Quick reminder - don’t forget to click the heart button, it helps more people see the post.
A diagnosis of Alzheimer’s requires the presence of amyloid plaques and p-tau. That diagnosis can now be made using simple blood tests 10 to 20 years before any cognitive symptoms, which gives us a long runway to do something about it.
Drug companies are now testing their newest drugs at that early stage. But that approach assumes the only problem is the amyloid and p-tau, and it skips the most important question: why are those levels elevated in the first place?
Years before a brain scan can find amyloid plaque, your body is already sending warning signs that point to the answer. Even your cholesterol can be one of them.
Last week, I wrote about how your brain handles its own cholesterol and how problems transporting it can lead to beta-amyloid buildup.
This week I want to show you what the cholesterol in your blood can tell you about your Alzheimer’s risk and why the standard test panel misses most of it.
Inflammation, oxidative stress, and high blood sugar affect the health of your cholesterol, and they are also risk factors for Alzheimer’s.
Let’s start with the standard cholesterol panel you’ve seen many times. It measures total cholesterol, LDL, HDL, and triglycerides.
If your LDL is high, you’ll probably be prescribed a statin. If your HDL is low, it may not be mentioned at all, and if your triglycerides are high, you may be told to cut back on fat and sugar.
What the panel doesn’t tell you is how healthy your cholesterol is, or whether high triglycerides are a sign of insulin resistance. You can check that second one yourself by dividing your triglycerides by your HDL.
Under 2 is a good sign. Over 3 points to insulin resistance.
Back to your cholesterol. Did you know that in a 2023 study of more than 31,000 people already taking statins, inflammation was a stronger predictor of heart attacks and death than LDL?
People with high inflammation were at high risk no matter how low their LDL was,
How could that be if it’s high LDL that leads to heart attacks?
Because LDL causes harm when it’s damaged, and inflammation is what damages it and makes plaque break open, so someone with low LDL and high inflammation can still have a heart attack.
Here are a few basics about cholesterol:
Your liver and your cells make cholesterol because every cell in your body needs it. Your body uses cholesterol for the health of your cell membranes, to make your sex hormones and vitamin D, all of which your brain relies on.
Cholesterol can’t easily travel through your blood on its own, so it’s carried on particles called LDL and HDL. That means LDL and HDL aren’t actually cholesterol, they are particles that cholesterol hitches a ride on.
LDL carries cholesterol from your liver out to the cells that need it. HDL picks up the excess from your cells and blood vessels and brings it back to your liver for recycling or disposal.
Ultimately, your cholesterol is a good thing.
LDL gets the bad reputation because it’s the particle that ends up in artery walls when plaque forms. But your LDL number only tells you how much cholesterol those particles carry, not how many there are or whether they’ve been damaged.
Damaged LDL is what leads to plaque. But plaque alone isn’t what causes most heart attacks.
Here are six Alzheimer’s risk factors that also damage your LDL. When you reduce them, you lower your Alzheimer’s risk and improve the health of your cholesterol at the same time.
1. Inflammation:
In your arteries, inflammation can go on for years without any symptoms, even if your hs-CRP is optimal. An MPO test could catch that earlier. Inflammation injures the artery lining so LDL gets stuck more easily, speeds up the damage to LDL, and weakens plaque so it’s more likely to break open, which is what causes most heart attacks.
That’s how someone with low LDL can still have a heart attack. Inflammation can be measured with simple blood tests, the most common one is hs-CRP, and it’s driven by the same five things that damage LDL.
So the goal is healthy LDL particles, which often means fewer of them, enough HDL to clear the excess cholesterol out, and low inflammation.
Low HDL usually comes from the same place as damaged LDL: high blood sugar and insulin. Sitting too much, smoking, and carrying extra weight around your middle also lower it.
2. High Insulin and Blood Sugar
When your blood sugar stays high, sugar sticks to your LDL particles, the same way it sticks to your red blood cells. LDL coated with sugar stays in your blood longer, which gives it more time to get damaged.
High blood sugar also keeps your insulin high, and high insulin tells your liver to turn the extra sugar into fat and ship it out in particles that become LDL. You end up with more LDL particles, and they’re smaller and denser, which makes it easier for them to slip into your artery walls and start the process of plaque.
High insulin also raises triglycerides and lowers HDL, so you end up with more LDL particles and less HDL to clear the excess.
A statin can lower those particles, but lowering your insulin by changing your diet gets to the real problem.
High blood sugar and insulin are also among the strongest risk factors for Alzheimer’s.
Over time, brain cells stop responding well to insulin and can’t use sugar for fuel efficiently, and the same enzyme that breaks down insulin also clears amyloid, so when insulin stays high, less amyloid gets cleared.
Dr. Dale Bredesen calls this the glycotoxic type of Alzheimer’s. It’s one of the most common drivers of the disease.
Insulin should be a standard blood test, but it’s not. You can ask your doctor to test it.
