Latest / Hardiness with Dr Paul Taylor / The biggest thing that is shrinking your brain, and how to combat it: Wisdom Wednesdays

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The biggest thing that is shrinking your brain, and how to combat it: Wisdom Wednesdays · Hardiness with Dr Paul Taylor

• 0:05
  Speaker 1: Everyone, Welcome to another edition of Wisdom Wednesdays.
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  Speaker 2: Today we are going to talk about a hidden fat
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  Speaker 2: that may be aging your brain.
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  Speaker 1: And if you're familiar with this podcast, you'll probably know
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  Speaker 1: that that fat is visceral fat. And there's a pretty
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  Speaker 1: fascinating long term study that suggests that visceral fat, which
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  Speaker 1: as you probably know, is the stuff that is stored
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  Speaker 1: inside your abdominal cavity, so it's around your organs, it's
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  Speaker 1: underneath your stomach muscles. It appears that this is associated
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  Speaker 1: with accelerated brain shrinkage and poorer cognitive function as we
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  Speaker 1: get older. And here's a really interesting part body weight,
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  Speaker 1: body mass index BMI and this fat that you can
• 0:49
  Speaker 1: pinch under the skin, we're not consistently associated with these
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  Speaker 1: changes in brain structure. It's only visceral fat that stands
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  Speaker 1: out as a signal. So the message is simply not
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  Speaker 1: to lose weight, it's about were that fat actually is stored.
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  Speaker 2: So let's unpack the study.
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  Speaker 1: So the researchers in this one they combined data from
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  Speaker 1: four previous lifestyle interventions. These were trials called the Direct,
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  Speaker 1: the Cascade of the Central, and the Direct Plus studies,
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  Speaker 1: and these studies included.
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  Speaker 2: A variety of different dietary approaches.
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  Speaker 1: They included low fat diets, Mediterranean diets, lower carb diets,
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  Speaker 1: and green Mediterranean diet rich in polyphenols and plant biased proteins,
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  Speaker 1: and some also included structural physical activity. Now, the original
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  Speaker 1: interventions lasted between eighteen and twenty four months, but the
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  Speaker 1: researchers managed to follow five hundred and thirty three of
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  Speaker 1: the participants for another five to six years and so
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  Speaker 1: got some better longer term data. And they were obviously
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  Speaker 1: slightly older adults. And they used MRI to measure both
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  Speaker 1: abdominal fat and the structure of the brain. They also
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  Speaker 1: assess cognitive function using a standard cognitive function test in
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  Speaker 1: Montreal Cognitive assessment that's used in lots of studies, and
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  Speaker 1: that measures areas such as memory, attention, language, and executive function. Now, importantly,
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  Speaker 1: the researchers separated abdominal fat into three different categories. There
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  Speaker 1: was the superficial subcutaneous fat that's the stuff that you
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  Speaker 1: can pinch just under your skin. Then there was deeper
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  Speaker 1: subcutaneous fat, and then there was visceral fat, which sits
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  Speaker 1: inside the abdominal cavity and surrounds the organs, and it
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  Speaker 1: turns out that not all fat behaves in the same way.
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  Speaker 1: So the subcutaneous stuff that's primarily a storage tissue, whereas
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  Speaker 1: visceral fat is way more biologically active. You may have
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  Speaker 1: heard me talk about this before. It acts almost like
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  Speaker 1: an endocrine or hormonal organ It releases inflammatory chemicals called
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  Speaker 1: adible kinds, and it contributes to insulin resistance, poor blood glucose,
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  Speaker 1: and also metabolic dysfunction. Now that's been established in lots
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  Speaker 1: of other studies. Now, the researchers here they looked at
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  Speaker 1: how much visceral fat people lost during the original lifestyle
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  Speaker 1: intervention and how much visceral fat they were exposed to
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  Speaker 1: over the following decade. And those who lost more visceral
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  Speaker 1: fat during the original intervention tended to have higher total
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  Speaker 1: brain volume, more gray matter, and healthier hippocampal score years later. Now,
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  Speaker 1: the hippocampus is heavily involved in learning and memories, you
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  Speaker 1: probably know. And there's this thing called the hippocampal occupancy
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  Speaker 1: score that gives researchers an indication of how much the
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  Speaker 1: hippocampus has shrunk relative to the space around it. So
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  Speaker 1: lower scores generally means greater atrophy or shrinkage of the hippocampus,
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  Speaker 1: which is clearly not good.
