microbiome does is interact with our nervous system.
8:34
And it does this through a huge network of nerves
8:38
that are sometimes called our second brain.
8:41
They're as big as a cat's brain.
8:43
And they probably evolved around our intestine before even our brain was formed
8:48
as when we were in the womb.
8:51
And this network of of nerves connects to the brain primarily through the vagus
8:56
nerve.
8:57
This is like a fast internet cable
9:00
that picks up what's going on in our gut microbes through the gut lining
9:06
picking up signals in every single layer of the gut.
9:09
So right through to the the tiny connections right on the inside of the
9:13
mucosa through every layer.
9:15
So they are actively sensing everything that's going on there.
9:20
All these neurons interconnect.
9:22
They're picking up signals from the gut microbes
9:27
that are sending chemicals such
9:30
as short- chain fatty acids
9:32
which they make when they break down fiber.
9:34
They might be getting them directly from the microbes
9:37
or from the the cell wall of the microbes.
9:39
They might be getting it from uh some hormones
9:43
that the microbes are making. these endocrine hormone sensing uh cells in the gut
9:50
lining like GLP1 that's uh people now know is how ampic works.
9:56
They're picking up uh you know hostile chemicals, good chemicals.
10:01
Everything is is going through to these little little tiny neuron endings
10:05
and they're being fed into this vagus nerve through this incredible cable to our
10:11
brain where it tells the brain what's going on.
10:15
This discovery has really changed our whole idea of the the gut brain axis
10:20
because we used to think the brain was telling the gut what to do.
10:24
Turns out most of the traffic is from the gut to the brain.
10:27
People conceptually thought the brain uh was separate to the body.
10:33
And this is the carteesian view really
10:37
that has penetrated and been very persistent in medicine for centuries
10:43
and still means the reason
10:44
that psychiatrists and uh medical doctors don't really mix
10:49
and that we have separate hospitals
10:50
and separate training.
10:52
And yet now the latest science is showing
10:54
that there really is very little difference.
10:58
The brain is just another organ.
10:59
It is not the brain controlling the rest of the body.
11:03
It is just another organ
11:06
and it relies on the gut for most of its information.
11:10
Many people have vaguely heard about inflammation.
11:14
I was unusual because
11:16
as a kid uh I heard about it a lot
11:19
because my father was a professor who focused on inflammation.
11:22
Before it was trendy
11:23
and well it was trendy briefly
11:25
then it went out of fashion.
11:26
Now it's definitely back and everyone needs to know what it means.
11:30
It's a normal response we all have to a threat in in our bodies
11:35
whether it's uh stress
11:37
or it's an infection
11:39
or something alien to us.
11:42
Our body responds.
11:44
It sends all these white cells from our body to
11:47
that site and triggers a whole careful reaction
11:51
that gets rid of
11:52
that threat as quickly
11:54
as it can and goes back to normal.
11:56
Now, we currently have uh problem of what's called chronic inflammation,
12:01
which means it lasts too long.
12:03
So instead of getting a brief brief spike of uh inflammation in response to
12:11
a threat say some bad food uh
12:15
that returns to normal our bodies uh have become in some way uh changed
12:23
so that that threat level stays up.
12:26
So we are suddenly going through life at a a a threat level
12:32
that isn't our baseline.
12:34
That may be due to our environment of terrible food.
12:38
Uh it could be due to pollution, pesticides, all kinds of things.
12:43
But or it could be due to our stressful lives and social media.
12:48
Whatever the cause, it's true
12:50
that in the west we have stress levels based on the levels of inflammation
12:56
or our immune system
12:57
that are higher than you would find in Africa
12:59
or India or uh where our ancestors came from.
13:03
I also learned a lot of it
13:04
because I was a rheatologist originally in my one of my early careers before
13:10
I I changed several times
13:12
and saw patients with rheumatoid arthritis um autoimmune disease who suffered a lot
13:20
and they were constantly tired
13:22
because of the inflammation in their joints
13:25
which spread to their bloods.
13:26
I didn't think much about it
13:28
because we thought they were tired
13:30
and depressed because their joints hurt.
13:34
And that's really what we were told.
13:35
Oh, it's normal.
13:36
They are uh tired and depressed.
13:39
They've got quite bad crippling arthritis.
13:42
But it turns out it was just the reaction in the brain to what
13:47
was going on in the rest of the body.
13:49
We now know that many mental health problems,
13:53
virtually all of them have been studied so far,
13:56
have above average levels of inflammation and they also have abnormal gut microbes.
14:06
So there's a link between uh mental health disorders
14:10
which nearly all of them have reduced energy
14:14
and reduced mood to some extent. even in forms like psychosis
14:22
and schizophrenia or even in uh ones you don't regard
14:27
as mental health but brain problems like epilepsy
14:29
or migraine.
14:29
This is also true.
14:31
So there's a general increase in inflammation in the blood.
14:35
There's also a general uh abnormality of the gut microbes compared to uh people
14:43
who don't have any mental health problems.
14:45
So we're seeing this picture developing whereby we are getting uh much more common
14:53
ground to explain this explosion in mental health problems.
14:58
That's that's based not on the old theory of uh a deficiency in certain
15:04
brain chemicals or an excess of brain chemicals
15:08
but due to this underlying inflammation
15:11
which probably starts in the gut
15:13
and then sends those signals to the brain.
15:17
So an obvious question is where does this inflammation come from?
15:22
What's triggering the body to in a way overreact
15:27
and keep overreacting to stimuli rather than dealing with the problem,
15:32
getting rid of it,
15:33
going back to the base state
15:34
which is what we know
15:36
that our healthy ancestors had.
15:39
Inflammation is both a cause and a consequence of many things we're talking about.
15:44
The most obvious cause in the west of this uh pandemic of mental health
15:50
problems is the fact
15:52
that since the 1970s,
15:53
we've been eating uh an increasingly bad diet.
15:58
The standard American diet, the SAD diet, which is denuded of fiber,
16:03
it's plenty of saturated fats and it's full of ultrarocessed food.
16:09
All of which have been shown in uh particularly mouse models to cause inflammation
16:16
in the gut of those mice leads to many more bad bugs compared to
16:21
good bugs.
16:22
There's not much for the good bugs to eat.
16:24
The bad bugs take over.
16:26
They like an inflammatory environment
16:28
and they actually produce chemicals
16:30
that will stir up uh the gut lining
16:34
and that environment to in a way be more toxic
16:38
and raise the levels of the immune cells in the body
16:42
that think in a way they're infected
16:45
or diseased in some way.
16:47
So I think that's the unifying idea of how uh bad food on a
16:52
long-term basis causes this increase in the imu the immune cells
16:57
which you've got to remember
16:59
that the gut microbes probably by evolution are there to pick up signals from
17:04
the environment tell the brain who
17:06
that can't really see outside the little skull what's going on.
17:10
Gives it an idea of what's going on.
