# Cholesterol (HDL, LDL)

Category: Metabolism

Also known as: Cholesterol, cholesterol, ldl, HDL, hdl

HDL and LDL are often called "good cholesterol" (High Density Lipoproteins) and "bad cholesterol" (Low Density Lipoproteins) because of a slight association between their ratio and heart disease, but in fact the ratio that suggests freedom from heart disease suggests…

9 passages · 2 authors · 2007–2025 · Most-cited: [Ray Peat](https://bioenergeticoracle.com/md/voices/ray-peat/index.md)

Canonical page: https://bioenergeticoracle.com/concepts/cholesterol-hdl-ldl

## Synthesis

**Cholesterol** is a central protective molecule whose synthesis and circulation are powerfully regulated by the body, with its primary function being the production of defensive steroids like **progesterone**, **DHEA**, and **pregnenolone**. [Source 4, 5] Peat argued that the common designation of LDL as "bad" cholesterol is fundamentally mistaken, as LDL is the primary delivery system carrying cholesterol to the brain, ovaries, testicles, adrenal glands, and skin for steroidogenesis. [Source 1, 2] He maintained that cholesterol is protective against many kinds of poisoning, including heavy metals, and that a total cholesterol level around 160 to 220 mg% is generally reasonable, with low cholesterol (around 140 mg%) often indicating an inability to produce enough of these protective substances due to liver or intestinal damage. [Source 3, 5]

The lipoproteins HDL and LDL are both defensive and anti-inflammatory, but they respond to different physiological demands. [Source 2, 6] LDL serves as the delivery system for cholesterol itself, while the protein component of HDL has more specific *antitoxic effects*, binding bacterial endotoxins and participating in detoxification. [Source 2, 4] Because HDL rises defensively against chemical irritants, Peat cautioned that a very high HDL is not necessarily a sign of good health; it can be driven up by *estrogen*, *alcohol*, radiation, chlorinated hydrocarbons, and even the peroxidation of fish oil. [Source 2, 6, 8] He suggested that a ratio of roughly two or three parts LDL to one part HDL is usually reasonable, but emphasized that the interpretation is not simple. [Source 6] Roddy has reiterated this framing, noting that while a high HDL indicates the body is mounting a defense, it is not a desirable state. [Source 8]

The size of the **LDL particle** is a critical factor in its atherogenicity, a nuance Peat highlighted as embarrassing for the medical establishment. [Source 9] Smaller LDL particles have a greater surface area exposed to oxidative factors in the serum and are more rapidly degraded into toxic substances, whereas people with larger LDL particles are remarkably resistant to heart disease. [Source 9] Dietary cholesterol and saturated fats, such as those from butter and eggs, have been shown to increase LDL particle size, generating a less atherogenic lipoprotein profile. [Source 4, 9] Peat cited studies where a high-cholesterol diet did not negatively influence the atherogenicity of LDL, and where the consumption of butter was associated with larger LDL particles compared to margarine. [Source 4, 9]

Cholesterol levels are intimately tied to *thyroid function*. [Source 7, 8] Thyroid hormone increases the turnover of cholesterol and its conversion into protective steroids, making it a major factor in controlling inflammation. [Source 4] In hypothyroidism, the pituitary secretes more TSH, which itself has pro-inflammatory actions, and cholesterol rises as a compensatory defense. [Source 4, 5] Roddy has described total cholesterol as "one of the best thyroid tests," noting that a very high cholesterol level obviously indicates extremely low thyroid function, while a sharp decline in total cholesterol follows the administration of thyroid hormone. [Source 7, 8] Conversely, when cholesterol is too low, it presents a more challenging situation requiring troubleshooting of why the liver is not making enough. [Source 8] Peat observed that the rising cholesterol commonly seen with aging is probably only a partial compensation for declining thyroid function. [Source 9]

## People also ask

### Why did Ray Peat consider LDL to be protective rather than harmful?

Peat argued that LDL is the primary delivery system carrying cholesterol to the brain, ovaries, testicles, adrenal glands, and skin for the production of protective steroids like progesterone and DHEA, making its designation as "bad" cholesterol fundamentally mistaken.

### What does a very high HDL level indicate in the bioenergetic view?

The corpus describes HDL as having antitoxic effects that rise defensively against chemical irritants, so Peat cautioned that a very high HDL can be driven up by estrogen, alcohol, or other stressors and is not necessarily a sign of good health.