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  Speaker 2: And people with.
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  Speaker 1: Greater relative exposure so over time who had the most
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  Speaker 1: visceral fat, they also showed faster expansion of the brain's
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  Speaker 1: ventricles the senate spaces in between. These are these fluid
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  Speaker 1: filled spaces in and around the brain, and when your
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  Speaker 1: brain tissue shrinks, these spaces become larger, and that expansion
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  Speaker 1: is considered one of the structural signs of brain aging.
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  Speaker 1: And you see those really expanding Alzheimer's disease as the
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  Speaker 1: brain tissue shrinks.
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  Speaker 2: So higher long.
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  Speaker 1: Term visceral fat exposure was also associated with poorer overall
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  Speaker 1: cognitive scores and poorer memory scores, and these relationships remained
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  Speaker 1: even after the researchers are accounted for age, sex, diet,
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  Speaker 1: and body mass index BMI. Now some of you might
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  Speaker 1: be thinking, yeah, well, this is not good, but this
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  Speaker 1: is an association study, and there are often other factors
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  Speaker 1: that are involved in observational association studies. But this study,
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  Speaker 1: it followed people for many years, and it used objective
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  Speaker 1: MRI measurements and found that visceral fat was more strongly
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  Speaker 1: related to brain outcomes than either BMI or subcutaneous fat,
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  Speaker 1: which makes the finding pretty difficult to ignore. And they
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  Speaker 1: also they looked at what might be driving it, was
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  Speaker 1: it information, was it cholesterol, triglycerized blood glucose control, And
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  Speaker 1: the factor that stood out most was glucose regulation, So
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  Speaker 1: higher fasting blood glucose and higher HbA one C, which
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  Speaker 1: is a kind of a three month measure of blood glucose.
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  Speaker 1: That appeared to help explain the relationship between visceral fat
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  Speaker 1: and poorer brain health and cognitive health. And that makes
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  Speaker 1: biological sense. We know that excess visceral fat makes a
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  Speaker 1: body less responsive to insulin, and over time that implerred
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  Speaker 1: glucose regulations. Damage is blood vessels, increases oxidative stress, and
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  Speaker 1: interferes with the brain's ability to use energy effectively. And
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  Speaker 1: some of you may have heard me talking about Researchers
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  Speaker 1: mention Art can describe Alzheimer's as type three diabetes. Now,
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  Speaker 1: the brain represents only two percent of our body weight roughly,
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  Speaker 1: but it uses roughly twenty percent of our energy and
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  Speaker 1: even more whenever we're stressed or in deep cognitive tasks,
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  Speaker 1: and it is a really energy demanding organ. So that
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  Speaker 1: is why when our metabolic health deteriorates, the brain actually
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  Speaker 1: plays the price. And there was another really interesting finding
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  Speaker 1: in this paper. They found that the relationship between visceral
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  Speaker 1: fat and poorer cognitive performance was strongest amongst people whose
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  Speaker 1: brain volume was still relatively well preserved, which is a
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  Speaker 1: bit surprising among people who already had substantial brain atrophy.
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  Speaker 1: The visceral fat had of an additional association with cognitive performance,
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  Speaker 1: and the researchers here suggested that the visceral fat related
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  Speaker 1: cognitive changes may act as an early warning signal. It's
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  Speaker 1: a bit like the canary in the coal mine. So
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  Speaker 1: cognitive performance may begin to deteriorate before obvious structural brain
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  Speaker 1: change has become advanced. And that kind of makes sense
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  Speaker 1: that the cells become damaged before they disappear and get
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  Speaker 1: killed off. And once that significant brain shrinkage has occurred,
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  Speaker 1: other structural, vascular, and metabolic problems may become the dominant
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  Speaker 1: drivers here.
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  Speaker 2: So what do we do with all of this information?
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  Speaker 1: Well, the good news is actually that visceral fat is
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  Speaker 1: actually highly modifiable.
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  Speaker 2: It responds often, it responds more.
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  Speaker 1: Quickly to lifestyle changes than subcutaneous fat, and when people
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  Speaker 1: lose around.
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  Speaker 2: Five to ten percent of their body weight.
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  Speaker 1: They may often know they often do lose a disproportionately
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  Speaker 1: larger amount of visceral fat. But you don't need to
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  Speaker 1: obsess over a particular diet. We know that low carb diets,
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  Speaker 1: Mediterranean diets, lower fat dits, and time restricted feeding can.
