What a Long Lunch Taught Me About Gut Health and the Midlife Brain
If you read the last post — the one about sitting around a table at Bang Bang Noosa wondering whether I cut the mustard — I promised you something.
“Your brain, for reasons we'd get to later, will thank you for it.”
Well. This is the later.
I’ll start with the lunch itself, because it turns out it was doing something I hadn’t fully considered at the time.
Herbs everywhere. Lime. Chilli. Pickled vegetables. Coconut. Different fibres and aromatics arriving in waves across a shared table. Wine. Slow conversation that went nowhere in particular and everywhere that mattered.
Looking back, that meal was practically a microbiome masterclass disguised as a Saturday lunch. And the more I’ve been reading about gut health and brain function, the more suspicious I’ve become of the idea that meals like that are somehow frivolous.
Which brings me to plant diversity.
Not veganism. Not “eat more salad”. Not another food rule dressed up in a slightly different jumper. Just diversity — the actual variety of plant foods landing in your gut across the course of a week.
One of the more interesting ideas emerging from microbiome research is the suggestion that diversity matters — specifically, eating around 30 different plant foods across the course of a week. When I first heard that number I assumed it was the kind of thing that sounded achievable in theory but would turn out to require a full personality transplant in practice.
It doesn't.
The gut microbiome research is genuinely fascinating. The science is still evolving, but what keeps emerging is that diversity appears to matter in ways that extend well beyond digestion. Mood, appetite, sleep, blood sugar, stress resilience. Even brain health. These systems don't operate independently of each other, and the gut influences far more of them than we originally thought.
One description I came across recently compared the mass of neurotransmitters active in your gut — the ones that directly influence your hormones, your mood, your energy, your anxiety — to a cat's brain.
Well, the size of one anyway.
What counts is broader than most people realise. Vegetables, fruit, legumes, grains, nuts, seeds, herbs, spices. Even coffee. And chocolate. Those last two made me disproportionately happy, and I'm choosing not to examine that too closely.
The point is that a handful of parsley counts. Pepper counts. Cinnamon counts. The chickpeas in your soup count. The chia seeds and berries in your yoghurt count. Once you start actually noticing, what becomes clearer isn't how hard 30 is to reach — it's how narrow most of our diets have become without us ever making a conscious decision about it. Same meals, same shopping list, same rotation of foods we've decided are "healthy" and therefore eat on repeat forever. Not because we're lazy. Because life is busy and decision fatigue is real, and nutrition messaging has spent decades making food feel like a subject that requires a degree to navigate.
And perhaps that’s part of why meals like that Bang Bang lunch feel so restorative — the slow ones, the shared ones, the ones with herbs and chilli and three different pickles arriving without announcement — is that your nervous system and your gut are not separate conversations.
What I like most about the 30 plants idea is that it moves the conversation away from moralising food entirely. You're no longer asking, "Was I good today?" You're asking, "How much variety did my body experience this week?" That is a much more interesting and useful question. And it has the considerable advantage of not making you feel like a failure because you ate pasta last Thursday.
Now. I want to talk about stock paste.
Bear with me.
A standard homemade vegetable stock paste (or chicken or meat paste) — the kind you make once, keep in a jar in the fridge and reach for whenever a recipe calls for stock — typically contains celery, carrot, onion, tomato, zucchini, garlic, bay leaf, basil, sage, rosemary, and parsley. That’s eleven plants. In a tablespoon. That you stir into whatever you’re cooking without giving it a second thought.
I’ll be straightforward about what that does and doesn’t mean. A tablespoon of stock paste won’t replace eating an actual bowl of vegetables. The volumes per plant are small, and volume matters for fibre and nutrients. But for diversity of plant exposure across a week — for the variety conversation happening in your gut - it’s doing more work than most people realise. Tim Spector’s guidance is that there’s no strict serving threshold. A teaspoon of herbs counts. Small amounts matter. The goal is variety, not just volume.
So every time a recipe calls for a stock cube — soup, risotto, braises, sauces, grains, tray-bakes, whatever is happening on Wednesday night - that little spoonful of stock paste is widening the diversity of plants landing in the meal.
The other thing I like about homemade stock paste is that it naturally absorbs the slightly sad produce drawer economy of adult life.
The celery that’s gone a bit limp.
The parsley threatening emotional collapse.
Half a zucchini.
The lonely carrot.
Random herbs you bought with good intentions three days ago.
All of them can become stock paste.
Which means this isn’t about perfection or buying exotic ingredients. It’s about making it easier to eat a wider variety of plants without having to think too hard about it.
The vegetable stock paste recipe I use is from Cookidoo — it’s in the app if you have a Thermomix. The ingredient list reads like a who’s who of the produce drawer. Takes about 30 minutes (most of it hands off) and lasts for months in the fridge.
If you don’t have a Thermomix, the same principle applies to any homemade stock paste or good soffritto. The point is the variety, not the method.
Incidentally, this is where I think tools like Thermomix earn their place in a midlife kitchen — not because they confer any special nutritional powers, but because they reduce the friction between knowing what you'd like to eat and actually making it. More on-hand ingredients actually used. More meals made from scratch on nights that otherwise would have gone sideways. Less distance between intention and dinner.
The broader point isn’t complicated. Eating a wider variety of plants than you currently do is probably worth doing. It doesn’t require perfection, a new personality, or seventeen new recipes. It requires some attention to variety, a willingness to rotate what you buy, and possibly a jar of stock paste in the fridge.
If you’re curious how a Thermomix reduces the distance between good intentions and dinner, I run demonstrations in your kitchen on the Sunshine Coast, or face-to-face online anywhere else in Australia. Seeing it in action answers questions better than reading about it ever will.
Sources
Johnson, A. J. et al. (2019). Daily sampling reveals personalized diet-microbiome associations in humans. Cell Host & Microbe, 25(6), 789–802.
McDonald, D. et al. (2018). American Gut: An open platform for citizen science microbiome research. mSystems, 3(3).
Cryan, J. F. & Dinan, T. G. (2012). Mind-altering microorganisms: The impact of the gut microbiota on brain and behaviour. Nature Reviews Neuroscience, 13(10), 701–712.
Mayer, E. A. (2016). Gut feelings: The emerging biology of gut-brain communication. Nature Reviews Neuroscience, 12(8), 453–466.
Spector, T. (2022). Food for Life: The New Science of Eating Well. Jonathan Cape.
ZOE. (2024). Eating 30 plants per week: How to do it and why. Retrieved from zoe.com/learn/30-plants-per-week
ZOE. (2024). 7 surprising things that count toward your 30 plants per week. Retrieved from zoe.com/learn/surprising-foods-for-30-plants-per-week
