New Marijuana Studies: Pot Hurts Your Brain

marijuana fieldBefore we start this discussion, please hear these words:  this is not about your right to smoke marijuana.  I don’t care if you spend every waking moment high as a kite, as long as you don’t operate heavy machinery or endanger anyone else.  I do not care.  That’s not my business.

However, I’m worried about your brain, because scientists are worried about it.  I also worry that some states have gotten so caught up in the political correctness of marijuana that they have fast-tracked legalizing it without fully understanding the science of what it does, and the biggest thing it does is reduce the circulation to every cell in your body, including the brain.  New studies have linked using marijuana to a higher risk of dementia, depression, and even schizophrenia.

The part of the brain that marijuana particularly seems to affect is the hippocampus, which is the same region of the brain that’s damaged in Alzheimer’s disease.  Wait a minute, hippo-what?  Let’s backtrack a minute, and:

Get to Know Your Hippocampus!

Actually, there are two of these in the brain, so technically it’s “hippocampi.”  There’s one on the right side, and one on the left, roughly over each ear, about an inch and a half inside your head.   

When you make a new memory, it happens in your hippocampus.  When you file that memory away in your brain and assign emotions to it, that happens in your hippocampus.  When you smell fresh oranges and think of that box of fruit your grandfather used to send your family at Christmas:  that happens in the hippocampus.  When you see an ad for “White Linen” perfume and think of the crush you had on your high school math teacher, who used to bathe in the stuff:  that happens… you guessed it.

Now, within the hippocampus, there are different compartments.  One handles spatial memories; in fact, when scientists studied London cab drivers, who have to commit the intricate labyrinth of 500-year-old city streets largely to memory, they found a connection to growth in the rear part of the hippocampus. 

marijuana bagsThe hippocampus is where, when you sleep, you process all the stuff you saw and felt during the day, and then you ship it off to your brain’s equivalent of the warehouse where they put the Ark of the Covenant after Indiana Jones found it – long-term memory.  The hippocampus is the triage area.  It’s short-term memory we’re talking about here, people. 

So, what happens when the hippocampus is damaged?  Well, autopsy studies of people with amnesia have shown damage to the hippocampus.  Damage here is linked to problems remembering names and events.  Dates, too. 

Is there any redundancy – a failsafe against damage, since we have two hippocampi?  Well, not exactly, because they’re specialized.  Damage to the left hippocampus can affect your ability to come up with the right words, and damage to the right can affect your ability to process visual information.

Cell degeneration in the hippocampus is connected to the onset of Alzheimer’s.   

Hold that thought.

Risk of Alzheimer’s

Marijuana causes abnormally low blood flow to virtually every part of your brain.  In a study published in the Jan. 12, 2017, issue of the Journal of Alzheimer’s Disease, scientists at Amen Clinics in California looked at the brains of more than 26,000 patients at American neuropsychiatric clinics between 1995 and 2005.  Of these, nearly 1,000 were pot smokers. 

All of the marijuana users had abnormal blood levels in the brain, particularly in the same regions of the brain affected by Alzheimer’s, namely the hippocampus.  They used SPECT imaging to show the brains of marijuana users compared to controls (people who did not smoke pot), and the difference was striking.   Every single pot smoker had “significantly lower blood flow” in the right hippocampus compared to the controls.  Even the investigators were surprised.  Lantie Elisabeth Jorandby, a psychiatrist and one of the study’s co-authors, said when the paper came out, “What struck me was not only the global reduction in blood flow in the marijuana users’ brains but that the hippocampus was the most affected region, due to its role in memory and Alzheimer’s disease.  Our research has proven that marijuana users have lower cerebral blood flow than non-users.”  The study’s authors concluded, “The most predictive region distinguishing marijuana users from healthy controls, the hippocampus, is a key target of Alzheimer’s disease pathology.  This study raises the possibility of deleterious (harmful) brain effects of marijuana use.”