17:12
It's this consciousness and it's picking up these signals
17:16
and if those signals are bad food,
17:20
inflammation, heightened you, fear, it's like, gosh, there's something bad going on here.
17:26
Let's signal that back to the brain.
17:29
What does the brain do?
17:30
It goes into some sort of lockdown mode, a sickness behavior,
17:34
some people call it, which is quite natural.
17:37
It it's getting a signal from its main communicator, the gut,
17:42
along the vagus nerve.
17:43
It tells it all kinds of is happening down here.
17:46
This is not good.
17:48
We're getting really bad signals.
17:50
How do we react in evolution?
17:52
We'd say it's like an infection.
17:54
We lower our mood.
17:56
We lower our sociability.
17:57
We lower activity.
17:59
We tell the body we're tired, so we rest.
18:02
And that's what you get fatigue, mood change, and all the other associated factors,
18:08
and you end up with what we're calling depression.
18:12
That's my way of thinking about this problem for perhaps the commonest factor that's
18:18
changed in our lives in the last 50 years.
18:20
And particularly why in kids,
18:22
we're seeing this this pandemic at the moment. kids
18:25
that have had mothers
18:27
that were had terrible diets
18:30
that passed that on to the kids
18:32
and then basically they've had ultrarocessed foods for the the whole of their lives
18:39
uh without ever having any real food to nourish any the few good microbes
18:43
there are.
18:44
Only the bad ones have been surviving in
18:46
that jungle uh just on the fats
18:49
and the scraps and the artificial sweeteners
18:51
and the chemicals etc.
18:53
So I think that for me is the the key model.
18:59
You can also uh think of other ways
19:04
that you might get inflammation
19:05
and my research in this area is not
19:07
that I've done it myself
19:08
but looking at the the literature is
19:11
that many of the risk factors for mental health disorders are all the same.
19:16
So it doesn't matter
19:18
which of these so-called 300 different disorders you have the risk factors are the
19:21
same. childhood stress,
19:23
trauma, poor diets and um living in urban environments.
19:29
All of these things increase stress
19:32
and they now know
19:33
that that stress you can see
19:35
as an increase in inflammation in the in the immune system.
19:40
So just psychological stress can also cause this
19:43
as well as uh in a way dietary
19:46
or gut stress end up with the same common pathway.
19:50
After a bad night's sleep or some stress,
19:54
your body seems to crave fatty and sugary things that are unhealthy.
19:59
And we've all experienced
20:00
that after a a poor night's sleep
20:02
or a hangover or whatever it is.
20:05
You reach for the the one thing that you think you you need,
20:09
but it turns out you're wrong.
20:11
Your brain's given you the wrong directions,
20:13
and this is going to make you probably feel worse.
20:16
So this sort of explains this loop people get in particularly uh with depression
20:23
or anxiety.
20:24
The brain is telling them to do one thing
20:26
that actually is making it worse.
20:28
And so it really explains why people with low mood
20:31
and depression end up eating badly
20:33
and can't get out of it
20:35
and it's making them worse. hadn't really thought about the gut brain connection quite
20:40
as much.
20:41
But about nine years ago, my mother uh suffered a stroke.
20:46
She ended up uh in a care home with uh dementia.
20:51
Each time I visit her, you know,
20:53
I am reminded of the fact
20:56
that so many of us now are potentially facing this fate in old age.
21:02
And it's not something
21:03
that anyone really wants. dementia is probably the the worst way to go.
21:09
So, it's made me think about this more
21:12
and start to look how my own research could potentially have an impact
21:20
or help not only myself
21:22
but other people prevent dementia
21:25
or at least delay it uh considerably.
21:29
It turned out my mother with her stroke
21:31
and subsequent acceleration of dementia probably had what's called vascular dementia
21:38
which is a fairly general term
21:40
that affects about one in three people who get dementia.
21:45
It's the second commonest form
21:47
and it tends to occur in phases
21:51
so that the blood supply to the brain is getting progressively diminished
21:56
and knocked off probably by atherosclerosis in the arteries uh supplying the brain.
22:03
The other type of uh dementia
22:06
that many people hear about is Alzheimer's
22:09
which is probably the commonest form of dementia perhaps affecting uh 60% of all
22:15
cases and it can start in a similar way with uh loss of memory
22:22
or cognitive function and
22:23
then progresses uh at a m usually a more sustained pace um
22:30
that doesn't have these separate phases. is
22:33
and that's caused slightly differently it being distinguished by having these protein folds in
22:40
the brain these amaloid
22:42
and these towel proteins
22:43
that have led to some of the damage in the brain
22:46
as the brain has been shrinking now we don't know they are causal it
22:51
could be that these proteins just are part of the damage after it's occurred
22:57
but we believe that there are some common causes of both these types of
23:04
dementia that the risk factors seem to be quite similar in both cases.
23:08
We can link this back to gut poor gut health. the picture of gut
23:13
health that uh where you have a low ratio of good to bad bugs,
23:17
you've got poor diversity of species
23:20
and you got an inflammatory component going on there is a major risk for
23:26
both types of dementia
23:27
as is things like type 2 diabetes
23:30
which probably is involves the energy supply to the brain
23:34
which affects both.
23:37
So for practical purposes,
23:39
you should be trying to prevent both kinds of uh dementia
23:43
because they have a big overlap in the causes
23:45
although they can look very different at the end.
23:49
So we have gut microbes all through our intestinal tract
23:54
and that re means from our mouth to our anus
23:59
and some bits are harder to access than others.
24:02
It's very hard to know what's going on in the middle bit,
24:04
the small intestine, because it's very hard to reach.
24:09
And so we rely generally on what's happening in stool samples,
24:12
but we also can look at what's happening in our mouths
24:15
and our saliva where
24:17
which is teeming with microbes
24:19
that are there basically to protect us,
24:22
but also start the first bit of digestion of food.
24:26
And just like in our colon,
24:28
there's a little colony of microbes there
24:32
that uh interact with each other
24:34
and you have good ones
24:35
and you have bad ones.
24:37
And if you provide an environment that uh doesn't clear away your food,
24:44
leaves food waste, the bad bugs will accumulate and they can lead to inflammation.
24:50
And this tends to happen um at the interface between your teeth
24:54
and your gums.
24:56
And we know that gum disease is very prevalent in in the west.
25:00
Perodontitis and specific bugs absolutely love the environment there.
25:06
You get slight redness
25:07
and swelling which is a sign of inflammation
25:11
and you can generally see it there.
25:13
Your gums might be slightly tender, might be swollen, might be red.
25:17
And in certain cases,
25:18
they will bleed if you uh floss them or brush them hard.
25:22
That's a sign that you've got inflammation there that they're bad bugs living there,
25:28
eating the bits of food.
25:31
They form plarkes.
25:32
And a plaque is a a complicated structure that's made by these microbes
25:38
that builds up like a protective shield.
25:41
So that in a way they can keep uh digging away,
25:46
eating things uh and they're protected from you uh brushing them away.
