Scientists Say These 5 Things Prevent Dementia (Do Them Now)

If you're like me, as you start getting into your  40s, your 50s, your 60s, you start to worry about   the prospect of dementia later in life. And  we often think of this in fatalistic terms.    If my grandmother got it and my father got it,  then that's it. I'm probably going to get it.    And I remember thinking more along those lines  myself, but reading the scientific research has   completely changed how I think of dementia. The  Lancet Commission on Dementia reported that 45%,   nearly half of all dementia cases worldwide can  be prevented with specific modifiable factors,   not genetic destiny, not bad luck, things that  you can actually change. And in 2024, they added   two new factors that they think have gathered  enough evidence to justify being put on the list.    And most people are not being told about this. So,  we're going to go through all of that. Now, the   reason I make these videos is most of the content  out there on this topic is not that helpful.    They're either trying to sell you a supplement  or scare you or giving you silly lists of five   foods that are going to change your brain today. I  think we all know that's not how this works. Yes,   food and diet matters. We're going to talk about  that in a minute, but you want to get the full   picture. So, we'll go over the key risk factors  that matter most for you specifically. Obviously,   we can't go back in time. We can't change the  education we got as kids. We can't change our   genetics. And those things matter. We're not going  to pretend they don't. But if you're watching this   video, chances are you're in your 40s, 50s, 60s,  and that's exactly when we have the most power to   change our future. The window of time you're in  right now. So, we'll focus on five risk factors   that are modifiable and that are more surprising.   There are some other things on that list that we   already know like smoking, alcohol, obesity. We're  not going to spend too much time on those. We'll   focus on five factors that are less well-known and  that you have the power to change today. and we'll   go over a landmark trial that surprised a lot of  people, surprised even us scientists, and that   directly contradicts what a lot of people believe  about dementia. And we'll wrap up with the one   thing I would prioritize above all else if I could  give you just one action from this whole video.    So, here's the first factor. Most people when they  think of dementia think of things in the brain,   amyloid plaques, tau protein, something going  wrong inside your skull. And that's not wrong,   but it's incomplete. Your brain accounts for only  2% of your body weight, but 20% of your blood   flow. It just guzzles energy. And so if the little  blood vessels that feed your brain are damaged,

brain cells can't get the nutrients and the oxygen  they need. When your blood pressure is too high,   and I'm talking about a sustained elevation,  right? Hypertension, not a one-time high value   at the doctor's office, your blood vessels are  damaged over time and plaque builds faster.    This is the exact same process that narrows your  coronary arteries and can lead to a heart attack.    Except here it's the arteries that feed the brain.   And so the neurons, the brain cells that depend on   that blood flow, they start to starve. And you  might notice some differences. You might notice   that you're getting more forgetful, but at first  you dismiss that as normal aging. But that is   not normal aging. That is vascular injury that  accumulates over years. Untreated hypertension   during midlife is one of the scariest risk factors  for dementia precisely because it happens under   the surface while we feel just fine. So here's  what that means for you personally. If your   blood pressure has been running high throughout  your 40s, 50s, 60s, you're not just at higher   risk of a heart attack or a stroke. you're also  opening the door to dementia later in life. Okay,   so how do we fix it? Number one, know your  numbers. Blood pressure is a simple measurement   and it's one of the most modifiable risk factors  on this list. And we got a whole video on tips   to lower blood pressure, the best foods, the best  workouts. So I'll link that in the end. Now, the   next factor surprises a lot of people because it's  got nothing to do with blood vessels and we often   don't connect it to dementia and that's losing  your hearing or losing your vision. In fact,