In a blog post (http://www.amenclinics.com/blog/amen-research-marijuana-affects-blood-flow-brain/) the study’s authors talk about their findings.  There are also images of two brains (one from a marijuana user, and one from the control group) and it’s kind of like looking at a fresh piece of fruit vs. one that’s been in a dehydrator and put into some trail mix.  “Our research demonstrates that marijuana can have significant negative effects on brain function,” the investigators wrote.  “The media has given the general impression that marijuana is a safe recreational drug, this research directly challenges that notion.  Several studies of perfusion imaging in marijuana users have shown similar results compared to ours. A small … PET study in a sample of 12 marijuana users used a randomized clinical trial design to examine brain perfusion before and after marijuana use. The study results found frontal, temporal and occipital lobe hypo-perfusion (lower than normal blood flow) – all findings concordant with our study.”

In previous posts here at Vital Jake, we have talked about the importance of cerebrovascular health in preventing dementia.  Good blood flow to the brain is really important.  Trust me, you want good circulation up there, and there are ways to do this, which we’ve talked about in previous posts.   If you exercise and eat right and do all the things that have been proven to help reduce your risk of dementia – and then smoke pot, you might be wasting all that effort.

Risk of Schizophrenia

In a landmark report released by the National Academies of Sciences, Engineering, and Medicine, scientists said what we don’t know about marijuana “poses a public health risk.”  And yet, 28 states and Washington, D.C., have legalized marijuana for medical use, and eight states and D.C. have legalized it for recreational use. 

marijuana budThe report also said there is strong evidence to link using marijuana to the likelihood of developing schizophrenia and other causes of psychosis, with the highest risk among the most frequent users.   

The Royal College of Psychiatrists issued a statement that says, “There is growing evidence that people with serious mental illness, including depression and psychosis, are more likely to use cannabis or have used it for long periods of time in the past.  Regular use of the drug has appeared to double the risk of developing a psychotic episode or long-term schizophrenia.”

Now, you may wonder, does marijuana actually cause these problems, or are people who are prone to depression and/or schizophrenia trying to self-medicate, to find some relief of their symptoms?  That’s a reasonable question.

It appears that marijuana is more likely to be the cause than the cure.   Australian scientists followed 1,600 adolescents, aged 14 to 15, for seven years.  They found that “while children who use cannabis regularly have a significantly higher risk of depression, the opposite was not the case – children who already suffered from depression were not more likely than anyone else to use cannabis. However, adolescents who used cannabis daily were five times more likely to develop depression and anxiety in later life.”

Other studies show that the risk of schizophrenia or bipolar disorder appears to be dose-related, especially in adolescents.  Australian scientists found that adolescents who smoked pot were more likely to develop a psychotic illness, and to develop it about 2.7 years sooner, than those who did not.  These kids may also have a genetic predisposition to a psychiatric illness; so it may be that the ones who developed problems had a lower threshold for damage.  Would they have developed it without the marijuana use, however?  Nobody knows.

Risk of Depression

In another imaging study of 48 people, published in the Proceedings of the National Academy of Sciences, scientists showed that smoking marijuana increases the risk of depression, anxiety, restlessness, and other “negative” emotions.

They showed it in an interesting way, by looking at how the brains of study participants – pot smokers and controls – reacted to dopamine, the “feel-good” neurotransmitter (brain chemical) that affects your emotions, your movements, your ability to sense pleasure and pain, to learn, to pay attention, and to think.  Dopamine affects your mood, your sleep, and your memory, too.   

Dopamine is also part of your brain’s reward system.  Eat a sugary snack: get a hit of dopamine.  Do cocaine:  get a hit of dopamine. 

The ADHD drug Ritalin, a stimulant, raises the levels of dopamine in the brain, too, and this is what the researchers used in the study.

The pot smokers met the criteria for marijuana “abuse or dependence.”  That is, they smoked a lot of pot.  In personality tests and brain scans, the pot smokers had “significantly blunted” responses to dopamine compared with controls.  They were more lethargic, apathetic, anxious, and depressed.  Psychiatrist Nora Volkow said the scientists believe dopamine has a “downstream effect” in another area of the brain called the striatum, where your motivation comes from.

The study’s authors expressed their concern that “moves to legalize marijuana highlight the urgency to investigate effects of chronic marijuana in the human brain.” 

They used the word “urgency” because they are worried that people may be doing themselves significant harm.   