25:52
So our teeth, it turns out,
25:54
are a really good place to look for inflammation.
25:57
And remarkably, we we we learned about 10
26:01
or even 15 years ago
26:03
that dental decay was related to heart disease.
26:07
And there were certain microbes they found very early on.
26:10
I think it was strep mutans is associated with uh increased risk of heart
26:15
attacks.
26:15
This was very strange when that first came out.
26:18
I remember now we were able to look much more broadly at all the
26:21
microbes.
26:23
We know that poor uh mouth uh hygiene means high rates of bad microbes
26:30
compared to good ones.
26:31
These are pro-inflammatory.
26:32
And if you're not brushing and flossing your teeth,
26:36
you have roughly a 25% increase in heart disease.
26:41
And some studies are showing anything between 20
26:43
and 50% uh increase in uh dementia
26:49
and cognitive decline.
26:50
So suddenly we've got a really good example of how um uncontrolled inflammation in
27:00
our bodies can have a direct effect on areas we hadn't really thought linked
27:05
at all like our brain.
27:06
I think this gives people the idea uh of how important it is
27:12
and how preventive action can work
27:13
because if you then brush your teeth regularly,
27:17
you'll reduce that risk perhaps by half.
27:20
So rather than 50%, you're down to 25%.
27:24
But if you then floss um
27:26
which is gives you an extra say 30
27:28
or 40% of cleaning you do
27:31
that really well and you can get rid of the plaque
27:33
and get rid of the bleeding
27:35
and the the inflammation you can get right back to zero.
27:38
So I think this is a marvelous example of how we need to battle
27:42
inflammation in our bodies really to save our brain health.
27:46
Well it's hard for the average person to know what their gut health is
27:49
like.
27:50
Basically, it means that your uh your trips to the toilet are regular.
27:56
You look at your stool and you see, is it fairly soft?
28:01
You don't want to be a cowpat.
28:02
You don't want to be a sheep dropping.
28:05
You want something in between and you are going once or twice a day.
28:10
If that's the case
28:11
and you're not getting any bloating
28:13
and you're not having constipation
28:16
or diarrhea or,
28:17
you know, a lack of regularity, then you're probably pretty healthy.
28:22
If the opposite is true and you're having any of these problems,
28:25
your stools look rather strange, they're, you know, they're varying,
28:29
you're only going once or twice a week,
28:32
then it's highly likely you have uh gut problems
28:35
and uh you need some dietary help.
28:38
We talked earlier about thinking about your mood and energy.
28:42
Are you fatigued?
28:43
Is your mood lower than it should be?
28:45
Are you getting uh some bloating?
28:48
These are signs you do have gut health issues and you should address them.
28:54
Improving your plant intake will improve your fiber.
28:57
You know, do a bit of exercise, have some more water, etc.
28:59
Having done that, if you want to test your gut microbiome,
29:03
which I think will be standard of care in five years time,
29:06
it's very difficult at now to know who to go to.
29:09
Your general family physician may or may not be able to help.
29:13
A functional uh medicine doctor probably will,
29:16
and we're seeing more of those more holistic type of uh doctors appearing,
29:21
but uh it's not something that's very easy to do.
29:26
But I think a good gut microbiome test is much more useful to you
29:31
than getting your your genes tested
29:33
or your DNA.
29:35
It's really your metabolic blood pressure.
29:37
Um, if your gut health is good,
29:40
most of the rest of you is going to be pretty good.
29:42
And if it's bad, you're going to have problems.
29:46
Chapter 3.
29:47
Eight tips for maintaining a healthy gut ecosystem.
29:51
The old way of thinking about nutrition is the way I was taught
29:57
and doctors are still being taught is
30:01
that essentially there's only four things you need to know about nutrition.
30:05
It's calories, how much fat there is, how much protein there is,
30:09
and how much sugar there is.
30:10
If you get those four things right, everything else will follow.
30:15
We've been following that advice for the last 40 years
30:19
and it's been a complete disaster.
30:22
It doesn't make sense scientifically anymore.
30:25
Uh it's only really helped the food companies uh sell us more crappy products
30:30
and it's led to a disaster uh of unbelievable scale for the public health.
30:37
Real food, unlike fake food that is made just from a few ingredients,
30:42
contains thousands of chemicals.
30:44
And all of these uh play a role in our body
30:47
because they then nourish the trillions of microbes inside our gut to produce thousands
30:54
of other chemicals that our body can't produce.
30:57
It's only by focusing nutritional health guidelines on this new organ in our body,
31:03
our gut microbes, that it all makes sense.
31:06
We have to have a seismic shift in our idea about nutrition in order
31:11
to make healthy progress
31:13
and focus on gut health
31:16
and what are the key principles to improve all of our gut microbes
31:20
which will help us.
31:22
As I've been studying the gut microbiome,
31:24
I've been obviously thinking of how I can translate
31:27
that science into progress
31:30
and practical tips for people in various ages
31:33
and states of how they can improve their gut health.
31:36
The first one is what we call mindfulness.
31:40
And this seems a bit strange.
31:41
What what's he talking about mindfulness for?
31:44
Well, I remember when I uh started to change my diet,
31:47
I decided to be vegan.
31:49
It was an easy way to change your diet.
31:52
as a a temporary fix
31:54
if you like because it meant
31:56
that when I was going to medical conferences I would stop
32:00
and think before I just took something from
32:01
that tray from that buffet I would say what's in it uh was there
32:07
meat in it or is there dairy in it
32:10
and we don't need to be
32:12
that extreme all you need to do is to think about what you're eating
32:16
just for a second before you grab it
32:19
or you put it in your mouth
32:21
So mindfulness in this context means just stop
32:26
and think am I hungry do I need this what's in it you know
32:31
and what what are those contents are they going to uh have an effect
32:36
on me and then what effect is
32:38
that going to have on me
32:39
if I do eat them.
32:40
So these sort of three steps
32:42
that I think are important in mindfulness is an important realization
32:46
that food is much more than just calories. uh is it going to affect
32:50
my mood?
32:51
How am I going to feel in three hours time?
32:53
Uh what what are the long-term consequences?
32:56
But also, is it going to be really tasty?
32:58
Am I going to really enjoy it
33:00
or am I just being forced by marketing by big food to eat this
33:05
rubbish that I don't really want?
33:07
So there three uh steps in this this concept of mindfulness.
33:13
We just want people to stop and think.
33:15
That's number one.
33:18
So the second principle,
33:19
probably the most important
33:21
that we've found scientifically is to eat a diversity of plants.
33:27
It's not about eating the same plant many times a week.
33:32
We think that the science is pointing us to is something around 30 different
33:37
plants a week gives you optimum gut health.
33:41
This is a study
33:42
that I took part in with the British gut
33:44
and the American gut about 10 years ago where we saw
33:47
that the sweet spot for gut health was people eating around 30 different plants
33:52
a week.
33:53
It looks like it might be slightly more than that,
33:55
but certainly 30 is a really good target.
