Hey everyone, it's Mikki here, you're listening to Mini-Mikkipedia on a Monday, and today I want to chat about a systematic review actually that I came across a couple of weeks ago now, and it really aims to answer the question, can diet fix hot flushes?

And of course, you know, if you're a woman in this age group, you'll know there are any number of supplements that you could purchase with the promise of being able to resolve a lot of those perimenopause and menopausal symptoms that are really disruptive for sleep.

And I saw this paper in the American Journal of Clinical Nutrition, it really sort of sparked my attention.

So today I want to chat through what this review says.

But then also lean a little bit on the work of my good friend, Lara Bryden, who's a naturopathic doctor, originates from Canada, but on the podcast several times at this point, and now lives in Christchurch, and just sort of have a look at the practical side of it as well.

So I'm sure that you guys are familiar with Lara, and you hopefully you own her books because they are like little Bibles.

But I did really want to see what the systematic review found.

And then also try and bridge that gap between that and what you might find in a book like Lara's, who's such an experienced clinician and has worked with thousands of women over the years.

So the review was a research team out of Bond University, and it wanted to look at just randomized controlled trials only, women aged 40 to 65, and just looking at food actually.

So no supplement trials, no isoflavone capsules, no extracts.

They wanted to know what happens when you change.

Just what's on the plate, either by adding a specific whole food, following a structured dietary pattern, or cutting calories.

So they screened over 4,300 records and ended up with 15 trials covering just over 1,950 women.

The outcomes were vasomotor symptoms, so hot flushes and night sweats, psychological symptoms like low mood and anxiety, and cognitive symptoms like memory and attention.

So of those 15 trials...

12 enrolled only post-menopausal women, one included a mix of pre, peri, and post.

One didn't report menopausal status at all, which was interesting.

So if you are 46, your cycles are all over the place, and your sleep has fallen off a cliff, so this review might not be about you.

It's about women who really are already through that transition.

And the authors say that too, you know, perimenopause is when symptoms are often worse, and it's a stage with the least trial done.

That hopefully is changing, but anyway.

The second thing which was interesting, I thought, was just how small and short these trials were.

So the median trial, the average length of a trial, had 84 women, and it ran for 12 weeks.

Eight of the 15 were soy studies.

So when we talk about the evidence on diet and menopause, what we mostly have is a stack of short soy trials in post-menopausal women,

plus a handful of one-off studies on pretty much everything else.

So the headline finding is that soy foods may reduce hot flushes, which is good news, right?

So when the researchers pulled four trials, giving five comparisons and about 200 women,

soy came out ahead of the control with a standardized mean difference of around 0.8.

So in plain language, it's a moderate to large effect on paper, which you certainly don't want to sniff at.

And interestingly, the soy came in all sorts of forms.

Soy flour.

Soy milk.

A cereal bar.

And soy nuts.

However, when they pulled trials on overall vasomotor symptoms,

so the broader sort of bother of hot flushes and sweats rather than just counting flushes,

the result wasn't significant.

So when they pulled trials on psychological symptoms, also not significant.

And every pulled result was rated very low certainty using the GRADE system,

which is a four-year study.

It's a formal way that researchers grade how much confidence you can place in a body of evidence.

Very low is the bottom rung, right?

It means the true effect could be quite different from what was estimated.

So, you know, why is it so shaky?

And partly it's because the trials disagreed with each other a lot.

The heterogeneity is high, meaning that the results jumped around far more than you'd expect just from chance.

And partly because of where the big effects came from.

The two strongest results in the hot flushes were the ones that were the most significant.

The two strongest results in the hot flush analysis both came from one soy nut trial,

split into subgroups of 12 women and 7 women.

19 women were doing a lot of the heavy lifting in that headline number.

It's just so small, right?

And there's also a biological reason why soy results are so inconsistent.

Soy isoflavones can be converted by gut bacteria into a compound called equal,

which is more biologically active.

Only about 30 to 50% of people are equal,

and that depends on your gut microbiota, your diet, and things like antibiotic use.

