Retail has bought as much GLD in 2025 as in the previous 5 years.
ZeroHedge
4. Open AI vs. Historical Young Start Up Cash Burners
Jim Reid Deutsche Bank On the subject of ChatGPT, it’s been eye-opening to read of the predicted losses that OpenAI will likely experience in the next few years. Based on a Wall Street Journal report, which cited company projections provided to investors over the summer, OpenAI forecasts revenue of $345 billion between 2024 and 2029. Assuming this is all cash, we then calculate $488bn of spending, mainly to pay for access to compute, to arrive at their projected cumulative free cash flow of $143bn. And that was before the most recent announcements of $1.4 trillion in data centre commitments. A broker has more recently said the cash burn could exceed $200bn by 2030.
I thought it would be interesting to look at the largest cumulative losses in history from a young company or a start-up before they turned in a profit. So I asked ChatGPT to give me a table of these companies, detailing the total losses and over which years. We used this to create today’s CoTD. We added in OpenAI’s expected cash burn and also included its rival Anthropic, also using data from the Journal. I double-checked the historic numbers against Bloomberg data and they were broadly in line.
ChatGPT also pointed out that some companies had reported larger annual losses, citing AOL Time Warner’s $99 billion loss in 2002 and a similar size loss for AIG in 2008. Meanwhile, Fannie Mae and Freddie Mac lost $77bn and $59bn respectively within only three quarters when the GFC struck. However, these were well established companies with long track records of profitability before huge troubles hit.
5. Mag 7 Outperforms QQQ and SPY 9 of Last 10 Years
Koyfin
6. Quality Stock Factor Underperforming 2025
Quality Underperformance…BofA noted, Globally, the Quality style has underperformed by 5.5% YTD, and the Global Steady Compounders have experienced the worst 12-month relative return in 25 years. 3 reasons stand out. Firstly, the global earnings cycle is improving, and earnings stable Quality stocks tend to lag in upturns. Secondly, the Risk style – almost the opposite of Quality – has had one of the best years on record. Thirdly, a few themes have driven market performance this year (including AI, Defense, Gold, Rare Earth, Nuclear Energy, and Quantum Computing) and these stocks have a high average beta (1.28).
Zachary Goldberg-Jefferies
7. American Eagle Stock One Tick from New Highs
StockCharts
8. Japanese Government Bond Yields Highest in 20 Years
Mohamed A. El-Erian
9. International Stocks on Track for First Outperformance vs. U.S. in 16 Years
If you randomly picked a trading day for the Dow Jones Industrial Average between 1930-2020, there is over a 95% chance that the Dow would close lower on some trading day in the future. That means that roughly 1 in 20 trading days would provide you with an absolute bargain. The other 19 would give you the feeling of buyer’s remorse at some point in the future. Link
More than 10 funds will distribute at least 25% in capital gains this year. Link
Since the 1990s, the World Portfolio has grown from 75% to over 200% of world GDP. Link
Of the largest 10 stocks in the S&P 500 Index in 1985, none are still in the top 10.Link
The Thiel Fellowship has a 5.9% Unicorn hit rate. Link
Just 3% of companies generated all the shareholder wealth in the US stock market from 1926-2022. Source: Bessembinder
If you break down the distribution of cumulative returns for stocks in the S&P 500 for the past 25 years:
The median/arithmetic return was 59%/452%.
The average return has been greater than the median for The S&P 500’s constituents in 20 out of the past 24 years. Source: S&P Dow Jones Indices
In 1812, financial stocks—banks and insurance companies—constituted an estimated 71% of total U.S. stock-market capitalization. No other sector even amounted to 14%. Link
Alternative Investing
There are more private equity funds than McDonald’s restaurants in the world. Link
Nearly half of gold production is used for jewelry. Link
39% of U.S. land area is used by farms, totaling 876 million acres of farmland. Link
On Jan. 1, 2015, there were 1,345 alternative mutual funds in existence. Only 341 still existed on June 30, 2025 – a 75% mortality rate. Link
In 2021 alone, 478 (30.7%) of all U.S. unicorns hit the $1B mark. Link
Most unicorns exit after a median (average) of 8 (9) years, counting from founding. “Exit” means going public, acquisition, or liquidation/bankruptcy. Link
