Cholesterol is absolutely vital for our existence - Attia

the essential nature of cholesterol

 

 

 

 

“Cholesterol is absolutely vital for our existence.       

  Peter Attia, MD

 

Let’s note right off the bat, there’s no such thing as ‘good and bad’ cholesterol. As shown below, cholesterol is a single natural substance – the grandmother steroid – featuring a four-ring structure of carbon atoms.

All steroid hormones (such as Vitamin D) are made from cholesterol, but, as we shall learn, cholesterol is much more than a hormone.

 

Cholesterol is made in a complex 27-step process from the 2-carbon substance called acetyl-CoA. The 4-ring structure is the chemical signature of a steroid. On the bottom left, there’s a hydrocarbon tail (HO), where cholesterol esterifies (or attaches) to other molecules and a hydroxyl group- top right.

 

Classified as a fat-soluble lipid, cholesterol is not a fat, it has no calories, and it’s not a source of energy. Cholesterol is a sterol – a high molecular weight alcohol. Animals, plants, and microorganisms require different sterols.

 

Cholesterol is the animal sterol – found in every cell in animal bodies. It is true that, as a minor component, cholesterol can be found in plant membranes, but the sterols  sitosterol and stigmasterol predominate in plants.

 

According to UK lipid biochemist Michael Gurr:   “Only cholesterol will allow animal cells to function as required. Without cholesterol, our bodies would not function properly and we would die.”

 

Cholesterol waterproofs our trillions of membranes, making it possible for our cells to regulate their internal environments – policing and maintaining “cellular security.” Cholesterol also plays a key role in intra and inter-cellular communications and signaling.

 

Cholesterol ensures that the cell’s lipid bi-layer (two layers of fat in phospholipid form) is neither too rigid nor too flexible. If that’s not enough, cholesterol is the goddess-like precursor to all adrenal, steroid and sex hormones such as estrogen and testosterone. Without cholesterol, we could not stand, move, think, respond to stress – or reproduce!

 

Cholesterol is also a major component of bile, an emulsifier required for dietary fats to be broken down and utilized. As a constituent of bile – on its singular route out of the body – cholesterol coats our slowly transiting feces. Only the liver can order cholesterol out of the body – and much of it is recycled.  Sorry Cheerios!

The liver is the main site of cholesterol synthesis, but every cell can make cholesterol (except nervous tissue).  Our bodies contain up to 100 grams of cholesterol – 90 percent in cell membranes and the rest dissolved in adipose and other tissues. The highest concentration (25 percent) is in the nerve cell connections and in the myelin that protects brain and nervous tissue.

 

In particular, infants need a large amount of cholesterol for proper brain development – and very large amounts of cholesterol are supplied in human milk – not in formula. Cholesterol is needed to properly form the part of the brain that allows the eyes to develop normally. In young and old alike, cholesterol is a primary raw material for many healing processes.

As an example, when an injury occurs on the Teflon-like, slick endothelial layer in an artery – say from high blood sugar – the body’s first responders are cholesterol, blood platelets, specialized white blood cells, and other materials that patch up the injury – similar to a scab forming over a break in the skin.

In the Optimal Diet, eggs are a “free food.”

 

“Cholesterol is absolutely essential for life,” writes Peter Attia, MD, President and co-Founder of the Nutrition Science Initiative:

“The animal body must have cholesterol to function properly and  to manufacture vital hormones and chemicals.”

And, for people whose bodies may not properly synthesize cholesterol, cholesterol in food may be a conditionally essential nutrient.

As you may note, the medical profession has utterly failed to properly describe the essential nature of cholesterol. Future editions of Diet Heart News will continue to expound on the importance of cholesterol and saturated fat in the American diet.
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Read the complete article here.

LDL is not “bad cholesterol” & it cannot build up in artery walls. Read the truth.

Cholesterol: Friend Or Foe?

