Monthly Archives: December 2016

How to Reduce Your Dementia Risk in 2017

2017 is almost upon us, and that means it’s time for New Year’s resolutions. Many of us resolve to lose weight, quit smoking, or spend less money. However, I’d like to suggest a new resolution for you to try out this year: improving the health of your brain. Though Alzheimer’s disease and other dementias are not completely preventable, there are a variety of steps you can take to substantially reduce your risk. The younger an age you start implementing these simple lifestyle changes, the more benefits you will reap, but it’s never too late to start protecting your brain.

Tip #1: Improve Your Oral Hygiene

Nearly half of all adults in America have periodontitis, a severe form of gum disease that gradually destroys the bone sockets holding your teeth in place, resulting in tooth loss. Recent evidence suggests that the bacteria  that cause periodontitis may be able to enter the brain, and their presence has been correlated with reduced cognitive function. Protect your mouth and your brain by brushing twice per day, flossing once per day, and visiting the dentist twice per year. To read more see How Oral Hygiene Protects Your Brain From Dementia

Tip #2: Get Your Daily Dose of Vitamin D

A recent meta-analysis concluded that vitamin D deficiency is a strong risk factor for dementia. Vitamin D is not easily obtained through food, but our bodies can synthesize it when our bare skin (without sunscreen) is exposed to sunlight. The time required to meet your daily dose of vitamin D depends on your skin tone, the amount of sunlight available, and how much skin you have exposed. On a sunny summer day, 10-15 minutes is often enough. You may want to consider taking vitamin D supplements during the winter, if you live in an often-cloudy area, or if you do not go outside every day.

Tip #3: Reduce Your Risk of Diabetes

Nearly 30 million Americans (around 10% of the total population) have diabetes, and another 86 million are prediabetic. People with diabetes have an approximately 54% higher risk of Alzheimer’s disease. According to the NIH’s Diabetes Prevention Program, even people at high risk of diabetes can prevent the disease through a combination of weight loss (5-7% of your total body weight), a healthy diet, and regular exercise. The National Diabetes Education Program offers lots of great tips for transitioning to a healthier lifestyle. To read more see Alzheimer’s Disease: Diabetes of the Brain?

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The impact of dietary choices on the risk of type 2 diabetes. Source

Tip #4: Get Your Brain Health Checkup

Healthy Brains is a website created by the Cleveland Clinic Lou Ruvo Center for Brain Health. The website is centered around the six pillars of brain health: physical exercise, food/nutrition, medical health, sleep/relaxation, mental fitness, and social interaction. One of my favorite parts about the site is the Brain Health Checkup, a free quiz that takes around 20 minutes to complete. After taking the quiz, you can read personalized tips on how to improve your brain health. Click here to check it out.

 Tip #5: Get Enough Sleep

You’ve probably heard a million times about the health consequences of sleep deprivation, but did you know that it may also increase the risk of Alzheimer’s? The Baltimore Longitudinal Study on Aging found that people over the age of 70 who report little sleep or low-quality sleep have higher levels of amyloid beta (a toxic protein linked to Alzheimer’s disease) in their brains. Additionally, a 2013 study found that amyloid beta and other toxic substances can actually be flushed out of the brain during sleep.

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Age-based recommendations from the National Sleep Foundation. Source

Tip #6: Adopt the Mediterranean Diet

The Mediterranean diet is often praised for its cardiovascular benefits, but recent studies show that it’s also great for your brain. This diet, commonly consumed in places like Italy and Greece, has been linked to a reduced risk of Alzheimer’s and improved cognitive function in older adults, as well as a longer average lifespan. The Mediterranean diet is characterized by high consumption of plant-based foods including fruits, vegetables (especially leafy greens), whole grains, legumes, and nuts. Red meat and dairy are consumed no more than a few times per month, replaced instead by poultry or fish.

Tip #7: Be Socially Active

Engaging in social interactions is a great way to stimulate your brain, and having a large social network is correlated with a reduced risk of dementia. While a causal relationship is difficult to determine, social engagement has also been shown to improve overall quality of life, especially for older adults. For introverts, there are many ways to be socially active besides going out with friends. These could include adopting a pet, conversing on social media websites, volunteering, or joining a community group.

Tip #8: Get More Exercise

This one might already on your list of resolutions, but here’s one more reason to get off the couch. Studies have consistently shown that people who get regular physical exercise have a substantially lower risk of Alzheimer’s disease and other dementias. Aerobic exercise, such as walking, jogging, biking, or dancing, seem to have the biggest protective effect on brain health. The CDC recommends that adults get 2.5 hours of moderate aerobic activity or 1.25 hours of vigorous aerobic activity each week, plus at least two sessions of muscle strength training.

