The 2022 edition of the annual Week of Care, the largest event for the welfare and health care sector in Flanders, is focusing on "brain health."
During the week, more than 200 health facilities, companies, educational institutions and other actors open their doors to the public to give them a peek behind the scenes.
The message visitors have been receiving is that there are many ways to keep our brains healthy – and some of these activities are not what would immediately come to mind.
Regular exercise, healthy eating and getting enough sleep are very important to keep your brain healthy for a long time. These are well known factors in maintain good brain health. But other, less obvious factors also play a role. For example, oral bacteria are linked to diseases such as Alzheimer's and Parkinson's. Even the quality of your relationships has a surprisingly large influence.
Exercise to create brain fertilizer
Walking, dancing, swimming or any other sport is not only good for your body, but also for your brain. This is evident from dozens of studies, in people of all ages. "Exercise keeps the brain healthy," says KU Leuven professor Davy Vancampfort. "There is a lot of evidence for the beneficial effects of exercise."
A ground-breaking study on sport and brain health appeared in a paper by the National Academy of Sciences in 2011. In the study, 120 elderly people were divided into two groups.
One group did medium intensity aerobic training three times a week, while a control group did stretching exercises three times a week. One year later, there was a remarkable difference in the hippocampus, a region of the brain that is important for information processing and memory.
"The hippocampus had increased in volume in the people who had exercised three times a week," says Vancampfort. "They also scored better on memory tests. In the stretching group, on the other hand, the hippocampus had shrunk."
The growth of the hippocampus is partly due to the production of brain-derived neurotrophic factor (BDNF), or abrineurin, during physical activity. This substance is important for the production of new brain cells and for the connections between brain cells. It is therefore sometimes called "fertilizer for the brain".
The production of BDNF during exercise also explains why regular exercise helps to prevent and reduce symptoms of depressive. "There's a lot of evidence for the link between low levels of BDNF in the blood and depression," Vancampfort says.
Exercise does much more than fertilise your brain. "Your brain is stimulated in different areas," says Professor Mathieu Vandenbulcke of KU Leuven, a psychiatrist and expert in neurodegenerative diseases.
"You stimulate the motor networks, which are important for performing movements. At the same time, you also stimulate many other networks that are important for your memory, to orientate yourself in space or to make estimates. That's all very important as we age. And so, you strengthen it by moving a lot."
Good sleep hygiene and the brain cleaning crew
But there is bad news for those who often lie awake at night. There is a clear link between sleep deprivation and the risk of dementia. This is evident from a large study of 8,000 British people over fifty.
Those who slept less than six hours were 30 percent more likely to suffer from dementia than those who slept seven hours a night. While experts cannot say for sure that sleep deprivation causes dementia, they do admit that the two often go together.
There is a possible explanation for the surprising link between sleep and dementia. During your deep sleep, it's like a cleaning crew is pulling through your brain. It cleans up waste products, so that your brain can function optimally again in the morning.
"Harmful substances are removed during deep sleep," says Mathieu Vandenbulcke. "These include the amyloid β protein, which we know plays an important role in Alzheimer's. This may explain, among other things, why sleep deprivation is linked to an increased risk of Alzheimer's."
That doesn't mean you have to sleep extra-long to give the cleaning crew more time. A recent study published in the renowned journal Nature Aging concludes that seven hours of sleep is ideal for middle-aged and older people. People who sleep about seven hours have fewer symptoms of anxiety and depression, and they also score better on cognitive tests. Those who slept much shorter or longer scored worse.
Of course, you don't have to panic if you don't sleep exactly seven hours. That can make sleep problems worse. It’s just worth bearing in mind that sleep hygiene is very important.
Loneliness can be as unhealthy as cigarettes
According to a large review study, published in 2019, long-term loneliness also increases your risk of dementia.
"Long-term loneliness is linked to a 26% higher risk of dementia," says Davy Vancampfort, one of the study's authors. "Other research indicates that loneliness is about as bad for your health as fifteen cigarettes a day."
