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How Can You Avoid Dementia? We Just Don’t Know — So Why Not Try a Healthy Life?

Diving into the research around brain health produces more questions than answers.

Crawford Kilian 15 Apr

Crawford Kilian is a contributing editor of The Tyee.

[Editor’s note: Tyee contributing editor Crawford Kilian is spending 2019 exploring dementia and brain health.]

Venture into the subject of dementia, and you soon feel you’ve stumbled into a kind of quantum world.

Like quantum physics, in dementia not everything is knowable, and nothing is certain. Causes and effects are likely or unlikely, but only in a statistical sense. Studies produce contradictory results and uncertainty rules.

Consider some of the things that seem to be, maybe, sort of “risk factors” associated with eventual dementia. According to Health Canada, these include lack of physical activity, obesity, unhealthy diet, tobacco use, harmful use of alcohol, social isolation, lack of cognitively stimulating activities, diabetes, hypertension, and depression.

Many of those can kill you all by themselves, long before you might be diagnosed with dementia. Being physically active, staying slim, eating properly, not smoking and so on are self-evidently good ideas — even if the “good life” in North America discourages them. But such sensible behaviour is no guarantee of avoiding dementia.

Research into Alzheimer’s and other dementias seems endless, but it often undercuts itself. A good education seemed to be insurance against dementia, until it wasn’t. Smoking seemed to be a sure path to dementia, until it wasn’t. The benefits of a Mediterranean diet turn out to be “observational.”

Bacteria that cause gum disease have been found in the brains of dementia cases. So maybe fighting those bacteria might reduce the risk of dementia. Mid-life anxiety may be linked to dementia, so maybe meditation and mindfulness would help, the British Medical Journal tells us.

But it won’t be much help if you live in Ontario near roads and highways: A 2017 Lancet study found that dementia seems more frequent in people who live within 50 metres of a major traffic road and never move.

Schrödinger’s brain

Quantum physicists like the thought experiment of Schrödinger’s cat, in which a cat inside a box can be considered both dead and alive — until we open the box and see.

Similarly, our forgetfulness may or may not collapse into dementia until it’s diagnosed (or until our brains are examined after we die).

Lacking a clear-cut cause, we dream of a cure. And some recent research is moderately encouraging. A tweaked form of benzodiazepines, developed by the Centre for Addiction and Mental Health in Toronto, appears to reverse memory loss caused by depression and aging.

What’s more, it does so by repairing and rejuvenating damaged nerve cell receptors. But the effects lasted for just two months with daily treatment, and the researchers don’t claim a cure — only that “the molecules could help to prevent the memory loss at the beginning of Alzheimer’s, potentially delaying its onset.”

Similarly, researchers at Boston University recently showed that they could improve “working memory” in older adults by synchronizing some kinds of brain waves using electrodes. After 25 minutes of stimulation, older subjects’ memory performance matched those of younger participants. The improvements “lasted longer than what could be evaluated in the present study.” But the researchers made no promises of an electronic “thinking cap” that could restore old brains and lost memories.

An ounce of prevention

If a cure remains only a hope, what about simple prevention — or at least delaying the onset of dementia?

Even the routine advice is open to question. Physical activity? A 2018 study found “Evidence regarding effects on dementia prevention was insufficient for all physical activity interventions.”

Vitamins and supplements? According to the Cochrane Review “low-certainty evidence” is the best that can be said for some of them. The authors of one of the reports concluded, “At the moment, it is not possible to identify any supplements which can reduce the risk of people with [moderate cognitive impairment] developing dementia or which can effectively treat their symptoms.”

How about cognitive training in reasoning and problem-solving? Blood pressure management? Physical activity? A 2017 report found “None of the interventions evaluated in the AHRQ [Agency for Healthcare Research and Quality] systematic review met the criteria for being supported by high-strength evidence, based on the quality of randomized controlled trials and the lack of consistently positive results across independent studies.”

But it did find that promoting lower blood pressure in midlife would be helpful in “preventing, delaying, and slowing clinical Alzheimer’s-type dementia.”

Better said, the message would be that lower blood pressure, more physical activity, and good nutrition are keys to living well. Living well, we’re told, is the best revenge; it may also be the best prevention, at least for some of us.

For all the ongoing research, Alzheimer’s and the other dementias remain in the quantum-weirdness world of statistical probabilities. It’s an old question — is the human brain capable of understanding anything as complex as itself? So far, the answer is “not very well.”

Still, the research should go on. And while it does, we should also explore how to reduce the harm, both personal and social, that dementia will assuredly inflict on us for the foreseeable future.  [Tyee]

Read more: Health, Science + Tech

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