3. Gas Helping Transports…Good for Economic Outlook…Transports Breaking Out to New Highs
StockCharts
4. Netflix -22% from Highs…50day Close to Crossing Below 200day on Chart
StockCharts
5. The Market is Bearish on Netflix Buying Warner Bros…What Would They Be Gaining?
chartr
6. Another $1 Trillion Bump in Money Markets
The Big Picture
7. Interesting Chart on from Callum Thomas Blog on Bond Bear Market
Bonds Basing? It’s a question many are pondering, and while TLT is still basically in bear market, we’re also seeing a clear basing process in progress.
9. Members of House are Quitting Congress at Record Rate-AXIOS
Axios
10. 7 Ways to Learn Faster and Improve Your Memory, Backed by Neuroscience-Inc.
1. Test yourself.
A classic study published in Psychological Science in the Public Interest shows self-testing is an extremely effective way to speed up the learning process.
Partly that’s because of the additional context you create. Test yourself and answer incorrectly and not only are you more likely to remember the right answer after you look it up, but you’ll also remember the fact you didn’t remember. (Especially if you tend to be hard on yourself.)
So, don’t just rehearse your sales pitch. Test yourself on what comes after your intro. Test yourself by listing the four main points you want to make. Test your ability to remember cost savings figures, or price schedules, or how you will respond to the most common questions or types of customer resistance.
Not only will you gain confidence in how much you do know, but you’ll also more quickly learn the things you don’t know — at least not yet.
2. Learn two or three things at (nearly) the same time.
The process is called interleaving: studying related concepts or skills in parallel. Instead of focusing on one subject, one task, or one skill during a learning session, purposely learn or practice several subjects or skills in succession.
One theory proposed in a study published in Educational Psychology Review is that interleaving improves your brain’s ability to differentiate between concepts or skills. When you block practice one skill, you can drill down until muscle memory takes over and the skill becomes more or less automatic. When you interleave several skills, any one skill can’t become mindless.
And that’s a good thing, because you’re instead constantly forced to adapt and adjust. You’re constantly forced to see, feel, and discriminate between different movements or different concepts.
And that helps you really learn what you’re trying to learn, because it helps you gain understanding at a deeper level.
Speaking of adapting …
3. Change the way you study or practice.
Repeating anything over and over again in the hopes you will master that task will not only keep you from improving as quickly as you could; in some cases, it may actually decrease your skill as well.
According to research published in Johns Hopkins Medicine, practicing a slightly modified version of a task you want to master helps you “actually learn more and faster than if you just keep practicing the exact same thing multiple times in a row.” The most likely cause is reconsolidation, a process where existing memories are recalled and modified with new knowledge.
Say you want to master an investor pitch. Do this:
Rehearse the basic skill. Run through your pitch a couple of times under the same conditions you’ll eventually face when you do it live. Naturally, the second time through will be better than the first; that’s how practice works. But then, instead of going through it a third time …
Wait. Give yourself at least six hours so your memory can consolidate. (Meaning that you may need to wait until tomorrow before you practice again, which, as you’ll see in a moment, is a great approach.)
Practice again, but this time:
Go a little faster. Speak a little — just a little — faster than you normally do. Run through your slides slightly faster. Increasing your speed means you’ll make more mistakes, but that’s OK — in the process, you’ll modify old knowledge with new knowledge, and lay the groundwork for improvement. Or …
Go a little slower. The same thing will happen. (Plus, you can experiment with new techniques — including the use of silence for effect — that aren’t apparent when you present at your normal speed.) Or …
Break your presentation into smaller chunks. Almost every task includes a series of discrete steps. That’s definitely true for presentations. Pick one section of your pitch. Deconstruct it. Master it. Then put the whole presentation back together. Or …
Change the conditions. Use a different projector. Or a different remote. Or a lavaliere instead of a headset mic. Switch up the conditions slightly; not only will that help you modify an existing memory, but it will also make you better prepared for the unexpected.
4. And keep modifying the conditions.
You can extend the process to almost anything. While it’s clearly effective for learning motor skills, the process can also be applied to learning almost anything.
