[6 min read]
- There is a growing body of evidence that viruses are associated with dementia.
- Dementia is a diagnosis given when someone experiences the combination of cognitive and functional impairment.
- A study of public health data in Wales found that people who recieved a shingels vaccine had a lower rate of dementia onset.
- Eating well, regular exercise and new and challenging activities also support brain health.
- A Providence Swedish aging and brain health expert shares more on the study and what we know about dementia and brain health.
According to the National Institutes of Health, dementia affects some 6 million people and accounts for 100,000 deaths per year in the United States. By 2060, the number of new dementia cases in the country is expected to double. In a recent study, researchers found significant evidence that the shingles vaccine may offer protective benefits against dementia. To learn more about dementia, brain health and the significance of this study, we spoke with Kyle McIntyre, ARNP, DNP, AGNP-C, a brain health expert at the Providence Swedish Center for Healthy Aging.
What is dementia?
Dementia is an umbrella term. Alzheimer's, Lewy Body, Vascular Dementia, Frontotemporal Dementia - these are all different types of dementias. Kind of like how freestyle, butterfly, and breaststroke are all different types of swimming strokes. Dementia is a diagnosis we give when someone experiences the combination of cognitive impairment and functional impairment. For example, not being able to draw a cube and remember a set of words after 5 minutes are ways to measure cognitive deficits. Let's say someone experiences both these visual and memory deficits on a test - that could qualify someone for the cognitive impairment piece. Let's go further and say this same person with a mild cognitive impairment now has trouble following tax forms to file their yearly taxes - something they have never had trouble with before. The addition of this functional decline would mean we could describe said person as having dementia, i.e., functional and cognitive decline.
Alzheimer's disease, like most dementias, is terminal. Alzheimer's is categorized predominantly by the symptom of rapid forgetting. For example, early in the disease someone may forget what activities they took part in day after day. Later in the disease, the person may appear to forget events from minute to minute. This is because anatomically, Alzheimer's is a neurodegenerative process that starts around the hippocampus, a critical brain structure for memory, and moves outward to the cortex - the outer portions responsible for all kinds of functions from decision-making to language, to the planning of movements, etc. When I say neurodegenerative, I mean the literal tissue of the brain becomes damaged and eventually dies. These days, there is strong evidence that types of protein called amyloid are responsible for the damage we see in Alzheimer's. Tau, another protein, also accumulates and is thought to cause damage in Alzheimer's.
How does dementia typically progress?
Dementias diagnosed before age 65 tend to have strong genetic determinants - meaning a specific gene leading to sharp decline. Maybe 4-8 years from the time of diagnosis to significant impairment and death. These types of familial dementia are rarer. It is more common for dementia to be diagnosed above the age of 65, which is a late onset. Later onset dementias typically progress slowly - maybe over the course of 5-15 years from the time of diagnosis to the time someone passes away with significant deficits. It is important to keep in mind that these ranges are general – every situation is different and predicting disease progression can be very difficult to do. Many times, folks will pass away from other comorbid conditions or acute illnesses, though dementia certainly can contribute to the overall illness burden people experience.
In terms of signs and symptoms, different dementias have different patterns and different signs and symptoms. Generally speaking, the signs and symptoms map to the part of the brain being affected. We already talked about the rapid forgetting associated with hippocampal atrophy in Alzheimer's. In frontotemporal dementia, for example, one may see personality and language deficits related to the damage and atrophy of the frontal and temporal lobes, which are areas of the brain critical for behavior and language. Memory impairment in frontotemporal dementia often comes later.
There is evidence that viruses may contribute to the development of dementia. Can you talk about this?
There is a growing body of evidence that viruses, for example, herpes family viruses - the same one that shingles belongs to (Herpes Zoster) - are associated with dementias. The evidence currently is either at the epidemiological or basic science level. Epidemiological studies in the context means looking at characteristics of different populations rather than applying a treatment. Well, these large population-based studies show that viruses like shingles and influenza (the virus responsible for the flu) are associated with neurological diseases like dementia. Exactly how viruses like shingles cause the development of dementia is still an area of intense study. We do know that herpes family viruses live dormant in root nerves along the length of the spine. Herpes viruses - when reactivated or in an initial infection - cause neural inflammation. Evidence in human cells grown in laboratories shows that amyloid inappropriately aggregates during acute inflammation. Amyloid has also been shown to aggregate inappropriately in herpes infected neurons.
