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Last month, we learned that there is a new partner in the fight against Alzheimer’s: The Bill and Melinda Gates Foundation is investing $100 million in Alzheimer’s disease research. The pledge stems from both recognition of the devastating personal and global impact of Alzheimer’s as well as the need to develop new therapies. We all know someone who has suffered from this devastating neurodegenerative disease.

As the race to find a cure continues, I’d like to take the time to clarify some common misconceptions about Alzheimer’s disease and its parent term, dementia.

1. Alzheimer’s is a type of dementia, but they are not interchangeable.

Alzheimer’s and dementia are often paired together. This leads to the confusion that they are separate entities, but in fact, Alzheimer’s is actually a subset of dementia. I think it helps to think of dementia as the tree and Alzheimer’s, vascular dementia, Lewy body dementia, secondary dementias, etc. as the extending branches. Nonetheless, Alzheimer’s is the most common type of dementia, accounting for 60-80 percent of all dementia diagnoses.

2. Dementia is not just a “memory loss” disease.

The American Psychological Association made this very important distinction in its latest edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). In the previous edition, one of the required criteria for a dementia diagnosis was memory loss. However, the current edition now directs clinicians to broaden their search and identify impairment across several cognitive domains. These domains include learning, language, executive function, complex attention, perceptual motor function, and social cognition.

In particular, this change affects the diagnosis of Alzheimer’s in men. Currently, almost two-thirds of Alzheimer’s diagnoses are given to women despite post-mortem studies showing that the disease affects the sexes equally. In women, Alzheimer’s usually manifests as memory impairment. In men, however, the disease most significantly impacts behavior, motor skills, and language in its early stages. Because women typically present with symptoms most commonly associated with Alzheimer’s, there is a clear disparity between the rates of diagnosis between the sexes – men have been more likely to be misdiagnosed. Men also tend to have an earlier age of onset, around 60 years old, compared to women who are usually diagnosed in their 70s, 80s, and 90s. Hopefully, with this revision in the DSM, more men will be accurately and promptly diagnosed with Alzheimer’s and receive the care needed to manage this devastating disease.

3. Cognitive decline doesn’t always lead to dementia.

Many people fear going to the doctor when memory problems first arise because they think there's only one outcome – the dreaded Alzheimer's diagnosis. But memory and other cognitive issues can be due to all sorts of causes, including temporary states like delirium, normal age-related changes, mild cognitive impairment, or dementia. Even a mild cognitive impairment diagnosis doesn’t ensure a future dementia diagnosis. According to a recent study performed by the Mayo Clinic, only 29 percent of patients diagnosed with mild cognitive impairment progressed to dementia after five years.

4. Not all types of dementia are progressive.

Although the most common types of dementia are progressive, some are actually reversible. Alzheimer’s, frontotemporal, mixed, vascular, and Lewy body dementia are examples of progressive dementia. However, vitamin B12 deficiency, normal pressure hydrocephalus, and underactive thyroid syndrome are just the underlying causes behind a few types of dementias which, with adequate treatment – can be reversed. Medications such as certain antidepressants, antihistamines, and narcotics have also been known to cause dementia-like symptoms that can be reversed when the patient stops taking the drug. As an Alzheimer’s diagnosis has a process of elimination methodology, it is especially important that reversible dementias are excluded first before settling on a progressive dementia diagnosis.

5. Lifestyle changes can help reduce the risk of dementia.

There are steps you can take now that will help lower your risk of developing dementia in the long run. One of the best things you can do now to remain “cognitively sharp” throughout your life is a change towards healthy lifestyle choices. Studies have shown that regular exercise, a routine nutritious diet, maintaining normal blood pressure, engaging in social contact, not smoking, and treating depression are just a few ways to help prevent or lower your risk of developing dementia.

Preventive Strategies for Dementia. Reprinted from “Dementia prevention, intervention, and care,” by G. Livingston, A. Sommerlad, V. Orgeta, S. G. Costafreda, J. Huntley, D. Ames, ... & C. Cooper, 2017, The Lancet.
Source: Preventive Strategies for Dementia. Reprinted from “Dementia prevention, intervention, and care,” by G. Livingston, A. Sommerlad, V. Orgeta, S. G. Costafreda, J. Huntley, D. Ames, ... & C. Cooper, 2017, The Lancet.

Let’s look at the evidence behind one of these lifestyle choices – exercise.  

Physical activity is a commonly cited protective factor against dementia. By working out and increasing your heart rate, more blood circulates through the brain. This has a positive effect on cognitive health by stirring the formation of blood vessels which leads to increased brain volume. Acting as a type of cognitive reserve, or “cognitive buffer,” larger brain volume means more synaptic connections to help absorb the effects of dementia so that cognitive function is not noticeably affected. Exercise benefits many cognitive domains like executive function, attention, processing speed, and memory. In one study, exercising three or more times a week correlated to a 32 percent reduction in risk of dementia, while other reports say the reduction in risk is as high as 50 percent.

So, while we await the big scientific breakthrough that reverses the effects of dementia, let’s focus on the ways we can stay a step ahead of it now. Take nutrition supplements or eat meat and shellfish to maintain healthy Vitamin B12 levels, and do your best to maintain healthy lifestyle habits. Also keep an eye out for impairments in multiple cognitive domains, not just memory. Eating well, exercising regularly, and regular social contact are not only beneficial for cognitive health but mental health too. Be vigilant and stay cognitively strong!

References

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