Written by Natasha Campbell-McBride, MD

Sunday, 04 May 2008 19:17

The art of medicine consists in amusing the patient while nature cures the disease. --Voltaire In our modern world, cholesterol has become almost a swear word. Thanks to the promoters of the diet-heart hypothesis, everybody "knows" that cholesterol is "evil" and has to be fought at every turn. If you believe the popular media, you would think that there is simply no level of cholesterol low enough. If you are over a certain age, you are likely to be tested for how much cholesterol you have in your blood. If it is higher than about 200 mg/100ml (5.1 mol/l), you may be prescribed a "cholesterol pill." Millions of people around the world take these pills, thinking that this way they are taking good care of their health. What these people don’t realize is just how far from the truth they are. The truth is that we humans cannot live without cholesterol. Let us see why. Our bodies are made out of billions of cells. Almost every cell produces cholesterol all the time during all of our lives. Why? Because every cell of every organ has cholesterol as a part of its structure. Cholesterol is an integral and very important part of our cell membranes, the membranes that enclose each of our cells, and also of the membranes surrounding all the organelles inside the cell. What is cholesterol doing there? A number of things. Structural Integrity First of all, saturated fats and cholesterol make the membranes of the cells firm—without them the cells would become flabby and fluid. If we humans didn’t have cholesterol and saturated fats in the membranes of our cells, we would look like giant worms or slugs. And we are not talking about a few molecules of cholesterol here and there. In many cells, almost half of the cell membrane is made from cholesterol. Different kinds of cells in the body need different amounts of cholesterol, depending on their function and purpose. If the cell is part of a protective barrier, it will have a lot of cholesterol in it to make it strong, sturdy and resistant to any invasion. If a cell or an organelle inside the cell needs to be soft and fluid, it will have less cholesterol in its structure. This ability of cholesterol and saturated fats to firm up and reinforce the tissues in the body is used by our blood vessels, particularly those that have to withstand the high pressure and turbulence of the blood flow. These are usually large or medium arteries in places where they divide or bend. The flow of blood pounding through these arteries forces them to incorporate a layer of cholesterol and saturated fat in the membranes, which makes it stronger, tougher and more rigid. These layers of cholesterol and fat are called fatty streaks. They are completely normal and form in all of us, starting from birth and sometimes even before we are born. Various indigenous populations around the world, who never suffer from heart disease, have plenty of fatty streaks in their blood vessels in old and young, including children. Fatty streaks are not indicative of the disease called atherosclerosis. Lipid Lifesavers All the cells in our bodies have to communicate with each other. How do they do that? They use proteins embedded into the membrane of the cell. How are these proteins fixed to the membrane? With the help of cholesterol and saturated fats! Cholesterol and stiff saturated fatty acids form so-called lipid rafts, which make little homes for every protein in the membrane and allow it to perform its functions. Without cholesterol and saturated fats, our cells would not be able to communicate with each other or to transport various molecules into and out of the cell. As a result, our bodies would not be able to function the way they do. The human brain is particularly rich in cholesterol: around 25 percent of all body cholesterol is accounted for by the brain. Every cell and every structure in the brain and the rest of our nervous system needs cholesterol, not only to build itself but also to accomplish its many functions. The developing brain and eyes of the fetus and a newborn infant require large amounts of cholesterol. If the fetus doesn’t get enough cholesterol during development, the child may be born with a congenital abnormality called cyclopean eye.1 Human breast milk provides a lot of cholesterol. Not only that, mother’s milk provides a specific enzyme to allow the baby’s digestive tract to absorb almost 100 percent of that cholesterol, because the developing brain and eyes of an infant require large amounts of it. Children deprived of cholesterol in infancy may end up with poor eyesight and brain function. Manufacturers of infant formulas are aware of this fact, but following the anti-cholesterol dogma, they produce formulas with virtually no cholesterol in them. Vital Brain Matter One of the most abundant materials in the brain and the rest of our nervous system is a fatty substance called myelin. Myelin coats every nerve cell and every nerve fiber like the insulating cover around electric wires. Apart from insulation, it provides nourishment and protection