[Cynthia Thurlow] (0:00 - 0:35)
One of the things that gets mentioned so much is the change in the way that we store fat and how it moves to our abdomen, which is a very, very common thing. There's two types here, right? Some women will notice that they can kind of pinch it, right?

And they're putting on weight, adipose tissue around their waist. Other women are less aware of it. And actually they may even have more of what's known as visceral fat that you can see on a scan.

What do you think is behind that? I know changes in hormones seem to affect it, but how is the gut playing a part in the changes in body fat?

[Angela Foster] (0:35 - 6:26)
Yeah, so I think every woman listening, it's important that we are getting bioimpedance readings. So we're getting a sense of our fat-free mass to our muscle mass, because that is objective. As opposed to you step on a regular scale, it gives you a number, but it's not differentiating how much is muscle, how much is fat-free mass.

So that's number one. But there's a lot of things that impact metabolic health as we're ageing. Number one is loss of skeletal muscle.

Less skeletal muscle we have, the less insulin sensitive we are. And so that skeletal muscle decline starts at 40. It's anywhere from three to 8% per decade.

I would imagine if you have not been lifting and not been exercising, that skeletal muscle mass loss may be more significant. And to give everyone a visual depiction of what we're talking about, think about a fillet versus a rib eye. Now, equally yummy, right?

One has a lot of fat and marbling, that's the rib eye. The other is predominantly muscle meat. The muscle meat is young muscle.

The sarcopenic loss of muscle mass is the rib eye. We don't wanna be the rib eye. So we want to actively work against this.

So number one, loss of muscle mass will yield loss of insulin sensitivity. And I always think of that as like the first tip off. Number two is with less oestrogen in our bodies, we lose insulin sensitivity.

So those are two things that tend to have a large net impact. Depending on the individual, some women may also have a loss of testosterone. And testosterone can impact body composition quite significantly.

I would add fourth to that, and I will loop this all back to the gut, is this stress resilience. So we become less stress resilient. And so when cortisol goes up, we tend to put fat deposition around our abdomen.

So we'll talk about truncal obesity. It doesn't have to be overt. We have 40 times more cortisol receptors in our abdomen.

So when someone says to me, I went through a stressful period, I noticed I had body composition changes. I understand that physiologically why that happens. And let's be very clear.

This is that sandwich generation as you astutely stated. Our kids are getting older. Our parents are getting older.

We're probably at a time in our careers where we have more responsibility. I think for a lot of people, middle age is both wonderful and also stressful. And so I think we add that in.

And then when we're looking at the gut microbiome and what's changing, we know that with a decline in hormones, we're getting alterations in insulin sensitivity. We are getting alterations in inflammation. And some of that is a by-product of changes in diversity.

Think about it as there's different species of bacteria and other microorganisms, and it tends to become much more inflammatory. So just by virtue of changes in diversity, we have a reduction in short-chain fatty acids, which are important signalling molecules that help reduce inflammation. I mentioned the estrobilone.

And so the estrobilone is the oestrogen processing part of the microbiome. And it's designed to help, the oestrogen gets broken down through the liver, ends up in the gut, and we're designed to break down with the use of an enzyme called beta-glucuronidase, break that oestrogen down and poop it out. But if we're chronically stressed, guess what?

We're gonna recirculate that oestrogen. So it magnifies all the effects. So when I think about how many things about body composition are impacted by the health of the gut, that is at a very basic level.

It is literally everything. The gut is this main communicator with the rest of the body. Plus when we are inflamed, we are sending inflammatory signals and cytokines and things through the vagus nerve, through the bloodstream.

I think about we're more prone to leaky gut and leaky gut will provoke an immune response and then lead to underlying food sensitivities because we'll leak food particles into the bloodstream. So there's many, many layers to shifts in body composition, not the least of which I'm gonna say this again, if we are not dealing with our underlying stress and trauma, that will absolutely contribute. If your body does not feel safe.

And for a lot of women, they have subjugated their childhood experiences. We know that based on research, individuals that had significant underlying trauma as a child, and we're not necessarily talking about big T trauma, we're talking about the more insidious little T trauma, neglect, abuse, substance abuse by a parent, et cetera, financial stressors, that puts you at greater risk for metabolic disease, greater risk for substance abuse, greater risk for autoimmune conditions. And once you've had one autoimmune condition, you're more likely to have others and women are four to five times more likely to develop autoimmune conditions.

These are things like celiac, rheumatoid, lupus, Hashimoto's, you are four to five times more likely in perimenopause and menopause to be diagnosed with an autoimmune condition. I have four, all in remission, but it's because I do a lot to quiet my parasympathetic nervous system and support my body. But I think a lot of people do not necessarily think about body composition changes with gut health.

But I would make the argument that if you're not thinking about what's going on in the gut, you're missing out on opportunities. And there's a whole other conversation around Keystone bacteria and things that can be impacted vis-a-vis these declines in beneficial bacteria. But I'll save that for another conversation because it can get a little bit in the weeds, but there's a lot to body composition changes beyond being incredibly frustrating, unfortunately, incredibly common, but they are not permanent per se.

I think that's one thing I wanna make sure that I say is that these do not have to necessarily be permanent issues. There are definitely things we can do to kind of buffer up against those changes that are happening.

[Cynthia Thurlow] (6:27 - 7:10)
I think what I'm really hearing from you here, Cynthia, from all the research and also 25 years of experience of working with patients is that stress is the kind of elephant in the room that most people are not considering. Whether that is physical stress, right, that's going on, emotional stress, previous trauma, all of it comes up in midlife that we need to pay attention to and start dealing with, right, if we haven't already. It's fundamentally affecting our health in a way that perhaps we hadn't realised before.