Here are some things to think about:

Another study from Imperial College London found that long-term pot use destroys dopamine.  Dopamine levels decline as we age, already; they also decline in Parkinson’s disease. 

People who already have a history of depression might not be ideally suited for marijuana.

People with a higher risk of stroke (high blood pressure, high cholesterol, prior heart disease, a history of TIA, or cerebrovascular disease) should not use marijuana because it will almost certainly diminish circulation even further and this could make them more likely to get dementia.

©Janet Farrar Worthington

Regular disclaimer: This is a blog. It is not an encyclopedia article or a research paper published in a peer-reviewed journal. If a relevant publication is involved in the story, I mention it. Otherwise, don’t look for a lot of citations, especially if I’m quoting from a medical professional.

,

Preventing Dementia: What You Need to Know

I’ve had a lot of requests to print a talk I recently gave. Here it is. — Janet

Recently, I took part in a large, two-day dementia seminar in Prescott, Arizona, presented by Prescott United Methodist Church for the community.  There was a full house both days; hundreds of people came, which shows that the need is great for all kinds of information about dementia. 

But with all the doctors, nurses, social workers, financial people, and other experts talking about caring for people with dementia, and caring for the caregivers, and the desperate needs for daycare, home care, and for respite care so that exhausted, stretched-to-their-limit caregivers can have a break, there was only one person who talked about preventing dementia.  I was it.  What’s wrong with this picture?

Why was I the only one?  Why aren’t very many doctors talking about this?  Why do so many patients and their families hear that there is nothing they can do?  I wasn’t there to paint an artificially rosy picture.  I know what it’s like to try to care for someone with dementia; I know what it costs, financially, physically, mentally, spiritually.  It’s happened to two people I love, and it’s heartbreaking. 

But I also know from my work as a science writer that dementia is not always inevitable, and new research has shown that even when someone has Alzheimer’s, changes in diet, sleep, and exercise may make symptoms better. 

Many people have asked for copies of my talk, so here it is.  Longtime readers of this blog will find some of this material familiar, but I’ve collected it all into one place.  I’m sharing it with you now because I want you to know that there really is hope.

* * *

I’m going to start talking about the brain via an organ I know a little bit better: the prostate.  Bear with me.

Scientists have long known that, at autopsy, many men are found to have prostate cancer that never spread, never caused a problem, and never needed to be treated. They died with it, not of it. Sometimes, diseases only show up at autopsy. Men live a good long life and never show any signs of disease, and yet, when they die, there it is under the microscope.  But the disease never got out of hand. Men died with it, not of it

I did not know, until I interviewed Dr. Richard O’Brien, that the same thing happens with Alzheimer’s. O’Brien, who was Chairman of Neurology at Johns Hopkins Bayview Medical Center, now Chairman of Neurology at Duke, told me that some people, at autopsy, have Alzheimer’s pathology. They have the telltale brain plaques and protein tangles seen in Alzheimer’s disease – but they never develop any cognitive impairment. Other people have the exact same pathology, and they die of heartbreaking dementia. Why is this?

O’Brien sees opposing forces at work in the brains of people as they age.

In Alzheimer’s, the tipping point – the game-changer, the key factor that weights the scales toward dementia – seems to be ischemic diseaseStroke, or mini-stroke. “With a given amount of Alzheimer’s disease pathology in the brain,” O’Brien told me, “there are two forces at work. One is driving you to become demented, and the other is protecting you from being demented. The biggest force that we’ve found thus far is cerebrovascular disease.”

This does not mean that everyone who has had a stroke or who has cerebrovascular disease is going to get Alzheimer’s. That’s not what he’s saying at all.

What it does suggest is that if someone has significant atherosclerosis, or has had a stroke, even if it’s asymptomatic – AND also has the plaques and tangles, that is a very powerful predictor that he or she will develop dementia.

The body has a limited capacity for insults. Stroke is an insult. Plaques are an insult. Think of a boxer who can take a lot of punches, but he can only withstand so much. The brain has a tipping point, too. O’Brien believes that “either one of these alone isn’t enough, but the two existing together in the same brain are enough to tip you over.”

Here’s some very good news:

Doctors are getting better at spotting and treating the risk factors that lead to stroke. Two recent studies found that the incidence of dementia has declined over the last 30 years. “The primary reason for that is the treatment of coexisting cardiovascular risk factors,” O’Brien says.

