[ANGELA FOSTER] (0:00 - 0:07)
Voting, abdominal weight gain or a tolerance of certain foods. Could the perimenopause transition itself be changing her gut environment?

[TIM SPECTOR] (0:07 - 0:15)
Well, the answer is definitely yes. The body and the microbes are changing. The diet is still the same.

These are having effects on the brain. These are having effects on the gut.

[ANGELA FOSTER] (0:15 - 0:29)
Inspector, you are the original pioneer of microbiome research, one of the top 100 most cited scientists in the world in terms of food itself and anxiety. How much is down to the gut microbiome and how much is hormonally driven?

[TIM SPECTOR] (0:29 - 0:41)
Hormones can interfere with your microbes, particularly in the premenopause when hormone levels are really changing rapidly. The body's saying, hey, what's going on here? The microbes are sending out distress signals that can trigger depression.

[ANGELA FOSTER] (0:41 - 0:44)
What can people understand about their gut health in order to have a happier brain?

[TIM SPECTOR] (0:45 - 1:01)
The two big players, inflammation and stabilising metabolism. Minimising any stress and inflammation signals going to the brain via the immune system in our gut. Make sure that the metabolism is stable.

And if you do that, the brain will give the appropriate predictions in terms of your mood and your energy.

[ANGELA FOSTER] (1:01 - 1:05)
What are the key things that we can do to protect ourselves?

[TIM SPECTOR] (1:05 - 1:12)
Make sure you have your protein, but have it in the form of beans and legumes. Sleep, exercise and diet all go together and it must be part of a package.

[ANGELA FOSTER] (1:12 - 1:42)
Tim Spector, you are the original pioneer of microbiome research, one of the top 100 most cited scientists in the world, multiple times bestselling author and the author of the new book, Good Mood Food. If a woman in her 40s is eating the same food she always has, but she starts to experience new changes, bloating, abdominal weight gain, poor tolerance of certain foods and changes in her mood. Could the perimenopause transition itself be changing her gut environment?

And what do we actually know about what's happening?

[TIM SPECTOR] (1:43 - 2:53)
Well, the answer is definitely yes. We see this a lot. We've studied hundreds, I'd say there's over 50,000 women in this particular time of life.

And putting on weight, having these GI symptoms is very much part and parcel of this because the body and the microbes are changing and the diet is still the same. And the effects of that mean that different chemicals are going around the body. These are having effects on the brain.

These are having effects on the gut and they are altering metabolism and all downstream effects. So we're now in a position to much better understand a lot of these pre and menopausal symptoms that before were just a bit wild and out there and no one really understood them and thought that, often called psychosomatic or anything else. So I think we now have a very clear link about what's going on and how microbes, food and hormones are interacting.

[ANGELA FOSTER] (2:53 - 3:13)
And I'd like to dive into that with you. But when we're looking at mood and some women will experience bouts of anxiety alongside this, we often think about mindset in terms of our own psychology. So we think we can think our way out of it.

How much is the gut actually impacting our mood, more so the brain or mind itself?

[TIM SPECTOR] (3:14 - 9:14)
I think we have to make a real shift here in our understanding of what we think the mind and the brain are. You have to view the brain and how we think as not separate to the rest of the body. We have this mistaken old fashioned view that the brain is in charge and the body will just do its work.

And this comes back to 17th century philosophers and Descartes about separating brain and body. And it's now very true that you can't just will yourself out of most of these things. And it's like, that's the whole problem we've got into with mental health and everything and a bit of a stigma around it, because it's been seen that if you are in that state, it's either because it's your own fault, it's your genes, or you just lack willpower to get you out of it.

And I think what we're increasingly realising is the brain, it's a little box, it only weighs three pounds, but it takes 25% of all our energy. And it effectively is isolated from the rest of the body by this skull. And it can only find out what's going on in the world, according to the signals that you send it.

And so these signals are coming from places like our skin, our eyes, our ears, but importantly, our gut. And the gut brain connection is the biggest one out there. We have the longest nerve in the body called the vagus nerve, that sends all these signals up to the brain.

And so we have to realise that in order to change things like our mood, we have to change the inputs to the brain so that our mood is actually appropriate. Because when people have anxiety or mood, it's a mismatch between what's expected and what's happening. So the brain is not firing properly.

I'm sorry, I'm getting into a bit too much detail here. But I've been very excited because I'm researching the brain a lot in the last couple of years. And I just think we've got so much wrong about how to understand things like mood and anxiety, you've got to understand a bit how the brain's working.

And the brain is working as a prediction machine, not totally responsive to, you know, it doesn't wait for signals and then do things. It is always anticipating ahead of time what's going on. And that's why for things like depression, anxiety, the signals it's getting upset its prediction mechanisms.