33:58
It turns out it doesn't matter if you're vegan or vegetarian or an omnivore.
34:04
It's the people that eat the most plants have the healthiest gut,
34:07
which I think is is really interesting. 30 plants to many people say
34:11
that sounds way too much.
34:14
The average American probably has between 10 and 12 plants a week.
34:18
How do I get, you know, how do I get over double that?
34:21
Well, you got to remember what a plant is.
34:23
It's a it's not only a fruit and a vegetable,
34:26
but it's also a nut.
34:28
It's every different type of seed.
34:31
It's an herb.
34:32
It's a spice.
34:33
It's even things like coffee, which is a fermented bean.
34:38
So when you just change your mind a bit about what plants are,
34:43
then it becomes easier and fun to add them to your plate.
34:47
Think about more rather than less.
34:50
Most diets are all about excluding things.
34:52
And what we're trying to do for our gut health is to in include
34:56
more things.
34:57
We've got little microbes just waiting around for
35:00
that bit of baobob
35:02
or that particular nut
35:06
or seed or berry. uh the chemical
35:08
that comes from it.
35:09
So the more you can give your gut microbes, the better.
35:15
My third guideline is to eat three fermented foods daily.
35:21
So I've spent the last three years researching fermented foods
35:24
and have a book on
35:25
that subject.
35:26
And what was really interesting is I I didn't think it was a topic
35:30
worth discussing three years ago
35:32
because the science wasn't really up to it.
35:36
But I've been convinced by a couple of studies.
35:39
The first was from my colleague Christopher Gardner at Stamford,
35:44
a very detailed but small study of adults who were told to eat five
35:49
fermentss a day,
35:51
comparing that group to a high-fiber group.
35:53
And what they showed was
35:54
that not only did the gut health improve in the fermented group particularly the
36:00
immune system was impacted
36:02
and they had around 25% less inflammation.
36:07
So suddenly moving from anecdote
36:10
and lots of small not very good studies in the literature uh
36:13
that were all pointing the same way
36:15
that fermented foods were good for you to suddenly a mechanism
36:17
that this can really impact your immune health in different ways to just rather
36:22
than just eating lots of fiber
36:23
and plants.
36:24
People think what is a ferment?
36:26
A fermented food is something that's been transformed by microbes into something better.
36:31
So you transform milk into cheese much more interesting than milk.
36:35
You transform grapes into wine.
36:38
Uh you're transforming cabbage into sauerkraut.
36:41
So think the 4Ks.
36:42
Keir, uh kimchi, kraut, kombucha.
36:48
Kombucha is uh fermented tea, which is all really good for you.
36:53
Most cheeses, if they're not, uh made artificially in in in factories, are good.
37:00
Yogurt is great.
37:02
All the soy products that you see in Japan, miso paste,
37:06
all these krauts and pickles
37:08
that are fermented in salt are really good for you.
37:11
So variety is important.
37:14
They've all got plenty of different microbial species
37:17
and they're probably better for you than just taking probiotics from the pharmacy
37:21
or the drugstore.
37:21
So my recommendation is to build up to three fermentss a day
37:26
as an extra boost for your immune system
37:29
and your gut microbes. a big fan of fermented foods now
37:32
because the science has finally caught up.
37:36
The fourth guideline is to diversify your protein.
37:40
We're going through a protein craze at the moment where every product has added
37:46
protein in it.
37:48
Every uh American thinks they're deficient in protein.
37:52
And um there's nothing wrong with protein.
37:55
It's not particularly harmful.
37:58
But if you don't uh need it, you lose it.
38:02
You can't store it.
38:03
So you pee it out or it gets converted to fat.
38:06
If you are trying to get more protein
38:09
and perhaps 10% of people are lacking in protein
38:12
because they're unwell,
38:14
they might be elderly.
38:16
They're uh trying to uh build body mass
38:19
or try and not lose it too much
38:21
as they're on the these um weight loss drugs.
38:25
Then my view is you should be trying to think about other protein sources
38:29
rather than just uh red meat.
38:32
The one that comes to mind are beans
38:34
and lentils uh things
38:36
that have really high protein content
38:39
but also contain lots of fiber.
38:42
This means your microbes can actually use
38:44
that at the same time
38:45
as your body's getting
38:47
that protein.
38:48
So that's a real reason why we should be switching eating many more beans
38:53
and pulses than we are currently.
38:55
They're very cheap, they're accessible, they're good for the planet,
38:58
and our microbes love them.
39:02
Guideline number five is focus on quality, not calories.
39:07
For decades, we've been obsessed with the calorie
39:11
as the main source of describing food
39:15
and nutrition about whether it's healthy
39:17
or not.
39:18
There are hardly any uh nutrition scientists who now believe in the dominance of
39:23
the calorie.
39:25
It's only a tool for the food companies to make rubbish food uh seem
39:30
more healthy because it is lower in this magic term.
39:35
The science tells us that these uh in the vast majority of people fail.
39:41
It's really impossible for most people to follow a calorierestricted diet for more than
39:47
a few weeks.
39:48
And even if they do lose weight, as most people do,
39:51
uh virtually everybody regains it because your body's appetite signal is turned up.
39:58
The brain has finally tuned to know
40:01
if you're uh not getting enough energy
40:05
and it switches up its thermostat to ramp up your hunger signals.
40:11
Your body is designed by evolution to overcome that pure uh calorie signal.
40:17
The other problem with calories,
40:19
not only the fact
40:19
that it's it's virtually impossible to calorie count
40:22
and and lose weight,
40:23
is that it disguises the food in ways
40:27
that gets us to stop thinking about the quality of what we're eating.
40:32
And that's what the food companies have been doing for the last uh 40
40:36
or 50 years,
40:38
trying to switch our thought away from the fact
40:41
that they are just making this uh crap food out of a few ingredients
40:47
that have government surpluses,
40:49
away from the food we should be eating, which are whole foods,
40:52
which is what our gut microbes want to eat.
40:55
They want to eat a variety of foods
40:58
that are in their original state
41:00
that have the the casing uh
41:03
that contains most of the fiber.
41:04
They want the skin on it.
41:06
This is where most of the nutrients
41:09
and ingredients are that uh we need for our bodies to work really well.
41:13
This is a really important step
41:15
as people um try to disregard the calorie
41:20
which effectively doesn't have a major role in our any of our plans
41:25
and we ignore the calorie completely.
41:29
So tell people it doesn't matter.
41:31
It's all about the quality of the food,
41:33
how it's going to impact your gut microbes.
41:35
And once you do that,
41:36
it's very liberating for people to think I don't have to worry about this.
41:40
And generally, if something's got low calorie on it, it's a poor quality food.
41:45
You should be avoiding it.
41:48
Number six, avoid high-risk processed foods or high-risisk ultrarocessed foods.
41:53
These are the foods
41:54
that make up 50 to 70% of the American diet hire in kids.
42:01
And most those foods are really harmful for us.