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The many benefits of exercise for your brain. Source

Tip #9: Protect Your Brain From Injuries

Traumatic brain injuries (TBI’s), which may be the result of contact sports, falls, or car accidents, affect nearly 1.7 million Americans each year. TBI’s, including mild injuries that do not necessarily cause a concussion, have been repeatedly linked to an increased risk of Alzheimer’s disease. TBI’s are especially damaging in children, whose brains are still in the process of developing. Minimize your risk of a TBI by wearing a helmet when playing contact sports, installing house fixtures to protect from falls, and always wearing a seatbelt while driving.

Tip #10: Never Stop Learning

Lifelong education, whether formal or informal, is vital for keeping your brain active and maintaining proper cognitive function. Formal education could include taking classes at a nearby community college or online, teaching yourself a new language, or learning to play an instrument. More informal types of mental stimulation could include reading, doing crossword puzzles, social interaction, or attending musical or theatrical performances.

 

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AlzScience’s Five Most Popular Articles of 2016

As 2016 approaches a close, it’s a good time to reflect on the past year and prepare for the next one. It’s been six months since I created AlzScience, and I have to say it’s one of the best decisions I’ve ever made. The support and feedback I’ve received for this project has been phenomenal, and I thank you all for that. This is something that I hope to continue for many years to come.

In celebration of 2016, I’ve compiled the top five most popular AlzScience articles based on total number of views. I encourage you to check them out if you weren’t able to read them the first time around. Also, if you have any topics that you would like me to write about in the upcoming year, feel free to contact me via WordPress, Facebook, or Twitter!

#1: The MEND Program Shows Promise for Reversing Cognitive Decline

#2: The Genetics of Alzheimer’s Disease

#3: Alzheimer’s Disease: Diabetes of the Brain?

#4: The Role of Metals in Alzheimer’s Disease

#5: A New Approach to Predicting Risk of Alzheimer’s Disease

 

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Could Flashing Lights Reverse Alzheimer’s Disease?

Yes, you read that title correctly: flickering lights are actually being investigated as a treatment for Alzheimer’s disease. When I first heard about this study, I was pretty skeptical of the idea that some fancy flashing lights could yield any sort of cognitive benefit. However, as strange as it sounds, this idea is based in some solid science, and it may help to shed light (pun intended) on our search for an Alzheimer’s cure.

This technique works by playing with the electrical signaling in our brains. Brain waves, more formally known as neural oscillations, are the result of rhythmic firing of neurons. A specific type of high-frequency brain waves called gamma oscillations have recently been the focus of a lot of neurological research. The function of gamma oscillations remains largely a mystery, but they’re believed to be involved with high-order brain processes such as learning and memory. Interestingly, past studies have shown that gamma oscillations are disrupted in people with Alzheimer’s disease.

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The five types of brain waves. Image Source

In a study published this week in the journal Nature, researchers sought to further investigate the link between gamma oscillations and Alzheimer’s disease. The research team, led by MIT professor Li-Huei Tsai, used a genetic mutation to simulate Alzheimer’s disease in mice. They found that these mice had reduced gamma oscillations in the hippocampus, a part of the brain associated with long-term memory. These reduced oscillations were apparent very early in the disease’s progression.

Tsai and her colleagues next wanted to know whether correcting these disrupted oscillations could help reverse the symptoms of Alzheimer’s disease. They used a technique called optogenetics to artificially induce gamma oscillations in their mice. This involves inserting a fiber-optic thread into the mice’s brains and using light pulses to stimulate neural activity.

After only one hour of induced oscillations, the hippocampi of these mice had 50% reduced levels of amyloid-beta, a toxic protein that is considered the hallmark of Alzheimer’s disease. This may have been due to a type of brain immune cell called microglia. Following the oscillatory period, the microglia in the mice’s brains became more active in clearing away clumps of harmful amyloid-beta.

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A mouse hooked up to an optogenetics apparatus. This technique allows researchers to control neural activity in real time. Image source

The next step in the experiment was to stimulate gamma oscillations using a less invasive technique. Tsai’s team exposed the mice to lights that flickered at a rate of 40 flashes per second, the same frequency as gamma oscillations. After one hour of exposure, the mice had a nearly 58% reduction of amyloid-beta in the primary visual cortex, a similar amount to what was observed with the optogenetic method. The flickering lights also reduced the accumulation of phospho-tau, another toxic protein related to Alzheimer’s disease.

So, does this mean that you should start staring at flashing lights to help stave off Alzheimer’s disease? Well, not exactly. The mice’s reductions in toxic brain proteins as a result of the flickering lights were localized only to the primary visual cortex, the part of the brain directly involved with processing visual information. Other brain areas, including the memory-controlling hippocampus, were not affected. It’s likely that other methods will need to be developed to stimulate gamma oscillations in non-visual parts of the brain.

Like any ground-breaking study, this research raises more questions than it answers. Did induction of gamma oscillations using optogenetics result in any improvement of the mice’s memory? How long do the reductions in amyloid-beta and phospho-tau persist after the stimulation is removed? How can we noninvasively induce gamma oscillations in non-visual brain regions? Would this have the same result in humans as in mice? Many of these questions are currently being investigated by Tsai’s lab and other groups of researchers. While still preliminary, this study opens up a whole new world of exciting research into the involvement of gamma oscillations in Alzheimer’s and other neurological diseases.