In one placebo-controlled trial that tested a woman's equal status first,

isoflavones improved hot flushes and sweating only in the producers.

So two women can eat exactly the same tofu and have two very different experiences.

Therefore, a trial full of non-producers will make soy look useless.

And remember, only 30 to 50% of people are equal.

So that's a really big number.

And also another point that I do want to make is, you know, is soy safe?

And is it acting like estrogen?

I did speak to Dr. Lise Altshuler on the podcast about this time last year,

actually on the safety of soy, and it is definitely something that she recommends,

including for people who are cancer thrivers.

So isoflavones bind estrogen receptors far more weakly than your own estrogen, and they do prefer,

a different receptor subtype.

So a 2025 meta-analysis of randomized trials found that they didn't meaningfully change

endometrial thickness, vaginal tissue, follicle stimulating hormone,

or estradiol levels in postmenopausal women.

So they behave more like a gentle modulator than a hormone.

And the review's practical suggestions is around 50 milligrams of isoflavones a day,

which is roughly two serves of traditional soy foods.

So think a glass of milk,

a serve of tofu or tempeh, or a bowl of edamame.

Another thing that Dr. Lise mentioned was that products like soy,

those processed soy bits that you get in like cereal bars and cereals and things like that,

they don't actually have the isoflavones in them.

So I wouldn't necessarily go to that really processed soy stuff.

I would just stick to the more whole food type soy.

Anyway, now there's another interesting part of this paper in it that came across a trial from

Australia.

In the late 90s.

So Delais and colleagues had postmenopausal women eat bread made with soy,

bread made with linseed, or plain wheat bread as the low phytoestrogen control.

Hot flushes dropped 22% on soy, which wasn't significant.

They dropped 41% on linseed.

And in the wheat control, they dropped 51%, which was crazy.

You would not expect that.

A year-long Canadian trial gave women 40 grams of flaxseed a day on

their diet, or wheat germ as a placebo.

Both groups improved significantly from where they started on hot flushes,

night sweats and overall vasomotor symptoms.

And there were no difference between the groups.

The thing that makes the hot flush research really hard is that hot flushes respond strongly

to placebo, and they also seem to wax and wane on their own, right?

Add in the fact that most women sign up for a trial when their symptoms are at their worst,

and some of them will naturally get better regardless of what they eat, then add that diet,

trials are almost impossible to blind.

So if you're handed a bag of soy nuts every morning, you know you're in the soy group.

Most of these outcomes are self-reported in a symptom diary.

So none of this means that women in these trials didn't feel better.

Obviously, they did.

It just means we can't easily pin the improvement on that particular food.

So I think that's really worth remembering when we feel a little bit underwhelmed by

papers like this.

The other pattern is that women are more likely to feel better when they eat less food.

The other pattern is that women are more likely to feel better when they eat less food.

The other pattern is that women are more likely to feel better when they eat less food.

The other pattern that runs through this review is that whenever a diet looked impressive,

weight loss was usually a part of that puzzle.

So there was a trial, actually, the Bernard trial, where women were on a low-fat vegan diet

plus half a cup of whole soybeans a day, and it produced one of the bigger reductions in

vasomotor symptoms in the whole review.

It's also a trial where the intervention group lost about 4.5 kilos in 12 weeks,

which is pretty significant.

In the control group, who just carried on with their usual diet, they lost just under one kilo.

So is that the soybeans, the vegan diet, or the weight loss that actually improved everything?

The trial design can't separate them.

So really, it's sort of anyone's guess, though I will say that weight loss is

one way that you can significantly improve your vasomotor symptoms.

Same story with mood.

A year-long American trial of over 400 post-menopausal women found a

calorie-restricted diet improved mental health scores,

a diet plus exercise improved depression and stress scores.

A companion paper from that same trial suggested those improvements tracked weight loss,

which averaged about 8.5% with diet alone and nearly 11% with diet plus exercise,

which kind of is pretty impressive, actually.

And, you know, for cognition, the evidence is a little thin.

A MIND diet trial in Iran, so MIND stands for...