### How does thyroid function relate to cholesterol levels?

Peat and Roddy described thyroid hormone as increasing cholesterol turnover and conversion into protective steroids, so high total cholesterol often indicates low thyroid function, while cholesterol levels drop sharply when thyroid hormone is administered.

## Related concepts

- [Cholesterol](https://bioenergeticoracle.com/md/concepts/cholesterol/index.md)
- [Free Fatty Acids (FFAs, NEFA)](https://bioenergeticoracle.com/md/concepts/free-fatty-acids-ffas-nefa/index.md)
- [Thyroid](https://bioenergeticoracle.com/md/concepts/thyroid/index.md)
- [Adrenaline](https://bioenergeticoracle.com/md/concepts/adrenaline/index.md)
- [Age Pigment (Lipofuscin)](https://bioenergeticoracle.com/md/concepts/age-pigment-lipofuscin/index.md)
- [Albumin](https://bioenergeticoracle.com/md/concepts/albumin/index.md)

## Cited passages

Passage numbers match the `[Source N]` markers in the synthesis above.

### Source 1 — Glossary

Ray Peat · Glossary

> Cholesterol (HDL, LDL)
>
> HDL and LDL are often called "good cholesterol" (High Density Lipoproteins) and "bad cholesterol" (Low Density Lipoproteins) because of a slight association between their ratio and heart disease, but in fact the ratio that suggests freedom from heart disease suggests susceptibility to cancer. LDL ("bad") is extremely good because it is used as the source for producing progesterone and DHEA.

### Source 2 — Ray Peat Full Interview: Cholesterol, PUFA, Coconut Oil, Thyroid, and the Metabolic Truth

Ray Peat · Interview · Jul 12, 2025 · https://www.youtube.com/watch?v=lQB95tLW7eE

> **Josh Rubin:** So we're talking cholesterol. Can you explain just the... You can get as deep as you want, I know, but the basics for people and the differences between HDL and LDL?
>
> **Ray Peat:** Both of them are able to... participate in detoxification, the protein that helps to carry the cholesterol in the bloodstream itself has some very specific anti-stress, even anti-viral activity. So they're part of our ability to respond to stress, the protein as well as the the cholesterol associated with the protein. And they're both defensive and both important, but the LDL is mostly the one that carries cholesterol into the places where it's needed, the brain, the ovaries, testicles, and adrenal glands, but anywhere you're making steroids, and that includes the skin. Skin is probably our biggest endocrine gland. The brain is the next. And then the ovaries, testicles, and adrenals. And the HDL has probably some more specific antitoxic effects where the LDL is more delivery system of cholesterol itself. And toxins will tend to increase the HDL relative to the LDL toxins. Most types will increase both of them defensively, but the chlorinated hydrocarbons radiation, estrogen, and alcohol, for example, will increase the HDL relative to the LDL because it has some more specific antitoxic effects.

### Source 3 — Blood Pressure Regulation Heart Failure and Muscle Atrophy

Ray Peat · Interview · Jul 20, 2012 · https://www.youtube.com/watch?v=A8Ce3BdRpds

> **Caller:** It's come down quite a lot: 49 is the HDL and 46 is the LDL.
>
> **Herb Doctor 2:** You know what the total is?
>
> **Caller:** I think it's 147.
>
> **Herb Doctor:** That's pretty low.
>
> **Herb Doctor 2:** How old are you?
>
> **Caller:** 54.
>
> **Herb Doctor:** What a total cholesterol of 154 would be for that caller? And how could he avoid future heart attacks ?
>
> **Caller:** And how long can I stay on Simvastatin before it affects me negatively ?
>
> **Herb Doctor 2:** Do you know what your cholesterol was before you had a heart attack?
>
> **Caller:** It wasn't that high. High end of normal.
>
> **Ray Peat:** I doubt that there is any connection at all between the cholesterol and the heart attack. If it was in a normal range, you might actually not have had enough protective effect from cholesterol. It depends on what your exposure was, because cholesterol can protect you from heavy metal poisoning, many kinds of poisonings.
>
> **Caller:** It's the first I've heard that cholesterol is protective. I’ll look into that.
>
> **Herb Doctor:** On Dr. Peat's website there are several articles specifically on cholesterol and it’s cardio-protective and anti-inflammatory health effects. And I said at the beginning of this show, there are two recent articles, both peer-reviewed, demonstrating clearly that cholesterol was beneficial in the outcome of heart failure patients, what Dr. Peat has been saying for a long time.

