Some amount of forgetfulness – say, forgetting where you parked your car after you leave the shops— is normal, especially when you’re busy or have a lot on your mind.
But for something like 1 in 10 Australians, that forgetfulness will eventually progress into Alzheimer’s disease.
Decades of research have shown that the buildup in the brain of toxic proteins, called beta amyloid and tau, can lead to Alzheimer’s.
What’s less clear is what causes these proteins to accumulate.
Some new studies have begun to explain this process, revealing that the causes of Alzheimer’s disease go beyond genetics and unhealthy habits (though those are important factors, too).
Here, some of the most unusual causes new science is pointing to.
YOU’RE ON ANTI-ANXIETY MEDS
A class of medications called benzodiazepines, which include the popular drugs lorazepam (Ativan), alprazolam (Xanax), and clonazepam (Klonopin), are frequently used to treat anxiety and insomnia.
Although studies evaluating the safety and efficacy of these drugs have evaluated only their short-term use (generally three months or so), many people take them long-term.
A study published in the British Medical Journal followed 1796 Canadians with Alzheimer’s disease and 7184 healthy controls for six years and found that taking benzodiazepines for more than three months was associated with up to a 51 per cent increase in Alzheimer’s disease.
If you need benzodiazepines only on occasion, you’re probably safe.
But if anxiety and insomnia are regular issues for you, consider cognitive behavioural therapy, which has been found to effectively treat both conditions – without the potentially harmful side effects of drugs.
YOU’VE HIT YOUR HEAD ONE TOO MANY TIMES
With tens of thousands of Australians getting a sports-related concussion each year, lots of us are familiar with the worries that can accompany a head injury.
Most people recover without a hitch, but for others, the inflammation that helps to heal the damaged brain tissue becomes chronic.
Here is where the potential links to Alzheimer’s disease can be found, says psychiatrist and neuroscientist Dr Brian Giunta.
Cells in your brain called microglia play an important role in inflammation. “When the microglia are constantly in a pro-inflammatory state, they are less able to clear amyloid beta from the brain,” Giunta says.
Without microglia to clear the proteins, it can build up in the brain and kill neurones.
It’s still not clear why the inflammatory process stays switched on in some people or how many cases of Alzheimer’s disease are potentially linked with traumatic brain injury, Giunta adds.
YOU’RE REGULARLY SLEEP-DEPRIVED
Besides making you drowsy behind the wheel and giving you the midnight munchies, lack of sleep can also speed up the development of Alzheimer’s disease, according to a study published in the Neurobiology of Aging.
“Sleep problems are common in people with Alzheimer’s disease, but it wasn’t clear whether this was cause or effect,” says pharmacologist and immunologist Dr Domenico Praticò.
In a mouse model of Alzheimer’s disease, Dr. Praticò and colleagues found that letting these mice sleep for only four hours a night increased the amount of tau in their brains.
It also altered learning and memory, as well as how well neurones were able to communicate with each other.
Chronic sleep deprivation, Dr. Praticò explains, stresses the brain and body (which is why you may be so tired), which speeds up the harmful processes leading to Alzheimer’s disease.
“Sleep deprivation is a form of chronic stress on the body. It’s also the time when the brain gets rid of bad things,” such as excess amyloid beta protein, Dr. Praticò says.
A study in the Journal of Neurology, Neurosurgery, and Psychiatry identified links between loneliness and the development of dementia.
The researchers found that feelings of loneliness in older adults gave them 1.63 times the odds of developing dementia during the three years of the study.
Scientists don’t know what's driving this association, but the implications are clear: staying connected is good for you.