3. Browned and charred food
Sugar doesn’t only stick to LDL. When it bonds to proteins and fats throughout your body, it forms compounds called AGEs (advanced glycation end products).
Your body makes them when your blood sugar is high, and you also eat them, because grilling, searing, frying and browning food at high heat creates a lot of them. A beef stew has far fewer than the same beef cooked on the grill.
AGEs stiffen your blood vessels and inflame their lining, including the vessels that feed your brain.
AGEs also form inside the brain when blood sugar runs high, and they’re found in the amyloid plaques and tau tangles of Alzheimer’s patients.
Older adults with higher AGE levels have shown faster cognitive decline.
4. Too much omega-6 oil
Too much processed omega-6 oil leads to oxidized LDL, which means LDL that’s been damaged by unstable molecules called free radicals.
Oxidized LDL is the kind most likely to build plaque, but it’s not on a standard test panel either.
The fat that oxidizes most easily is the omega-6 fat found in soybean, corn, cottonseed and sunflower oil.
You’re likely eating far more of it than you think, because it’s in so many foods. Chips, crackers, tortillas, salad dressings, mayonnaise, granola and protein bars, store-bought cookies and baked goods, frozen meals, margarine, and almost anything fried or cooked in oil at a restaurant are common sources.
Eating a lot of them, without enough omega-3 to balance them, means more of that easily damaged fat ends up inside your LDL.
You do need omega-6, and the place to get it is whole foods like nuts, seeds, and avocados. There, it comes packaged with the nutrients that protect it.
This affects your brain, too. Your brain needs omega-3 from foods like fatty fish to help keep inflammation in check, and when omega-6 far outweighs omega-3, the balance tips toward inflammation.
Inflammation in the arteries triggers plaque buildup, and the inflammatory signals it sends out through your blood reach your brain, too.
Inflammation in the brain triggers more amyloid as part of its defense, and over time it also makes the brain’s immune cells worse at clearing amyloid away.
What about saturated fat? It gets blamed for heart disease more than any other fat, yet it’s the most stable fat you can eat, so it doesn’t oxidize easily. The source matters, for example, make sure your beef is grass-finished.
That doesn’t make it unlimited. Saturated fat raises LDL in some people, and APOE4 carriers tend to see a bigger rise because their livers clear LDL from the blood more slowly.
That’s why the ReCODE protocol has APOE4 carriers keep saturated fat lower. Olive oil, avocados, nuts and seeds become their main fats instead.
5. Toxins
Oxidation speeds up when your body is dealing with toxins. Heavy metals, pesticides, air pollution and mycotoxins from mold all increase oxidative stress and use up the antioxidants that protect your LDL.
Mold is especially easy to overlook, since it can come from water damage you can’t see in your home, office or car.
These same toxins reach the brain. Air pollution is now on the list of major modifiable risk factors for dementia, heavy metals like lead and mercury are linked to cognitive decline, and mold toxins can trigger the brain’s defenses, including amyloid.
The toxic type of Alzheimer’s often shows up in people diagnosed with early-onset, who have no family history.
6. A leaky gut
This one surprises people, because it starts with something LDL does right. LDL has a second job: to grab bacterial toxins in your blood and help neutralize them.
When your gut lining is damaged, pieces of bacteria called LPS leak into your bloodstream, and LDL picks them up.
LDL carrying LPS gets oxidized more easily, which adds to the damage in your artery walls.
LPS in the blood also keeps your immune system switched on, and that ongoing inflammation can weaken the blood-brain barrier. LPS has been found in the brains of people who died with Alzheimer’s, right alongside amyloid.
Chronic immune activation from sources like this is the biggest driver of cognitive decline I see.
The cholesterol connection to Alzheimer’s
Each of these five risk factors affects your brain directly, and they also reach it through your blood vessels. When damaged LDL builds plaque in the carotid arteries in your neck and the larger arteries inside your skull, those arteries narrow, and less blood reaches your brain.
Your brain uses about 20% of your oxygen and fuel, so it feels that loss.
The same six risk factors also damage the tiny vessels deeper in your brain through high blood sugar, inflammation and oxidative stress.
The blood-brain barrier is made from the lining of those tiny vessels. As they’re damaged, the barrier starts letting in inflammatory molecules that should never reach your brain.
Is lower cholesterol always better?
No. Your body needs cholesterol, and in the ReCODE protocol total cholesterol under 150 mg/dL is a red flag.
What you want is healthy LDL particles that aren’t damaged or excessive, and enough HDL to keep cholesterol moving.
A statin can lower your LDL number, but it doesn’t fix the sugar, the oils, the toxins or the gut problems doing the damage to your heart and your brain.
Fix those things, and you’ll likely see healthier cholesterol and blood vessels, which are crucial for a healthy brain.
Next, I’ll show you 9 markers to ask your doctor to test and where to start. Paid subscribers also get 15% off professional-grade supplements through my Fullscript dispensary, 25% off plasmalogen precursors, and my Brain Health Resources list. See paid-subscriber perk here.