4. Say it out loud.
Mentally rehearsing is good. Rehearsing out loud is better.
Research published in Journal of Experimental Psychology: Learning, Memory, and Cognition found that compared with reading or thinking silently (as if there’s another way to think), the act of speech is a “quite powerful mechanism for improving memory for selected information.”
According to the researchers, “Learning and memory benefit from active involvement. When we add an active measure or a production element to a word, that word becomes more distinct in long-term memory, and hence more memorable.”
So don’t just practice that investor pitch in your head. Rehearse out loud. That way you’ll remember what you thought, and also what you heard yourself say.
5. Learn in bursts.
Once you’ve drafted that pitch, run through it once. Then take a few minutes to make corrections and revisions.
Then step away for a few hours, or even for a day, before you repeat the process, because a study published in Psychological Science shows “distributed practice” is a much more effective way to learn. Why?
The study-phase retrieval theory says each time you attempt to retrieve something from memory and the retrieval is more successful, that memory becomes harder to forget. If you go over your pitch back to back to back, much of your presentation is still top of mind — which means you don’t have to retrieve it from memory.
Another theory regards contextual variability. When information gets encoded into memory, some of the context is also encoded. That’s why listening to an old song can cause you to remember where you were, what you were feeling, etc., when you first heard that song. The additional context creates useful cues for retrieving information.
Either way, distributed practice definitely works. So give yourself enough time to space out your learning sessions. You’ll learn more efficiently and more effectively.
Why? One factor is what psychologists call sleep-dependent memory consolidation. As the researchers write:
Converging evidence, from the molecular to the phenomenological, leaves little doubt that offline memory reprocessing during sleep is an important component of how our memories are formed and ultimately shaped.
Sleeping after learning is definitely a good strategy, but sleeping between two learning sessions is a better strategy.
Or in non-researcher-speak, sleeping on it not only helps your brain file away what you’ve learned, but it also makes that information easier to access — especially if you chunk your learning sessions by studying a little the next morning.
7. Exercise.
Want to learn information faster? A study published in Scientific Reports found that moderate-intensity workouts — keeping your heart rate between 50 and 80 percent of max — dramatically improve recall and associative learning and increase your brain’s ability to absorb and retain information.
Want to learn or improve a task where motor skills are involved? According to a different study published in Scientific Reports, 15 minutes of cycling at 80 percent of max heart rate (“intense” exercise) resulted in better memory performance than 30 minutes of moderate exercise, which was better than no exercise at all.
In other words, exercising hard for 15 minutes “fired up” participants’ brains and allowed them to learn motor skills better and faster. To a lesser degree, so did 30 minutes of moderate-intensity exercise.
And then there’s this. A study published in Proceedings of the National Academy of Sciences shows exercise can increase the size of your hippocampus, even if you’re in your 60s or 70s, helping to mitigate the impact of age-related memory loss.
Yep: Exercise helps make your brain healthier, too — which helps you be smarter and stay smarter.
1. Investor Allocation to Bonds Hit Previous Lows…Internet Bubble and GFC
Topdown Charts
2. Investment Grade Corporate. Bonds AI Exposure-WSJ
WSJ
3. Tether Gold Buying
Tether vs. gold. “Even the crypto world itself is warming to gold. As the chart shows, Tether has been steadily buying more of it over the last 18 months. It now owns about the same amount as Mexico or South Africa … If even DeFi is buying it, the case for gold’s bull market remaining intact is quite hard to refute.”
Daily Chartbook
4. Vanguard Allows Investors to Buy IBIT
Vanguard finally dips a toe into crypto waters as bitcoin’s bounce goes past $91,000
Vanguard began allowing clients to purchase third-party crypto exchange-traded funds, including BlackRock’s iShares Bitcoin Trust ETF.
Bitcoin increased approximately 6%, to over $91,000 on Tuesday, despite a 31% decline from its record high, reached in October.
The average cost basis for U.S. spot bitcoin ETFs since January 2024 was around $84,000 — a level that could indicate further selling if breached.
Vanguard on Tuesday for the first time started letting clients buy crypto exchange-traded funds managed by third parties — just in time for a bounce in the beleaguered digital asset.