And then you get these symptoms, which are basically a distress because the prediction doesn't match reality. And you get these errors in prediction. So that's why realising that you can do things to alter your mood, external to just thinking about it hard and trying to do things and realise it's the fault of your you because we are conceptually the same as our brains is really important that what you eat is quite crucial to your mood.

We know that in mouse experiments, you can consistently make mice anxious or relaxed depending on what microbes you put into their intestines. And you can switch it on and off like that. Now, it doesn't mean we're exactly the same as humans, but it shows us that mechanism is there.

And that is why there are now many randomised controlled trials for anxiety and depression showing that if you give people a gut friendly diet, they are going to improve by improve their symptoms more than you would if you gave them just a standard antidepressant. So I think we now know there's a really clear link between the gut and the brain, and it works in both ways. The gut can, in a way, alter how the brain works and the brain by sending stress signals, you know, that's picking up from the rest of the body can also affect our gut.

And I think we have to move away from this idea that, you know, our mood and our emotions are actually just our brain, you know, ourselves just need to be put, you know, we just need to pull ourselves together. And this accounts for a lot of the stigma behind it. I think it's really important that we realise that.

And interesting in the studies, the company I co-founded Zoe, we do lots of studies, randomised studies, either improving people's diet with the Zoe app, improving prebiotics, or doing unrelated studies where we give people fermented foods or fasting. And in every one of those studies, the first things that people notice and, you know, our average person in these studies is about age about 60, is an improvement in mood and energy. And that's in the first two weeks of changing your diet.

So I think, you know, it's only really all this is all this science is really quite recent. And I've only also changed my mind on it, because of the evolving science, but on the small level with mice, and then these huge population studies, because in the past, no one ever measured mood or energy, particularly energy. If you go and see your doctor, your GP, when was the last time anyone said, well, you know, what's your energy level like on a scale naught to 10?

You know, they wouldn't do it. It's not computed as essentially a brain problem, rather than you're working too hard, or your muscles are not working.

[ANGELA FOSTER] (9:14 - 9:56)
It's very interesting, isn't it? Especially when I think about women and the vulnerability that I think as women we have because of the way our hormones change across menstrual cycle from during that the course of that month, and then postnatal depression, you can have, and then again, in perimenopause, I know that, you know, I had a background of postnatal depression, and then bipolar episodes. And for me, it was the whole holistic piece that helped me.

But I'm curious when we look at that, because we do see quite a few mood changes in midlife in women, both in terms of mood itself and anxiety, how much we understand is down to the gut microbiome, and how much is hormonally driven, and also how those two things interrelate.

[TIM SPECTOR] (9:56 - 12:39)
Yeah, well, it's very new science. Obviously, we've known, you know, for over 50 years, the role of hormones, but thought that was the only things playing a role. But we now know that hormones can interfere with your microbes, which means that they then produce different substances.

For example, we know that microbes break down food, and they can produce many chemicals, things like short chain fatty acids, which have an effect on our immune system. And we've shown in our studies that female hormones as they're changing, going up and down can alter how many of those microbes are doing that job, which means that the amount of inflammation signals going to the rest of the body will alter at that time. So it could well be that, particularly in the premenopause, when hormone levels are, you know, really changing rapidly, and the body's saying, hey, what's going on here, the microbes are sending out signals, distress signals to the rest of the immune system, and then that goes to the brain.

And that can trigger things like depression, because any inflammation in the brain is a common trigger for mental health symptoms, whether it's anxiety or depression. And the same, we see this most strongly, as you were saying, in postnatal depression, which, you know, ranges from affecting one in three women, you know, with a few baby blues all the way to, you know, near suicidal consequences with everything in the middle. But the mechanism is essentially the same.

It's this disruption of the signals going to the brain, because the body's struggling to keep up its accurate predictions of what reality is. And the reality is that actually, life's not that bad, you know, you just had a baby, whatever. And suddenly, you know what it's I mean, my wife suffered with this for a week.

So I still remember, you know, these, it's the most obvious time when you realise your brain is malfunctioning, it's just sending you the wrong signals. You know, you should be happy, but you're crying, but we're beginning to understand why. So that that's really important.

And I think it is at these particular times of greatest change in life that women in particular suffer, suffer them need to realise that that's when they need to be focussing all their efforts on improving the things they can modify, like sleep, exercise, and importantly, most importantly, diet.

[ANGELA FOSTER] (12:39 - 13:23)
You mentioned a few moments ago that when you look at the Zoe diet, and people are eating in alignment with that, they tend to see improvements in energy and mood within two weeks. That's very quick. When we look at neurotransmitters and things like serotonin, that boosts reduced anxiety and dopamine improves mood.