None of these treatments prevents the Alzheimer’s pathology from building up – but they “prevent it from becoming manifest. So you die with your plaques and tangles, but you’re still cognitively intact.”

So, what can you do to protect your brain?

One thing is Exercise. In a report published in the Annals of Internal Medicine, scientists followed about 20,000 people who took part in treadmill testing in the 1960s as part of a cardiovascular study. Today, these people are in their eighties, nineties, or are deceased. “The scientists found that the people who had been in the fittest 30 percent of that group had a dementia rate that was half that of the other people in the cohort… One of the side effects of regular exercise is a significant reduction in your risk of dementia.”

Another huge factor is cognitive reserve, and this is from education. It turns out that people who go to college tend to have more cognitive reserve than people who don’t.  If you didn’t go to college, don’t worry.  If you read and learn a lot, you are building up a cognitive reserve, too. Learning a language or playing a musical instrument, doing research for your work, or singing in a choir – basically, anything that challenges your brain, as opposed to sitting on the couch and staring passively at the TV – these have beneficial effects on your ability to think, on the brain’s ability to make neural connections.

Not being obese plays a similar role, too. Fat, especially belly fat, changes your levels of hormones. It also increases your risk of dying of cancer. Scientists are still figuring it out, but chances are good that obesity is not of great benefit to the brain.

“People with certain types of personality traits are less likely to get demented,” says O’Brien.  Wait, personality traits?

pexels-photo-156731People who are positive and upbeat seem to have some protection from dementia. Why? Well, it may be that people who are positive are more likely to educate themselves and exercise.  The good news is that positivity and resilience can be learned. You can actually become more positive by working on gratitude, being around more positive people, and being more connected to your family and community. 

Positive people may also be more likely to do crossword puzzles or sign onto Luminosity, although O’Brien doesn’t think doing a puzzle here or there is enough by itself; in other words, you probably can’t Luminosity yourself out of dementia.  Now, one study published in the New England Journal of Medicine showed that people who did crossword puzzles had a lower rate of dementia than did people who spent a lot of time watching TV. But O’Brien thinks the brains of people who choose to do crossword puzzles are different from those of people who like to watch TV. “If you forced the people who are watching TV all the time to do crossword puzzles, would they have a lower incidence of dementia? I doubt it.”

Cognitive reserve is a very robust thing, according to O’Brien. “If you look at the neurons of people with high levels of cognitive reserve, they’re pretty resistant to the toxic effects of Alzheimer’s disease pathology. They actually have bigger neurons in the key areas of the brain. Their neurons are more healthy, even if there’s a lot of Alzheimer’s disease pathology.”

And then there’s diet.

O’Brien suspects that the Mediterranean diet might have a significant effect on dementia, because it also has significant effects on cardiovascular health. “The data’s pretty clear that if you can prevent cerebrovascular disease, your chances of becoming demented are much lower.”

In 2014, scientists at UCLA published a priority research paper in the journal, Aging, that showed for the first time, memory loss being reversed.  It wasn’t because of a drug or procedure, but a comprehensive and personal approach that showed how Alzheimer’s is a complex disease, affected by diet, exercise, and even sleep.  All of these things contribute to the brain’s plasticity, said Dale Bredesen, the study’s principal investigator.  Ten people with memory loss, some with brain scan-confirmed patterns of Alzheimer’s, participated in a small study called MEND, for Metabolic Enhancement for NeuroDegeneration.

The participants made dramatic lifestyle changes.  They avoided simple carbs, gluten, and processed foods.  They ate more fish, did yoga, and meditated.  If they didn’t sleep well, they took melatonin.  They took vitamin B-12, vitamin D-3, and fish oil.  Within 6 months, 9 patients had a noticeable improvement in memory.  One patient, who was in the late stages of Alzheimer’s, did not show improvement, so there may be a point at which it’s too late.  But these findings suggest that at least early on, changing your metabolism can improve your cognitive function. 

Six of the people in the study who’d had to quit working were able to return to their jobs.  Some patients were followed up to two and a half years, and the memory improvements remained.  Larger studies are under way.

