Wisdom Wednesdays: How does eating ultraprocessed food affect brain insulin and behaviour?

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Episode Transcript

Speaker 1 (00:09):
Hey, everybody, welcome to another edition of Wisdom Wednesdays. So
you'll have heard me talking about ultra processed food and
the health risks of ultra processed food and how I
increased ultra processed food consumption has been shown to dramatically
increase your risk for a whole host of different chronic diseases.
But what about the impact of overeating with ultra processed

(00:34):
food on brain function? And this study was answered. Now,
this question was answered in a study of twenty nine
young men who didn't have any health issues. And what
they actually did with these guys is get them to
overeat with ultra process snack foods for five days, and

(00:55):
they measured the brian's responsiveness to insulin and the reward
sensitivity in the brain and whether it impacted upon liver
fat as well.

Speaker 2 (01:07):
So let's dive into some of the details.

Speaker 1 (01:09):
So they ad a what's called a hypercaloric diet, which
means that basically more calories than they needed, and it
actually added about eleven hundred calories on top of their
normal intake of twenty six hundred a day. And those
extra calories included over seventy grams of fat and one

(01:31):
hundred grams of carbohydrate and consisted of ultra processed snack foods,
and the control group maintained their usual diet and calorie intake,
and the caloric intake did not differ between the groups
before the intervention, and it's seven days after the intervention
when they had resumed their habitual diets.

Speaker 2 (01:53):
And the primary outcome that.

Speaker 1 (01:55):
The researchers were looking at was the impact or the
action of insulin in the brian and especially the neural
activity in response to intrinhasal insulin administration, and that's how
they basically measure the impact in the brain. And then
the secondary outcome that they were looking at was the

(02:16):
liver fat content and also performance on a reward learning task. Now,
compared to the control group, the guys who had the
extra unhealthy snack foods had the following effects at the
end of the intervention. They had increased brain insulin action
in three different brain regions. They had increased liver fat content.

(02:42):
They had increased punishment sensitivity in this task that they
did i e. Their brains were more responsive to negative reinforcement,
and they had decreased reward sensitivity ie Their brains were
less responsive to positive reinforce, and then seven days after

(03:03):
resuming their normal diets, that group had decreased brain insulent
action in two brain regions, increased punishment, and decrease reward sensitivity,
patterns that were still evident but no longer statistically significant.
So what they say is is the impact on their
brain lasted for about seven days but was trailing off,

(03:27):
and there were no detectable differences between the groups, the
control group and the intervention group, and their desire to eat,
their food cravings, their body weight and composition, and metabolic
parameters such as their insulin resistance or inflammatory markers. So
they were really just looking at liver fat and the
impact on the brain. So let's talk about the big

(03:50):
picture and the implications of this study. There is now
a body of research that shows that our brains respond
to short term changes in the diet even before it
impacts on weight gain.

Speaker 2 (04:06):
And although lots of this research has.

Speaker 1 (04:09):
Involved animal studies that showed changes in brain function to
do with memory, cognition, and metabolism, similar results have been
reported in human trials, and this study contributes to the
research by showing that less than one week of basically

(04:29):
shitty food can actually reduce brain insolince sensitivity in young men.
This is really important because as we get older, our
insolince sensitivity drops off. So if it's having this impact
just in seven days of young men, what's the impact
on older adults whether insolence and sensitivity is dropping. And

(04:52):
why this is really important for brain health is that
we know that lack of insolince sensitivity in the brain
and contributes to Alzheimer's disease and other forms of dementia. Now,
they internusal insulin and when they stick inchoin up your nose,
that reaches the brain directly, and that actually allows the

(05:14):
researchers to show very sensitively how the brain is actually
responding to insulin without affecting our blood sugar or our
blood inchlin levels. Now, this is important because brain insulin
and sensitivity. What's going on is that insulin binds to
receptors in regions such as your hypothalmus, which regulates our hunger,

(05:39):
a hypocampus, which is involved in memory, and then the striatum,
which is involved in reward and addictive behavior. And that
means that insulin action in the brain when it's normal,
can suppress your appetite, regulate your mood and your motivation
around food.

Speaker 2 (05:58):
And support learning and memory.

Speaker 1 (06:00):
And this study is important because it was showing that
just after one week, there was reduced rewards sensitivity and
there was increased brain insulin activity in areas to do
with feeding behavior. And this study is important because it
was a short study, it was only seven days, but

(06:21):
it actually showed that it changed brain activity and particularly
around food. And this really means that you know, going
on a binge for a week can really change how
your brain perceives food. And the other thing in this
study was that they showed that there was rapid liver
fat accumulation and that can lead to insulin resistance and

(06:44):
that's a hallmark of early non alcoholic fatty liver disease.
So basically, seven days of a shit that your brain
starts to fall apart and so does your liver.

Speaker 2 (06:55):
And this adds to a growing.

Speaker 1 (06:57):
Body of research that shows how the brain actually rapidly
reacts to dietary changes, and this study suggests that the
those brain changes may persist even after that dietary change
has actually stopped. And maybe why when people just start

(07:19):
to lose it a little bit in terms of their diet,
that it is so hard to get back on track.

Speaker 2 (07:26):
So that's it for this week. Folks, catch you next time.