We talk about most of the serotonin being made in the gut. But my understanding is that isn't the brain also makes it its own. However, it seems that the gut itself needs to be happy in order for the brain to be happy.

Is that the mechanism before we dive into the foods that can support people? It sounds like it's very complex and emerging science. But what can people understand about what they need to think about with their gut health in order to have a happier brain?

[TIM SPECTOR] (13:23 - 16:55)
I think we need to move away from the idea that there are these super neurotransmitters, a bit like superfoods. We've put on a pedestal serotonin and dopamine. For the last 50 years, we've been told that mental health problems are a deficiency in these nerve chemicals, and that you can have a drug like antidepressant SSRI, which effectively increases the amount of serotonin in the synapses in your brain.

We go very deeply about why that science is flawed. But I think you just have to look at, take any survey of 100 people who've had these drugs, only about a third benefit from them. Most take them, but not sure there's much benefit.

At the extreme end, they can save lives. But for people with mild to moderate depression or anxiety, for many women, they're pretty useless. There's an increasing doubt that serotonin is the real player here, and that it was by chance that these drugs worked.

Because what's interesting is anyone who's taken these drugs knows they can take about six to eight weeks to work. The serotonin levels go up within 12 hours in the brain. You could argue, well, that may not be the mechanism of action.

They do have a slight anti-inflammatory action. And increasingly, the view of the latest research in neuroscience is that all these symptoms are related to each other, whether it's anxiety or depression or postnatal depression or even attention deficits and even Parkinson's and psychosis. They're related to inflammation levels in the brain and some metabolic disturbances that are very general, holistic problems, rather than just this one neurotransmitter.

Just a few years ago, I would have said, yes, we need to produce more serotonin in our guts so it can go to our brain and help our brains. Now, my latest reading, I've abandoned that idea. I think that that's very much old school, and clinical practise will soon keep up with that.

We just need to be thinking much more holistically of saying, well, how can I make sure the inflammation signals going to my brain are optimum, that we're minimising any stress and inflammation signals going to the brain via the immune system in our gut? How do I make sure that metabolism is stable and therefore also not sending any signals which you would get from someone with diabetes or having big sugar spikes or anything like this? They're the two big players, inflammation and stabilising metabolism.

If you do that, the brain will sense that everything is going really well in the outside world and your world, and it will give the appropriate predictions in terms of your mood and your energy. That's the current way of thinking. It's been led by these real breakthroughs in neuroscience and the microbiome.

[ANGELA FOSTER] (16:55 - 17:05)
Very interesting. Inflammation and metabolism are the two primary, which actually is also the things that go adrift commonly in midlife for women.

[TIM SPECTOR] (17:05 - 18:09)
Exactly. We know that inflammation levels go up. We know that you get insulin resistance goes up as well.

It all starts to make sense when you take a bigger picture and you stop blaming just one chemical in the body, which seems highly unlikely that the 350 psychiatric syndromes or disorders, each caused by a different level of chemical imbalance, that just seems nonsense. I think we're going to, hopefully in the future, see this science reflected in practise and that we start seeing the brain as one organ rather than lots of little bits. We look at brain health overall, because if you're trying to prevent things or help things like depression or anxiety, it looks like you'll also be able to prevent things like dementia and Parkinson's.

Exactly the same risk factors, exactly the same treatments, just a different time scale.

[Speaker 3] (18:09 - 19:52)
For years, the gold standard for muscle performance has been protein and creatine, but there's a piece most high-performing women are still missing, and it sits deeper than anything in your current stack. Every workout, every long day, every demand on your body runs on cellular energy. At the centre of that system are your mitochondria, and from your mid-30s onwards, accelerated by the hormonal shifts of perimenopause and postmenopause, mitochondrial function naturally declines.

Energy production becomes less efficient. Strength, recovery, and resilience starts to compound in the wrong direction. Mitopur by Timeline contains urolithin A, which supports mitophagy, your cell's process for clearing out damaged mitochondria and restoring more efficient energy production.

18 years of research and 25 human clinical trials back this. One study showed a 12% improvement in muscle strength in 4 months with no change in exercise. Performance starts at the cellular level.

When your mitochondria are working efficiently, everything above that, your training, your focus, your recovery, operates at a higher level. I've been taking Mitopur every day for over a year. I've seen real improvements in my strength in the gym, my power output on the bike, and my energy throughout the day.

But the moment that convinced me the most was when I stopped it for 6 weeks. My energy dropped noticeably. That told me more than any improvement stat could.

