How Mr LC Reversed Cognitive Decline at 79 — And What the Latest WHO Guidelines Say You Can Do To Protect Your Brain Health
Mr LC was 79 when he first came to see me, his wife by his side. He’d come in about a wound on his leg that just wouldn’t heal. But within a few minutes of chatting, I noticed something else — he kept circling back to the same stories, the same questions. His memory was clearly slipping.
He’d been living with high blood pressure, high cholesterol, type 2 diabetes, and poor circulation in his legs for years. His wife was adamant everything was “under control.” Still, something told me it was worth digging deeper into his metabolic profile and exactly what medicines he was taking. There was a lot: a blood pressure tablet, aspirin, three different diabetes medications, and a hefty dose of a statin. His baseline HbA1c (average blood sugar) was slightly higher than we prefer at 6.3%, and his HDL (“good”) cholesterol was quite low. Otherwise, his numbers looked good on paper.
It was after the consultation that his wife quietly told me what she hadn’t said in front of him: he’d been diagnosed with Alzheimer’s. He was still in denial. She was terrified — not just of losing the husband she knew, but of what lay ahead for her as his carer. She also admitted something else: she’d felt embarrassed by her husband’s memory lapses, and the two of them had gradually withdrawn from social situations rather than risk an awkward moment in front of others.
That conversation changed the direction of his treatment — and it wasn’t only about food.
On the medical side, I suggested we try a ketogenic way of eating — not only for his diabetes and cholesterol, but because I believed it could give his brain something it was desperately short of: a fuel source it could actually use. I also stopped his statin, given how directly these drugs interfere with the brain’s ability to use fat for fuel.
On the social side, I encouraged his wife to connect with others facing similar challenges — carers and couples navigating a similar diagnosis — so she wouldn’t feel so alone in it, and so the two of them could build new social connections rather than continue withdrawing.
On the movement side, I learned Mr LC had been a keen tennis player in his youth, and I encouraged him to pick up a racquet again — outdoor play, fresh air, and physical activity all support metabolic and brain health, and it gave him back something he used to love.
His wife was nervous about all of it, but willing to try.
What happened over the next nine months surprised all of us:
| Marker | Before | 9 Months Later |
|---|---|---|
| Diabetes medications | 3 medications | Small dose of metformin only |
| HbA1c | 6.3% | 4.8% |
| Blood pressure medication | Required | Stopped |
| HDL (“good”) cholesterol | Low | More than doubled (optimised) |
| Leg wound | Unhealed for a long time | Healed within 3 weeks |
| Cognitive test score | 20/30 | 26/30 |
But the part that meant the most was his memory. His wife didn’t need a test score to tell her he was improving — she could see it in the conversations they were having again, in the moments he was simply more present. And beyond the numbers, he had his tennis back, and they both had a social circle again.
Mr LC and his wife still follow a low-carb, ketogenic way of eating today.
The last time I saw Mrs LC, she said: ‘Although it was hard to change our way of eating at first, we will never go back. I can see the difference in my husband. And, I feel the difference in my own energy. Thank you for helping us despite my scepticism.’
Why This Story Matters Right Now
Mr LC’s turnaround isn’t a fluke, and it isn’t just one doctor’s anecdote. It reflects exactly what the World Health Organization just confirmed at a global level.
In July 2026, WHO released updated guidelines on reducing the risk of cognitive decline and dementia, giving countries evidence-based recommendations to help prevent or delay dementia across the life course. The numbers behind this update are sobering: more than 57 million people currently live with dementia worldwide, with nearly 10 million new diagnoses every year, and Alzheimer’s disease accounts for an estimated 60–70% of cases.
Here’s the part that should give every one of us hope: while there’s no cure for dementia, up to 45% of the risk can be attributed to modifiable factors — things like tobacco use, alcohol, social isolation, physical inactivity, air pollution, and noncommunicable diseases such as high blood pressure and diabetes.
Nearly half the risk is, in principle, within our control.
What the New WHO Guidelines Actually Recommend
The updated guidance builds on WHO’s original 2019 recommendations, reflecting years of new evidence. The core recommendations include:
- Cognitive training and stimulation, plus staying socially engaged — recommended for adults with normal cognition or mild cognitive impairment
- Increasing physical activity
- Stopping tobacco use
- Reducing alcohol consumption
- Adopting a healthy diet
- Reducing exposure to air pollution — a new addition to this edition of the guidelines
- Managing cardiometabolic conditions — hypertension, diabetes, and high cholesterol
- Considering hearing aids as part of a risk-reduction strategy where hearing loss is present
One detail is particularly worth highlighting, because it cuts against a lot of popular wellness messaging: WHO does NOT recommend supplementation with B- vitamins, vitamin E, omega-3 fatty acids, or multivitamins/minerals for reducing dementia risk in the absence of a diagnosed deficiency — the evidence doesn’t show a clear benefit that outweighs the potential harms. This is a good reminder that a pill is rarely a shortcut around the foundational work of nutrition, movement, sleep, and metabolic health.
You can read the full WHO announcement here.
Connecting the Dots: Mr LC and the Lifestyle Medicine Pillars
Mr LC’s story is really a case study in several modifiable factors working together:
- Nutrition — shifting his fuel source away from glucose-dependence toward one his brain and metabolism could use more efficiently (ketones)
- Managing cardiometabolic conditions — his blood pressure, blood sugar, and true cardiovascular risk markers all improved
- Medical reassessment, not just medication — questioning whether a long-standing prescription (his statin) was actually serving his brain health
- Physical activity — returning to tennis gave him structured movement, fresh air, sunshine exposure, and a source of joy, all of which support metabolic and cognitive health
- Social connection — rebuilding a social circle rather than withdrawing in embarrassment addressed one of the most underrated modifiable risk factors for dementia
- Circulation and vascular health — reflected in how quickly his leg wound finally healed once his metabolic picture improved
This is the heart of lifestyle medicine: looking at the whole person, and recognising that the brain doesn’t operate in isolation from the rest of the body — or from our relationships.
Your Turn: Where Does Your Risk Stand?
Mr LC’s story shows what’s possible. The WHO guidelines show what the evidence supports at a population level. But the most useful question is a personal one: which of these modifiable factors apply to you or someone you love — and what’s one thing you could start addressing this week?
To help you answer that, I’ve put together a Brain-Health Risk Checklist — a simple, one-page self-assessment against the WHO’s modifiable risk factors, with practical first steps for each one, downloadable here.