The news, first reported by Bloomberg, was confirmed by Vanguard on Tuesday. The company noted that its clients could buy products like BlackRock’s iShares Bitcoin Trust ETF
, other third-party cryptocurrency ETFs and mutual funds for purchase through its brokerage platform.
5. Healthcare Stocks Have Biggest One Month Outperformance in 25 Years
Bespoke Investment Group. So far this month, the Health Care sector is outperforming the broad S&P 500 by more than ten percentage points. As shown below, that hasn’t happened since November 2000!
Bespoke
6. CSCO Stock About to Get Back to Internet Bubble Highs 25 Years Ago
The Return of Cisco
7. Holiday E-Commerce Has Tripled in 10 Years
In 2015, just 17% of American online holiday shopping took place on smartphones — a share that’s expected to hit 57% this year, per Adobe estimates. Total online spending has surged more than 3x over the same period and now, with some shoppers turning to AI for product discovery and recommendations, that growth seems likely to continue.
Indeed, from November 1 through 28, AI-referred traffic to retail sites was up 805% from the same period last year. More than 4 in 10 consumers already use AI to shop, a survey from Mastercard found— led by 61% of Gen Z, who rely on it for deal-checking and filtering out bogus reviews. www.chartr.com
8. Ecommerce vs. Department Store
Jack Ablin Cresset Capital In-store traffic continued its long decline, though the drop was moderate. This year recorded a 3.6% year-over-year decline in Black Friday foot traffic according to RetailNext, while Sensormatic reported a 2.1% slide. These numbers represented an improvement relative to earlier weeks, suggesting that meaningful in-store demand persists, particularly in higher-quality malls and value-focused stores. Observations from multiple malls across the country described steady crowds, even if consumers were more cautious once inside.
Cresset
9. New York City Increasing Apartment Supply Thru Office Conversions
About thirty years ago, Jerry Shereshewsky invented “Cyber Monday” as an alternative to Black Friday. The idea was that you’d wait until you got to work on Monday after the Thanksgiving break (where there was high speed internet and you wanted to avoid doing drudge work) to do your shopping from your desk. After all, who wants to get trampled at a big box store?
Of course, since then, the hype machine that is Black Friday has shifted its focus from mobs in the store to mobs online. And the media is still all in in promoting the orgy of consumption and fake deals that happens today.
We’re still going to shop for the holidays. A blog post probably isn’t going to change that. But perhaps we can counter the downward spiral of Amazon’s recommendations, fake reviews and search ads with some AI oomph of our own.
With Claude’s help I built a simple “project” that lets me automatically do powerful research and searches with no junk or distractions. Here’s a bit of what it gave me when I asked it for ‘healthy dog chews’:
If you have a claude.ai account, here’s how to do it. It takes about a minute to set it up. You’ll find that the searches are way slower than the instant overoptimized Amazon results, and the pause is worth it.
Open your Claude account on the web or in their app and look for PROJECTS on the left hand column. Until Claude taught me about this, I had no idea it existed.
Start a new project. Name it something fun and then hit Create Project to save it.
On the next page, it will ask you to “add instructions”. Hit the plus sign to the right…
Copy what’s below and you’re done. Now, every time you do a search with this project, you’ll find thoughtfully researched results. As a bonus, I’ve added a line that adds my affiliate code, which generates royalties for charity (this year, it’s buildon.org.) Feel free to delete that or substitute your own.
All you need to do is hit the + sign in the basic Claude user text entry box every time you want to use it. The first choice is “use a project”.
One other benefit: when it finds something great that’s not on Amazon, you’ll know it when you click through and it’s not there. Then you can go buy it somewhere else…
Okay, here’s the text to copy and paste:
You help people find products worth buying by cutting through Amazon’s ad-filled, fake-review-laden search results. When someone tells you what they’re looking for, do actual research and recommend 4-5 genuinely good options.
How to research:
Use web search for every query. Check multiple source types:
Be opinionated. If something is the clear winner, say so. If a category has safety issues or scams, warn them. You’re a knowledgeable friend who actually did the homework—not a hedging AI or a generic listicle.