If you want to support your cellular foundation and get more from every workout, every demanding day, and every year ahead, use code ANGELA at timeline.com forward slash ANGELA for 20% off your order. That's timeline.com forward slash ANGELA and code ANGELA for 20% off your order.

[ANGELA FOSTER] (19:53 - 20:02)
I know this is something you've been studying quite a bit in relation to dementia. What are the key things that we can do to protect ourselves?

[TIM SPECTOR] (20:02 - 23:10)
First is to have an optimum diet and make sure your gut microbes are as good as they can be. That means, you know, following basic ZOE principles, eat 30 plants a week or more, eat the rainbow, have three fermented foods a day, which is, interestingly, we could talk more about that, but they reduce inflammation levels by 25% in studies. It's like mini steroids.

Avoid ultra-processed food, at least not all of them, but the ones that affect your health, which is about a third of them. You know, they're the real culprits. And then do things like have a better overnight fasting, so you have at least 12 hours overnight when you're not eating to rest your gut.

And things like trying to make sure you have your protein, but have it in the form of beans and legumes rather than just steaks. They're the main gut ones which are good for your brain. And then you've got, of course, the other lifestyle factors such as doing regular exercise and getting a good night's sleep really important for your brain as well.

So sleep, exercise, and diet really all go together. They all influence each other, and it must be part of a package. So, and again, you know, they're all to some extent modifiable.

The other thing I've learned that's a bit unrelated is, you know, what to do for your brain to keep it going. And there was a big craze about doing Sudoku or crossword puzzles, if you remember a few years ago. That's probably rubbish.

What's really good is to learn something new, not keep doing the same thing again and again. The brain is actually quite a plastic and can still form connections even when you're old. It's obviously much easier when you're young.

You know, if you learned a foreign language when you're 18, it's much easier than when you're 50 or 70. But you can still change things even when you're over 60. And doing things that are complicated, like learning a new musical instrument, learning complicated dance routines, learning another language where you have to speak it, write it, and read it.

These are things that are really good for you. So, you know, there isn't one thing. If you want to do it all, then the people that generally manage all of them are the ones that are going to age slowest and have the healthiest brains.

But, you know, this is probably the biggest threat facing us at the moment. And, you know, one of the reasons I wrote the book is because, you know, like most people have their relative with dementia. My mom has dementia.

And, you know, 50% of women are looking at that. If they're age 50 or more now, they're on course to get dementia, which is horrific. So, we all should be trying to prevent it and taking this really seriously because it used to be a fairly rare disease.

[ANGELA FOSTER] (23:11 - 23:48)
Yeah. I also have a mother with dementia. And I think it is a very difficult thing to watch.

And I think many women actually are very motivated to get this right. Because I think, especially as women, I think we get insights into what it feels like when your brain isn't fully online. You know, people talk about pregnancy brain or in perimenopause.

And I think you get these glimpses of what it feels like to not have those words at your fingertips. And it sort of warms you, I guess, a little bit earlier to make these changes. I'm very interested in what you say around fermented foods.

What are the key fermented foods that we should look at introducing into our diet?

[TIM SPECTOR] (23:49 - 26:42)
Well, they're all good. I don't want to go down the superfood route again, because I talk about and Zoe talks about is adding more to your plate, not excluding stuff. All right.

So, that's the philosophy here is that we're not about cutting stuff out. So, they're all good. I mean, everyone probably knows about cheese, may not have thought of it as a health food because many doctors are still saying it's bad for you.

But it is good for you. And it's good for you because it's fermented dairy. Whereas just drinking milk really isn't particularly good for you.

And then you've got yoghurts, which are fine if they're not children's yoghurt and they don't have sweeteners and fake fruit in it. Then you've got kefir, which is like super yoghurt. And again, if you avoid all the artificial flavoured ones and you go for the natural ones, you're going to get four times more microbes than in yoghurt.

They're great. I think people should be more adventurous and try the krauts because they're a combination of probiotic and prebiotic. So, sauerkraut, if it's real sauerkraut and not in vinegar, then you can add that to so many things, add it to soups, to salads.

You have it with your cheese. And I make my own beet kraut, which is one of my favourites. It's so versatile and it's a fantastic taste.

And then if you're more adventurous, you go for kimchi, which is a spicy form of sauerkraut, really packed with healthy microbes. We did a study when I was writing my book on this called ferment that some of them had up to 60 different microbes in them, so species. So, they can be an important part of your diet.

Then you've got drinks like kombucha. Again, lots of them around now. Just pick the non-sugary, non-artificial ones.

They're not all brilliant. And then you've got the other Japanese type soybean ones. And the one I use all the time is miso paste.