According to Mathieu Vandenbulcke, a first possible explanation for this has to do with stress. "Prolonged loneliness is very stressful and persistent stress is toxic to the brain. The brain cells make fewer new contacts. Substances are also released that have a negative impact on the inflammatory response that plays a role in Alzheimer's."
Stress can also damage the brain in another way. "Prolonged stress leads to the production of a lot of cortisol, an important stress hormone," says Vandenbulcke. "That then damages the hippocampus, a brain region that's important for storing memories."
So, loneliness causes inflammation in your brain... and it damages brain areas that are important for your memory. Moreover, your brain is less stimulated if you have little social contact, which also plays a role. It is, as is often the case with the brain, a combination of factors.
The good news: social contact protects your brain as you age. "You can see that very clearly in a long-term study from Harvard University," says Vandenbulcke. "Warmth and happiness within relationships seem to have a greater effect on the brain than genes, heart and blood vessels and other physical factors. Relationships turn out to be extremely important."
Healthy mouth, healthy brain
It may sound strange, but it is true: the health of your brain is closely linked to the health of your mouth.
"We see a clear link in large studies between oral hygiene and neurodegenerative disorders such as Alzheimer's, Parkinson's and dementia," says professor of microbiology Marie Joossens from UGent. "The associations are very strong, only we don't understand the mechanism very well yet."
A first possible explanation has to do with the blood vessels. "Poor oral hygiene is clearly linked to reduced blood vessel quality," says Joossens. "As a result, the irrigation of the brain is also less good. That could then contribute to dementia."
A second possible mechanism has to do with mouth infections caused by mouth bacteria. "Our body responds by producing inflammatory proteins. These then end up in the blood. In that way, they end up in the brain, where they cause problems."
There may also be a link between gum disease and depression. "Gum disease would be my first suspect if I ever became depressed," writes Edward Bullmore in his book ‘The Inflamed Brain.’ "Doctors often forget that because they see it as a matter for dentists. Most dentists, on the other hand, are not paid to think about the link between gum disease and depression."
Nevertheless, you have to be careful about coming to conclusions too quickly. "In depression, it is very difficult to distinguish cause and effect from each other," says Marie Joossens. "People who are depressed are often less motivated to take good care of their teeth. It is therefore possible that it is an accidental association and there is no causal relationship. We still need to investigate that further."
In the coming years, we will undoubtedly learn a lot about the curious connections between the mouth and the brain. Still, you don't have to wait for the results of all that research. There are plenty of reasons to pay extra attention to your oral hygiene now, by brushing and flossing well. You prevent toothache and sore gums... and possibly you also keep your brain healthy.
Boost those blood vessels
In addition to a healthy mouth, strong blood vessels are also very important. "You certainly have to protect them," says Mathieu Vandenbulcke. "For me, healthy blood vessels are the most important factor if you want to keep your brain healthy for a long time. Anything that's good for your heart and blood vessels is also good for your brain."
And vice versa: what is bad for your blood vessels is also bad for your brain. "High cholesterol, high blood pressure, being overweight, smoking, old-age diabetes... All of those factors significantly increase your risk of dementia. So, you should these treated quickly, if you have any of these problems."
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You can keep your blood vessels strong through a healthy lifestyle: exercise enough, don't smoke, and eat healthily.
"Healthy food is very important," says Vandenbulcke. "The Mediterranean diet ⎯ including olive oil, leafy vegetables, unsalted nuts, berries and fatty fish ⎯ seems to have a positive effect on the heart and blood vessels. It also contains many vitamins that protect the brain. It is suspected that this double effect reduces the risk of dementia."
But is there also room for a glass of wine or a pint of beer in a healthy diet?
"It depends on the quantity," says Vandenbulcke. "One glass a day could have a beneficial effect but drinking too much is certainly not good. Alcohol is toxic and it damages the brain. So, one glass is fine, but three glasses or more is not good for your brain."