### Source 4 — Cholesterol, longevity, intelligence, and health.

Ray Peat · Article · 2007 · https://raypeat.com/articles/articles/cholesterol-longevity.shtml

> Ever since the time of Virchow, who called atherosclerosis arteritis deformans, the inflammatory nature of the problem has been clear to those who aren't crazed by the anticholesterol cult. We are all subject to a variable degree of inflammatory stimulation from the endotoxin absorbed from the intestine, but a healthy liver normally prevents it from reaching the general circulation, and produces a variety of protective factors.
>
> The HDL lipoprotein is one of these, which protects against inflammation by binding bacterial endotoxins that have reached the bloodstream. (Things that increase absorption of endotoxin—exercise, estrogen, ethanol—cause HDL to rise.) Chylomicrons and VLDL also absorb, bind, and help to eliminate endotoxins. All sorts of stress and malnutrition increase the tendency of endotoxin to leak into the bloodstream.
>
> Thyroid hormone, by increasing the turnover of cholesterol and its conversion into the protective steroids, is a major factor in keeping the inflammatory processes under control. In hypothyroidism, the pituitary secretes more TSH to activate the thyroid gland, but TSH itself has a variety of pro-inflammatory actions. The C-reactive protein (CRP), which is recognized as a factor contributing to atherosclerosis, is increased in association with TSH. CRP activates mast cells, which are found in the atheroma plaques, to produce a variety of pro-inflammatory substances, including histamine.
>
> The belief that cells are controlled by a plasma membrane, and that cholesterol's main function is to participate in that membrane, has led to a culture that treats cholesterol physiology with little curiosity. A different perspective on the cell starts with a recognition of the lipophilic nature of the structural proteins (not "membrane proteins," but things like cytoskeleton-cytoplasmic ground substance, spindle, centrosome-centrioles, nuclear matrix, etc.), with which lipids interact.
>
> Modifying an extremely complex system, the living substance, cholesterol participates in complexity, and must be investigated with subtlety. I suspect that the physiological meaning of cholesterol has to do with movement, stability, differentiation, memory, and sensitivity of the parts of the cells, that is, with everything physiological.
>
> The functions of cholesterol parallel the functions of other sterols in plants and other types of organism.

### Source 5 — One Radio Network: Ray Peat with Patrick Timpone — December 20, 2021

Ray Peat · Interview · Dec 20, 2021

> **Patrick Timpone:** Well, what does that tell us about the healthy and the
>
> **Ray Peat:** We powerfully regulate the amount of circulating cholesterol because it's an essential factor in our health. And the reason cholesterol rises is that it's a defensive substance. If you increase the amount of blood and just look at the ovaries production of progesterone, the amount of cholesterol in the blood going into the ovary exactly corresponds to the amount of progesterone coming out of the ovary on the other side. And that means that when the blood level of cholesterol rises, your body is increasing it so that the defensive protective organs including DHEA, progesterone, and pregnenolone and so on, that these will be increased protectively.
>
> **Patrick Timpone:** So that's one of the arguments why folks try to get that cholesterol number up?

### Source 6 — Ask the Herb Doctor: Heart II

Ray Peat · Interview · Jun 21, 2013 · http://l-i-g-h-t.com/files/herb-doctors-heart-2.mp4

> ## Caller: HDL vs. LDL Cholesterol
>
> **Caller (Southern Humboldt):** What do you think of the ratio between HDL and LDL cholesterol?
>
> **Ray Peat:** Both of them are anti-inflammatory. The protein which carries the cholesterol has a major biological effect defending against irritants. However, studies show a correlation between very high HDL and inflammatory diseases like cancer, because HDL rises defensively against chemical irritants. For example, drinking too much alcohol or exposure to fish oil peroxidation will raise your HDL defensively.
>
> **Caller (Southern Humboldt):** So you are saying HDL is the bad cholesterol?
>
> **Ray Peat:** No, it is defensive. But having it high doesn't necessarily mean you are on a good diet program.
>
> **Caller (Southern Humboldt):** What is a good ratio?
>
> **Ray Peat:** It isn't that simple, but a ratio of two or three LDL to one HDL is usually reasonable.

