Ray Peat on cholesterol

The link between hypothyroidism and arteriosclerosis

"Several researchers showed in the 1930s and 1940s that hypothyroidism causes arteriosclerosis and that thyroid supplementation corrects this. In people whose thyroid gland was removed, serum cholesterol increased while their metabolic rate slowed down, and when they were given dried thyroid to normalize their metabolic rate, their serum cholesterol normalized immediately accordingly."

September 2018 – Ray Peat's Newsletter

The role of cholesterol in progesterone production

"The rising cholesterol had a protective function. For example, if the amount of cholesterol flowing into an ovarian artery was increased, the amount of progesterone flowing out of an ovarian vein increased proportionally, as the raw material was converted into the product."

September 2018 – Ray Peat's Newsletter

The popularity of the lipid bilayer cytoplasmic membrane

"In the 1960s, the lipid bilayer of the cytoplasmic membrane was a real hype, and the physical properties of cholesterol and saturated fatty acids were popularly used to explain everything in terms of membrane fluidity. (Between January 1964 and the present, PubMed lists more than 37,000 entries on the lipid bilayer.)"

September 2018 – Ray Peat's Newsletter

Cell stiffness and degenerative changes unrelated to cholesterol

"The actual physical stiffness of entire cells and their environment is very important. For example, excitotoxicity (Fang et al., 2014) and other forms of energy deficiency can stiffen cells, and persistent energy deficiency as well as inflammation lead to degenerative changes—such as tissue calcification, fibrosis, and invasive, disordered cell movement. These stress-induced stiffenings of the cell substance and matrix are not directly related to the local amount of cholesterol."

September 2018 – Ray Peat's Newsletter

The role of cholesterol in the flexibility of red blood cells

"When the cholesterol level of red blood cells is experimentally lowered, they become more rigid, and restoring the normal cholesterol level restores their flexibility."

September 2018 – Ray Peat's Newsletter

Comparative cholesterol content in fat and muscle tissue

"In the body, adipose tissue with a high fat content has a significantly lower cholesterol content than muscle tissue. This is partly because muscles produce more cholesterol than adipose tissue, but also because the structural proteins of the cells have a high affinity for cholesterol. As a result, fat and proteins are mutually soluble."

September 2018 – Ray Peat's Newsletter

Composition of the protoplasm and cholesterol as a lubricant

"I think it's correct to view protoplasm as a complex type of solution made up of proteins, water, cholesterol and other lipids, nucleic acids, ATP, and smaller amounts of other substances, with a viscosity that changes when small alterations in the solutes shift the balance of cohesive forces. Due to its molecular shape and hydrophobicity, cholesterol acts as both a lubricant and a stabilizer of this complex system. It reduces cell stiffness by increasing protein mobility."

September 2018 – Ray Peat's Newsletter

Paradox of the lipid bilayer membrane doctrine

"The fact that cholesterol strengthens cells and protects them from breaking down under stress obviously has nothing to do with a lipid bilayer membrane. This membrane doctrine has made it seem paradoxical that the loss of cholesterol makes cells stiffer and weaker at the same time. Gilbert Ling has been pointing out the numerous paradoxes faced by proponents of the lipid boundary membrane for 65 years, yet the membrane doctrine continues to prevail."

September 2018 – Ray Peat's Newsletter

Discovery of the oxidation impurity of commercial cholesterol

"About 40 years ago, someone noticed that the commercial cholesterol used for research purposes was contaminated by oxidation and that pure cholesterol did not produce the same toxic effects."

September 2018 – Ray Peat's Newsletter

Composition of foam cells and their influence on cholesterol regulation

"The foam cells found in atherosclerotic plaques contain cholesterol esters, primarily cholesteryl eicosapentaenoate, cholesteryl docosahexaenoate, cholesteryl arachidonicate, cholesteryl linoleate, and cholesteryl oleate. The oxidation of these fatty acids produces acrolein and related compounds that block the cells' ability to regulate cholesterol."

September 2018 – Ray Peat's Newsletter

PUFA and the impairment of normal cholesterol functions

"In combination with unstable polyunsaturated fatty acids, cholesterol cannot perform its normal functions. The unstable polyunsaturated fatty acids inactivate the corrective (ABCA) protein that removes the damaged form of cholesterol."

September 2018 – Ray Peat's Newsletter

Cholesterol in the young and aging brain

"The healthy young brain contains a very large amount of cholesterol, almost exclusively in pure, non-esterified or free form – more than 99.5%, according to Orth and Bellosta (2012, citing Bjorkhem and Meaney, 2004). The aging, degenerating brain contains an increasing amount of esterified cholesterol."