So, I never use stock cubes anymore. I only use miso paste and it's free of ultra-processing and it's much more delicious. It brings this huge, savoury umami flavour and also some health benefits.

When you think of fermentation, you don't always think of having to have it on its own. You could incorporate it in many dishes. And that's why in the cookbook, there's lots of ways of, for example, adding in kefir into curries or instead of making swaps, instead of you might've put cream or something into a pasta dish, you can put kefir or yoghurt.

And it's just a different way of thinking. So, how you can incorporate it into your three meals a day without really having to be seen as an effort.

[ANGELA FOSTER] (26:42 - 27:05)
Yeah, I love that idea. It's like when you put Greek yoghurt into porridge oats, it makes it nice and creamy and you're adding it. I was going to ask you a question for all the cheese lovers among us.

Does it matter? You think about Parmesan. I always hear that's really good because it's fermented, it's unpasteurized.

Does it matter if the cheese is pasteurised? Does that make a difference to the bacteria we're going to benefit from and lowering inflammation?

[TIM SPECTOR] (27:05 - 28:44)
It makes a slight difference, but not enough to say you should only eat raw milk cheese. So, on average, raw milk cheeses have a greater range of microbes than the ones on pasteurised cheeses, but you still get health benefits from pasteurised cheese. And even things like Philadelphia cream cheese have microbes in them.

If you keep it in the fridge, after two weeks, you will get a blue mould on it. It does show it's alive. But Kraft dairy slices, which I've had one on my shelf for five years, never go mouldy.

So, I don't think there's anything live in them. But in general, virtually all cheeses, as long as it's made properly, it's good for you. Even standard cheddar from a supermarket will still be healthy for you.

So, it is a healthy choice and we just need to change our mindset. And yeah, I'm a big cheese lover too. If you can get one that's raw milk, and because I think we ought to promote that Kraft side of our industry, and the UK now has double the number of different cheeses of France, which I think is fantastic.

They have really interesting rinds outside where you've got a lot of the extra fungi and microbes and things. So, I think supporting small manufacturers of cheese is really important, even if they're doing it pasteurised because British laws make it really tricky for these dairies to work under constant inspections and things. But yeah, it's all good.

[ANGELA FOSTER] (28:44 - 28:50)
So, when we're looking at things like Brie or Stilton, when we see the mould, that's good for our gut microbiome.

[TIM SPECTOR] (28:50 - 29:12)
Yeah. So, that's why blue cheese, where they inject those blue lines into it, they're actually spraying mould in there and it grows nicely in those air pockets. This diversity is all good for us.

Yeah. More bigger range, yeasts and bacteria, they're all good.

[ANGELA FOSTER] (29:12 - 29:33)
Yeah. I saw a new thing around, like a study that was on developing yeast protein, which is quite interesting. I've written down here miso paste to swap out stock cubes.

I think that's a really good tip. You mentioned there that when we're looking at ultra-processed foods, there's about a third of them that are not good for us. What are the things we need to think about that raise inflammation in our body?

[TIM SPECTOR] (29:33 - 31:08)
So, if we look at ultra-processed foods, how they might do that, the first thing is that they make you overeat. So, if you have two meal plans, identical in calories, but one is ultra-processed, the other isn't, you'll overeat by about 25%. And so, they're designed to make you eat more than your body wants you to.

So, that then leads to fat accumulation in your body. And if you have fat accumulation, you're naturally producing more inflammation. So, that's one route.

The second route is you're depriving your body generally of fibre and any nutrients. So, your good microbes will die off and the balance will shift to the pro-inflammatory microbes in your gut just because you're starving them if you're really hardly getting any fibre. And that's because you're eating all these ultra-processed foods or snacks.

Then you've got the additives in there, things like artificial sweeteners, emulsifiers, gums, some preservatives that have a negative effect either on your gut lining or on the gut microbes themselves. And that tends to make them produce, again, inflammatory chemicals in response. So, there's three different ways, but they're all pointing in the same direction, tickling the immune system to just think that we're facing like an infection or we're unwell.

And that signal then goes all around our body. By often, you can feel tired and unwell purely from your diet.

[ANGELA FOSTER] (31:09 - 31:36)
When we're thinking about this, if somebody is eating a really healthy, diverse diet, they're getting lots of fibre, they're getting some fermented foods, beans, lentils, all these things, but they love a diet. How pro-inflammatory could that habit be? And is it an 80-20 rule?

If we're getting lots of nutrients in, so it's not replacing foods, it's just kind of adding off. How much do people, I see the internet awash with these views on diet coke at the moment, how harmful might that be?