42:05
There isn't a universal definition of an ultrarocessed food.
42:09
We think that ultrarocessed food itself is is too broad a term
42:13
because it most people use
42:15
as anything that has got an additive in it.
42:17
Some of those additives can be like vitamin C,
42:20
therefore not particularly bad for you, whereas others are are dreadful.
42:24
And the worst ones,
42:25
the ones we categorized
42:27
that make up 25% of uh the American diet have a number of components
42:34
that make them particularly harmful.
42:36
Remember, these are foods
42:37
that are mainly made from cheap ingredients
42:41
that are government subsidized like uh like maze uh like uh soy
42:48
and uh wheat and sugar.
42:53
These are things that are plentiful
42:55
and taxpayers are paying for them to be cheap
42:58
and they have surplus of it.
43:00
So they've got to make create foods with them
43:03
and they do that really effectively.
43:05
and they try and upsell them by adding additives to them
43:09
that change their color
43:12
and they change their texture
43:14
and they change their taste.
43:18
And some of these additives are not too bad.
43:20
Others are quite unhealthy and others are really unhealthy for us.
43:25
Some of them are associated with cancer.
43:27
Some of associated with mental health problems in kids.
43:30
You have emulsifiers which glue them together which are bad for our gut microbes.
43:35
You've got artificial sweeteners
43:37
which uh many of them develop from the petrochemical industry
43:42
which our bodies are not used to
43:44
that cause our microbes to produce funny strange chemicals in response
43:50
and are generally harmful.
43:52
You've got others that we still don't know how bad they are.
43:55
That that's the additives.
43:57
Then you've got uh the hyper palatability
44:02
that the companies use a mixture of salt,
44:05
sugar, and fat in those combinations to make
44:07
that food override your normal fullness signal.
44:12
So they do this very deliberately.
44:14
We all know we've eaten a big bag of chips
44:17
or whatever it is in front of the TV
44:20
and it's it's got potato,
44:22
which is starch in it.
44:23
It's got um salt.
44:26
It's got usually um some some uh fats in there and it's that sugar,
44:32
salt, fat in the perfect combination
44:35
that these brilliant food scientists have created
44:37
that will tickle our brains into uh thinking we can keep eating them
44:42
and we just don't get full.
44:44
So hyper palatability is a component of 70% of these foods.
44:49
The other component that you need to be looking out for is is it
44:53
something that you can eat super quickly.
44:56
Uh its structure has been taken away.
44:58
So you strip off all those bits of plants
45:01
that make it necessary to chew it
45:03
and you've just got the inside uh bits.
45:06
So we end up eating baby food.
45:08
They melt in your mouth, dissolve away.
45:10
You can keep eating them without even noticing it, without exercising your jaw.
45:16
And then finally, the best from the food company's point of view are foods
45:20
that you can get lots of energy in really quickly without noticing it.
45:25
And this is called calorie density.
45:28
The worst offending foods have those.
45:30
So these are the the four categories.
45:32
The ones to look out for are the ones
45:33
that have all of those components.
45:35
And that makes up 25% of the American diet. breakfast cereals uh for kids,
45:41
uh most children's yogurts, um most savory snacks, most cookies, uh most ready meals,
45:50
most u sodas and drinks, even if they are low calorie.
45:56
So, not only is it bad for your gut microbes,
45:59
it's also going to make you uh keep eating
46:03
and become obese and have all those problems of diabetes,
46:06
etc.
46:06
I don't think it's realistic to cut them all out completely.
46:10
And my view is that yeah, you can still have the odd uh treat,
46:16
but don't have any of these as a regular part of your diet.
46:21
Number seven, try and eat the rainbow.
46:24
You may have heard that before, certainly been around a while,
46:27
but we now know why it's good to eat the rainbow.
46:30
Rainbow plants and uh especially fruits and vegetables have rich colors.
46:36
And that's what we're looking for
46:38
when we trying to select something to put on your plate is to try
46:41
and get as bright
46:42
and as varied as possible
46:43
because plants that have these bright colors tend to also have high levels of
46:49
a defense chemical called polyphenols.
46:52
Plants like humans, you know,
46:55
have a defense mechanism and this is their defense mechanism.
46:59
They are fighting off insects
47:00
and sunlight and d dr dr dr dr dr dr dr dr dr dr
47:01
dr dr dr dr dr dr dr dr dr dr drought etc with these
47:04
chemicals that turn out to be actually very good for us.
47:08
They used to be called antioxidants which is a rather vague scientific term.
47:12
We now know that our microbes can use these polyphenols
47:17
as a form of fuel.
47:20
If they're getting this, it's like they're getting extra gasoline.
47:23
And so this engages all our microbes to be healthier.
47:27
So as well as breaking down the fiber in the these plants,
47:31
they're also getting these extra chemicals
47:33
which is acting as a fuel
47:35
which makes them even more productive.
47:38
So nature's given us these clothes, bright colors.
47:41
For example, you got a store uh you got an iceberg lettuce there
47:46
and you've got a rosolo,
47:48
an Italian one with lots of purple uh leaves on it. always go for
47:53
the brightly colored one
47:54
that will have a thousand times more uh polyphenols than the uh ubiquitous iceberg
48:02
lettuce whose only advantage is
48:05
that it stays forever in your fridge.
48:07
It has no nutritional value other than
48:09
that it will come still be there after your vacation.
48:13
The other clue in nature is they can be bitter as well.
48:16
So, slightly bitter tasting plants like your broccololis, the cruciferous vegetables.
48:22
Uh, nuts and seeds.
48:24
You've got uh extra virgin olive oil, which is my oil of choice,
48:29
is really high in polyphenols.
48:31
The best ones will make you slightly cough,
48:33
and you want them to be really nice and young.
48:36
You've got dark chocolate. over 70% is generally healthy
48:40
because that cacao bean has really been um fermented
48:45
and is uh really strong in polyphenols
48:48
as is coffee.
48:49
If you like a drink uh the the the only one I'd recommend for
48:53
your gut health is probably red wine
48:56
which has high levels of polyphenols uh again in moderation.
49:00
So they're the tips
49:02
that nature's given us uh to identify why eating the rainbow
49:06
and bitter foods are actually good for us.
49:11
The final tip is try and give your gut a rest.
49:16
And by that I mean timerestricted eating. 20 years ago
49:20
and certainly when I was at medical school was the idea
49:23
that we should be uh grazing not feasting.
49:28
Things have now changed
49:29
and we now realize
49:30
that constant grazing is what your gut microbiome doesn't like at all.
49:36
We know how important sleep is for our health.
49:39
Uh getting eight hours a night can really extend your lifespan,
49:43
improve your immune system.
49:44
Well, the same is true for our gut microbes.
49:47
They have a circadian rhythm.
49:49
They actually go to sleep and they need this time to repair the gut.
49:54
So if it's eating all the time and you're having late night snacks,
49:58
early breakfast, they're not getting the natural time they need
50:03
that our ancestors had for millions of years to clean up our gut,
50:07
particularly the lining of the gut where the mucosa is.
