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A simple dietary tweak to improve blood flow to the brain: Wisdom Wednesdays · Hardiness with Dr Paul Taylor

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  Speaker 1: Hey, everybody, Welcome to another edition of Wisdom Wednesdays, and
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  Speaker 1: today I want to talk about pretty interesting paper that
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  Speaker 1: I just read that explored a pretty novel mechanism for
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  Speaker 1: improving brain function and blood flow in older adults. And
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  Speaker 1: the reason this matters is that as we auge, one
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  Speaker 1: of the things that declines in the brain is vascular function,
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  Speaker 1: which is basically the efficiency with which the blood is
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  Speaker 1: delivered to the brain, and that starts to deteriorate as
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  Speaker 1: we each and it's thought to be one of the
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  Speaker 1: drivers of age related cognitive decline. So this study asked
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  Speaker 1: a pretty simple question, if you give healthy older adults
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  Speaker 1: skin roasted peanuts every day for a decent period of time,
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  Speaker 1: can you measurably improve cerebral blood flow and does that
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  Speaker 1: then translate into better cognitive performance? And the answer, at
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  Speaker 1: least from this trial is to some degree yes. And
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  Speaker 1: this was a randomized, single blind crossover trial in thirty
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  Speaker 1: one healthy older adults. Their average AIDE was about sixty
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  Speaker 1: seven And this is important because this is the aids
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  Speaker 1: where we start to really see cognitive decline kicking in.
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  Speaker 1: So the participants were instructed to eight sixty grams of
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  Speaker 1: unsalted skin roasted peanuts per day for about sixteen weeks,
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  Speaker 1: and then they compared the results against the control period
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  Speaker 1: of the same people having no peanuts and for at
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  Speaker 1: the same time, and they had an eight week washout
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  Speaker 1: in between, so an eight week gap where basically the
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  Speaker 1: effects of the peanuts would have basically washed out. So
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  Speaker 1: it's a really solid design. I really like that because
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  Speaker 1: eights participant acts as their own control and that takes
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  Speaker 1: our variability amongst individuals and genetic differences in this sort
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  Speaker 1: of thing, right. So, the primary outcome in this study
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  Speaker 1: was global cerebral blood flow and that was measured with
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  Speaker 1: a sophisticated MRI technique called arterial spin labeling. The secondary
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  Speaker 1: outcome that they were looking at was cognitive performance using
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  Speaker 1: what's called the Kantab battery. So this is a battery
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  Speaker 1: of cognitive performance tests that's used a hell of a
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  Speaker 1: lot in research. Now the cognitive tests is important here
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  Speaker 1: because they didn't just ask people whether they felt sharper.
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  Speaker 1: They actually used this validated computerized battery and that covered
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  Speaker 1: things like memory, psychomotor speed, and executive function. So for memory,
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  Speaker 1: they used a few different tests delayed matching to sample.
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  Speaker 1: Then pert associates learning and verbal recognition memory. Right. Then
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  Speaker 1: for psychomotor speed they used reaction time, which is actually
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  Speaker 1: a very good indicator of your brain function, and then
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  Speaker 1: for executive function they used something called the multitasking test
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  Speaker 1: and also spatial working memory tests. So they did lots
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  Speaker 1: of different assessments of cognitive function, and the standout cognitive
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  Speaker 1: result was in verbal memory and specifically the delayed recall
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  Speaker 1: condition of what was called the verbal recognition memory task.
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  Speaker 1: So after the peanut intervention, participants correctly identified about one
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  Speaker 1: point four words more after a twenty minute DELAA, which
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  Speaker 1: worked out too roughly almost a six percent improvement. That
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  Speaker 1: was the key memory finding in the study, and they
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  Speaker 1: didn't find improvements in any of the other tests. But
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  Speaker 1: compared with the control period, peanut consumption increased global cerebral
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  Speaker 1: blood flow by three point six percent and gray matter
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  Speaker 1: blood flow by four and half percent. Now, they also
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  Speaker 1: saw significant increases in blood flow in the frontal and
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  Speaker 1: temporal lobes, along with broader increases across cordical and subcordical regions. Now,
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  Speaker 1: they did not see any significant changes in the occipital
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  Speaker 1: or the perietal lobes, and the hippocampus. They got a
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  Speaker 1: trained upward, but it didn't reach statistical significance. Now, now
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  Speaker 1: this really matters because the frontal and temporal regions, they
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  Speaker 1: are heavily involved in higher cognition and memory processing, and
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  Speaker 1: one of the types of dementia is frontal temporal dementia.