 

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Sniffing Out Dementia: What Your Nose Can Tell You About Your Brain

Detecting Alzheimer’s disease can be tricky, especially in its earliest stages.  Alzheimer’s is frequently misdiagnosed, due in part to the expensiveness and complexity of the current diagnostic tools. According to a 2012 examination of the National Institute on Aging’s Alzheimer’s Disease Centers, physicians may fail to detect more than 1 in 10 Alzheimer’s cases.

Alarmingly, some centers also had a false positive rate of more than 50%, meaning that half of the patients who were diagnosed with Alzheimer’s actually did not have the disease. The symptoms of these individuals may have been due to other conditions such as vascular dementia or thyroid dysfunction. An incorrect diagnosis could have resulted in the true cause of these patients’ memory loss going untreated (see Is It Really Alzheimer’s? 10 common misdiagnoses you should know about).

However, there might be a simpler and more cost-effective way to help diagnose Alzheimer’s disease: your sense of smell. As strange as it sounds, your nose can provide some key insight into the health of your brain.

Sniffing Out Dementia

Just like vision and hearing, our sense of smell tends to gradually deteriorate as we get older. Anosmia, the complete inability to smell, affects more than 50% of people over the age of 65 and 75% of people over 80. This likely contributes to the loss of appetite that many elderly people experience, as our sense of smell is closely tied to our ability to taste and enjoy food. Changes in the nose’s smell receptors and in the parts of the brain responsible for olfactory processing are likely to blame for age-related anosmia.

While anosmia is common among all elderly individuals, it seems to be especially prevalent in certain neurological conditions, including dementia. The frequency of anosmia among dementia patients has been known since the 1970s, but only recently has this observation begun to attract the attention of researchers.

The ability to identify different odors is frequently impaired in early-stage Alzheimer’s patients, with complete anosmia appearing in the later stages of the disease. A small study involving 90 patients with mild cognitive impairment found that individuals with greater olfactory impairment were more likely to progress to Alzheimer’s disease during the two-year study period. Many of these patients were unaware of their own inability to smell.

#AlzFact: Peanut butter might help identify early-stage Alzheimer’s. A small study from the University of Floria found that Alzheimer’s patients have difficulty smelling peanut butter, especially with the left nostril.

An olfactory assessment called the Pocket Smell Test has shown promise as a diagnostic tool for Alzheimer’s disease. In a small 60-patient study, this simple three-item test was able to distinguish Alzheimer’s from vascular dementia and major depressive disorder with 95% accuracy, a dramatic improvement from the 50% false-positive rate by NIA physicians that I described earlier. All of the Alzheimer’s patients in the study had two or three incorrect responses to the smell test, while nearly all of the vascular dementia and depression patients had zero or one incorrect response.

Another small study suggested that smell tests could also be used to distinguish Alzheimer’s from semantic dementia, frontotemporal dementia, and corticobasal dementia. Notably, smell tests would probably be less useful for distinguishing Alzheimer’s from Parkinson’s disease, since anosmia seems to be equally common in these two conditions. However, simple smell-detection tests could serve as an inexpensive method to improve the accuracy of Alzheimer’s diagnoses when combined with more traditional diagnostic tools.

Could Infections Be To Blame?

The reasons for the prevalence of anosmia in patients with Alzheimer’s or other dementias remain poorly understood. One interesting hypothesis, first proposed back in 1986, posits that the olfactory nerve (which transmits smell information from the nose to the brain) could serve as a potential entry point for environmental toxins or microbial agents to reach the brain. This has since been dubbed the olfactory vector hypothesis.

The brain is protected from external agents by the blood-brain barrier, which prevents most microbes and chemical substances from crossing between the nervous system and the blood. Olfactory neurons are unusual in that they are directly exposed to the external environment, making them vulnerable to infiltration. Unlike any other sensory cells, olfactory neurons connect directly to the brain without any intermediate synapses. Microbes can taken advantage of this direct connection as an ideal route to bypass the blood-brain barrier.

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Olfactory neurons (shown in yellow) serve as a direct connection between the nasal cavity and the brain. Image source

Animal studies show that the viruses that cause polio, influenza, rabies, hepatitis, and herpes are all capable of infecting the brain via the olfactory nerve. In addition, many environmental toxins including metals, chemicals, and nanoparticles can be taken up by olfactory neurons and transported to the brain. This may help explain why prolonged exposure to air pollution or certain industrial chemicals can greatly increase the risk of Alzheimer’s (see Air Pollution, Aluminum, and Vitamin D Deficiency Linked to Dementia Risk).

The olfactory vector hypothesis remains a speculative model, and more evidence is needed to prove whether infiltration of the brain by external agents via the olfactory nerve can lead to Alzheimer’s. It is an intriguing idea that certainly warrants further study.

 

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