September 2018 – Ray Peat's Newsletter

Carcinogenic nature of PUFAs and interest of the pharmaceutical industry

"While there remains a great reluctance to acknowledge the carcinogenic nature of PUFA, findings such as these have prompted the pharmaceutical industry to consider using its ACAT inhibitors (which block the binding of PUFA to cholesterol) to treat cancer."

September 2018 – Ray Peat's Newsletter

Conversion of cholesterol into a toxin by PUFA

“Polyunsaturated fatty acids transform cholesterol into a kind of toxin, a disorganizing factor that leads to neurodegeneration, hardening of the arteries, cataracts, chronic kidney disease and cancer, by binding to the normally protective cholesterol.”

September 2018 – Ray Peat's Newsletter

Liver response to a deficiency of polyunsaturated fatty acids

"If the diet lacks polyunsaturated fatty acids, the liver synthesizes saturated fatty acids and exports its cholesterol mainly in combination with palmitate, which does not promote lipid peroxidation, or in the non-esterified, free form."

September 2018 – Ray Peat's Newsletter

Reversing liver degeneration through diet

"A lifelong accumulation of PUFA gradually impairs the protective functions of the liver, but these functions can be gradually restored by supplying carbohydrates and saturated fats without polyunsaturated fatty acids, along with some of the factors that have been depleted along with free cholesterol, especially pregnenolone and progesterone."

September 2018 – Ray Peat's Newsletter

Progesterone therapy for male infertility and sports-related infertility

"Progesterone is the precursor (after acetate and cholesterol) for all other steroid hormones and can therefore also be used in men. It (or its precursor pregnenolone) has been used for prostatitis, arthritis, and male infertility. Large amounts would likely suppress LH and lower testosterone synthesis, but smaller amounts (especially in older men) appear to increase sperm count and motility. In male and female athletes who become infertile, it seems to be the appropriate therapy, usually in combination with thyroid hormones."

Nutrition For Women

Dietary cholesterol and liver cholesterol production

"Since a healthy liver produces cholesterol to compensate for a deficiency in the diet, avoiding cholesterol-rich foods does not necessarily lead to lower cholesterol levels in the blood."

Nutrition For Women

Influence of vitamin C on cholesterol and related nutrients

"According to current knowledge, vitamin C lowers cholesterol levels in the blood. Eggs are rich in cholesterol, but they also contain lecithin, which apparently makes cholesterol usable or at least less harmful. Niacin and vitamin E also help regulate cholesterol. High insulin levels, caused by sugar consumption, seem to play an important role in cholesterol's ability to damage blood vessels."

Nutrition For Women

Link between high cholesterol, hypothyroidism and heart attacks

"High cholesterol usually indicates low thyroid function. If thyroid function is reduced, cholesterol is not efficiently converted into progesterone. The actual cause of heart attacks appears to be hypothyroidism and its effects, including a loss of magnesium."

Nutrition For Women

Eggs and their protective role against cholesterol deposits

"Eggs could actively protect against the formation of cholesterol deposits for several reasons. One of the men who discovered insulin, Best, later showed that choline (a component of lecithin) can prevent fatty degeneration of the liver."

Nutrition For Women

Comparison of the effects of margarine and butter on circulatory diseases

"Animal studies show that margarine causes more cardiovascular disease than butter or cholesterol."

Nutrition For Women

Influence of thyroid hormones on metabolic rate and body temperature

"In the 1930s, it was known that thyroid hormones increase the metabolic rate and raise body temperature. Since serum cholesterol decreased in proportion to the increased metabolic rate due to thyroid supplementation, it was suggested that cholesterol measurement be used to diagnose hypothyroidism."

November 2020 – Ray Peat's Newsletter

Aging skin, progesterone and vitamin D

"It has been known for several decades that the production of progesterone and DHEA steadily declines with age, and in recent years it has been found that aged skin produces only about half as much vitamin D as young skin when exposed to sunlight. Old skin contains about half as much cholesterol as young skin, so it is not surprising that the substances derived from it are also reduced."

November 2018 – Ray Peat's Newsletter

Cholesterol levels and the appearance of aged skin

"The characteristic cloudiness of aged skin is the result of an accumulation of layers of dead cells on the surface. While the living, underlying skin cells contain significantly less cholesterol than normal, the inert cells exhibit an increased amount of cholesterol sulfate. If the level of free cholesterol in the skin is experimentally increased, the skin regains its ability to shed the dead superficial cells. Conversely, if it is experimentally lowered, for example by a statin, the skin takes on the structure and appearance of aged skin. Aging appears to be a state of cholesterol deficiency."