The study found that the shingles vaccine offers protective benefits against dementia, can you discuss this?
Yes, this was a very compelling study. In the study, the researchers used electronic health data to look at people who got the shingles vaccine versus people who did not. The data came from a large public health data set in England and Wales. The shingles vaccine was rolled out around September 2013, however, if you were more than 80 years old at the time, you were ineligible for the vaccine. This rule created an almost random assignment of people who got the vaccine, splitting people into a treatment (vaccine) group and a non-treatment group (no vaccine). The researchers call this a "natural" experiment and a set of conditions that are quasi-experimental. After the researchers evaluated the vaccinated versus non-vaccinated groups, they found a 20% lower risk of developing dementia in the vaccinated group compared to the non-vaccinated group.
The researchers are unsure exactly why the vaccinated had a lower rate of dementia diagnoses, but they think it is more than just the effect of shingles prevention. They think the vaccine itself provides immune system-stimulating effects that prevent any type of shingles activation that could lead to downstream effects like neural inflammation, deposition of tau and amyloid, and the development of dementia. Females also tend to have greater immune stimulatory effects from vaccines compared to males.
Does it mean that the vaccine offers protection against specific conditions such as Alzheimer’s or Lewy Body dementia?
No, the Wales study did not distinguish between Alzheimer's or Lewy Body dementias in their analyses. They specifically only searched for a dementia diagnoses as a consequence of vaccination (or lack of) - not the development of a specific type of dementia. It’s important to keep in mind that the Wales study only looked at the live-attenuated vaccine. We do not use the live-attenuated vaccine here in North America. We use a recombinant vaccine, called Shingrix which is more effective at preventing shingles and the nerve pain that often ensues. And because it does not contain a live (but weakened) virus, it is safe for people with lowered immune systems. Win-win! Getting the shingles vaccine is already associated with a lower risk of developing dementia. The Shingrix vaccine may be even more effective at helping people live longer without dementia compared to older (and now retired) Zostavax vaccine.
What are your other recommendations or things to keep in mind for keeping our brain healthy and preventing conditions like dementia?
- Eat lots of different fruits and veggies. Besides tasting good, people who eat a variety of different fruits and vegetables experience less cognitive decline over time. We’re talking about half your plate full of veggies here!
- Get moving. 150 minutes of moderate intensity aerobic exercise per week and 2 days a week of full body resistance training. You need to get at least a little breathy (not breathless!) and resistance training does not have to mean free weights - can be body weight, resistance bands, ropes.
- Focus on getting seven to eight hours of sleep per night.
- Limit alcohol to no more than one drink per day.
- Challenge your mind. The mind needs something novel - if that means brain games, great! If you're already good at brain/word games, what about learning a different workout routine, trying a different recipe, crafting, or learning an instrument?
- Be kind. Compassion, mindfulness, and a positive outlook are huge. Meditation is great too.
- Take your mental health seriously. It’s a brave and time-worthy thing to do because you matter, you are worthy, and you deserve happiness.
- Remember that vaccines are safe, including Shingrix. If you have further questions you should speak with your health care provider or even your local pharmacist. Why leave yourself vulnerable to infections and pain? Get vaccinated!
- If you are older than 50 and received the Zostavax vaccine but not the Shingrix vaccine, you would likely be eligible for the Shingrix vaccine. I encourage you to talk to your healthcare provider or pharmacist for further details.
Learn more and find a physician or advanced practice clinician (APC)
Swedish’s Center for Healthy Aging offers comprehensive, compassionate care focused on enhancing your quality of life throughout all its stages. Our multidisciplinary team works together to create holistic, evidence-based care plans that include programs and services designed to support brain health as you age.
Whether you require an in-person visit or want to consult a doctor virtually, you have options. Contact Swedish Primary Care to schedule an appointment with a primary care provider. You can also connect virtually with your provider to review your symptoms, provide instruction and follow up as needed. And, with Swedish ExpressCare Virtual, you can receive treatment in minutes for common conditions such as colds, flu, urinary tract infections and more. You can use our provider directory to find a specialist or primary care physician near you.
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