Mediterranean DASH Intervention for Neurodegenerative Delay,

and it blends the Mediterranean diet with the well-known DASH diet,

which stands for Dietary Approaches to Stop Hypertension.

It was, you know, very big in the early 2000s.

Anyway, so a MIND diet trial in Iran showed large improvements in memory.

It had 22 women in one arm and 15 in the other, and it was over 12 weeks.

So when, in effect,

looks enormous in a tiny trial, you sort of need to treat that result with caution.

It's not that representative of what you might find in a bigger cohort.

There was another trial, a Thailand trial, that of 5-2 intermittent fasting,

and it found that fasting on its own didn't improve cognition at all,

but the exercise arm did, so I thought that was pretty revealing.

So in terms of dietary patterns, diets like the DASH, like the Mediterranean,

diet and the MIND style of eating, I mean, it might help mood and maybe cognition,

but losing weight, if you're carrying extra, does seem to help across the board,

though no one's managed to sort of cleanly separate it from what people were eating.

And that's worth noting when you come across those newspaper headlines telling you Mediterranean diet

is the way to go. I mean, it's great, but it's not the only way to go.

So if the systematic review couldn't really pinpoint any sort of dramatic

wins in terms of what's going to help with these sort of menopausal symptoms, where would you go?

And this is where I love chatting about Lara's work, because she has spent

over 25 years in clinical practice, mostly with women.

She's the author of Period Repair Manual, a new edition of that is about to come out at some

point soon, the Hormone Repair Manual, and more recently, Metabolism Repair for Women.

Now, the interesting thing,

is that I really want to point out here, is that a trial, like the ones that I was just discussing,

tests one thing in one group for like 12 weeks, mostly in women already past menopause.

A clinician sees perimenopausal women over months and years, changes several things at once,

and adjusts based on what happens. And they're just different types of all kinds of knowledge.

Trials are much better at telling you whether something works on average,

and clinical experience is much better about telling you,

what's practical, what people will actually stick to, and what to try next.

What clinical experience can't do is rule out placebo and the natural ups and downs of symptoms.

However, let's look at Lara's main sort of practical recommendations,

and put them next to what the evidence says.

So the first one, alcohol. I mean, Lara is pretty blunt, as she should be,

that alcohol is no friend in perimenopause, as I would tell you as well. It disrupts sleep and can

trigger hot flushes. And of course, the physiology backs that up. Alcohol dilates blood vessels and

fragments sleep, which is exactly what you don't need when your thermostat is already jumpy.

And I mean, of course, you guys know that I love a beer and a wine, and Lara might also be partial

to a beer. So it's not about never drinking again, but it's just about whether noticing that the wine

that you have in the evening time, how disruptive is this of your sleep? And how much is that related

to the hot flush you might have later on? And for some women, it does. And there's also magnesium

and taurine. And this is something that Lara really recommends and describes it as something

of a golden combination for perimenopause, helping sleep, mood and hot flushes. And she does favor

gentler forms like magnesium glycinate, as I do. And so there is definitely literature around the

use of magnesium glycinate and taurine. And taurine is an amino acid that acts on GABA and glycine

receptors in the brain, sort of the same calming system that magnesium supports. So Lara appears

them as a combination for the wired, anxious, can't sleep side of perimenopause. And while

there's no human randomized controlled trial on the combination of the two, there's definitely

plausible mechanism plus clinical experience here. And I often on the basis of what Lara recommends,

also pass on the information to women that I work with as well. And they often come to

give their own supplements. Lara also puts a lot of weight on building muscle and on insulin

resistance and sensitivity in midlife. And of course, we're completely aligned with that.

Evidence here is much stronger than for any single food. Resistance training improves insulin

sensitivity, protects muscle and bone and helps with body composition. And there is research

showing a relationship between strength training and reduced vasomotor symptoms as well. So

completely on point there.