November 2018 – Ray Peat's Newsletter

Low cholesterol and its effects on mental health

"Low serum cholesterol has been linked to depression, suicide, violence, and increased cancer mortality. Since statins cross into the brain and inhibit cholesterol synthesis there, reduced mitochondrial function is undoubtedly a factor in the psychological side effects they can cause."

November 2018 – Ray Peat's Newsletter

Synergy of cholesterol and progesterone

"The functions of cholesterol are similar in many respects to those of progesterone. In the pregnant uterus, for example, the relaxing effect of progesterone is supported by cholesterol (Smith et al., 2005). In the brain, nerve excitation is controlled by glutamic acid via a receptive protein that binds this neurotransmitter, and the function of this protein depends on cholesterol; a reduction in cholesterol prolongs nerve excitation."

November 2018 – Ray Peat's Newsletter

Interaction of the cell nucleus with cholesterol and lipids

"Within the cell nucleus is a highly organized substance, the nuclear matrix, which interacts closely with the rest of the cytoskeleton and enables the DNA to be expressed according to the needs of the cell and in response to its environment. Cholesterol and other lipids are essential for the specific, highly organized interactions between the DNA and the rest of the cell apparatus."

November 2018 – Ray Peat's Newsletter

The role of cholesterol in maintaining stem cells

"Cholesterol is involved in maintaining stem cells and controlling their maturation into functional cells. A cholesterol chelator, cyclodextrin, which affects cellular cholesterol, causes cardiac stem cells to mature into functional heart muscle cells: β-CD fulfilled its effect by increasing free intracellular cholesterol."

November 2018 – Ray Peat's Newsletter

Excitatory signal transmission and cholesterol in the brain

"Excitatory signaling appears to contribute to the loss of cholesterol in the brain during aging; the amount of cholesterol in synapses decreases with age (Sodero et al., 2011). Although excitatory (glutamatergic) stimulation lowers cholesterol in the brain, environmental enrichment (meaningful experiences) increases it (Levi et al., 2005) and also reverses the age-related decline in cholesterol-derived neurosteroids."

November 2018 – Ray Peat's Newsletter

Accumulation of cholesterol esters and neurodegeneration

"In the brain, the accumulation of cholesterol esters (at the expense of free cholesterol) increases with age and contributes to neurodegeneration. Interventions that detach cholesterol from fatty acids have a neuroprotective effect in a worm model of Parkinson's disease."

November 2018 – Ray Peat's Newsletter

Lipofuscin formation from polyunsaturated fatty acids

"The age pigment lipofuscin is formed by the oxidation of polyunsaturated lipids. The polyunsaturated fatty acids, which accumulate with age, have been known as the main source of this material for about 80 years. These fatty acids inhibit the synthesis of cholesterol."

November 2018 – Ray Peat's Newsletter

Increase in cholesterol ester concentration with age

"At birth, the concentration of cholesterol esters is very low, and this proportion remains low until about the age of 20, when growth slows down. After the age of 20, cholesterol esters accumulate at about five times the rate of cholesterol accumulation. After the age of 40, cholesterol esters become the main component of the lipids in blood vessels."

November 2018 – Ray Peat's Newsletter

Stress-induced increase in serum cholesterol as an adaptive response

"The stress-induced increase in serum cholesterol is an important protective adaptation."

November 2018 – Ray Peat's Newsletter

Methods for reducing the formation of cholesterol esters

"Besides avoiding polyunsaturated fatty acids (n-3 and n-6) in the diet to reduce the formation of cholesterol esters and mitigate the age-related decline in cholesterol synthesis, progesterone supplementation is another way to reduce ester formation (Synouri-Vrettakou and Mitropoulos, 1983; Miller and Melnykovych, 1984; Jeng and Klem, 1984; Mulas et al., 2011; Anchisi et al., 2012). Lidocaine is another inhibitor of cholesterol ester formation (Bell, 1981; Bell et al., 1982) that is likely to be beneficial in certain degenerative diseases."

November 2018 – Ray Peat's Newsletter

The role of cholesterol in the production of neurosteroids

"Cholesterol is the precursor to pregnenolone, progesterone and the other neurosteroids, and its own properties include stabilizing effects similar to those of progesterone."