50:11
This is really important as an immune barrier and the healthier that is,
50:16
the healthier generally our immune responses are.
50:18
So give your gut 12 to 14 hours to recover overnight
50:24
and this is the basis of timerestricted eating.
50:26
The way timerestricted eating seems to work is through a number of mechanisms.
50:32
The first is by leaving
50:33
that gap uh in time your microbes are not focusing on eating
50:39
and you have a a defense team
50:41
that comes out at night.
50:42
A bit like in American football you have a different teams for offense
50:46
and defense. defense comes out.
50:48
It cleans up the lining of your mucosa.
50:51
That tidies up the gut lining, makes it more efficient, helps the immune system.
50:55
You're also getting metabolic advantages
50:57
so that uh your gut health is generally better the next day
51:01
because it's all been tidied up for you.
51:03
There isn't that much debris lying around
51:06
and you get less unhealthy bugs over time.
51:09
It also seems to be uh better for your mental health.
51:14
A lot of this is uh anecdotal,
51:17
but we did do a large study in ZOE of 140,000 people asked them
51:23
to do timerestricted eating.
51:24
A third of people hated it.
51:26
They were snackers and they just found it really difficult.
51:30
A third loved it.
51:31
They're still doing it years later.
51:33
And what we we learned was the people
51:36
that that were adhering to it had improved mood,
51:40
energy, and less hunger from doing it.
51:43
So there do seem to be other benefits
51:44
that we still uh are looking at.
51:47
And it also helps you avoid snacking
51:49
and we know that uh mindless snacking accounts about 25% of calories in in
51:56
in the United States
51:57
and the UK.
51:58
So it just makes you a bit more thoughtful about what you're eating
52:02
if you're trying to give your gut microbes a rest.
52:04
Timerestricted eating is a form of intermittent fasting,
52:08
but you're not restricting calories. you're just eating the same food you would normally
52:12
eat,
52:13
but in a more limited time frame.
52:16
So, for people wanting to give it a go,
52:18
I would say the easiest thing is to start with a little rule like
52:22
leave at least 2 hours before going to bed where you're not eating anything
52:26
else except maybe some black tea
52:28
or or or water.
52:30
That way, your gut will have a chance to recover
52:33
and hopefully you'll notice the difference the next morning.
52:36
And if that works, then you can extend it and maybe say, "Okay,
52:40
I can try this uh for a 12-hour overnight fast as well."
52:45
We are moving to the idea
52:46
that many people can do very well just having two main meals a day
52:51
or maybe combining breakfast
52:52
and lunch.
52:53
The concept of brunch many people are enjoying around the world
52:56
and see actually I feel quite good at the weekend
52:58
when I do that.
53:00
I don't necessarily need to eat first thing in the morning.
53:03
And I think we're realizing
53:04
that this this idea of three big meals
53:08
and maybe three snacks events has been forced on us by the food industry.
53:14
Mr.
53:14
Kellogg was probably the first one to say
53:16
that everyone had to have a breakfast before doing anything otherwise you'd be unable
53:22
to work.
53:28
It's Kelloggs for breakfast and a happy happy day.
53:28
I personally find, you know,
53:30
I'm doing this interview now
53:33
and I decide not to have breakfast
53:35
because I'm actually sharper uh
53:37
when I haven't eaten just before it.
53:40
So, for me, uh two or three meals, no major snacking events,
53:44
eating relatively late.
53:46
I eat until say finish eating maybe 8:30 at night
53:51
and then will try
53:52
and not have anything to eat before about 10:30 the next morning.
53:55
That suits me.
53:56
When we asked the 140,000 ZOE members what they preferred,
54:03
they found two-thirds preferred that same rhythm.
54:05
One-third uh couldn't miss breakfast.
54:08
They said, "I really like my breakfast.
54:09
I'm hungry when I get up.
54:11
I want to have my breakfast
54:12
but then I'll finish eating around uh 6 6:30
54:16
and so people have different rhythms
54:19
as we discovered.
54:20
I think there is a bit of personalization to this
54:23
and you have to find the one
54:24
that suits you but my advice would be don't follow what the big food
54:28
companies want you to do.
54:31
Uh do experiment find out what works for you and follow that.
54:35
So there you go.
54:36
There are my eight guidelines.
54:38
The key message is you got to eat for your gut microbes.
54:42
If they're happy, you're going to be happy.
54:47
Chapter four.
54:48
Why the internet gets dieting all wrong.
54:52
I think it's very hard at the moment for the average public who's not
54:56
a scientist,
54:57
not a doctor to know what to do for their health.
55:00
Reports, you know, one day that coffee is bad for you,
55:04
another day coffee is good for you.
55:06
Uh eggs are good for you. one day and eggs are bad for you.
55:10
Public has to realize
55:11
that the media thrive on these stories on these scare stories.
55:17
Uh they love food stories.
55:20
So you know our newspapers and social media are full of all this stuff.
55:24
So the the key is to not overreact
55:27
and to realize that your core diet is the most essential
55:31
and that if you are looking after your gut microbes
55:35
and you're doing most of those those eight things we discussed,
55:41
it doesn't really matter what else you do
55:43
or don't do because the majority of your plate every day is going to
55:47
be full of good stuff.
55:49
Whether you have eggs, whether you have coffee,
55:50
whether it's good or bad is not going to be crucial to your health.
55:54
What is crucial is
55:55
that majority of the time you're doing the right thing. 80% rule is what
56:00
I love is you 80% of the time you're doing uh things right
56:05
and you don't worry about the odd time the you may have the odd
56:08
trip to McDonald's once a month.
56:11
If your gut health is good, it will cope with the rest.
56:14
All good scientists should change their minds when the data changes.
56:20
And I've made lots of mistakes in my career.
56:24
Most of it not my necessarily my fault.
56:26
There was some data on margarine being healthier than butter.
56:30
So I changed our fridge back, this is 20 years ago,
56:33
to having these low-fat spreads and kicked out the butter.
56:39
My wife objected.
56:41
She's she's uh French speakaking so she wouldn't have any of it.
56:44
She kept the butter so we had separate compartments.
56:47
And I realized that I I got it wrong
56:48
and now there's no low-fat artificial ultrarocessed spreads in my fridge.
56:55
So I'm constantly changing my view on many of these things.
56:59
I'm much more open-minded than I think I was before.
57:02
So it's an exciting time uh to be a scientist.
57:06
I think what is important to realize is
57:09
that science is moving on at a pace.
57:12
It takes on average 20 years for doctors to change their practice from the
57:18
time that uh a new uh scientific discovery has been uh proven.
57:24
So there's a big lag between what the latest science is delivering
57:29
and what the latest practice is
57:31
or what your insurance is going to pay for etc etc. the public is
57:35
stuck in the middle here.
