The controversial neurologist who believes you can dementia-proof your brain

Telegraph

30-04-2025

Dr Dale Bredesen, a neurologist who has worked in many of California's major universities, is known for boldly claiming that Alzheimer's disease can be reversed – even in the case of severe degeneration after several years living with the condition.
In 2014, Dr Bredesen was touted as the first doctor to have successfully reversed memory loss in people diagnosed with the disease, after a small study he led at UCLA. He has since written two books about the power of a dementia treatment regimen he has designed, called ReCODE.
He has now written a third, called The Ageless Brain. It is no less defiant of the current medical consensus. Research has shown that 'there is no reason why anyone should get dementia in the first place,' Dr Breseden claims, 'and the idea that there's nothing that can be done for people who already have the disease is just outdated at this point'. With dementia cases set to triple worldwide by 2050, this is exactly the news that many of us are desperate to hear. But could such a thing really be true?
That our lifestyles go a long way in determining our dementia risk is solid scientific fact. 'There is some evidence that certain diets, such as the MIND diet which is based on the traditional Mediterranean diet, can help to prevent dementia or slow cognitive decline,' says Barbara Sahakian, a professor of clinical neuropsychology at the University of Cambridge. 'I am yet to see any method that can reverse Alzheimer's symptoms, however.'
'There is currently no cure for any type of dementia,' agrees Dr Richard Oakley, an associate director of research and innovation at the Alzheimer's Society, though 'around 45 percent of dementia cases could be prevented or delayed with lifestyle and societal-level changes'. Engaging in just 35 minutes of physical exercise per week, for example, has been associated with a 41 per cent lower risk of developing dementia compared with a completely sedentary lifestyle.
The earlier in life we adopt a regimen of clean eating and frequent exercise, the better, for the health of our brains. But there is much we can do in midlife, says Dr Bredesen, who is far more optimistic than most of his colleagues in the field.
In fact, 'your forties and fifties are really the sweet spot when it comes to dementia prevention,' Dr Bredesen says. Though we are living for longer, 'our brain spans aren't yet matching our lifespans,' he explains, and our 40s and 50s are the right time to make sure that you stay sharp into your eighties and beyond.
'People find that they're pretty healthy throughout their 30s, but that things start to feel different when they hit 40, and then andropause and menopause comes in from around 50 and makes everything different again,' says Dr Bredesen. 'This is when the first signs of cognitive decline might set in, like slower mental processing and worsened memory, and at this point, there really is a tremendous amount that you can do to reverse them and make sure you never get dementia.'
That said, it won't be easy. 'Reversing or preventing dementia is extremely difficult, because it involves wholesale change in the way a person is living their life, what they're eating, how they're exercising, socialising and sleeping,' explains Dr Bredesen. The good news is that 'getting even a few of these right is enough to massively reduce your risk of developing Alzheimer's'.
Here is Dr Bredesen's prescription for a lifestyle that could successfully ward off dementia.
Make sure you eat the right diet (and it isn't the one you think)
What we eat affects the health of our brains – and most of us know that now. But the best diet for your brain goes a step beyond the Mediterranean diet and the advice to eat lots of vegetables and oily fish, according to Dr Bredesen. His ReCODE protocol includes a ketogenic (high fat, low carbohydrate) diet, with a small amount of fasting, both 'to reset the body's sensitivity to insulin' and avoid insulin resistance in the future.
Insulin resistance is thought to affect up to 40 per cent of people aged over 40. Those who are overweight and inactive are most at risk, but this issue is typically identified through a blood test. Insulin resistance is problematic when it comes to dementia risk because it can lead to a build-up of amyloid and tau, two proteins that are thought to damage brain cells. Ketones meanwhile, a type of chemical produced by the liver in the process of breaking down fat, may be helpful in delaying or preventing the onset of Alzheimer's disease, according to some research. 'The purpose of this diet is to restore insulin sensitivity and to restore your body's ability to make ketones when needed,' Dr Bredesen explains.
For this, the doctor prescribes a diet that's heavy in cruciferous vegetables like Brussels sprouts and cabbage, as well as fermented foods such as sauerkraut, though produce sprayed with insecticides and herbicides is to be avoided (as these can contribute to toxic exposure, another risk factor for dementia). Low-mercury fish, pastured chicken and eggs as well as grass-fed beef are in, while grains, dairy products and simple carbs like white bread and pasta are out. Fibre and healthy omega-3 fats from sources such as avocados, nuts and seeds are given a starring role: like sauerkraut, both 'help your gut microbiome, which we know now is crucial in protecting your brain,' Dr Bredesen says.
It's also best for your brain, he believes, to fast for 12 hours overnight, and for at least three hours before bed – meaning that if you eat dinner at 7pm, you should have breakfast at 7am the next day, no earlier and no later. A small amount of fasting before bed and in the morning helps to regulate your glucose levels, Dr Bredesen explains, a key factor in insulin sensitivity. He doesn't advise however that people who want to ward off dementia try intermittent fasting or fast for much longer than 12 hours at a time, as 'you don't want to starve your body of the energy it needs'.
Exercise a lot, in different ways