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  Speaker 1: So they offer central argument is that the improvement in
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  Speaker 1: verbal memory may be at least partially explained by this
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  Speaker 1: improved brain perfusion. Now, they also find interestingly that systolic
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  Speaker 1: blood pressure fell by about five millimeters of mercury and
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  Speaker 1: their pulse pressure failed by about four millimeters of mercury
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  Speaker 1: during the peanut period. So one possibility is that the
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  Speaker 1: peanuts improved systemic vascular function, so overall vascular function, which
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  Speaker 1: then impacted upon the Brian circulation. So let's get into
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  Speaker 1: the mechanisms because this is where it gets interesting. The
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  Speaker 1: first proposed mechanism is l organing. So peanuts are rich
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  Speaker 1: in l organing, which is a precursor for nitric oxide.
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  Speaker 1: So nitric oxide is one of your body's major vassal dilators,
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  Speaker 1: so it helps your blood vessels to relax in wine,
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  Speaker 1: and that improves what we call endothedial function and blood flow.
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  Speaker 1: So if you increase nitric oxide availability, you may improve
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  Speaker 1: vascular responsiveness and blood flow, including in the Brian and
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  Speaker 1: this is one of the most plausible mechanisms here. The
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  Speaker 1: second mechanism is the fatty acid profile. Peanuts are rich
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  Speaker 1: and unsaturated fats, particularly monoensaturated and polyunsaturated fats, and these
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  Speaker 1: are known to support cardiovascular and vascular health. They may
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  Speaker 1: also contribute to better cerebral blood flow over time. Third,
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  Speaker 1: and this is important because they use skin roasted peanuts
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  Speaker 1: and you get the polyphenols in flavonoids in the skin.
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  Speaker 1: In fact, lots of fruits as well. A lot of
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  Speaker 1: the real benefits is in the skin. And this paper
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  Speaker 1: it discusses compounds like resoviatrol, phenolic acids, and flavonoids, and
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  Speaker 1: the whole idea is that these polyphenols and flavonoids actually
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  Speaker 1: exert antioxidant and anti inflammatory effects which may also improve
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  Speaker 1: nitric oxide availability so gain This ties back to vascular
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  Speaker 1: function and blood flow. And then there's a fourth possible mechanism,
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  Speaker 1: and that was fiber and the gut brain axis, so
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  Speaker 1: peanut intake. Peanut's got quite a bit of fiber in them,
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  Speaker 1: and the authors noted that the fermentation of fiber by
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  Speaker 1: microbes that produces short chain fatty acid, and these short
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  Speaker 1: chain fatty acids such as buttreate, proprenate, and acetate, they
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  Speaker 1: influence and brain function and may even cross the blood
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  Speaker 1: brain barrier. Now, they were pretty careful here, the authors,
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  Speaker 1: This is a speculative, but I've seen lots of other
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  Speaker 1: papers around those benefits of short chain fatty acids. So
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  Speaker 1: the overall picture is that your peanuts are Peanut intake
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  Speaker 1: may improve cognition indirectly, not by some magical effect on
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  Speaker 1: neurons directly, but by improving our vascular health, our brain
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  Speaker 1: blood flow, and possibly reducing that vascular stiffness and blood pressure.
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  Speaker 1: In other words, better plumbing and better pipes, better flow
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  Speaker 1: through those pipes, and better function. Now, while these effects
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  Speaker 1: were reasonably small, particularly on the cognitive function aspects, that
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  Speaker 1: increased blood flow I think is really really significant, and
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  Speaker 1: it's not just peanuts. It's a wider picture. Here. We
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  Speaker 1: see that berries do similar things. We see that other
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  Speaker 1: fruits and vegetables that are high in these polyphenols and
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  Speaker 1: flavonoids also do better things. So the key thing here is,
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  Speaker 1: if you want to protect your brain, it's about eating
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  Speaker 1: a low HI diet, where HI stands for human interference.
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  Speaker 1: You know, we have coexisted with natural foods for all
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  Speaker 1: of human history, and it's only lately that we've been
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  Speaker 1: supplanting those foods with ultra processed foods, which cause damage directly.
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  Speaker 1: But the other impact that they do is they crowd
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  Speaker 1: out these natural foods from our diet. So it's time
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  Speaker 1: to getting back to eating like our ancestors. If you
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  Speaker 1: want a healthy brain. That's it for this week, folks,
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  Speaker 1: Catch you next time.