You don’t need as much sleep as you age; you will inevitably get dementia if you live long enough; older people shouldn’t exercise strenuously for fear of injury. We grow up hearing such tropes, but many of them are not borne out in science.
 

Sleep

“The need for sleep is still there,” says John A. E. Anderson, head of the Cognition and Neuroscience of Aging Lab at Carleton University. “And sleep is actually incredibly important.”

Anderson says during sleep, the interstitial spaces between cells open up and move waste out of the brain.

“Proteins, which we know are associated with Alzheimer's disease — like tau and amyloid and other waste — get moved out,” Anderson says. “So, sleep is not only restorative, it also clears out waste from the brain.”

He says sleep is also where we rehearse memories, which means our brains are working to store memories so they can be retrieved later on. While he admits getting sleep becomes more difficult as we age, he adds that practising good sleep hygiene — having regular bedtimes and exercising, for example — can help.

Cassandra Morrison, assistant professor of cognitive neuropathy at Carleton University, says some people function on six hours of sleep and others require eight, but that number doesn’t diminish with age. She says that getting sleep as we age can often require a daytime nap to make up for the nighttime sleep we’re not getting.
 

Exercise

The idea that older adults should avoid exercise so they don’t injure themselves is also false.

“If you’ve never exercised or engaged in hiking or running marathons, you probably shouldn’t just all of a sudden start doing that, but that applies to everyone,” Morrison says, adding that adapting to any age-related limitations is key. “If you used to do white-water kayaking, you might instead go kayaking on the Rideau Canal. You might not weight-lift as intensely as you used to, but it doesn’t mean you should not do it at all.”

She notes that strength, balance and function can all be maintained in spite of age.
 

Sexuality 

The idea that sexuality and intimacy fade away with age is another ageist generalization.

“Many older adults remain sexually active, even with health conditions,” she says. “Medications are a bigger determinant, especially because a lot of medications for older adults cause erectile dysfunction. But being sexually active doesn't necessarily mean having direct intercourse. There are other aspects, like physical intimacy, and other ways to engage in that.”

The high number of sexually transmissible diseases in long-term care indicates that people are indeed still engaging.
 

Dementia and Alzheimer’s disease

Risk of dementia increases with every decade, but it’s not inevitable that people will get it.

“Alzheimer’s is certainly not inevitable, and it’s not healthy aging,” Anderson says, adding that there is a disproportionate risk for women, which is now an active focus of research. It’s not just because women live longer, either. Studies have shown that it relates to estrogen, which women lose after menopause, while men maintain it because their testosterone turns to estrogen in the brain.

Ways to prevent it include keeping one’s brain young and active, eating a Mediterranean diet and exercising. Not having a genetic predisposition also helps, but engaging in mitigating activities will improve your odds of not getting it even if it’s in your family. Having a challenging career and speaking multiple languages have been shown to slow the onset of Alzheimer’s by as many as five years. Learning to play an instrument also fits the category.

“Anything you haven’t done [before] — like learning an instrument — is an excellent thing to do,” Anderson says. “There are also social benefits if you do this with other people [because] isolation and depression are quite predictive of cognitive decline as well.”

Morrison agrees, some cognitive decline is part of healthy aging — forgetting where we put our keys, for example, or losing our processing speed, but the latter decline starts to happen at 30 years of age. If our ability to manage our finances, cook dinner or manage our medications remains, it’s a good sign that cognitive decline is minimal.

“It’s the use it or lose it idea,” she says. “If you’re continually learning new things, it’s extra stimulation for the brain.”  
 

Osteoporosis

Osteoporosis is more common in women, but it does occur in men, too. One in three women over the age of 50 develops some form of the disease, while one in five men will.

“Because of the loss of estrogen during menopause, women are at an increased risk,” Morrison says. “But you’re also at increased risk for heart disease, cholesterol problems and various types of cancer.”

Women with osteoporosis are more likely to have hip fractures, she says, but men have a higher risk of mortality if they do have a related injury. 

“It’s important to get screened for this — get the bone density test — and take all measures that reduce the incidence, like exercise, not smoking, not drinking and [addressing] vitamin deficiencies like calcium and vitamin D.”