Don’t recommend anything you couldn’t verify across multiple sources. If you can’t research a category well, say so.
Breadth Thrust: Yet as noted, we’ve seen a sharp surge in breadth — and if you look at the first chart you can see we had a few months of deteriorating breadth… this can sometimes act as a sort of stealth correction. Then add to that the point that there was probably a bit of offside money waiting for a pullback to buy.
But onto this chart, Subu has put together analysis tracking the activation of DeGraaf + Zweig Breadth Thrust signals. While no indicator is infallible, this is a pretty good track record, and seasonality tends to also be decent in December. So it’s certainly some bullish food for thought.
Subu Trade
4. Foreigners Buy $650B of U.S. Stocks in the Last 12 Months
US net capital inflows. “Foreign private purchases of US equities totaled a record $646.8 billion over the past 12 months. Over the past 12 months, foreign private purchases of US equities outpaced those of US Treasury notes and bonds.”
MSN
5. S&P 500 Effective Tax Rate Has Been Falling for 40 Years
Topdown Charts
6. Housing Market Slowing But Here are Top Cities Increases Since 2020-Bespoke
Bespoke
7. Motgage Rates are Normal…It’s Huge Increase in Prices and Lack of Supply
Wolf Street
8. Referral Traffic to Retail Sites from Generative AI +1200% in October…16% More Likely to Purchase-Barrons
WSJ
9. Philadelphia Apartment Searches Coming from NYC
The Philadelphia Inquirer
10. Lifestyle and Environmental Factors for Alzheimers
Lifestyle and Environmental Factors
Lifestyle habits and environmental exposures play an important role in brain health and may influence the risk of developing Alzheimer’s disease.
Social Isolation: Social isolation increases the risk of dementia by up to 60 percent.
Lack of Mental Stimulation: Low cognitive activity can accelerate mental decline, whereas mentally stimulating work is associated with a lower risk of developing dementia later in life.
Chronic Stress: Chronic stress leads to prolonged elevated cortisol levels. High cortisol can damage the hippocampus, impair neuronal plasticity, promote neuroinflammation, and accelerate amyloid beta and tau pathology.
Lack of Sleep: Poor or insufficient sleep may contribute to protein buildup. Most people benefit from six to eight hours of uninterrupted sleep each night.
Unhealthy Diet: Diets high in processed foods, sugar, and unhealthy fats may raise the risk of Alzheimer’s disease by contributing to cardiovascular problems, reduced blood flow to the brain, and neuroinflammation.
Lack of Exercise: Regular physical activity supports heart health, blood flow, and oxygen delivery to the brain, which helps maintain cognitive function.
Excess Belly Fat: Excess abdominal fat, particularly visceral fat, promotes chronic inflammation, insulin resistance, vascular dysfunction, hormonal imbalances, and oxidative stress—all of which contribute to brain atrophy and cognitive decline.
Nutritional Deficiencies: Lack of certain micronutrients—such as manganese, selenium, copper, and zinc, and vitamins A, B, C, D, and E—may increase Alzheimer’s risk. People with Alzheimer’s disease have also been found to have lower brain levels of lutein, zeaxanthin, and lycopene.
Exposure to Pollutants: Higher exposure to fine particulate air pollution (PM2.5) is linked to more severe Alzheimer’s-related brain changes and greater dementia severity because these tiny particles can travel into the bloodstream and the brain, where they trigger chronic inflammation and oxidative stress.
Exposure to Environmental Toxins: A 2020 review found that infections caused by viruses, bacteria, or fungi can trigger inflammation, which may gradually shrink brain tissue and contribute to Alzheimer’s disease.
Nighttime Light Exposure: Greater exposure to outdoor light at night is linked to a higher risk of Alzheimer’s disease, especially in people under 65, because it disturbs the body’s natural circadian rhythm, increases inflammation, and weakens disease resistance.
Smoking: Smoking damages blood vessels and reduces blood flow to the brain, with studies suggesting a 30 percent to 50 percent increased risk of dementia. Quitting smoking, even later in life, can lower this risk.
Genetics
Both types of Alzheimer’s disease have significant genetic components, although they are driven by different underlying causes, ranging from direct gene mutations to a complex mix of genetic and environmental risk factors.
