You have two Brains. One of them is Starving

Connor Bubear
Jul 15
5 min read

"If man made it, don't eat it."

— Jack LaLanne

Most conversations about diet begin with addition. Eat more protein. Take this supplement. Add this superfood. The wellness industry has built itself around the idea that health is something you acquire through accumulation, that the path to a better body and a sharper mind runs through the checkout of a health food store.

But the most powerful dietary shift most people in midlife can make has nothing to do with what they add. It has everything to do with what they remove.

Because the body is not a passive vessel waiting to be optimised. It is a marvellous, self-regulating living machine with systems of extraordinary intelligence, systems that know how to digest, repair, regulate and restore, provided you stop obstructing them. The modern diet, built overwhelmingly around ultra-processed food, is doing exactly that. And the consequences extend far beyond the waistline.

Your Second Brain is Being Starved

Most people know they have a brain in their head. Fewer realise they have a second one in their gut.

The enteric nervous system, a vast network of around 500 million neurons lining the gastrointestinal tract, operates with a degree of autonomy that has led neuroscientists to refer to it as the second brain. It produces approximately 90% of the body's serotonin, the neurotransmitter most associated with mood regulation, emotional resilience and a sense of wellbeing. It communicates constantly with the central nervous system via the vagus nerve, sending signals that influence mood, cognition, stress response and immune function in real time.

This is the gut-brain axis, and it is one of the most significant and most under-appreciated relationships in human health. When it functions well, the downstream effects are profound: stable mood, sharp cognition, regulated stress response, robust immunity. When it is disrupted, the consequences are equally far-reaching: brain fog, low mood, heightened anxiety, poor sleep, systemic inflammation and accelerated cognitive decline.

What disrupts it most reliably? Ultra-processed food.

The Interference Problem

Professor Tim Spector, epidemiologist at King's College London and co-founder of the ZOE nutrition study, the largest personalised nutrition research programme ever conducted, has spent years documenting what ultra-processed food does to the gut microbiome. The findings are difficult to overstate.

Ultra-processed foods, those that fall into the NOVA classification's highest category of industrial formulation, are not simply low in nutrition. They actively damage the gut. Their emulsifiers, artificial sweeteners, preservatives and refined ingredients disrupt the delicate ecosystem of bacteria, fungi and other microorganisms that line the gut wall. They reduce microbiome diversity, one of the strongest markers of overall health. They compromise the integrity of the gut lining, allowing inflammatory particles to enter the bloodstream in a process known as intestinal permeability. And they impair the gut-brain signalling that governs mood, cognition and stress resilience.

Research published in JAMA Internal Medicine found that diets high in ultra-processed foods were associated with a 25% faster rate of cognitive decline. A separate analysis from the NutriNet-Sante cohort, tracking over 100,000 participants, found that each ten percent increase in ultra-processed food consumption was associated with a 10% increase in cardiovascular disease risk.

For midlifers specifically, the picture is more acute. Gut microbiome diversity naturally declines with age. The hormonal shifts of perimenopause and menopause directly affect gut function and inflammatory load in women. Declining testosterone in men compounds metabolic vulnerability. The midlife gut is both more susceptible to damage and more consequential to protect.

The Soil Problem

Here is where the food-first philosophy requires an honest qualification.

The nutritional content of conventionally grown food has declined significantly over the past century. Research from the University of Texas analysing USDA nutritional data found meaningful reductions in the protein, calcium, iron, riboflavin, vitamin C and other key nutrients in fruits and vegetables between 1950 and 1999, a consequence of industrial farming practices that have prioritised yield over nutritional density and depleted the mineral content of soils in the process.

This does not mean supplements are the answer. It means the source of your food matters as much as the food itself. A pasture-raised egg from a local farm is not the same nutritional proposition as a battery-farmed equivalent. Organic seasonal produce grown in living soil carries a different micronutrient profile to food grown at industrial scale with synthetic inputs. Quality, not quantity, is the operating principle.

My philosophy on this is straightforward: get as much as you possibly can from real food, sourced as well as your circumstances allow, and turn to supplementation only when there is a genuine and specific need that cannot be met through diet alone.

A Principle-Based Approach

Rather than a prescribed diet, what serves most people best is a set of principles that can be applied to any food situation, whether you are in a supermarket, a restaurant, a farmers market or someone else's kitchen.

Buy organic where you can. Prioritise pasture-raised meat, poultry and eggs. Choose seasonal fruits and vegetables, which are not only more nutritionally dense but more affordable when bought at the right time of year. Support local producers where possible. The farmers market is not just a shopping trip. It is a community experience that reconnects you to your food, to the people who grow it, and to the rhythms of the natural world that your body is still calibrated to.

And if circumstances allow, consider growing some of your own food, even a few pots of herbs or vegetables, or building a relationship with a local farm or smallholder. The closer you are to the source of your food, the more you know about what you are actually eating.

That knowledge is itself a health behaviour.

Restoration: The Reset Approach

For those whose gut health has been significantly compromised, the most powerful intervention is not addition but removal, followed by deliberate, gradual restoration.

A prolonged fast, undertaken carefully and ideally with appropriate guidance, can serve as a powerful microbiome reset. It reduces inflammatory load, initiates autophagy, the body's cellular cleaning process, and creates the conditions for a healthier microbial ecosystem to re-establish. The reintroduction phase is where the work begins: fermented foods such as kefir, natural yoghurt, sauerkraut and kimchi, diverse plant matter across a wide variety of colours and types, prebiotic-rich foods such as garlic, leeks, oats and bananas that feed the beneficial bacteria you are trying to rebuild.

This is not a detox in the commercial sense. It is a physiological process grounded in how the gut actually works. And the evidence for its effectiveness, both in the published research and in the experience of practitioners like Spector, is compelling.

Long Story Short

Health is not something you add. It is something you uncover by removing what is getting in the way. Here is where to start:

Remove before you add: the most powerful dietary change most people can make is reducing ultra-processed food, not adding supplements
Protect your gut-brain axis: your mood, cognition and stress resilience are downstream of your gut health. Feed it accordingly
Prioritise quality over quantity: depleted soils mean food provenance matters. Organic, pasture-raised and seasonal are principles, not luxuries
Support local where possible: farmers markets, local producers and growing your own food reconnect you to your food in ways that compound the health benefit
Restore deliberately: if your gut needs a reset, consider a structured fast followed by the slow reintroduction of fermented and diverse plant foods
Supplements last: exhaust real food options first. Turn to supplementation only when there is a specific, evidenced need