[TIM SPECTOR] (31:36 - 32:49)
I think the occasional one, if you're having one or two a week, would probably be fine. As long as you were displacing something good at the time. Always the question is, instead of what?

If you had a diet coke instead of real coke, that's probably good. But if it was instead of water, mineral water, mineral water would always be better. I think there's a difference between having something once a week and having it every day.

I'm much more worried about the regular consumption of a lot of these foods that we have without noticing. We can have them for decades without really knowing about it because we never really looked at the labels. We never really saw the magic that was behind those healthy-looking packets.

I wouldn't worry if someone's healthy and they're having a diet coke once a week as a treat, that's fine. But every day, I would worry, that'd be my level. And it goes for other things.

It probably goes for other treats. If you want a doughnut once a week, that's fine. Having a doughnut every day for your tea is probably not fine.

[ANGELA FOSTER] (32:51 - 32:53)
The poison is always in the dose.

[TIM SPECTOR] (32:53 - 33:50)
Yeah. And what it's replacing, whether you had a much healthier option instead and by choosing that, you're avoiding something else. That's something that rarely gets discussed on the level of, certainly on social media, when people are telling you bananas are deadly and things.

Well, it all depends compared to what and how often you have them. So often, people are bombarded with facts that are taken out of context. And I think that's very important that we get rationality and people don't eat individual items.

They eat three plates a day. And on that plate, you can put all kinds of things. You add one thing, it's going to possibly push something off.

Drinks are the same. We just got to think of it much more big picture rather than sort of micromanaging these things and getting upset about one ingredient.

[ANGELA FOSTER] (33:50 - 34:05)
When we're looking at food labelling, there are some things that get added that we don't kind of understand. I think they're to thicken, for example, sometimes in a yoghurt or ice cream, emulsifiers and different gums and things. How harmful are those?

[TIM SPECTOR] (34:05 - 36:14)
We don't have the full picture because there's been no funding really to explore these. And manufacturers are allowed to do their own research and just say, oh, we believe this comes under the rule of generally regarded as safe, GRAS rules. And they might, if they're lucky, give 100 times the dose to some rat and see if it gets liver cancer.

But that'd be about it. So most of these chemicals haven't been tested in the doses that they're used, and they certainly haven't been tested over decades. So a lot of it is guesswork based on a few that we do know about.

For example, we know that people have tested about six of the emulsifiers, the common emulsifiers and their effect on the gut and the gut lining. We know that, for example, carboxymethylcellulose is really very harmful, whereas another one, soy lecithin is less harmful. Very hard in these experiments to show that it has no harm.

But unless you, again, do long-term experiments and many more people. So it's a mixed bag at the moment. But increasingly, we're finding that manufacturers are adding, because each ingredient might get a bad name, they're changing the names of them or adding a combination of them to foods.

And that's particularly true with the artificial sweeteners at the moment. Most Sweden brands have a combination of two or three, and that's really hard to study the health effects of those. And it could be very individual.

So we know the emulsifiers, some people react to certain ones, maybe it's because their microbes react to them, because we all have very different microbes. So to really understand it properly is going to take a lot more work. But I think at the moment, where there's an easy choice to avoid it, we should take the precautionary principle and just say, well, this isn't something I want to have as my staple, whether it's that regular biscuit, the regular breakfast cereal, the regular supermarket bread.

[ANGELA FOSTER] (36:15 - 36:20)
So understanding how to read these labels and sticking to whole foods as much as possible is really important.

[TIM SPECTOR] (36:20 - 37:18)
Yeah. And ignoring the front of pack generally, because you'll see signs of low calorie, high protein, low fat, good for your immune system. You can completely ignore that.

That's all absolute scientific nonsense. And so these are 40 year old rules that need to be sorted out. But the food manufacturers love them because they can tweak their products and make them sound good.

You can make something immune friendly by just adding a bit of copper to something or zinc in minute amounts. Doesn't help your immune system at all, but makes someone think it's healthy when actually it's really unhealthy. And protein is the other big thing at the moment.

Only 10% of people are actually protein deficient, but majority of Britons, when they see a label that says high in protein, they associate it with being a healthy health food.

[ANGELA FOSTER] (37:18 - 37:29)
Yeah. Because there's so much around eating higher protein and holding onto muscle. But actually, as you say, and I've heard you talk a lot about, is we can get this from plant-based foods.

But also give you fibre.

[TIM SPECTOR] (37:30 - 37:54)
Yeah. They'll have the massive bonus of giving you the fibre, which only 10% of us are getting enough or 5% are getting enough of. So we're massively deficient in fibre.

So any attempt to improve our protein ought to be not instead of fibre, using high fibre, high protein foods like beans and legumes as an easy example.