PSEN1 or PSEN2 Genes: Early-onset Alzheimer’s can sometimes be inherited, known as familial Alzheimer’s disease, caused by mutations in the APP, PSEN1, or PSEN2 genes. These mutations lead to the overproduction of amyloid beta, which accumulates into amyloid plaques in the brain.
APOE Gene: The APOE gene is a well-known risk factor for late-onset Alzheimer’s. A 2024 study found that people with two APOE4 genes almost always showed Alzheimer’s-related brain changes by age 55, and most developed abnormal amyloid levels by age 65.
The process happens in distinct phases, or “epochs,” according to new research, as the structure of our neural networks changes and our brains reconfigure how we think and process information.
For the first time, scientists say they’ve identified four distinct turning points between those phases in an average brain: at ages 9, 32, 66 and 83. During each epoch between those years, our brains show markedly different characteristics in brain architecture, they say.
The findings, published Tuesday in the journal Nature Communications, suggest that human cognition does not simply increase with age until a peak, then decline. In fact, the phase from ages 9 to 32 is the only time in life when our neural networks are becoming increasingly efficient, according to the research.
During the adulthood phase, from 32 to 66, the average person’s brain architecture essentially stabilizes without major changes, at a time when researchers think people are generally plateauing in intelligence and personality.
And in the years after the last turning point — 83 and beyond — the brain becomes increasingly reliant on individual regions as connections between them begin to wither away.
“It’s not a linear progression,” said Alexa Mousley, a postdoctoral researcher associate at the University of Cambridge, who is the study’s lead author. “This is the first step of understanding the way the brain’s changing fluctuates based on age.”
03:59
The findings could help identify why mental health and neurological conditions develop during particular phases of rewiring.
Rick Betzel, a professor of neuroscience at the University of Minnesota who was not involved in the research, said the findings are intriguing, but more data is needed to support the conclusions. The theories may not hold up to scrutiny over time, he said.
“They did this really ambitious thing,” Betzel said of the study. “Let’s see where it stands in a few years.”
For their research, Mousley and her colleagues analyzed MRI diffusion scans — which are essentially images of how water molecules move within the brain — from about 3,800 people from newborns to age 90. The goal was to map the neural connections across the average person’s brain at different stages in life.
In the brain, the bundles of nerve fibers that transfer signals are encapsulated in fatty tissue called myelin. Think of it like wiring or plumbing. Water molecules diffused in the brain tend to move in the direction of these fibers, rather than across them, meaning researchers can infer where the neural pathways are located.
“We can’t crack open skulls … we rely on non-invasive approaches,” Betzel said of this type of neuroscience research. “What we’re trying to figure out is where these fiber bundles are at.”
Based on the MRI scans, the new study maps the neural network of an average person across a lifespan, determining where connections are strengthening or weakening. The five “epochs” it describes are based on the neural connections the researchers observed.
The first phase is up to age 9, they suggest. The brain rapidly increases in gray and white matter; it prunes extra synapses and restructures itself.
From ages 9 to 32, there is an extended period of rewiring. The brain is defined by rapid communication across the entire brain and efficient connections between different regions.
Most mental health disorders are diagnosed during this time period, Mousely said: “Is there something about this second era of life, as we find it, that could lead people to be more vulnerable to the onset of mental health disorders?”
From 32 to 66, the brain plateaus. It’s still rewiring itself, but less dramatically and more slowly.
Then, from 66 to age of 83, the brain tends toward “modularity,” where the neural network is divided into highly connected subnetworks with less central integration. At age 83, connectivity declines further.
Betzel said the theory described in the study likely jives with people’s lived experiences with aging and cognition.
“It’s intuitively something we gravitate towards. I have two kids and they’re really young. I think all of the time, ‘I’m getting out of my toddler era,’” Betzel said. “Maybe the science ends up being there. But are those the exact right ages? I don’t know.”
In the ideal version of a study like this, he added, the researchers would have MRI diffusion data for a large group of people, each of whom were scanned during every year of life from birth to death. But that wasn’t possible because the technology wasn’t available decades ago.
