Hi everyone,
Something my guest said after we finished recording a podcast episode this week has stayed with me. The cameras were off, we were still in the studio, and we got onto where health testing and technology is going — not in five years, but now. Wearables that used to be clinical equipment like continuous glucose monitors, at-home tests that give you results in minutes, vagus nerve stimulators, a neurostimulation headset that treats depression at home, which is what this week's episode is actually about.
The question we kept circling back to was simple: the data is arriving faster than most people's ability to know what to do with it. Cortisol levels from a saliva swab, gut microbiome readings, HRV scores. All of it interesting, but most GPs don't have the training, the time or the framework to sit with you and interpret your Oura ring data or your microbiome tests. The longevity medicine space is growing but it's still small, expensive and largely private. AI tools are beginning to fill some of that gap, but something i’ve noticed with AI, is often the more data you throw at it, the more confusing the analysis becomes, and mistakes are often made.
It certainly feels like people are experimenting with their health more than ever, which is genuinely exciting. But could the gap between the data we're collecting and the guidance to interpret it be creating a new kind of health anxiety — one built not on ignorance but on information we don't quite know what to do with? Let me know if you’ve figured it out yet!
Emily x
🍬 Cutting out sugar completely may actually disrupt your gut microbiome
A new study found that cutting out sugar completely may disrupt the gut microbiome — suggesting that some natural sugars play a role in feeding beneficial gut bacteria, and that complete elimination is not the same as reducing processed sugar intake. Researchers compared mice on a completely sucrose-free low-fat diet with those eating a low-fat diet that included some sugar. Despite similar body weights, the sugar-free group showed worse blood sugar regulation, signs of insulin resistance, and more gut inflammation. The findings suggest that stripping out all sugar may unsettle the gut microbiome in unexpected ways. At the moment, this is animal research only — it tells us nothing definitive about humans.
💊 GLP-1 users moved less, not more, after starting
People taking weight-loss drugs like Ozempic and Mounjaro actually became significantly less active after starting treatment, not more — countering the assumption that losing weight naturally encourages movement. Researchers analysed Fitbit data from 753 adults with obesity on GLP-1 medications and found daily step counts dropped from around 5,000 to 4,500, while time spent in moderate-to-vigorous exercise fell from 28 to 22 minutes a day. The declines were sharpest in men and in people with joint or muscle pain. Because these drugs can also reduce lean muscle mass alongside fat, the study's authors say physical activity must be built deliberately into any treatment plan, not left to chance.
🧠 Blood cancer mutations may trigger Alzheimer's — an unexpected discovery
Researchers discovered that mutations linked to blood cancers may trigger Alzheimer's disease by creating overly inflammatory immune cells in the brain — an unexpected finding that could lead to new treatment approaches targeting inflammation rather than amyloid plaques. They compared brain tissue from 190 Alzheimer's patients with 121 healthy donors and spotted the same cancer-linked mutations turning up repeatedly. The researchers suggest blood tests could one day screen for Alzheimer's risk, and that existing cancer drugs might be worth exploring as treatments.
🌡️ Had PCOS? Menopause doesn't close the chapter
If you were diagnosed with PCOS at any point in your life, it's worth knowing that the condition — now being referred to as PMOS — may continue to affect your health after menopause. Harvard Health highlights that the risks linked to this syndrome, including those around heart health and metabolic function, don't simply resolve when your cycle ends. The name change itself signals something important: this isn't just a reproductive condition, and it doesn't belong only to your fertile years. If PCOS is part of your history, raising it with your doctor post-menopause could be a sensible step.
🩺 Who can see your wearable health data?
If you wear a fitness tracker or smartwatch, you're generating a steady stream of personal health data — and it may not be as protected as you'd assume. A discussion in JAMA highlights that in the US, health data collected by consumer wearables often sits outside the privacy rules that govern medical records. That means your sleep patterns, heart rate, and stress scores could potentially be shared with third parties in ways your GP's notes never could be. This is a US-focused policy conversation, but the underlying issue applies anywhere wearables are popular — including the UK. If you use one, it's worth reading the data-sharing settings in your device's app.