### Source 7 — How to assess metabolic and thyroid health with Danny Roddy

Danny Roddy · Interview · Jun 18, 2021 · https://www.youtube.com/watch?v=i2giM8RiauY

> **Strong Sistas:** Yeah, I think let's touch on cholesterol really quickly because a flashback a year ago, we were emailing, Sarah and I were emailing Danny about cholesterol. And for anyone that's been following us for a while, Sarah and I were definitely what's termed lean mass hyper responders. And I had a cholesterol close to 500. So this is LDL quote, bad cholesterol. I had LDL close to 500. Sarah was above 500. And then after introducing carbohydrates, reducing exercise, it was about, I think, four months in, I got my cholesterol levels rechecked and it dropped down to like 225. And so to me, that was like a huge sign that my thyroid had improved because Danny sent us all these papers, like literally a huge list of papers from like, what, the 40s and... 30s, 40s, and 50s.
>
> **Danny Roddy:** There's a lot of reasons. I don't know what I forgot what I sent you, but there's any year you want, I'll send you a paper from like confirming that exact same thing.
>
> **Strong Sistas:** Yeah. So he, he opened our eyes to high LDL cholesterol is very much a sign of hypothyroidism. Like there's, this has been well-documented. for in a number of papers. And it was shown by me introducing carbohydrates and improving my thyroid and metabolism that my cholesterol dropped in half within just a few months. And can you share your story about accidentally overdosing?

### Source 8 — Bioenergetic Helpline #5: High-Dose T3, DHT Experience, Ray Peat, Thyroid Resistance, H. Pylori

Danny Roddy · Interview · Dec 27, 2025 · https://www.youtube.com/watch?v=lb1OT_MbAYo

> **Danny Roddy:** my kind of arbitrary scale is like 160 to 200 and for hdl like an ldl the only way i think about that is a long time ago ray had said that like somebody asked him straight up what they should be and he said it was complicated but that you should have like some like three or four ldl per hdl that hdl can increase with estrogen exposure alcohol like over exercising can do it like endotoxin and so it's not really great to have your hdl really high it's good that it means your body's working like it's defensive but it's not good to have it high you know and then the ldl tends to follow the total and so if the total is high the ldl will usually be high as well and the ldl is the part of cholesterol that's turned into the steroids and but for what it's worth like i mean you probably infer this just from listening to these episodes but i think total is like one of the best thyroid tests and like i just talked to somebody their cholesterol was like seven or eight or something which is like well over like close to 300 or something like it's really high and so again that just makes life easy when your cholesterol is that high it's just like obviously the person is extremely low thyroid and then of course when your cholesterol is too low that's actually a lot more challenging you have to troubleshoot a bunch of stuff to figure out why the liver isn't making enough

### Source 9 — Cholesterol, longevity, intelligence, and health.

Ray Peat · Article · 2007 · https://raypeat.com/articles/articles/cholesterol-longevity.shtml

> I think editors of medical journals generally see themselves as the purveyors of enlightenment, i.e., as the pushers of the stylish and prestigious doctrines. (Selectivity of evidence to serve the received doctrine is the commonest form of scientific dishonesty.) But because their mental framework is culturally narrow, they sometimes publish things which later could turn out to be embarrassing (if inconsistency could embarrass such types).
>
> The recent discovery that the size of the LDL particle is a predominant factor in the development of atherosclerosis is one of those things that the editors and medical professors should find embarrassing. Smaller lipoprotein particles have a greater surface area exposed to the oxidative factors in the serum, and so are more rapidly degraded into toxic substances. People with larger LDL particles are remarkably resistant to heart disease, and the drug companies are looking for a way to turn their lipoproteins into products.
>
> But the conditions that govern the size of the LDL particles are physically and chemically reasonable, and are causing confusion among the doctrinaire.
>
> There have been several studies in India showing that consumption of butter and ghee is associated with a low incidence of heart disease; for example, according to one study, people in the north eat 19 times more fat (mostly butter and ghee) than in the south, yet the incidence of heart disease is seven times higher in the south.
>
> A study in Sweden found that the fatty acids in milk products are associated with larger LDL particles (Sjogren, et al., 2004). In a 35 day study, when butter (20% of the calories) was compared to various kinds of margarine (with more trans fatty acids) in a similar quantity, the LDL particles were bigger on the butter diet (Mauger, et al., 2003). But in a study of the habitual diet of 414 people, large LDL particles were found to be correlated with increased intake of protein, animal fat, and trans fatty acids (Kim and Campos, 2003).
>
> In a study of the effect of dietary cholesterol on the atherogenicity of the blood lipids, 52 people were given either an egg diet (with 640 mg. of extra cholesterol per day) or a placebo diet for 30 days. Those whose LDL increased the most on the high cholesterol diet had the largest LDL particle size (Herron, et al., 2004).

_Generated 2026-07-20 from the Bioenergetic Oracle corpus._