One sunny morning, 76-year-old Marijke, who was born in the Netherlands, and her husband Tom welcomed me for breakfast at their home in Loma Linda, an hour's drive east of Los Angeles.
Oatmeal, chia seeds, berries, but without processed sugary flakes or coffee - a breakfast as clean as Loma Linda's mission.
Loma Linda has been identified as one of the world's so-called Blue Zones, places where people live longer than average.
In this case, members of the Seventh-day Adventist Church community in the city are the ones who live longer.
They usually don't drink alcohol or caffeine, stick to a vegetarian or even vegan diet, and consider it a religious duty to take care of their bodies as best they can.
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This is their "healthy message", as they call it, and it has brought them into the limelight - the city has become the subject of decades of research into why their residents live better and longer.
Dr. Gary Fraser of Loma Linda University told me that members of the Seventh-day Adventist Church community there can expect not only a longer lifespan, but also an increased "health span" - the time spent in good health - four to five years longer for women. and seven years longer for men.
There is no big secret in Loma Linda.
Its citizens simply live a truly healthy life, mentally stimulated and extremely valuing the community that religion can provide them.
Lectures on healthy living, music gatherings and exercise classes are held regularly.
I spoke with Judy, who lives with 112 other people in a nursing home where there is always "an opportunity for heart- and mind-opening conversations," she tells me.
"What I didn't realize before is how much your brain needs socialization… without it, it seems to shrink and disappear," says Judy.
Science has always recognized the benefit of social interactions and avoiding loneliness.
But now it is possible to identify whose brain is aging faster than it should, so that it can be monitored and potentially better treated preventively in the future.
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As we move to personalized, predictive, preventative health care models, early diagnosis can be key in all areas of health - aided by the incredible capabilities of artificial intelligence and big data.
Andrej Irimija, associate professor of gerontology and computational biology at the University of Southern California, showed me computer models that estimate how our brain ages and predict its decline.
He made them using MRI scans, data from 15.000 brains and the power of artificial intelligence to understand the trajectory of both healthy aging brains and those undergoing disease processes such as dementia.
"It's a very sophisticated way to look at patterns that we don't necessarily know as humans, but an AI algorithm can recognize," he says.
Watch a BBC video on YouTube about digital dementia
Professor Irimija, of course, also looked into my head.
I had a functional magnetic resonance imaging done before the visit and, after analyzing my results, Professor Irimija told me that my brain is eight months older than my chronological age (although it seems that the part that controls talking has not aged that much. I could have done that myself to tell him).
However, Professor Irimija said that the results fall within the allowed margin of two years.
And private companies have begun to commercialize this technology.
The Brejnki company offers services at various clinics around the world.
Its founder, Owen Phillips, told me that in the future it will be easier to take MRIs.
"It's becoming more and more affordable for people to get an MRI, and the images it produces are getting better and better," he says.
“I don't mean to be geeking out on you here. But technology is just getting to the point where we can see things much earlier than we could in the past.
"And that means we can understand exactly what's going on in the brain of an individual patient. With the help of artificial intelligence, we can also support that."
Contrary to what Professor Irimija's analysis of my MRI scan told me, Brain's assessment took a year off my biological age from my brain.
I also received a printed 3D model of him, which seemed massive, and I was assured that it was life-size.
The goal here is not only a more precise approach to treatment, but also the ability to quantify how well various interventions work.
The dramatic increase in life expectancy in the last 200 years has also led to the rise of various diseases associated with aging.
I began to wonder if, if we lived long enough, dementia would knock on all of our doors.
Professor Irimija said that this is a theory that many have researched but not proven, adding that the goal is to find a way to push dementia, with a bit of luck, beyond our average lifespan.
And all this brings us back to the same point.
Every scientist and doctor, as well as everyone who lives in the Blue Zones, claims that lifestyle is key there.
Good nutrition, constant activity, mental stimulation and happiness are key to how our brain ages.
There's another important factor, too, according to Matthew Walker, professor of neuroscience and psychology at the University of California, Berkeley, and author of the bestselling book Why We Sleep.
"Sleep is the most effective way you can reset your brain and body health every day," he preaches.
"There isn't an operation in your brain that isn't wonderfully enhanced when you get enough sleep or measurably worse when you don't get enough sleep."
He talked about our brain's purification system, which works during our sleep to wash away the proteins beta-amyloid and tau - "the two biggest culprits of Alzheimer's disease".
Changes in sleep patterns are also associated with dementia.
Professor Walker described how we don't just see it in our sixties or seventies - it can start even during our thirties.
Therefore, identifying these changes by monitoring sleep can potentially become a "model for prevention in middle age".
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Fauna Bio, a biotech company on the outskirts of San Francisco, collects data on squirrels during and after hibernation.
In this state of lethargy, as it is known, the body temperature of squirrels drops and their metabolic rate decreases to only one percent of normal.
During this period, they seem to be able to regrow neurons and restore connections that the brain has lost.
The company's goal is to try to make drugs that will mimic this process in humans, without having to spend half a year underground.
Even if some crave just that.
Untreated depression has also been shown to increase the risk of dementia.
Professor Liana Williams from Stanford University has identified a method of "visualizing" some forms of depression in the brain with the help of magnetic resonance imaging and therefore can see if the treatment has had an effect.
This could help scientists better understand the root causes of various mental health conditions such as depression, as well as provide ways to quantify treatment progress in patients.
Few people put as much faith in science to achieve longevity as Brian Johnson - the tech entrepreneur who spends millions trying to stop biological aging.
Dozens of supplements, fasting for 19 hours a day, seemingly excruciating workouts and a series of (sometimes controversial) treatments are the things he hopes will help him turn back time.
But as 103-year-old Mildred, whom I visited in Loma Linda, convincingly said: "You have to be absolutely very careful with your diet, that's true, but I also don't agree with: 'You have to do this, you have to do that, you have to do this and that, and you absolutely must not do this!'".
She thinks that it is much more important to live a little and - let's make peace with it - I guess she knows.
Look at itand this one video: A man trying to rewind the years
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