hearing loss is one of the strongest risk factors  on the whole Lancet list. When you're hearing   worsens, your brain has to work harder. It has  to allocate resources just to fill in the gaps,   just to try to understand what people are saying.   And that means fewer resources left for other   tasks like memory or decision-m or whatever  else. So, you're not just losing your hearing,   you're also losing cognitive reserves that you're  going to need later in life. And hearing loss   leads to social withdrawal. People stop going  to parties, stop going to dinners because it's   exhausting and it's embarrassing. You can't  follow a conversation and so people isolate and   social isolation is its own factor on the list and  we'll come to that in a minute. So that's why they   consider hearing loss one of the strongest factors  on the list. It has multiple pathways leading to   dementia. On a personal note, my own mother has  lost a lot of hearing over the years. And so I   made sure to get her really high quality hearing  aid precisely because I was worried about this   prospect of dementia. And the truth is it's made  a huge difference. It's a lot easier for her to   communicate with me, with everybody else. So she  ends up being much more social with the device.    So, if you notice any hearing loss, even if you're  still relatively young, I recommend getting a full   hearing assessment from an audiologist. And  these tests, a lot of times they are free.    You can get them at many different centers. And  then we have the other side of the sensory loss,   which is vision loss, where you start to struggle  to read, to use a cell phone, to watch a movie,   to watch TV. So, you're shut out from a lot of the  world and a lot of learning sources. Vision loss   was one of the two new factors that the Lancet  Commission added to the list in 2024, and we'll   look at the other one in a second. Now, the next  factor doesn't require any equipment or test, but   it's the most emotionally difficult on this whole  list. Social isolation. Chronic loneliness is

associated with higher cortisol levels. Cortisol  is your stress hormone and cortisol is toxic for   your hippocampus, the region of your brain that  plays a central role in memory formation. So   the hippocampus is literally shrinking under that  consistent stress of social isolation. And to make   matters worse, socially isolated people are less  likely to eat well, to exercise, to seek medical   care. So everything tends to get worse. If you're  watching this and you or someone else in your life   has become more isolated over the years, maybe  you retired or spouse passed away or kids grew up,   moved to a different country. This is important.   The cognitive damage from that isolation is very   real, but the recovery from reconnecting is also  real. So, it's not too late. Just start simple.    Give someone you haven't talked to in a while  a phone call. This is something I'm working   on myself. Sometimes I just work too much and  I forget to socialize. So, I carve out time,   make sure I give someone a phone call or go  grab coffee or go to an exhibit or whatever   because this is important. Now, I know we're  going over a lot of information. So, let's talk   about a landmark trial that ties a lot of this  together and that might change your social habits,   maybe your eating habits, and then we'll wrap up  with the one thing you can do today. Remember that   landmark trial I mentioned in the beginning of the  video. Well, they actually used social activity.    They included that in their intervention. So,  let's talk about it because it has changed how   we think about preventing dementia. So this was  a randomized trial conducted in Finland with over