Let’s come back to exercise.

300_200_walk_gravelA study led by scientists from the University of Maryland School of Public Health, published in the Journal of Alzheimer‘s Disease, found that just 12 weeks of moderate exercise – basically, walking fast enough on a treadmill to get your heart rate up, but not so much that you couldn’t carry on a conversation with someone else while you did it – made a difference in how people’s brains functioned.

It made their brains work better; their neurons were more efficient. People could remember things more easily, and their brains didn’t have to work as hard to do it.

Scientist, J. Carson Smith, of the University of Maryland’s Neuroimaging Center, and said, “No study has shown that a drug can do what we showed is possible with exercise.”

The people in the study weren’t spring chickens, either. They ranged in age from 60 to 88. They weren’t athletes – far from it; they were considered “physically inactive older adults.” Some had already shown mild cognitive impairment. The people in both groups – those with the mild impairment and those with healthy brain function – improved their cardiovascular fitness by about 10 percent in the three months of the program.

They also improved their memory. MRI brain scans taken before and after the study showed “a significant improvement in 11 brain regions.” Even more exciting, the places in the brain that got better are the same ones that are affected in Alzheimer’s – the precuneus region, the temporal lobe, and the parahippocampal gyrus. Their word recall – remembering as many as possible out of a list of 15 words – improved.

What does this mean for you? It means that, whatever age you are, you can make your brain work better even with a small amount of effort. You don’t have to be in marathon-running shape. You don’t have to go grunt and sweat and dead-lift huge weights. Just walk for two and a half hours a week – 30 minutes a day, five days a week. If you don’t have 30 minutes, do it twice for 15 minutes. Any effort is going to pay off.

Other Things:

Prevent frailty. Frailty is your enemy.  But O’Brien says:  “I don’t think that falling apart when you get old is something that has to happen.”

Recently, Johns Hopkins geriatrician Jeremy Walston looked at what healthy older people have in common — at what they eat and don’t eat, and how they live – and came up with some practical tips. 

Nutrition:  Make Every Bite Count

If you do it right, just about everything you eat can help your body.  This doesn’t mean you have to eat just nuts and berries or be a food martyr who never eats comfort food.  What does it mean?

Eat Fresh Fruits and Veggies

grilled veggiesI know, duh.  Who doesn’t know that fresh fruits and vegetables are good for you?  But what’s in them matters, too. Walston says potassium is important, and “Fresh fruits and vegetables are rich in potassium.” 

When you get your blood pressure tested, it’s a fraction, one number over another.  That top number is systolic blood pressure, and potassium can lower it by several points.  It also helps regulate the heart rhythm.  If you are eating foods rich in potassium, this also means you’re not loading up on saturated fat, and this will help lower your cholesterol.

Get More Protein

As we get older, we need more protein.  “Protein helps muscles function better, and it is also important to help maintain muscle mass.” You don’t have to spend big bucks; you can get salmon in a can, or yogurt, or eggs, or an energy bar. Epic Bars are good sources of meat protein when you’re on the go.

Get Plenty of Vitamin D

Vitamin D helps keep your bones strong.  It also helps keep your muscles, heart, brain and immune system healthy, and can help prevent cancer.  Having low levels of Vitamin D is bad: A study published in the Archives of Internal Medicine found that people with the lowest levels of Vitamin D had more then twice the risk of dying from heart disease as people with higher levels.  You can get it from sunlight, 20 minutes a day twice a week or so, or in a supplement.  The National Institutes of Health recommends 600 international units of Vitamin D a day if you’re under 70, and 800 IU a day if you’re over 70.

Get your shots

Lower your risk of getting the flu, or pneumonia, or shingles by getting a shot. Anything you can do to prevent being laid up is a good thing. 

Keep Moving

My husband, Mark Worthington, is a gastroenterologist, and he tells me that many of the older people he sees fall into two categories.  He always asks them what they do, and some will say, “We volunteer, we hike, we love to go out to dinner with our friends.”  Others basically do nothing.  All day.  Not good.  These people tend not to do as well.