May 2019 – Ray Peat's Newsletter

Cholesterol after childbirth and mental health

"Several studies have found a link between lower cholesterol levels after childbirth and symptoms of anxiety and depression."

May 2019 – Ray Peat's Newsletter

Progesterone after childbirth and brain health

"With insufficient cholesterol, the normally high progesterone concentration after birth is unlikely to be maintained, and instead of brain regeneration, the various pro-inflammatory effects of serotonin and estrogen predominate, with consequences such as depression, joint pain, anxiety and cerebral edema."

May 2019 – Ray Peat's Newsletter

Conversion of animal cholesterol to steroids and the role of the thyroid gland

"In animals, cholesterol is the basic sterol molecule that is extensively converted into other substances, including steroid hormones. Thyroid hormones and vitamin A are required for this conversion."

Generative Energy Restoring The Wholeness Of Life

Historical evidence of thyroid deficiency in the USA

“Many researchers found (before the late 1940s) that about 40% of people in the USA showed signs of inadequate thyroid function (low oxygen consumption and high serum cholesterol) and benefited from taking a thyroid supplement.”

Generative Energy Restoring The Wholeness Of Life

Mitochondrial damage affects hormone production and energy.

"Since protective hormones depend on the mitochondria's ability to convert cholesterol into pregnenolone, it is clear that damage to the mitochondria impairs our supply of protective hormones while simultaneously causing energy production to fail. This forces the body to shift towards atrophy-promoting stress hormones, including cortisol."

Generative Energy Restoring The Wholeness Of Life

The role of thyroid hormones in cholesterol conversion

"Thyroid hormones tend to lower cholesterol levels by converting it into pregnenolone and other steroids."

Email Response by Ray Peat

Reassessment of the role of cholesterol in heart disease

"Given the clear and well-defined toxicity of adrenaline and free fatty acids, the role of cholesterol in heart disease begins to appear rather epiphenomenal."

June 1992 - Ray Peat's Newsletter

The role of blood cholesterol in immune function and allergies

"Both low and high blood cholesterol levels are associated with immunodeficiency. Most people I've spoken to who have multiple severe allergies have very low cholesterol levels, while hypothyroid people, who are very susceptible to infections, usually have high cholesterol levels."

December 1992 – Ray Peat's Newsletter

Effect of endotoxins on mitochondrial respiration and pregnenolone

"Bacterial endotoxins inhibit mitochondrial respiration, and this respiration is necessary for the intramitochondrial conversion of cholesterol to pregnenolone."

August-September 1992 - Ray Peat's Newsletter

Mitochondrial damage and impaired pregnenolone production

"If the mitochondria are damaged, the protective steroid pregnenolone (which is formed from cholesterol in the mitochondria) cannot be produced."

January 1991 - Ray Peat's Newsletter

Promotion of protective hormones with succinic acid and atropine

"The protective hormones can be used directly, or their synthesis can be promoted by the use of succinic acid, thyroid hormones, vitamin A and atropine-like drugs, as well as by maintaining adequate cholesterol levels."

January 1991 - Ray Peat's Newsletter

Unsaturated oils, cholesterol and increased cancer mortality

"It was already established decades ago that unsaturated oils lower cholesterol levels. However, studies showed that adding polyunsaturated oils to the diet did not prevent deaths from heart disease, but rather increased cancer mortality."

April 1991 - Ray Peat's Newsletter

Influence of cholesterol on the production of protective hormones

"The highest concentration of cholesterol in the body is found in the brain. The cholesterol level in the blood strongly influences the production of protective hormones such as progesterone."

October 1990 - Ray Peat's Newsletter

Positive feedback systems with progesterone and thyroid hormones

"However, the presence of some positive feedback systems (self-stimulation) shows that in our basic structure we are oriented in an expansive, upward direction. Progesterone (and its precursors pregnenolone and cholesterol) as well as thyroid hormones are involved in some of the important positive feedback systems that affect energy production, stress resistance and brain growth."

October 1990 - Ray Peat's Newsletter

Cholesterol conversion in the mitochondria and its effects on hormones

"Within the mitochondria, a cytochrome P-450 converts cholesterol into pregnenolone. The loss of both energy and steroid hormones would have far-reaching consequences."

January 1989 - Ray Peat's Newsletter

The role of thyroid hormones in estrogen breakdown and progesterone production

"While thyroid hormones promote the breakdown of estrogen, they are also essential for the production of progesterone. Vitamin A (along with cholesterol) is consumed at a high rate by the corpus luteum when sufficient thyroid hormone is present."

January 1988 - Ray Peat's Newsletter

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