Everything We Thought We Knew About Depression Is Changing
Most people who walk into a GP's room with depression don't say the word. They say they're not sleeping, that work feels harder than it should, that something is off at home, or that they don't quite feel like themselves. The label comes later, if it comes at all — and the gap between symptom and name is where a lot of suffering builds.
It often feels like flatness, not sadness
Ask people what depression feels like and you'll hear "numb" more often than "sad." A muting of pleasure, a thinning out of interest, a sense of going through the motions. Dr Kultar Garcha, a GP and Chief Medical Officer at Flow Neuroscience, who joined me on The Health Review podcast this week, described it well: patients rarely walk in and say "I think I have depression." They say their sleep is affected, their work is affected, there are issues in their relationships. They say they're just not themselves.
That's partly because depression is not one thing. It's a network state. Dr Garcha explained the brain as a prediction engine — constantly scanning the environment, trying to keep us stable and safe. In depression, that prediction engine develops a bias. The motivation to seek reward drops. The sense that effort will be worthwhile diminishes. The brain isn't broken — it's misaligned. And the area most commonly involved is the dorsolateral prefrontal cortex — the part of the brain responsible for planning, concentration, emotional regulation and working memory. Think of it, as Dr Garcha put it, as the conductor of the orchestra. In depression, the conductor goes quiet.
The SSRI conversation
For decades, the dominant treatment for depression has been antidepressants — SSRIs in particular. They work well for many people and have been genuinely transformative for others. But the conversation around their limitations is overdue. Dr Garcha was candid: side effects including weight gain, emotional blunting and sexual dysfunction are more common and more persistent than many patients are told. Sexual dysfunction in particular, he said, can continue for many years after stopping the medication — in some cases permanently.
There's also the question of the underlying theory. The idea that depression is caused by low serotonin — and that SSRIs correct this — has been significantly challenged by research in recent years. A major review published in 2022 found little direct evidence supporting the serotonin hypothesis after decades of it underpinning prescribing practice. Which raises an important question: if the mechanism is more complex than we thought, what does that mean for how we treat it?
The gut-brain connection
One of the most significant emerging areas is the relationship between the gut and the brain. We now know that the gut produces around 90% of the body's serotonin — and that the gut microbiome plays a direct role in mood regulation, inflammation and neurological function. Research is increasingly pointing to gut health as a meaningful contributor to depression, and gut-targeted interventions — including specific probiotic strains and dietary approaches — are beginning to show promise in clinical trials
The new treatment landscape
What's genuinely exciting is how quickly the treatment landscape is changing. Flow Neuroscience, which Dr Garcha represents, has developed a wearable device that uses transcranial direct current stimulation — a very gentle electrical current, equivalent to two AA batteries — to stimulate the prefrontal cortex and encourage those quieted neural circuits back into activity. It's been used by over 60,000 people across Europe and the UK, is now available over the counter, and recently became the first device of its kind to receive FDA approval in the US. In the largest at-home trial ever conducted, 57.5% of participants were in full remission after ten weeks — rising to 67% among those already taking antidepressants.
Beyond neuromodulation, the psychedelic research space is producing some of the most compelling data in psychiatry in decades. Psilocybin — the active compound in magic mushrooms — has now shown in multiple clinical trials, including major research at Imperial College London and Johns Hopkins, that it can produce rapid and lasting reductions in depression, including in people who haven't responded to conventional treatment.
Flow Neuroscience have kindly offered Health Review readers 15% off the device — use code THEHEALTHREVIEW at flowneuroscience.com. As always, speak to your doctor before trying any new treatment for depression.
What to do with this
If you've noticed two weeks or more of disrupted sleep, low energy, or loss of interest in things you usually enjoy, book a routine GP appointment and lead with those specifics.
You can self-refer to NHS Talking Therapies directly via the NHS postcode finder, no GP referral required.
If you're in crisis or worried about your safety, call NHS 111, or Samaritans on 116 123, any time. In an emergency, 999.
This feature is for educational purposes only and does not constitute medical advice. Always consult your own doctor before making changes to your health.
Emily x
The Wearable That Treats Depression at Home Without Medication — Flow Neuroscience's CMO Explains
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