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  Speaker 2: All work to reduce visceral fat.
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  Speaker 1: The most important factor for reducing it is creating a
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  Speaker 1: sustainable energy deficit. And the word sustainable is really important here.
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  Speaker 1: So a diet that causes rapid weight loss but makes
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  Speaker 1: you hungry, miserable, and antisocial is probably not going.
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  Speaker 2: To last for the next ten years.
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  Speaker 1: So it's really about adopting a sustainable eating practice rather
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  Speaker 1: than a diet. And now let's talk about exercise, because
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  Speaker 1: this is really really important. Aerobic exercise is effective for
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  Speaker 1: reducing visceral fat. Running, cycling, swimming, rowing, all of those
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  Speaker 1: sorts of things that raise the heart rate.
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  Speaker 2: They can reduce.
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  Speaker 1: Visceral fat even when total body fat does not change.
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  Speaker 2: Dramatically, and that points in pots.
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  Speaker 1: Important And this is about improving your metabolic health. Without
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  Speaker 1: seeing a massive change on the skills, you may be
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  Speaker 1: reducing the dangers fat around your organs while maintaining or
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  Speaker 1: even gaining some muscle. I mean, you know that vigorous
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  Speaker 1: cardio and high intensity interval training appear to be particularly
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  Speaker 1: powerful when they can be done by the individual. And
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  Speaker 1: resistance training plays a really important role here as well.
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  Speaker 1: It has been shown to reduce visceral fat, but it
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  Speaker 1: also helps to prefure of our muscle and improves our
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  Speaker 1: insolin sensitivity. We've got to realize that muscle is the
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  Speaker 1: biggest sink for glucose and at Actually, when you get
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  Speaker 1: more muscle and you're using your muscle, it really improves
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  Speaker 1: your insulin sensitivity and then has knock on effects to
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  Speaker 1: visceral fat.
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  Speaker 2: Other lifestyle things that are really important is sleep.
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  Speaker 1: A lot of people think about it as passive, but
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  Speaker 1: whenever you are sleep deprived, you significantly change hormones like
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  Speaker 1: grellin which encoades you to eat more and then left them,
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  Speaker 1: which causes you to move less, and then you're tired
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  Speaker 1: the next day and you're a lot less less likely
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  Speaker 1: to exercise. So sleep is really really important, particularly for
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  Speaker 1: our metabolic health. And then what about cold exposure. You know,
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  Speaker 1: I'm a big fan of that cold water immersion and
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  Speaker 1: other forms of cold exposure appear to activate brown fat,
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  Speaker 1: increasing heat production and energy expenditure. And it's a really
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  Speaker 1: interesting area of research. But the evidence at this point
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  Speaker 1: around cold exposure reducing visceral fat is pretty thin, but
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  Speaker 1: I think we're going to see that change as we
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  Speaker 1: go along.
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  Speaker 2: And look, the other thing is important in terms of
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  Speaker 2: nutrition of sorts.
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  Speaker 1: I forgot the AD is really reducing ultra processed foods,
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  Speaker 1: because all of those daets that people wrong when they
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  Speaker 1: were losing visceral fat were basically low in ultra processed foods.
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  Speaker 1: So again we're talking about here for lifestyle, for having
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  Speaker 1: longevity and health span, and particul for protecting your brain.
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  Speaker 2: It is the boring basics that win. Again.
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  Speaker 1: It's about moving regularly, a combination of a cardio, some
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  Speaker 1: lower intensity, some high intensity interval stuff, lifting some weights,
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  Speaker 1: eat a low HI diet, low human interference, get enough fiber,
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  Speaker 1: get enough protein, and protect your sleep and make sure
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  Speaker 1: your alcohol is within sensible limits. I mean, these are
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  Speaker 1: the things that have been shown over and over again
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  Speaker 1: to dramatically.
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  Speaker 2: Reduce your risk of Alzheimer's disease. And then the other
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  Speaker 2: one that I would throw in here.
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  Speaker 1: Is actually doing cognitively stimulating activities, and lifelong learning because
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  Speaker 1: that is very, very protective for your brain.
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  Speaker 2: So if you do all of those things.
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  Speaker 1: There is a much greater chance that as you get older,
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  Speaker 1: your brain will function as well as the body that
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  Speaker 1: you've worked hard on.
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  Speaker 2: That's it for this week, folks, catch you next time.