When it comes to dementia, any amount of movement is far superior to none at all – as shown by a recent study from the Johns Hopkins Bloomberg School of Public Health, which found that just five minutes of 'moderate to vigorous' exercise a day can cut dementia risk by over 40 per cent (if stuck to every day of the week, for four years). The reason for this seems to be that exercise increases flood flow, stimulating the growth of new brain cells and reducing inflammation, the chronic sort of which is linked to increased risk of cognitive decline.
But most of us struggle to find the time to exercise, and it only becomes less appealing as you age. So how can you get the most bang for your buck? Dr Bredesen, who is as evangelical about the benefits of regular exercise as any other expert in the brain, advises people to aim for at least 30 to 40 minutes of exercise a day, five times a week, to include three to four strength training sessions, for no more than 20 minutes at a time and regular cardio.
'The two kinds of exercise are very complementary in what they do for the brain,' says Dr Bredesen. 'Running is especially great because it improves your coordination. Any kind of aerobic exercise improves blood flow and promotes better sleep, while strength training improves insulin sensitivity. Anyone who's physically able to do so should be trying to build or at least maintain muscle and strength.'
Those in midlife should consider incorporating some high-intensity interval training (HIIT) into their weeks, Dr Bredesen adds. The practice combines the most useful aspects of aerobic and strength training, he explains in his book, and the combination of short bursts of exercise and short breaks 'does seem to do something special in the brain', though HIIT shouldn't be treated as a full replacement for longer aerobic or strength training sessions.
Dr Bredesen also recommends exercise with oxygen therapy to anyone with vascular problems, a predictor for dementia, as this can improve the oxygenation of a person's bloodstream and lower blood pressure. 'But that can be pretty expensive, and it's still important that people just get out if this is outside of their budget.'
At the end of the day, 'you just want to aim to get your heart rate up at least five times a week, every week,' Dr Bredesen says. 'A very gentle walk won't cut it, but going slightly uphill or more quickly than is comfortable is enough.' So goes the adage, that the best kind of exercise is the one that you'll stick to. 'Figure out what works well for you, and then add to that if you can. I like to play pickleball or some tennis with my wife.'
Get enough sleep (but not too much)
Most people in midlife could do with getting a bit more sleep – women especially. Perimenopausal women get less sleep than both postmenopausal and premenopausal women, according to some research, with more than half getting less than seven hours' sleep per night, deemed the minimum for good brain health.
The sweet spot for sleep is in fact seven hours, 'with at least an hour of deep sleep and an hour and a half of REM (rapid eye movement) sleep,' Dr Bredesen advises. But too much sleep is bad for the brain; regularly sleeping for nine hours or more 'is associated with risk for dementia'.
All this is because sleep helps to 'cleanse and restore' the brain, ridding it of unhelpful influences and preparing it for the next day ahead. REM sleep, when dreaming occurs, seems especially important. Research suggests that for every percentage decrease in the REM sleep we get, dementia risk rises by 9 per cent. Deep sleep meanwhile seems to be the crucial period in which the brain rids itself of waste products.
To know whether you're actually getting enough sleep each night – and enough deep sleep and REM sleep at that – it isn't enough to simply count the hours between your bedtime and your morning alarm. Though we might not remember it, the average person wakes between two and five times in the night, cutting the time actually spent sleeping.
'It is well worth investing in a fitness tracker that has a sleep function,' says Dr Bredesen. There are many commercially available options. While it may not come cheap, 'buying one is certainly cheaper than spending the last decades of your life in a nursing home'.
Train your brain with big and small challenges
Fitness is a matter for your brain as well as your body, Dr Bredesen says, and to protect yourself from dementia, you must challenge it over the course of your life. Research now shows that 'cognitive reserve' isn't enough, says the doctor. Instead you must constantly present your brain with new tasks and dilemmas.
That doesn't always have to mean putting your brain through a structured boot camp. Dr Bredesen recommends that people in midlife 'take on a small cognitive challenge each day, a medium cognitive challenge each month, and a big cognitive challenge each year'. It needn't be complicated, 'but some degree of intentional brain training has been shown time and time again to help prevent dementia'. The point is that each challenge encourages you to go about your life slightly differently, making your brain work harder and remain 'plastic', in a more flexible state of growth.
Examples of a small challenge include trying a new kind of puzzle (making the switch to sudoku if you're a regular crossword-er), visiting a new coffee shop or simply 'setting up your desk in a new part of the house if you're someone who works from home,' says Dr Bredesen.
A medium challenge meanwhile might entail cooking recipes from a cuisine you haven't yet tried your hand at, or listening to a new kind of music. 'But the key is that the nature of the challenge has to change each month – you can't have Italian food one month and sushi the next, and think you're sorted,' Dr Bredesen says.
A hard challenge, your year-long project, should involve 'true mastery' of a subject, says the doctor. Learn a language, become a chess expert or finally learn how to do algebra, 'so long as it has nothing to do with your day job, as you won't find the benefits of a more plastic brain here'.