High Cholesterol, Saturated Fats and Low-Carb Diets: What You Need to Know

By: Dave Asprey

High Cholesterol, Saturated Fats and Low-Carb Diets: What You Need to Know
  • Genes, lifestyle, and insulin resistance influence how you metabolize dietary fat, so people with identical diets can have different cholesterol numbers.
  • Cholesterol does not cause heart disease. Inflammation does.
  • Total cholesterol does not even predict cardiovascular disease (CVD) risk.
  • If you have “high cholesterol” you need to know your inflammation markers, ratio of total cholesterol to HDL cholesterol, cholesterol particle count, and triglycerides before you’ll have a real picture of your risk of CVD.
  • If your doctor tries to put you on mitochondria-damaging statin drugs based on total cholesterol or LDL cholesterol alone, find a better doctor.
  • If the more indicative lab tests show a truly elevated risk, you can modify the Bulletproof Diet for three months and re-test to see if your body’s fat metabolism regulates itself.
  • It is common for people to have higher cholesterol for several months after switching to a high-fat diet as the liver sheds built-up fat.
  • If you’ve had a recent injury or infection, your cholesterol levels will jump temporarily.

You’ve started the Bulletproof Diet. You’re eating a ton of vegetables, a little high-quality protein, and the good fats from grass-fed butter and Brain Octane Oil are turning your brain on like never before. You now know what everyone means when they say they feel Bulletproof — there’s no other way to describe it.

Then, you go in for some routine blood work and see a bunch of changes, and maybe higher cholesterol numbers. Maybe you’re worried. And confused.

If this happened to you, put down the oatmeal and margarine. With all of this newfound clarity and energy, do you really believe going back to your old ways will fix things?

More than likely, you don’t have the complete story of how your blood lipids actually look. Here’s an explanation of what’s going on:

This is personal to me. Nearly 20 years ago, in my mid 20’s, I was diagnosed with insulin resistance and high risk for heart attack and stroke. It’s one of the reasons I developed the Bulletproof Diet. Today, my insulin sensitivity is a perfect 1 (out of a scale of 160) and I have control over the real risk factors for heart disease. After tracking my data for many years on a high-fat diet made of the right fats, I’ve lost all fear of cholesterol.

In fact, here’s a huge meta study[1] of nearly 350,000 people showing that saturated fat intake is simply not associated with heart attack risk. I’d been duped.

Cholesterol and cardiovascular disease risk

Before we dive in, here’s an easy way to keep your lipoproteins straight: remember that you want high numbers for high-density lipoproteins (HDL). Low-density lipoproteins (LDL) are simplistically called “bad cholesterol.” The problem is that some LDL cholesterol can be good, and some can be bad, and details matter. Basic cholesterol tests don’t measure these distinctions. This article will show you what details to watch.

When people restrict carbs to 50 grams or less per day, as many people do when they start the Bulletproof Diet, they often see in an increase in HDL cholesterol.

This is a good thing. High HDL activates anti-inflammatory pathways and protects your heart from disease. Even though higher HDL keeps you alive, it will still bump up your total cholesterol numbers, and your blood work may raise eyebrows in the doctor’s office. But, it shouldn’t. Low HDL correlates strongly with a higher risk of metabolic syndrome and cardiovascular disease (CVD).[2] So is total cholesterol an indicator for CVD?

Conventional medicine doctors consider 200 mg/dL to be high, while integrative doctors tend to consider 240 mg/dL to be high. If you’re Bulletproof, you’re on Team Integrative Medicine for prevention. Still, most MDs acknowledge that total cholesterol does not accurately predict CVD, so they will order a complete lipid panel before doling out statins. Or at least they should.

Increasing saturated fat consumption can cause a beneficial shift in the types of LDL-particles, from small, dense LDL particles (the kind that are correlated with heart disease in some studies)[3] to higher numbers of larger, more buoyant LDL particles (which are not harmful and can be useful metabolically). When this happens, your LDL cholesterol will go up. This is what freaks people out — but hold onto your seat, because this shift is a good thing.

Read on to find out how to find out your particle composition. This really matters because in a small minority of people, saturated fat can increase the number of LDL particles (a metric called LDL-P which is not reflected in standard LDL cholesterol tests). But for the vast majority of people, insulin resistance brought about from high sugar and damaged vegetable oils is what raises these harmful particles.

Doc says you have “high cholesterol.” Now what?

Don’t panic. As mentioned before, total cholesterol doesn’t tell you much about your CVD risk. Doctors started tracking it a long time ago because it was one of the first things they could find in blood with primitive lab tests. Seriously!

One study found that nearly 75% of patients hospitalized for a heart attack had cholesterol levels that would indicate they were not at high risk for a cardiovascular event. These patients had LDL cholesterol levels that met current guidelines, and close to half had “optimal” LDL levels (less than 100 mg/dL).[4] Doctors would have told these folks that everything is hunky-dory and sent them away to eat more low-fat, high-fructose foods.

You can get one slightly useful piece of data from a standard cholesterol test. Specifically, you want to know whether the ratio of the total cholesterol (TC) to HDL cholesterol is high. In most cases, you’ll find that it hasn’t changed much since you started the Bulletproof Diet.[5]

If your total cholesterol to HDL ratio is higher, especially after 6 months on a higher-fat diet, you’ll want to dig deeper to see if you have high LDL-P. If you do, you’ll want more data.

For a better picture of your CVD risk, get a detailed cardiovascular blood test that measures particle number and size, as well as other markers of CVD.[6][7][8] You’re getting poked anyway, so go ahead and assess the markers that will give you the full picture. These are all signs that you’re at risk for CVD:

So what’s the real reason your cholesterol could be high?