Jeremy Walston says, “Stay active as long as possible.  Don’t sit for long periods of time, especially in the late afternoon or evening.  Studies show that those are low-activity times for many people, so it’s good to try to boost your activity during those times.”  Go for a walk after dinner.  Walking is good; in fact, you should walk a lot, or do some aerobic activity – there’s plenty to choose from. 

“It’s also important to do exercises that help you stay flexible, that help your balance and gait, and that help strengthen your muscles.  Don’t forget your shoulders,” which are important for maintaining core body strength and higher levels of function.  And if you have an “orthopedic issue,” like knee or hip trouble, address it, so you can keep moving as long as possible.”

However: 

Don’t Fall

Falling is bad.  The body literally takes a hit when you fall.  Many older people, who otherwise have been doing pretty well, take a turn for the worse after a fall.  Just being laid up for a few days can be difficult for the elderly because they tend to lose strength quickly.  The best way not to fall is to prevent it, says Walston.  “Things that can make you fall include: not watching your medication; vision problems; weakness in the lower extremities; and balance and gait problems.” 

One huge risk factor is easy to fix:  “low lighting and a cluttered living area.”  Make sure your rooms are well lit – that you not only have enough lights, but that the bulbs are high-powered enough so you can see where you’re going.  And go after the clutter.  It doesn’t take much – maybe a stack of books or magazines that slips over, a puzzle left by a grandchild on the floor, or pet toys – to make a walkway treacherous.  Sometimes, you’re so used to looking at clutter that you don’t see it.  This is why Walston recommends bringing in a friend or relative who is not used to your home, who can see potential trouble spots you haven’t noticed.

A personal note: When my aunt, who had dementia caused by a stroke, had to go to the nursing home, we asked what we could bring for her room.  They said:  Only one thing, because clutter makes demented people more agitated.  I figure, if demented people are the canary in the coal mine, and clutter stresses them out a lot, it most likely stresses us out, too, on a low level.  So not only can you trip on it, clutter agitates.

You can lower the odds of falling by working on your balance.  Tai Chi is a great way to do this, and so is yoga. 

What else?

“Cognitive risk factors include diabetes, elevated lipids, and high blood pressure,” says Walston.  Medications can keep all of these problems in check, which will help your blood vessels, which will help your brain.

Poor hearing:  If you don’t feel connected, you may tend to withdraw from the conversation, smiling politely, not engaging, because you don’t know what people are saying.  This is bad.  “Get a hearing aid if you need one.”  It won’t just help your hearing; it will help your brain.  There’s a feedback loop: When you stay connected, you are giving of yourself, talking and listening, and that stimulates your brain. When you don’t hear, you just sit there and don’t participate, you’re not getting that stimulation, and if you don’t use your brain as much as possible, you may lose function.

Depression:  If you are depressed, you are going to be withdrawn, you may not eat or sleep very well, and you may not get enough exercise.  Treating it is good “cognitive protection,” says Walston. 

Finally, Stay connected.  Talking to people — volunteering, driving, interacting with others in church, clubs, or other groups, being around family or friends – protects your brain.

©Janet Farrar Worthington

Regular disclaimer: This is a blog. It is not an encyclopedia article or a research paper published in a peer-reviewed journal. If a relevant publication is involved in the story, I mention it. Otherwise, don’t look for a lot of citations, especially if I’m quoting from a medical professional.

Exercise and Alzheimer’s – Part 2

Darth Vader BoxingI’m going to talk about the brain via an organ I know a little bit better: the prostate.

Bear with me.

Scientists have long known that, at autopsy, many men are found to have prostate cancer that never spread, never caused a problem, and never needed to be treated. They died with it, not of it. Why that is, is the subject of future posts, but trust me on this. Sometimes, diseases only show up at autopsy. People live a good long life and never show any signs of trouble, and yet, when they die, there it is under the microscope. For whatever reason, the disease never got out of hand. People died with it, not of it.

I did not know, until I interviewed Richard O’Brien, M.D., Ph.D., for an article for Breakthrough,  http://www.hopkinsmedicine.org/innovative/research/newsletter.html a publication of the Johns Hopkins Center for Innovative Medicine, that the same thing happens with Alzheimer’s. O’Brien, who was Chairman of Neurology at Johns Hopkins Bayview Medical Center, now Chairman of the Department of Neurology at Duke University School of Medicine, told me that some people, at autopsy, have Alzheimer’s pathology. They have the telltale brain plaques and protein tangles seen in Alzheimer’s disease – but they never develop any cognitive impairment. Other people have the exact same pathology, and they die of heartbreaking dementia. Why is this?