You've mentioned a few times the Estrobolone there and how important that is in terms of regulating oestrogen. What are some of the things that listeners to this podcast can start doing to optimise their Estrobolone?

[Angela Foster] (7:10 - 12:33)
Well, I think, you know, at a very simple level, like when you sit down to eat a meal, take four to five deep breaths. I mean, I know a lot of cultures and people will actually say grace. That's a great thing.

Like I grew up saying grace at the table. Admittedly, I don't necessarily do that every day, but I do take four to five deep breaths when I sit down to take a meal. I think nutrient-dense whole foods, and this does not per se mean that I ascribe to any particular nutritional paradigm, although I think it's important to be an omnivore.

I think eating both animal and plant-based foods I think is very important. I would say number one, other than protein, which I know your listeners are very savvy and know all about, is fibre. And fibre has now become the new F word because it is very polarising.

But if you look at the research, and I certainly have interviewed a lot of the experts, the scientists, fibre is missing in most people's diets. And fibre becomes really important, not just for the estrobilone because it helps you package up and poop out your oestrogen, but as we see a decline in short-chain fatty acids, which are these important signalling molecules. People have probably heard of things like butyrate.

Butyrate's one of these short-chain fatty acids that can actually cross the blood-brain barrier. Really important signalling molecule. The brain is designed to be impermeable and butyrate can cross the blood-brain barrier.

But when we eat fibre, fibre goes through our digestive system, gets to the large intestine or colon, and the colonocytes there actually ferment the fibre. And then what is created out of that are short-chain fatty acids. They're important for reducing inflammation.

They're important because they work concurrently to produce the mucin lining, which is mucus. I know everyone thinks gross. That is what protects the gastrointestinal tract.

In particular, the mucus lining of the small intestine because it is one cell layer thick. Remember I mentioned earlier, it's very easy to damage that one cell layer thick of the small intestine. Mucus helps protect that.

They're also involved in endogenous GLP-1 regulation. So GLP-1 drugs, everyone knows they're the rage. They're probably the most impactful drug class of my generation by far.

But our body makes endogenous GLP-1. And so short-chain fatty acids in conjunction with an important keystone bacteria, acromantia, are important for that. And so when I start to think about the things that are important for women, protein, fibre, being in a non-stress state, I would also say that just being cognisant of which nutrient-dense foods are gonna be beneficial.

So I think about cruciferous vegetables. I think about cauliflower, broccoli, kale as good examples. And I've said there's a huge amount of cruciferous vegetables.

I think about bitter greens or bitter herbs or bitter vegetables, radicchio, freeze, things like that. Because it's interesting, hydrochloric acid, which is what breaks down protein in the gut, declines, or stomach. Then digestive enzymes tend to decline, which can impact digestive fire.

What's interesting is very few people talk about the role of oestrogen and bile. So bile is a substance contained in the gallbladder that helps break down and emulsify fats. A lot of women will notice, like I just don't digest my food quite as well.

And so bitter greens can be helpful for bile because as oestrogen declines, you may find like if I eat a fatty meal, if I eat that ribeye or if I eat a duck or a salmon, which tend to be fattier protein sources, you're like, I just don't feel good. And so it could be with this decline in oestrogen, your bile production and your quality of your bile is changing. What's interesting is bitter greens, bitter foods can be very helpful for supporting the gallbladder.

So when I think about it on a very fundamental level, those are things along with, and I know people hate to hear this, polyphenol rich foods. So brightly pigmented fruits and vegetables, things that have a bite, like really good quality extra virgin olive oil should not be a benign taste. It should have a peppery bite to it.

Those are the polyphenols. These are really important signalling molecules in the body. But whether it's peppers, whether it's eggplant, whether it's whatever is in season, these can also be very important.

And I would say lastly, like things like water, water consumption. A lot of women will talk about brain fog and constipation. I can't tell you how many patients just by adjusting their water intake and how much water they're drinking during the day, they'll have better mentation and they'll also feel like they're less constipated.

Constipation is not benign. Obviously it's very much a personal experience, but those are some like key things that I think are really important along with alcohol abstinence. I know that that tends to be really polarising, but there's no research that suggests that alcohol is beneficial.

So if you're going to drink alcohol, do it sparingly, understand the risk of consuming alcohol. And certainly, there was a big podcast that came out with Huberman a few years ago that once I listened to that, that just reaffirmed I'd already been alcohol free. But I think that for a lot of people, they're conditioned to believe that a couple of glasses of wine per night isn't a big deal, but we know that that damages the microbiome, that's a toxin.

And whether or not, if it's just a sporadic, like it's a birthday celebration or someone graduates or it's a wedding, I think that's very different, but we really have to examine our relationship with alcohol.

[Cynthia Thurlow] (12:33 - 12:47)
I think that's another thing that women start to notice, right? Is you just can't metabolise alcohol in quite the same way as you used to. I've definitely preferred being alcohol free.

It's made a huge difference. And I know you are too.

Why does belly fat suddenly increase in perimenopause, even when you’re eating well and exercising? In this episode, Angela Foster speaks with Cynthia Thurlow about the real drivers behind midlife body composition changes, from hormones and muscle loss to stress, inflammation, and gut health.
They explore why cortisol and nervous system dysregulation play such a major role in abdominal fat storage, how the gut microbiome impacts oestrogen metabolism, and the simple strategies women can use to support metabolic health and feel more in control of their bodies again.

KEY TAKEAWAYS
Muscle loss reduces insulin sensitivity in midlife

Chronic stress increases abdominal fat storage

The gut microbiome influences oestrogen metabolism

Fibre supports hormone detoxification and inflammation reduction

Declining oestrogen impacts digestion and bile production

Gut health plays a major role in body composition

Midlife body composition changes are reversible with the right strategy