WAYS TO PROTECT
In many cases we can prevent our brains being ravaged by cognitive decline
About 50 million people worldwide suffer from dementia, and much has been written about how these numbers will only increase as the population ages. With this in mind, it’s easy to assume that the overall risk of getting dementia is increasing, too, but the opposite is true: the rate of dementia in the age 65 and older population is actually falling. If sheer numbers rise, it’s because so many of us are living much longer than earlier generations. And the older you get, the more susceptible you are to age-related illnesses.
WHAT IS DEMENTIA? It’s a bundle of symptoms associated with profoundly impaired thinking, memory and ability to function. Although most often connected to Alzheimer’s, it can also be caused by other i l lnesses, i ncluding Parkinson’s and cardiovascular disease. And a 2017 Lancet review of the recent research on dementia found seven conditions, including hypertension, obesity, untreated depression and untreated hearing loss, increased the risks of dementia.
The good news, according to Professor Gill Livingston, one of the authors of the Lancet review, is that if you improve those lifestyle factors, you should eliminate at least 35 per cent of dementias attributed to them. But this may be much too conservative an estimate.
Studies in the US, UK, Denmark and elsewhere have shown that it is more possible than ever to live a long life free from dementia’s ravages. And this might be true even for people whose brains have already undergone some of the physiological changes associated with dementia. Such brain abnormalities sometimes take decades to destroy the ability to remember, to communicate and make sense of the world. But despite existing damage, some of us remain remarkably dementia-resistant.
Here are five new findings that prove you can defend your brain against dementia.
GENES AREN’T NECESSARILY DESTINY
So, what about genes? Don’t they make dementia almost inevitable in some people? In the rare forms of early-onset Alzheimer’s that strike people aged in their 30s through
to their 50s, genes do determine disease. But this is not the case in late-onset dementia.
“The common gene that raises risk for Alzheimer’s in people 65 and over is called APOE-4,” says Professor Livingston. But, she points out, not everyone who has the APOE-4 gene gets the disease. And not everyone who gets dementia has the APOE-4 gene. In fact, according to Professor Livingston, “It only accounts for about seven per cent of the dementias.”
AN ACTIVE BRAIN IS A HEALTHIER BRAIN
Ongoing research conducted at the Rush Alzheimer’s Disease Center in Chicago since 1997 has shown that “Higher levels of cognitive activity are associated with better cognition,” says Rush neurology Professor Aron Buchman. He points to common intellectual pursuits such as reading books, writing letters and regularly seeking and learning new information such as another language. The Rush research found that the more such activities were part of someone’s life in their later years, the less mental decline a study participant exhibited.
But an important question remained: did these individuals escape dementia despite their brains showing physiological changes? Researchers got their answer when all the study participants agreed to donate their brains for autopsy upon death. The physical condition of the donated brains was about what would be expected of people in their 80s, 90s and beyond, including brain abnormalities. But these abnormalities hadn’t caused the expected i mpairment in those who had remained intellectually active.
The prevailing theory is because their brains had plenty of what scientists call cognitive or brain ‘reserve’, a reservoir of active grey matter available to compensate for age-related changes.
But what if it isn’t just brain ‘reserve’? What if entirely new brain cells are forming and compensating for damaged ones? According to a paper in the May 2019 issue of the journal Cell, the donated brains of people who died between ages 79 to 99 showed evidence that they
cont inued to grow new neurons their entire lives – even in their late 90s. And the better their cognitive function at the end, regardless of brain abnormalities, the more new neurons they had grown. Could lifestyle factors affect that growth? More research is needed, but it’s an intriguing possibility.
HEALTHY EATING, HEALTHIER BRAINS
A study published in 2006 found that by strictly adhering to the Mediterranean diet (higher consumption of whole grains, fruit, vegetables, olive oil and fish; low consumption of meats and sweets), you could lower your risk of Alzheimer’s by as much as 40 per cent.
Today researchers have taken diet one step further and confirmed the connection between it and dementia, and have created what is referred to as the MIND diet, a regime directly targeting brain health. The MIND diet is a combination of the Mediterranean and DASH diets (that restricts sweets, refined grains, fried and fast foods, red meat, butter and cheese). This combination has now been proven to reduce cognitive decline by about 50 per cent.
The most recent research, publ ished last year in the journal Neurology, found that an overall healthy diet is the key to reducing cognitive decline. Pauline Croll, lead author of the research, believes that focusing too narrowly on any particular foods might miss the bigger picture. “We did an extra analysis where we could see whether one food item would drive the entire association of all diet quality, and that was not the case. It’s the overall dietary pattern.”
Older people who ate the most healthfully, regardless of whether the diet was closer to a MIND diet, a Mediterranean diet or other recognised healthful eating habits, had larger – and therefore healthier – brains. What the healthiest diets have in common is an emphasis on plant-based foods, with fewer processed foods.
YOUR BEST DEFENCE: GET MOVING
It has already been established that people who followed the Mediterranean Diet and exercised routinely had as much as a 67 per cent lower risk of dementia. But more recent research on the effect of exercise shows even more promise.
The Rush Alzheimer’s Disease Center has been following a rolling (new people enter as older ones pass away) group of older people since 1994, trying to tease out the factors that help some stay cognitively healthy while others decline. The average age of participants as they enter the study is early 80s.
“In 2005, we began using a wrist device that measured physical
activity,” says Professor Buchman. The devices measured everything from sweeping the floor or gardening to more formal exercise like cycling. “We found that people who had higher activity had a decreased risk of developing dementia. They also had a slower rate of cognitive decline over time.” This research is ongoing.
As the participants died and donated their brains to the study, the researchers discovered that, just as with those who stayed intellectually active, those who stayed physically active offset cognitive decline. “The benefits of higher activity giving you better cognition held good regardless of any abnormalities that we measured in the brain,” says Professor Buchman.
Because the Rush research only measures activity starting when people are in their 80s, it didn’t tell us at what age activity must begin to be of benefit. But it has now been shown that activity at any age seems to help. Research published in Neurology last year found that, among older people with thinking problems that hadn’t progressed to dementia, those who took up and did aerobic exercise for 35 minutes, three times a week, for six months, were better able to pay attention, plan and complete some cognitive tasks.
GOOD FOR THE HEART IS GOOD FOR THE BRAIN
Numerous researchers have found a connection between dementia and diabetes, obesity, high cholesterol, atrial fibrillation and high blood pressure. High blood pressure, for example, has been linked to small brain lesions that can affect cognition.
“What is good for your heart is also good for your brain,” says Dr Silvan Licher of Erasmus University Medical Centre. “I think that’s something we should promote more.” Heart-healthy recommendations for diet and physical activity are much the same as brain-healthy ones.
“The important message today is that people may be able to reduce the risk of dementia and maintain brain health as they age,” says Professor Buchman.
You, me, all of us – whatever our ages – have the power to make small changes that increase our chances of living dementia-free, for life.