O’Brien sees opposing forces at work in the brains of people as they age. Think of the good Anakin Skywalker, still a part of the bad Darth Vader: a light-saber fight, now tilting toward the good side, now toward the dark side. Eventually, the good tips the balance, and Darth Vader dies on the good side, after having done a very helpful deed.

Well, in Alzheimer’s, the tipping point – the game-changer, the key factor that weights the scales toward dementia – seems to be ischemic disease. Stroke, or mini-stroke. “With a given amount of Alzheimer’s disease pathology in the brain,” O’Brien told me, “there are two forces at work. One is driving you to become demented, and the other is protecting you from being demented. The biggest force that we’ve found thus far is cerebrovascular disease.”

Note: This does not mean that every man who has had a stroke or who has cerebrovascular disease is going to get Alzheimer’s. That’s not what he’s saying at all. What it does suggest is that if a man has significant atherosclerosis, or if he has had a stroke, even if it’s asymptomatic – AND he has the plaques and tangles, that is a very powerful predictor that he will develop dementia.

The body has a limited capacity for what scientists call “insults.” Stroke is an insult. Plaques are an insult. Think of a boxer who can take a lot of punches, but he can only withstand so much. The brain has a tipping point, too. O’Brien believes that “either one of these alone isn’t enough, but the two existing together in the same brain are enough to tip you over.”

But there is very good news here:
Doctors are getting better at spotting and treating the risk factors that lead to stroke. In fact, two studies published last year found that the incidence of dementia has declined over the last 30 years. “The primary reason for that is the treatment of coexisting cardiovascular risk factors,” O’Brien said. He cautions that none of these treatments prevents the Alzheimer’s pathology from building up – but they “prevent it from becoming manifest. So you die with your plaques and tangles, but you’re still cognitively intact.”

So, what can you do to protect your brain? A huge one is exercise. The choices that we make today can help influence our risk of dementia later. In a report published in the Annals of Internal Medicine, scientists followed up on about 20,000 people who took part in treadmill testing in the 1960s as part of a cardiovascular study. Today, these people are in their eighties, nineties, or are deceased. “By searching the Medicare records for dementia diagnoses,” said O’Brien, the scientists “found that the people who had been in the fittest 30 percent of that group had a dementia rate that was half that of the other people in the cohort,” which confirms that “one of the side effects of regular exercise is a significant reduction in your risk of dementia.”

Another huge factor is cognitive reserve, and this is from education. It turns out that people who go to college tend to have more cognitive reserve than people who don’t. Note: I would imagine, although it hasn’t yet been proven, that if you haven’t been to college but you read and learn a lot, you are building up a cognitive reserve, as well. Learning a language or playing a musical instrument, doing research for your work, or singing in a choir – basically, anything that challenges your brain, as opposed to sitting on the couch and staring passively at the TV – all of these things have been shown to have beneficial effects on your ability to think, on the brain’s ability to make neural connections inside itself.

“All things being equal, people who go to college are much less likely to get demented,” O’Brien says, “people who are very fit are much less likely to get demented.” And there’s a third thing – “People with certain types of personality traits are less likely to get demented. Our latest data suggest that obesity is playing a similar role, too.” We already know (see my previous post on Low T) that fat, especially belly fat, changes your levels of hormones. What else does it do? Scientists are still figuring that out, but chances are good that obesity is not of great benefit to the brain.

Personality traits?
People who are positive and upbeat seem to have some protection from dementia. Again, why this is, is uncertain. It may be that people who are positive are more likely to educate themselves and exercise. They may also be more likely to do crossword puzzles or sign onto Luminosity, although O’Brien said he doesn’t think doing a puzzle here or there is enough by itself. One study published in the New England Journal of Medicine showed that people who did crossword puzzles had a lower rate of dementia than did people who spent a lot of time watching TV. But, O’Brien noted, this might be because the brains of people who choose to do crossword puzzles are very different from those of people who like to watch TV. “If you forced the people who are watching TV all the time to do crossword puzzles, would they have a lower incidence of dementia? I doubt it.”