Your body’s response to dietary fat will likely be different than your mom’s or your neighbor’s. That’s why some people’s cholesterol lowers when they increase dietary fat and some people experience a spike.

In addition to your individual wiring, other factors affecting LDL cholesterol response include:

  • Obesity
  • Insulin resistance
  • Diabetes
  • Hypertriglyceridemia
  • Gender[9]
  • Recent injury or infection

You and I deal with fats differently because there are so many influences in play.

But saturated fat has been the fall-guy when it comes to serum cholesterol levels and diseases like CVD and cancer. Remember the other, more prominent things that contribute to heart disease:

  • Insulin resistance / metabolic syndrome
  • Inflammation
  • Excessive consumption of refined carbohydrates
  • High-fructose corn syrup (HFCS)
  • Smoking
  • High blood pressure
  • Obesity
  • Physical inactivity
  • Pre-diabetes/diabetes
  • Unmanaged stress
  • Family history
  • Cholesterol is a protective metabolic response to toxin exposure or infection

All of these are tied to mitochondrial function.

High-fat diets reduce your risk of heart disease

An abundance of evidence shows that high-fat, low-carb diets improve cardiovascular risk factors when you eat the right kinds of fats. A comprehensive review of high-fat ketogenic diets says:

“There are nevertheless several lines of evidence that point to beneficial effects of [ketogenic diets] on these cardiovascular risk factors. The majority of recent studies seem to amply demonstrate that the reduction of carbohydrates can actually lead to significant benefits in total cholesterol reduction, increases in HDL and reduction of blood triglycerides.[10][11] Furthermore [ketogenic diets] have been reported to increase the size and volume of LDL-C particles which is considered to reduce CVD risk since smaller LDL particles[12] have a higher atherogenicity. There is a biochemical rationale behind the effects of KDs on endogenous cholesterol synthesis. A key enzyme in cholesterol biosynthesis is HMGCoA reductase (the target for statins), which is activated by insulin, which means that an increase in blood glucose and consequently of insulin levels will lead to increased endogenous cholesterol synthesis. Thus a reduction in dietary carbohydrate together with a correct intake of cholesterol will lead to an inhibition of cholesterol biosynthesis.”[13]

3 steps to improving your cholesterol levels

Don’t listen to the low-fat dogma. There’s plenty of steps you can take if there’s a jump in your small, dense particles (known as “LDL-pattern-B”) or an increase in triglycerides or other inflammatory markers.

1. Tweak your fats and cut carbohydrates

Reject the notion that vegetable oils should replace saturated fats to reduce cholesterol numbers. As always, avoid hydrogenated fats (found in cookies, crackers, chips, etc.) and omega-6 oils, such as corn, safflower, soy, and canola. Don’t eat anything fried, ever. Reduce your intake of refined carbohydrates, including fructose, sugar, bread, pasta, bagels (focus on non-starchy vegetables), and eat moderate high-quality protein. (Get The Bulletproof Diet Roadmap for your fridge – for free) and consult with a functional-medicine practitioner for advice on supplements and lifestyle changes.

You can even run your own experiment for 1-3 months. It’s OK to try reducing but not eliminating long-chain saturated fats (things like grass-fed butter and fat from grass-fed meat) for three months. Instead, get your fat from Brain Octane Oil, oily fish (omega-3 essential fatty acids), monounsaturated fats (olive oil), and small amounts of nuts and seeds (keeping in mind that lectins in seeds and nuts cause inflammation for lots of us.) Maybe you do better on 1 tablespoon of butter per day instead of 4. Or maybe your body loves a lot more. The data will tell you.

But it won’t tell you anything if you are still eating lots of sugar, processed foods, and bad oils.

2. Lose weight if you have to (you know who you are)

If you are overweight, you want to deal with it anyway! Losing weight can reduce high LDL-P and small, dense LDL particles. Cutting down carbs is the most effective way to do this. It won’t work if you’re losing weight while eating the wrong fats[14] from crappy vegetable oils.

3. Try intermittent fasting

The Bulletproof Diet and Head Strong cover intermittent fasting in detail because it’s so powerful for increasing your body’s energy production, fixing insulin resistance, and losing weight. Intermittent fasting can also reduce total LDL cholesterol and decrease the small, dense LDL particles.[15][16][17] Intermittent fasting will also contribute to a drop in triglycerides, to the tune of up to 32%.[18][19][20][21]

Bulletproof Intermittent Fasting uses Bulletproof Coffee (with no carbs or protein) in the morning to make Intermittent Fasting easier. Read all about intermittent fasting here. If you think you may be in the small minority of people who can get LDL-P from saturated fat, it’s OK to go light on the butter and heavier on the Brain Octane Oil. Brain Octane is technically saturated, but does not behave the same way in your body as other, longer saturated fats. (For instance, it doesn’t get stored as fat, and it raises ketones directly.)

Don’t forget to re-test! When you modify the Bulletproof Diet, repeat your labs in three months to see if you’ve hacked your lipids.

Most of all, don’t panic. How you feel is a direct indication of how your diet and lifestyle affect your mitochondria, and mitochondrial function (indicated by your energy levels) are the best signaling system for deciding what works and what doesn’t. The best doctors are open to discussing these factors and learning from their patients, too, so find a doctor that will have these conversations with you.

In my own labs, I pay the most attention to three inflammation markers — lp-PLA2, CRP, and homocysteine — because if anything in my lifestyle or diet is causing inflammation, it will show up there.

Remember, cholesterol and saturated fat do not cause heart disease — inflammation does.