So progesterone is another one. Now there was there is a placebo controlled trial and healthy

postmenopausal woman by Hitchcock and prior, which found nightly oral micronized progesterone reduced

vasomotor symptoms more than placebo. Obviously, this isn't diet, but it is worth mentioning. And

Gerilyn Pryor has been a mentor to Lara over a few decades now, I believe at this point,

and they've co authored papers together. Gerilyn Pryor is very,

very well revered in this space in terms of women's health. So that said if your flushes

are wrecking your sleep and your work, then of course, diet changes, super important,

but you should also talk to your doctor about what else might be available too. So all of that said,

if you've got like hot flushes, menopausal symptoms, what should you do? What I tend to do

with clients what I know Lara does, what I know she does, here's the first thing that I tend to do.

What I do is I take a prescription from a doctor. I'm going to have a prescription from a doctor and

then I will take a prescription from a doctor too. That means that I take a prescription from a doctor,

because that's the best way that I can do that. But I'd also have to have a prescription from an

does, what other practitioners do is you want to sort of treat it as an N equals one experiment on

yourself because the average result in a study doesn't tell you anything about how you're going

to respond. First thing to do is start at a simple symptom log before you change anything. Just a

week, nothing fancy, how many flushes, how many night wakings, a mood score out of 10. Without a

baseline you'll be judging everything on your worst night and you'll end up crediting or blaming

whatever you happen to change last. So it's really good to get a good line in the sand with that.

Give soy foods a proper go. So two serves a day of traditional soy foods for 8 to 12 weeks.

That's long enough to know whether or not you're going to see a difference and those kind of things

are tofu, tempeh, edamame beans, add soy milk in the mix. They're your best bet in terms of

soy based products and look if nothing shifts you might be

one step ahead of the next. So if you're going to change anything you're going to have to

one of those sort of 30 to 50% who do not produce Equal.

So it's useful information to have.

Run an alcohol experiment two or three weeks off

or at least none on weeknights and watch your log.

You might find it makes no difference at all,

but you might find your sleep changes dramatically.

Either way, at least you're making a good decision

based on your own data.

You need to get those foundations right.

Eat enough protein across a day.

Plenty of fiber and plants.

Because many of the improvements and symptoms

also tracked with weight loss.

If you are carrying excess body fat,

eating in this way will only help improve that as well.

So that's where the mood and the metabolic evidence sits.

And of course, that's how I build my programs.

And people like Lara,

it's what they recommend their clients do as well.

It supports body composition, heart health,

and energy all at the same time.

Obviously, exercise.

Lifting heavy things, doing your strength-based training

and your conditioning training.

So super important for all of the reasons

that I always talk about.

Try magnesium and taurine.

Glycinate in the evening.

It's a reasonable low-risk trial for sleep.

And then just see how that impacts you.

Some people don't notice any difference at all,

but some people swear by it.

Until you try it, you're not going to know.

And there is ethical nutrients.

They have a magnesium,

taurine blend.

It does have B6 in it, though.

So be mindful of the amount of B6 that you've sort of got.

So that's a really good,

really easily accessible place to get your magnesium.

Chemist's warehouse, pharmacies like that carry it.

And also, of course,

if your symptoms are significantly affecting your life,

see your GP.

Hormone therapy and progesterone,

they are evidence-based options.

And I would say that if you're going down that route,

I mean, everything I've talked about,

like with diet and stuff,

will only help sort of augment what you might get

if you were to look at something like that as well.

So to sort of close the loop on this,

there will be papers like the one looking at best diet patterns,

best foods to help improve symptoms.

But if there's not a ton of evidence in that space,

you need to sort of be able to bridge that gap

between what the evidence says

and also what really experienced clinicians like Lara does.

And, you know,

and then also be willing

to make changes yourself

and monitor over a period of eight to 12 weeks

to see how many of the recommendations

are relevant and are actually going to help you

because you really are your own best investigator

when it comes to your own health.

So, yeah, that's what I've got to say on that.

Hopefully that was, I don't know, interesting.

Maybe, maybe not.

Let me know.

I'm over on Instagram,

threadsandx at Mikki Williden,

Facebook at Mikki Williden Nutrition,

or head to my website,

at mikkiwilliden.com.

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All right, guys, you have the best week.

See you later.