Instead, the researchers combined nine different data sets containing neuroimaging from previous studies and attempted to harmonize them.
Betzel said each of those data sets varies in quality and approach, and the effort to make them correspond with one another could wash away important variability, ultimately leading to bias in the results.
Nonetheless, he said the authors of the paper are “thoughtful” and skilled scientists who did their best to control for that possibility.
“Brain networks change over the lifespan — absolutely. Is it discrete such that there are five exact change points? I’d say stay tuned. It’s an interesting idea.”
Cognitive decline starts decades before dementia diagnosis, but higher cognitive reserve can delay symptoms.
Education, complex work, and active learning could reduce dementia risk.
Exercise, social ties, and new experiences help grow brain networks and boost cognitive reserve.
With dementia now estimated to impact 42 percent of people who make it past age 55, everyone should be taking steps to help decrease their risk for developing the condition. Yet while much of the conversation focuses on supplements, diet, and pharmaceuticals, one of the less publicized tools to mitigate risk could be one of the most important.
For background, it’s key to understand that, as it relates to dementia, brain changes can begin decades before a person experiences symptoms of cognitive decline. Yet not all people with dementia-related changes in their brains experience clinical dementia, and there are major differences in the severity of cognitive impairment, even in people with similar brain pathology (like amyloid buildup). But why?
A major breakthrough in unpacking this complexity came from a 1994 study in the Journal of the American Medical Association (JAMA). In this publication, Yaakov Stern and his co-investigators looked at about 600 healthy adults aged 60 years or older and followed them for up to four years to look for the development of dementia. They discovered that people who had more formal education or more complex occupations had a significantly lower chance (less than half) of developing dementia. They proposed that “increased educational and occupational attainment may reduce the risk of incident [Alzheimer’s disease], either by decreasing ease of clinical detection of AD or by imparting a reserve that delays the onset of clinical manifestations.”
This early work has since been expanded, and the framework described by the early work is now classified as “cognitive reserve” (CR). There is now an increased understanding that multiple methods of expanding brain connectivity and even growth of new brain cells could help to delay or potentially even offset the risk of developing dementia. Many now recommend various steps to help raise CR, which, in addition to pursuing formal education and engaging in cognitively demanding tasks (e.g., a complex job), include certain leisure activities, exercise, and social engagement.
It is important to note that the brain protection associated with higher CR isn’t necessarily a prevention of dementia itself, but rather, may promote a delayed decline. Research recently published in the journal Neurology suggests that having higher CR leads to a slowing of progression in stages of brain decline that precede a diagnosis of Alzheimer’s disease, potentially compressing the cognitive impairment into a shorter period of time after dementia is present. With all this in mind, what are practical strategies to help boost CR?
Lifelong Learning: Education is one of the strongest contributors to CR. Higher educational attainment is linked to a significantly lower dementia risk in many studies, including up to a 44 percent reduction in some data. Importantly, this isn’t just about early life schooling. Learning later in life is an excellent step to continue to promote CR.
Cognitive Training: In one of the largest trials of its type, researchers in the ACTIVE Cognitive Training Trial tested whether 10 sessions of cognitive training (plus boosters after 11 and 35 months) could lead to improvements in cognition in around 3,000 people. They found that reasoning and speed training led to improvements in brain function observable 10 years later.
Physical Activity: Regular physical activity may be the most important daily activity for promoting brain health, but, specific to cognitive reserve, aerobic and resistance exercises may be especially beneficial for growing brain cells and protecting against dementia. One of the most striking examples is a 2011 study showing that one year of exercise (specifically walking) appeared to grow the brain’s memory center (the hippocampus).
Social Engagement: Strong and positive social interactions have been consistently linked with better brain health, but how? In a 2021 publication, researchers compared people’s social networks to brain imaging (MRI) testing. They found that people with more ability to span social roles had better cognitive testing and that this was linked to slowing of atrophy in parts of the brain linked to social processing.
Novelty: Our brains are tasked with responding to an incredible diversity of environmental inputs. However, consistently challenging ourselves with new experiences may be a way to beneficially augment this process to boost CR. To this end, learning a new instrument or a new language, traveling, or picking up a new hobby are great ways to inject novelty into your life.