Cognitive reserve is a very robust thing, according to O’Brien. “If you look at the neurons of people with high levels of cognitive reserve, they’re pretty resistant to the toxic effects of Alzheimer’s disease pathology. They actually have bigger neurons in the key areas of the brain. Their neurons are more healthy, even though there’s a lot of Alzheimer’s disease pathology.”

And finally, there is diet. O’Brien suspects that the Mediterranean diet might also have a significant effect on dementia, because it also has significant effects on cardiovascular health. “The data’s pretty clear that if you can prevent cerebrovascular disease, your chances of becoming demented are much lower.”

 

©Janet Farrar Worthington

Regular disclaimer:  This is a blog.  It is not an encyclopedia article or a research paper published in a peer-reviewed journal. If a relevant publication is involved in the story, I mention it. Otherwise, don’t look for a lot of citations, especially if I’m quoting from a medical professional. 

Can Exercise Reduce Your Alzheimer’s Risk? – Part 1

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Part one of a two-part discussion of exercise and Alzheimer’s.

I’m not one for guilt trips. Mainly, because guilt backfires. If you were my dad, or brother, uncle, grandfather, or son and I were to try to guilt you into doing something that you already know needs to happen, like exercise, you might make a few grudging trips to the gym, but you might also resent it, and me, and wish I would shut the heck up. I would, and do, feel the same way when somebody does that to me.

So, this isn’t about guilt.

Instead, it’s some really positive findings that have to do with Alzheimer’s disease. A couple of years ago, a study led by scientists from the University of Maryland School of Public Health, published in the Journal of Alzheimers Disease, found that just 12 weeks of moderate exercise – basically, this means walking fast enough on a treadmill to get your heart rate up, but not so much that you couldn’t carry on a conversation with someone else while you did it – made a difference in how people’s brains functioned. It made their brains work better; their neurons, or nerve cells in the brain, were more efficient. People could remember things more easily, and their brains didn’t have to work as hard to do it.

Just 12 weeks of moderate exercise causes your brain to work better.

The lead scientist, J. Carson Smith, of the University of Maryland’s Neuroimaging Center, and said at the time, “No study has shown that a drug can do what we showed is possible with exercise.” The people in the study weren’t spring chickens, either. They ranged in age from 60 to 88. They weren’t athletes – far from it; they were considered “physically inactive older adults.” Some of them had already shown some mild cognitive impairment, which suggests that they had a higher risk of getting Alzheimer’s. The people in both groups – those with the mild impairment and those with healthy brain function – improved their cardiovascular fitness by about 10 percent in the three months of the program.

They also improved their memory. MRI brain scans taken before and after the study showed “a significant decrease in the intensity of brain activation in 11 brain regions” while the oldsters did tasks including identifying famous people from back in their day – heart throbs like Frank Sinatra, for instance. Even more exciting, the places in the brain that got better are the same ones that are affected when some one has Alzheimer’s disease – the precuneus region, the temporal lobe, and the parahippocampal gyrus. Their word recall – remembering as many as possible out of a list of 15 words – got better, too, and Smith called this improvement “a very big step in the right direction.” In their paper, the scientists concluded that larger studies are needed to see if exercise can actually delay or slow the progression of Alzheimers disease.

What does this mean for you? It means that, whatever age you are, you can make your brain work better even with a fairly pitiful amount of effort. You don’t have to be in marathon-running shape. You don t have to go grunt and sweat and dead-lift huge weights and then drop them in an attention-getting way. Just walk for two and a half hours a week – 30 minutes a day, five days a week. If you don’t have 30 minutes, do it twice for 15 minutes. I don’t know if the results will be exactly the same, but I truly believe that this evidence shows that any effort is going to pay off. No guilt required.

 

©Janet Farrar Worthington

Regular disclaimer:  This is a blog.  It is not an encyclopedia article or a research paper published in a peer-reviewed journal. If a relevant publication is involved in the story, I mention it. Otherwise, don’t look for a lot of citations, especially if I’m quoting from a medical professional.