for every tiny structure in our brain and the rest of the nervous system. People who start losing their myelin develop a condition called multiple sclerosis. Well, 20 percent of myelin is cholesterol. If you start interfering with the body’s ability to produce cholesterol, you put the very structure of the brain and the rest of the nervous system under threat. The synthesis of myelin in the brain is tightly connected with the synthesis of cholesterol. In my clinical experience, foods with high cholesterol and high animal fat content are an essential medicine for a person with multiple sclerosis. One of the most wonderful abilities we humans are blessed with is the ability to remember things—our human memory. How do we form memories? By our brain cells establishing connections with each other, called synapses. The more healthy synapses a person’s brain can make, the more mentally able and intelligent that person is. Scientists have discovered that synapse formation is almost entirely dependent on cholesterol, which is produced by the brain cells in a form called apolipoprotein E. Without the presence of this factor we cannot form synapses, and hence we would not be able to learn or remember anything. Memory loss is one of the side effects of cholesterol-lowering drugs. In my clinic, I see growing numbers of people with memory loss who have been taking cholesterol- lowering pills. Dr Duane Graveline, MD, former NASA scientist and astronaut, suffered such memory loss while taking his cholesterol pill. He managed to save his memory by stopping the pill and eating lots of cholesterol-rich foods. Since then he has described his experience in his book, Lipitor: Thief of Memory, Statin Drugs and the Misguided War on Cholesterol. Dietary cholesterol in fresh eggs and other cholesterol-rich foods has been shown in scientific trials to improve memory in the elderly. In my clinical experience, any person with memory loss or learning problems needs to have plenty of these foods every single day in order to recover. Necessary Product Of The Body These foods give the body a hand in supplying cholesterol so it does not have to work as hard to produce its own. What a lot of people don’t realize is that most cholesterol in the body does not come from food! The body produces cholesterol as it is needed. Scientific studies have conclusively demonstrated that cholesterol from food has no effect whatsoever on the level of our blood cholesterol. Why? Because cholesterol is such an essential part of our human physiology that the body has very efficient mechanisms to keep blood cholesterol at a certain level. When we eat more cholesterol, the body produces less; when we eat less cholesterol, the body produces more. As a raw material for making cholesterol the body can use carbohydrates, proteins and fats, which means that your pasta and bread can be used for making cholesterol in the body. It has been estimated that, in an average person, about 85 percent of blood cholesterol is produced by the body, while only 15 percent comes from food. So, even if you religiously follow a completely cholesterol-free diet, you will still have a lot of cholesterol in your body. However, cholesterol-lowering drugs are a completely different matter! They interfere with the body’s ability to produce cholesterol, and hence they do reduce the amount of cholesterol available for the body to use. Dangers Of Low Cholesterol If we do not take cholesterol-lowering drugs, most of us don’t have to worry about cholesterol. However, there are people whose bodies, for whatever reason, are unable to produce enough cholesterol. These people are prone to emotional instability and behavioral problems. Low blood cholesterol has been routinely recorded in criminals who have committed murder and other violent crimes, people with aggressive and violent personalities, people prone to suicide and people with aggressive social behavior and low self-control. I would like to repeat what the late Oxford professor David Horrobin warned us about: "Reducing cholesterol in the population on a large scale could lead to a general shift to more violent patterns of behavior. Most of this increased violence would not result in death but in more aggression at work and in the family, more child abuse, more wife-beating and generally more unhappiness." People whose bodies are unable to produce enough cholesterol do need to have plenty of foods rich in cholesterol in order to provide their organs with this essential-to-life substance. What else does our body need all that cholesterol for? Endocrine System After the brain, the organs hungriest for cholesterol are our endocrine glands: adrenals and sex glands. They produce steroid hormones. Steroid hormones in the body are made from cholesterol: testosterone, progesterone, pregnenolone, androsterone, estrone, estradiol, corticosterone, aldosterone and others. These hormones accomplish a myriad of functions in the body, from regulation of our metabolism, energy production, mineral assimilation, brain, muscle and bone formation to behavior, emotions and reproduction. In