[ANGELA FOSTER] (37:54 - 38:20)
When we focus on these types of foods and we're focused on lowering inflammation, keeping blood glucose stable, having plenty of fibre fermented foods, do we see that we're able to ameliorate some of the adverse symptoms that women get during perimenopause? And also alongside that, what role does menopause hormone therapy play? Is that additive and we see improvements in gut health or does it have no impact?

[TIM SPECTOR] (38:20 - 40:05)
Well, we've done some observational studies, Zoe, on this and showed that symptoms of menopause do improve when we're going on a Zoe plan diet using our app. It's only over 50% of people noting improvements in things like hot plushes and sweats and mood changes. So we know that it does have that effect and some of that is coming from, we did measure in some women changes in blood inflammation levels, suggesting that part of that is you can actually reduce the inflammation levels.

Might be other mechanisms we don't fully understand. And we do know that HRT does seem to change the microbes. So we didn't do a longitudinal study, but cross-sectionally using lots of women's data, we saw an interaction between the HRT and the microbes and improvement in symptoms.

So it's suggesting that HRT, part of its action might be in helping balance the microbes better. And so therefore the effect of food is actually better on the body. So, but that's still our best theory, but we haven't proven it yet, but there's no doubt that in my view, HRT is very good for symptoms.

No one's sure. And it is generally positive for your gut microbes as well. Try diet first.

If diet alone doesn't do it, then HRT is good. But I think people often just reach for HRT without thinking about their diet because no one's ever raised it as a possibility. Doctors are trained basically just to give drugs.

[ANGELA FOSTER] (40:05 - 40:31)
And when we look at exercise, is, would you say that after all your research and the work that you do at Zoe, is it that, you know, doing a good amount of exercise every week, regular exercise, a combination of strength training, walking, some high intensity, but not tipping into too much endurance is the ideal place for your microbiome? Do we see adverse effects in people who are doing a lot of endurance-based training?

[TIM SPECTOR] (40:32 - 42:03)
Yeah. In general, elite athletes have rubbish microbiomes. So anyone who's pushing their body so much that there is, you know, the short-term result is the only thing that counts.

And maybe, you know, the huge stresses the body is under reflects in the gut microbiome. And it's really interesting because we used to, you know, it was an idea that you wanted to, when food transplants were in, you wanted to get some super elite athletes and they could transplant you into some weakling and you'd be, you'd be, you know, like super woman, but it turned out they were pretty, their microbes were terrible. And it's the sort of good amateur that has the best ones.

So I think you're right. Someone who's exercising at least, you know, four times a week, doing a little bit combination. There's some examples that you doing weight training can alter your microbes as well as doing endurance training.

So increasing evidence that as you age, you need different types of exercise and you want to hang on to your muscle as much as possible as well. So there seems to be some link between our muscles and our gut microbes as well. So there's a bit of a two-way communication channel there.

So current advice is, you know, to do regular but varied exercise whenever you can. So it's not just running or not just weightlifting or whatever it is. Variety is good.

[ANGELA FOSTER] (42:04 - 42:20)
In relation to eating lots of plants, it always concerns me when people focus on organic that we end up pushing away people from eating more diversity because they feel that everything has to be organic. How much do we need to be concerned by pesticides and things like that?

[TIM SPECTOR] (42:21 - 44:21)
Well, we should be concerned, but I think we've got to put it into perspective. Relative to some of the things we've talked about, like ultra processed foods, it's relatively trivial. There might be exceptions.

There's some evidence that, you know, in pregnant women or very young infants, they might have bigger influence if you're having large amounts of pesticides. But again, this rule about avoiding them if you're having them regularly, but the occasional, you know, non-organic thing isn't really a worry. But if you were having regular oat porridge every morning, and oats are one of the most highly sprayed grains we have, and you're having that for 20 years, I would be worried about that.

But I wouldn't be worried if you had that once a month. So, you know, there isn't yet really good evidence about switching to organic food that totally changes, transforms your health, like some of the other things we've been talking about. So I think it's much more important to keep eating fruit and veg, even if it's had pesticides on it, than to avoid them because you're worried about the pesticides.

So that's my general advice. But, you know, little things you can do, you know, if you're buying oats, make sure they're organic, you know, and if you're having strawberries every day, then you might make sure they were organic. The rest of the stuff, you know, whether you buy organic oranges or lemons doesn't matter because generally the skin protects you from them.

So there's a few things that you don't have to worry quite as much on. Personally, you know, if I have veg delivered, it'll be organic. But if I'm going to the shops, I'm not going to not buy some because I can't find an organic version.

And when you're travelling, as you know, you know, countries like the US sort of doesn't really exist. So you just make sure you get your fruit and veg and don't worry too much about it.