57:37
And I think what's important is to see when there's a consensus,
57:41
when there have been a number of studies
57:42
that are all pointing in the same direction
57:44
and they've got someone they trust
57:46
that is telling them yes,
57:49
the summary of this data convincingly is saying you need to do this.
57:53
I think the lesson here is
57:54
that the public needs to up their game a bit to be a bit
57:58
more educated to know
57:59
that I can create any outcome I want in a test tube.
58:04
You need to disregard that.
58:05
I can do the same thing in mice.
58:06
That would probably be pretty irrelevant.
58:09
Getting people to think, has this been tested in humans?
58:12
Was there a placebo arm?
58:14
Is this really going to change the practice of most people without just jumping
58:19
on every bandwagon that people want you to to jump on?
58:23
At the same time, realize that the guidelines that are out there from government,
58:27
etc. are very behind the times.
58:29
and realize that uh a lot of the stuff people might be seeing on
58:33
social media is probably too far ahead of the time just
58:36
so someone can talk about a test tube study
58:39
or a mouse study
58:43
that sounds exciting or wacky
58:43
or uh accounts for some weird theory.
58:45
There's lots of people on to looking at paleo diets or keto diets,
58:50
people who only eat meat
58:51
or people who only have really high levels of fat above 70%
58:56
that claim miraculous benefits from it.
58:59
Most of these diets work shortterm because if it's away from ultrarocessed foods,
59:04
then generally it's going to be healthy uh to that extent.
59:07
And so people who go on a carnivore diet,
59:10
which is a an idea of what our ancestors ate, uh,
59:14
a very selected idea of what our ancestors ate,
59:18
they will feel benefits for a few weeks, might lose usually lose weight.
59:22
Those people will then tell everyone about it.
59:25
Isn't it amazing?
59:26
People who go on very strict gluten-free diets, keto diets, carnivore diets,
59:31
seed oil free diets like the idea of excluding things.
59:35
So that suddenly you're belonging to this club of people
59:38
that are excluders and that's perhaps the attraction
59:41
and that's why most religions have some food based ideas
59:45
that keeps that community together.
59:47
So they they become a little group,
59:49
they feel better for the first six weeks and that's when the problems start.
59:55
So, a they might be very hard to sustain like a keto diet is
59:59
really hard to sustain those high levels of fat.
60:02
Most people feel rather sick.
60:04
And long-term your gut is suffering.
60:06
Any restriction to the amount of plants
60:09
that are going into your gut will start to have an effect of killing
60:14
off the good ones
60:15
and making the uh overgrowth of the bad ones
60:18
that are just uh eating the scraps of what of what you're eating.
60:23
And so long-term you have immune problems uh and gut health problems,
60:28
mental problems down the line.
60:30
So I think uh exclusion diets will work short term
60:36
and people might want to do
60:37
that as an experiment to see how they feel,
60:40
but then they've got to long-term start looking after their long-term gut health,
60:45
which is the thing that's going to keep them alive
60:47
and keep them free of diseases.
60:49
What I like about our message is that it's not about exclusion.
60:53
It's about inclusion at the very best level.
60:56
All that mattered was you're getting that big variety.
60:59
There's those those u 30 plus plants.
61:02
I get a lot of questions about uh organic food, for example.
61:07
Should we only be eating organic food?
61:09
How bad are these pesticides and these herbicides for us?
61:15
These are great questions that don't have simple answers.
61:19
It's always better, I think,
61:22
to eat non-organic vegetables than not to eat them at all.
61:28
Yes, our fruits and vegetables are sprayed with pesticides
61:32
and herbicides that are probably slightly negative for our health,
61:37
particularly if you're uh pregnant
61:40
or you're a young child
61:42
or you're have some immune problems
61:43
or you're sick.
61:45
For most of us, it's a low-level harm.
61:47
You want to avoid it, but it's not life and death.
61:51
And that's the way I I see about these things.
61:53
We should also be try
61:54
and supporting farming that's moving towards organic
61:58
because we'd all prefer to live in a world
62:00
that didn't have these chemicals sprayed to kill every kill all kinds of life.
62:06
And we do know that these pesticides harm our gut microbes.
62:10
So, they've been shown to be relatively safe for our genes.
62:14
They don't alter our genes,
62:15
but they do interfere with the genes of our microbes.
62:18
So, in theory, I don't want to eat pesticides uh at all.
62:23
The reality is it's tough.
62:25
I don't like paying twice as much for my food.
62:28
At home, what I do is I uh yeah,
62:31
I get organic food delivered on a weight a basis,
62:34
but when I'm out and about,
62:36
I'm not that worried about it
62:37
because it's better to eat vegetables
62:40
that have some uh chemicals on them,
62:42
wash them off than not to eat them,
62:45
and deprive your your gut microbes of a meal.
62:49
Now, some foods I would worry more about than others
62:53
because they're not all the same.
62:54
Uh if you look at oats,
62:56
oats have a terrible record because they're sprayed multiple times before harvesting.
63:01
So they can have um many times the levels of other crops.
63:07
So I'd always go for organic oats
63:10
and you can find those in stores now.
63:12
It's worth paying a little bit more for those.
63:14
Similarly with berries, if you can get uh organic strawberries that aren't sprayed,
63:20
they'll be much healthier.
63:22
But if you're talking about things like oranges or avocados,
63:25
I'm less worried because you don't not eating the skin
63:30
and a lot of the pesticide is is in
63:32
that skin.
63:32
So, it's a it's a slightly nuanced question, but personally,
63:36
I'm not obsessed so
63:38
that uh I get stressed every time I go out to a store
63:42
or a restaurant about not finding uh the exact product I want.
63:47
It's about not exposing yourself to things over long periods of time,
63:50
not the occasional uh event.
63:52
That's really important.
63:54
Another thing people ask me about is mercury content of large fish.
64:00
If I'm a fish fanatic
64:01
and I'm I'm having fish two
64:03
or three times a week,
64:05
I wouldn't want want to having the those same large fish
64:08
because I would be building up high mercury levels.
64:10
You might want to have your fish checked.
64:12
And there are places you can buy fish from
64:14
that have guaranteed low mercury levels,
64:18
but I'd be going for smaller fish
64:19
which are also more sustainable for the oceans.
64:22
My own personal choices of food are I'm thinking about uh the health consequences
64:28
of the food,
64:28
some ethical considerations about it, uh but also the effect on the planet.
64:34
Fish is particularly pertinent to
64:35
that because most of the fish we get is is uh grown in fish
64:39
farms. um some which are good,
64:41
some of which are bad.
64:43
So, it's good to be thoughtful, but in general,
64:46
go for small fish
64:47
that are more likely to be sustainable
64:49
and also have very high levels of the omega-3s
64:53
that are really good for your brain.
64:55
I'm often going to people in restaurants
64:59
and the they're very worried about the salt content
65:01
and they're asking uh for no salt to be added to their food.
65:04
This is a subject
65:06
that I was interested in
65:07
because I had high blood pressure diagnosed came on suddenly about 15 years ago
65:13
and I tried salt restricting for a couple of weeks
65:16
and see if it would change my blood pressure.