1,200 participants aged 60 to 77 all at risk of  cognitive decline, all at risk of dementia. The   participants were split randomly. Half of them  received general health advice, just standard of   care. The other half went through an extensive  program with five components. Healthy diet,   similar to a traditional Mediterranean diet, high  in fruits and vegetables, whole grains, limiting   added sugars and alcohol, moderate in salt, and  favoring healthy fats. Fish a couple times a week,   and they used canola oil, which is more popular  in the north of Europe as opposed to olive oil,   which is more popular in the south. Then they had  an exercise component, which included both cardio   and strength training. Third was a cognitive  training component. So some memory exercises,   some reasoning exercises as well. Fourth was  social activity as you said. So they made sure   the participants had regular meetings where they  interacted with each other to make sure they were   exercising that social muscle as well. And the  final component, the fifth component was managing   their health parameters. So they met with a nurse  and a doctor and they had their blood pressure,   their BMI, their waist circumference measured and  they also got some advice to improve on those.    After 2 years on the program, their cognitive  performance improved 25% more than the control   group that just got the general health advice.   And these gains were especially clear in two   specific domains. Executive function, which is  the ability to plan, to focus, to make decisions,   that improved 83% more than the controls.   And processing speed, which is the ability   to receive information and respond to it quickly  in real time, that improved by 150% more than the   controls. And the cool thing about this trial is  they kept following the participants years after   the trial was officially over. And five years  later, five years after the trial wrapped up,   they still saw a difference, still saw an  advantage cognitively for the folks that went   through the program. And when they compared the  folks that stuck the best to the advice, the best   adherent to the worst adherent during the trial,  they saw a difference, an advantage up to 9 years   after the end of the trial. So very interesting  results. Now, all of this is impressive,   but the part that surprised people the most was  when the investigators looked at participants with   different genetics because those data directly  contradict how a lot of people think and what a   lot of people believe about dementia. So, we're  going to look at that in detail next. First,   I just want to acknowledge some limitations  of this trial real quick because in science,   we want to look at the strongest evidence, but  we also want to acknowledge areas of uncertainty.    First, remember that the trial changed a lot of  different things, right? Diet and exercise and   social activity. So, we don't really know which  component or which combination of components   deliver the results. The trial can't tell us that.   Just that the full program seem beneficial. Also,   dementia typically develops over long time spans,  many years, decades even. So, a trial that lasts   two years, even with that followup, always leaves  some question marks. as far as long term. All of   that said, really interesting, really encouraging  results from this trial that show that we can   change how our brain works, our cognitive capacity  pretty quickly over a couple of years just with   habits that are achievable by most people. Now,  the scientists asked, does this still work even   for people who have a higher risk of dementia?   Carriers of the APOE4 gene, they have a higher   risk of developing Alzheimer's. So, does this type  of intervention still work for those folks? Now,   this is what we call an exploratory analysis. It's  not part of the original trial. So, we have to be   a little cautious with these results, but it still  provides interesting information. And not only did   the intervention work for those folks, there was  actually a trend towards a stronger improvement in   that group. So, this is really worth taking  a second and thinking about because it goes   directly against what a lot of people believe  about dementia. Having bad genetics, having a   rough family history doesn't mean our fate is  sealed. It doesn't mean we throw up our hands,   right? If anything, it makes these habits even  more important. So, this trial really made a   dent in the field because we're now beyond just  correlations. This is an intervention. Changing   our lifestyle affects not just our physical health  but also our brain health. Okay, but let's go back   to the five factors because there are two that  we haven't covered yet. Your blood sugar level

affects your heart, affects your kidneys, but it  also affects your brain. When your blood sugar is   consistently high, like we see in people with  diabetes, for example, that excess glucose in   your blood binds to different molecules and causes  glycation. It causes damage of your blood vessels   and the small vessels that feed the brain are  especially sensitive to this. So here's what that   means for you and your body. You want to know your  hemoglobin A1C, also known as glycated hemoglobin.    This is a three-month average of your blood  sugar levels. And so if your hemoglobin A1C is   consistently elevated, those small blood vessels  feeding your brain are being damaged. silently   without you noticing anything. So, you want to  make some changes. In fact, before you're in   the diabetes range, if it's over 5. 7% hemoglobin  A1C, you're in pre-diabetes range. And it's worth   making some changes before things deteriorate  further. We also have a whole video on lowering   hemoglobin A1C with healthy habits, with best  foods and everything. So, I'll link that in the   end as well. Now, let's look at the last factor  and this is another one, this is the second one   that was added in 2024 by the Lancet Commission.   Plaque in our arteries is caused by these   microscopic little particles that float around in  our blood. And scientists sometimes use a blood

test called LDL or LDL cholesterol to estimate the  number of these particles in our bloodstream. It's   not the cleanest metric. It's pretty imperfect,  but it's often used because most people have   gotten their LDL cholesterol measured a bunch of  times. So, in 2024, the Lancet Commission added   high LDL cholesterol to their list of risk factors  for dementia. This is not about diet debates,   diet wars. People who have more of these particles  in circulation, whether it's diet induced or   genetically induced, have more plaque. So the  arteries supplying the brain tend to narrow and   it causes vascular dementia. And the good news  is this process is completely preventable and we   know how to do it using the exact same tools that  stop heart disease. If you've never gotten a full   lipid panel, I recommend doing that. Getting not  just the LDL cholesterol and triglycerides, but   also getting your apoB and your Lp(a) measured.   Those two values are more reliable. They're more   accurate representations of your risk of heart  disease than your LDL cholesterol. So when in   doubt, I recommend looking at those. I check  these metrics myself and for my family members,   I measure apoB. I measure Lp(a). I measure  hemoglobin A1C. I respect these metrics   because the evidence overwhelmingly supports their  importance and because we have the power to change   them, we can change our future. And that brings  us to the last section here. And the single most   important thing I want you to take away from this  entire video. Everything we know about dementia   and preventing dementia was perfectly summed up  by the scientist who oversaw that landmark trial   we talked about. Professor Miia Kivipelto of the  Karolinska Institute in Stockholm, Sweden. She   said, "What is good for your heart is also good  for your brain. " So, I'm going to share with you   what I personally do to avoid dementia, and then  we'll wrap up with an actionable plan that you   can implement today. I check my blood pressure  regularly. I have a device at home. I look at it