[ANGELA FOSTER] (44:22 - 44:33)
Amazing. Before you go, could you leave us then with what would be your top three things for women to start doing and three things to either avoid or stop doing?

[TIM SPECTOR] (44:33 - 47:21)
Try and get your 30 plants a week. Okay. It's a great concept.

It means if you do that, you'll get all your fibre, you get all your nutrients, you don't worry about anything else. And if you want help doing that, you can try the Zoe app, for example, which does all the counting for you. You just take a picture of your food and it counts it so you don't have to keep post-it pads on your fridge or anything.

The second is to try and up your ferments to three or more a day. You may want to do this slowly if you're not used to it. But we did this study, you know, 10,000 people and two thirds of them managed it within two weeks.

But build it up slowly and slowly incorporate it and your taste buds will get used to it and you'll be, after a while, you'll be hooked and addicted. And the third tip I would have, I think, is give your gut a rest overnight and avoid late night snacking. I think that can have a really big effect on your gut and your mood and helps you sleep as well.

So just constantly think your gut microbes need to sleep just like you do and stop waking them up when you're having, you know, a secret biki or whatever before you're going to bed or whatever it is. Give them a nice long break. Don't always have breakfast first thing in the morning.

That improves your gut lining, reduces inflammation and I think you'll notice the difference. And then three things to avoid, I would say the worst ultra-processed foods. These are the ones designed to make you overeat, have all the additives, chemicals, etc.

You know, the worst offenders and they're the ones you're having regularly. So your breakfast cereals, your breads, your biscuits, your cakes, your ready meals, your frozen pizzas and most soft drinks. I would avoid looking at the front of pack when you're shopping.

So don't be fooled by all those supposed healthy signs on the front. They mean nothing. And if they have to put that on there, they're obviously desperate to sell their rubbish product.

And the final don't, I would guess is don't get fooled into thinking in the current protein phase where there are some women who are protein deficient, but most are not, that you need to do that by just having more red steak. Think beans, legumes, mushrooms. There's plenty of things in the plant world that will boost your protein.

Try tofu if you haven't done that as a great chicken substitute. Lots of ways to do that, help you and also help the planet.

[ANGELA FOSTER] (47:22 - 47:29)
Amazing. Thank you. And Good Mood Food is coming out end of October.

There's lots of recipes to help us all.

[TIM SPECTOR] (47:29 - 47:53)
Yes, there's an introduction, introduction about these new ideas about brain health and really over a hundred recipes designed to lift your mood with, you know, lots of ingredients, lots of plants, lots of ferments and lots of colour and great taste. It should cheer you up just looking at it. That's what I do when I feel a bit down, just look at a few recipes.

[ANGELA FOSTER] (47:54 - 47:58)
It's also got a very bright and colourful front of the book as well, makes it appealing.

[TIM SPECTOR] (47:58 - 48:00)
Blue was a brave choice, but I think it works.

[ANGELA FOSTER] (48:01 - 48:22)
Yeah. Yeah, I think it works. I'm excited to cook from it, Tim.

Thank you so much for everything you do, everything you put out into the world to make people's lives better. Thank you so much. We'll link to all of that in the description and we'll also link to my previous episodes with Dr Federica Amati and Dr Sarah Berry, both from Zoe as well.

They were really popular episodes. Thank you so much, Tim, for coming on. Really enjoyed.

[Speaker 4] (48:23 - 48:23)
It's been a pleasure, Angela.

[Speaker 3] (48:23 - 48:41)
If you're getting value from this show, the single best thing you can do to help us keep bringing you the highest calibre guests is to subscribe or follow wherever you listen or watch. It takes 10 seconds, but it genuinely makes a difference to the quality of the guests we bring you week after week.

Prof. Tim Spector and I talk about gut health, mood, inflammation and fermented foods in perimenopause, and the three diet changes he recommends to start today.

Microbiome pioneer, ZOE co-founder and Good Mood Food author Prof. Tim Spector explains why midlife mood changes are not psychosomatic: shifting hormones alter your gut microbes, which changes the inflammation and metabolic signals reaching your brain through the vagus nerve. He shares why serotonin was never the real lever, why inflammation and stable metabolism are, and why people in ZOE’s studies report better mood and energy within two weeks of changing their diet.

His three changes: 30 plants a week, three fermented foods a day and an overnight gut rest. We also cover ultra-processed food, protein versus fiber, HRT and dementia risk.

WHAT YOU’LL LEARN

- How perimenopause changes your gut and your mood

- Why inflammation matters more than serotonin

- Which ultra-processed foods to cut first

- His three gut changes to start today