65:19
I didn't notice the difference.
65:21
So, I started researching this
65:23
and it it turns out
65:24
that um for the the average normal uh 50-year-old,
65:30
cutting out salt virtually completely from your diet improves your blood pressure by about
65:35
1 to 2%.
65:36
If you have a problem with uh hypertension, blood pressure,
65:41
it might increase to about 4%.
65:43
And when I looked in detail,
65:45
it turns out that there's only about one in five people
65:48
that are really sensitive to salt.
65:50
Four out of five of us are not that sensitive.
65:52
So it has an exaggerated effect that most people aren't aware of.
65:58
So I tell people that if you're worried about salt, do a proper test.
66:02
Take your blood pressure three times a day for two weeks having no salt
66:08
salt at all,
66:09
which is horrible, and see what effect it has on your blood pressure.
66:14
What I also found out is
66:15
that eating just something like beetroot can increase can reduce your blood pressure three
66:21
times more than salt restriction.
66:23
Similarly, just changing your salt to a potassium salt can have three times the
66:27
effect of salt restriction.
66:29
So most people don't have to worry nearly as much as they are.
66:32
And I think it destroys a lot of the pleasure of eating
66:36
and stops them maybe enjoying vegetables
66:39
as much or fermented foods
66:40
as much because they're worried about the salt content.
66:42
That's why it doesn't come into my guidelines.
66:45
And if you're avoiding most of the ultrarocessed food,
66:47
you're going to be avoiding the salt.
66:49
There's really good data showing the salt you add at your table is negligible
66:53
effect on your health compared to all the rubbish you're getting consuming too much
66:57
ultrarocessed food.
66:58
When I was researching fermentation,
67:01
I looked at kimchi eaters
67:03
and then anyone who's had kimchi knows it's really tastes really salty
67:06
and when you make fermented foods,
67:07
you have to add a lot of salt.
67:09
They looked at um over 10,000 kimchi eaters in in in South Korea,
67:16
compared them to non-kimch eaters of the same age,
67:19
and they actually had lower blood pressure than uh the non-kimchas.
67:23
So, the benefits of having fermented foods and plants, and plants contain potassium,
67:29
outweighs any effect of the salt.
67:31
That's a great example of a nice simple solution being exaggerated
67:37
because of rather outdated research
67:40
that stayed in the in our in our minds.
67:44
Yes, salt has a role.
67:45
Most of it's an ultrarocessed food.
67:47
Eating plants would have a much better effect on your blood pressure than worrying
67:51
too much about salt.
67:52
A lot of people also think
67:54
that diet isn't that important
67:56
if you've got a rich supply of supplements
68:01
and there's a lot of marketing directed at people like
68:04
that to say you don't have to worry about your diet.
68:08
You just got this green powder you take every morning with 80 different uh
68:13
chemicals and vitamins.
68:14
That's all you ever need.
68:15
Again, that falls into this idea of reductionism. a nice simple solution to a
68:22
complex problem that usually by definition is wrong.
68:26
And all the studies suggest
68:30
that eating the food is always better than eating the chemical
68:36
that uh has been derived from
68:38
that food. because there are other things in the food
68:41
that aren't represented in
68:42
that highly purified chemical that's made often made artificially by yeast in factories.
68:49
Most of them are in China uh with all kinds of additives etc.
68:53
that make it very different to just having
68:56
that from uh a natural plant.
68:59
The example I like is for for years I was giving calcium replacement tablets
69:05
to my patients in rheumatology uh thinking I was helping their bones
69:11
and they'd be taking you know maybe a gram a day.
69:14
It turns out that taking something like that, your body doesn't deal with it.
69:20
And it's now been associated over uh six studies uh showing
69:27
that it's associated with increased risk of heart disease
69:29
and atherosclerosis with a hardening of the arteries.
69:32
So the calcium is being deposited in places
69:35
that you don't necessarily want it
69:37
because it's given in a form
69:39
that the body's not used to.
69:41
We normally break down calcium in tiny amounts from all the foods we're eating
69:45
or from mineral waters
69:46
and things like this
69:48
and it's gradually gets incorporated into our body.
69:51
So taking one big dose of it uh can have very different effects on
69:55
our body.
69:56
So that's why I'm always wary about supplements.
70:00
They can also interact with each other.
70:02
So they don't work. you know,
70:03
if you have zinc and you have iron at the same time,
70:05
they they stop each other working
70:09
and you don't know the quality of them at all.
70:12
And things like vitamin D, vitamin D is called the sunshine vitamin.
70:16
The body converts sunshine uh into vitamin D,
70:21
and that's how we get most of it in our in our bodies.
70:25
And that's how we've evolved.
70:28
But taking vitamin D is not a replacement for sunshine, for example,
70:32
because there's many other things in sunshine
70:35
that we still don't know about
70:37
that provide our bodies with a lot of benefits.
70:40
And there's a lot of epidemiology comparing people who go in the sun
70:43
and out of the sun uh showing
70:46
that even after having a melanoma for example,
70:48
people who go in the sun have a better immune system
70:51
and a a better uh outcome than people who are maybe just taking vitamin
70:57
D tablets.
70:58
So often we mistake a subset of of a food for being better than
71:04
the whole food or the whole um environment like like sun.
71:09
And there many other examples like
71:11
that where you know we just take one thing from a carrot
71:14
and call it keratene
71:16
and say that's going to be good.
71:17
We know carrots are good for you
71:18
but if you have too much kerotene it's probably bad for you.
71:21
We love to reduce um foods to one thing. we we can manufacture
71:26
that in huge quantities.
71:28
Marketing does the rest
71:30
and what seemed like a good idea is often really a pretty poor one
71:35
and can often be harmful for you.
71:37
If someone's offering you a single solution to a nutrition or a gut problem,
71:42
it's probably rubbish.
71:46
They're probably just trying to sell you something.
71:49
But we all as humans are suckers for the the simple solution.
71:53
The science of nutrition
71:54
as I've you know got into it really without biases 15 years ago is
72:00
one of the most complex sciences we have.
72:02
It's we were told it was the simplest all calories and macronutrients.
72:07
Turns out it's really complicated.
72:09
That means there isn't one single product or solution to it to it.
72:13
There isn't one vitamin that's going to cure you.
72:16
We need to take a more holistic view of it.
72:18
And that's that's a really important message.
72:21
We need to be doing things that aren't just for a six- week diet,
72:24
aren't just to lose weight.
72:25
It's how do you change all your habits
72:29
that you've you've accumulated all these bad habits.
72:31
How do you change them in this direction going forward?
72:35
Uh and do this for years so that your body is much healthier,
72:39
your brain is much healthier.
72:41
We make hundreds of food choices every day.
72:46
And the food choices we make are the most important choices we can make
72:49
for our health.
72:50
So make them wisely.
72:57
Want to support the channel?
72:59
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73:01
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