maybe a couple times a month. That's better than  having it measured once a year at the doctor's   office, which sometimes is unreliable. We have  a whole video on how to measure blood pressure   properly at home or not and all the mistakes  that people often make, including doctors. So,   I'll link that in the description. I make sure to  exercise most days. I often don't feel like going,   not going to lie to you. But, I push myself and  I end up going 3 to 5 days a week. I've never   regretted going to the gym. I only regret the  workouts I miss. I do some cardio and I also do   weights at the gym. I remember when I was in grad  school working towards my PhD reading something   that really blew my mind that physical activity  is actually more powerful to prevent dementia than   brain activity. Obviously, you want to do both,  but physical activity is actually more powerful   for brain health than brain activity, right? The  puzzles are learning something. So, that's kind   of mind-blowing. I also realized recently that I  wasn't doing much cardio at the gym because it's   boring to run on a treadmill staring at a wall.   So, I started going for walks first thing, 15,   20 minute walk around the neighborhood. And I do  that almost every day. And I also just bought a   bike recently. So, I'm going to start doing more  bike rides as well. I'm pretty careful about my   diet. It's not fundamentally different from the  diet they used in that trial. Pretty similar   on the basics. I get blood work as I said  every so often, maybe a couple times a year,   I look at ApoB, lp(a) once, you don't need to  measure that one all the time, fasting glucose,   hemoglobin A1C. There's many others but I would  say those are the main ones. I also decided I'm   going to get my hearing assessed soon, at my age  most people don't worry about it but I'll go in,   I'll take the free test, if it's normal great,  good news. Now there's one part that's easy for me   and one part that's harder. Cognitive training is  naturally embedded into my life. Reading studies,   interpreting, even my hobbies are nerdy. I like  to play chess. I love to read. I like to study   Japanese. So, the cognitive training is naturally  there. I don't need to worry too much about that.    And social interaction, as we said, I would  say that's my weak spot right now out of all   the factors. So, I make a conscious effort to fit  that in because it's important. This is the key,   guys. those consistent, not flashy, boring, but  evidence-based habits that are really going to   deliver the goods in the long run. So, let's wrap  up with a specific action plan. This is what I   would tell a family member who asked me for one  thing above all else that he or she can do today.    Start with your cardiovascular risk factors.   Blood pressure, blood sugar or hemoglobin A1C,

and cholesterol/ ApoB. Not because everything  else doesn't matter, but because these three are   measurable, they're modifiable, and the evidence  linking them to dementia is very strong. And next,   you can add regular exercise. Even a daily  walk can be a pretty good start. That's it.    That's the daily plan. You want to start simple.   Everything else we covered absolutely matters,   but this is the entry point. Get tested, know  your numbers, start working on fixing those. And   we got videos on each of those aspects. I'll link  the one on lowering hemoglobin A1C on the screen   here in a second. The others, how to lower ApoB,  how to lower blood pressure, I'll link below. If   you have a parent in their 60s, in their 70s, or  someone who would benefit from this information,   please share it with them. We don't sell anything.   We don't sell supplements, programs. We turn down   every sponsor. The only thing we care about is  that this information gets to the people who need   it. Here's that video on the best foods to lower  hemoglobin A1C. I'll meet you in there. Take care.