our stressful modern lives we consume a lot of these hormones, leading to a condition called "adrenal exhaustion." This condition is diagnosed very often by naturopaths and other health practitioners. There are many herbal preparations on the market for adrenal exhaustion. However, the most important therapeutic measure is to provide your adrenal glands with plenty of dietary cholesterol. Without cholesterol we would not be able to have children because every sex hormone in our bodies is made from cholesterol. A fair percentage of our infertility epidemic can be laid at the doorstep of the diet-heart hypothesis. The more eager we became to fight animal fats and cholesterol, the more problems with normal sexual development, fertility and reproduction we started to face. About a third of western men and women are infertile, and increasing numbers of our youngsters are growing up with abnormalities in their sex hormones. These abnormalities lead to many physical problems. Recent research has "discovered" that eating full-cream dairy products cures infertility in women.2 Researchers found that women who drink whole milk and eat high-fat dairy products are more fertile than those who stick to low-fat products. Study leader Dr Jorge Chavarro, of the Harvard School of Public Health, emphasized: "Women wanting to conceive should examine their diet. They should consider changing low-fat dairy foods for high-fat dairy foods, for instance by swapping skimmed milk for whole milk and eating cream, not low-fat yoghurt." The Liver And Vitamin Regulation One of the busiest organs in terms of cholesterol production in our bodies is the liver, which regulates the level of our blood cholesterol. The liver also puts a lot of cholesterol into bile production. Yes, bile is made out of cholesterol. Without bile we would not be able to digest and absorb fats and fat-soluble vitamins. Bile emulsifies fats; in other words, it mixes them with water, so that digestive enzymes can get to them. After it completes its mission, most of the bile gets reabsorbed in the digestive system and brought back to the liver for recycling. In fact, 95 percent of our bile is recycled because the building blocks of bile, one of which is cholesterol, are too precious for the body to waste. Nature doesn’t do anything without good reason. This example of the careful recycling of cholesterol alone should have given us a good idea about its importance for the body! Bile is essential for absorbing fat-soluble vitamins: vitamin A, vitamin D, vitamin K and vitamin E. We cannot live without these vitamins. Apart from ensuring that fat-soluble vitamins get digested and absorbed properly, cholesterol is the major building block of one of these vitamins: vitamin D. Vitamin D is made from the cholesterol in our skin when it is exposed to sunlight. In those times of the year when there isn’t much sunlight, we can get this vitamin from cholesterol-rich foods: cod liver oil, fish, shellfish, butter, lard and egg yolks. Our recent misguided fears of the sun and avoidance of cholesterol-rich foods have created an epidemic of vitamin D deficiency in the Western world. Unfortunately, apart from sunlight and cholesterol-rich foods there is no other appropriate way to get vitamin D. Of course, there are supplements, but most of them contain vitamin D2, which is made by irradiating mushrooms and other plants. This vitamin is not the same as the natural vitamin D. It does not work as effectively and it is easy to get a toxic level of it. In fact, almost all cases of vitamin D toxicity ever recorded were cases where this synthetic vitamin D2 had been used. Toxicity is almost impossible with natural vitamin D obtained from sunlight or cholesterol-rich foods because the body knows how to deal with an excess of natural substances. What the body does not know how to deal with is an excess of synthetic vitamin D2. Vitamin D has been designed to work as a team with another fat-soluble vitamin: vitamin A. That is why foods rich in one tend to be rich in the other. So, by taking cod liver oil, for example, we can obtain both vitamins at the same time. As we grow older, our ability to produce vitamin D in the skin under sunlight is considerably diminished. Taking foods rich in vitamin D is therefore particularly important for older people. For the rest of us, sensible sunbathing is a wonderful, healthy and enjoyable way of getting a good supply of vitamin D. Skin cancer, blamed on sunshine, is not caused by the sun. It is caused by trans fats from vegetable oils and margarine and other toxins stored in the skin. In addition, some of the sunscreens that people use contain chemicals that have been proven to cause skin cancer3. Immune System Health Cholesterol is essential for our immune system to function properly. Animal experiments and human studies have demonstrated that immune cells rely on cholesterol in fighting infections and repairing themselves after the fight. In addition, LDL-cholesterol (low-density lipoprotein cholesterol), the so-called "bad" cholesterol, directly binds and inactivates dangerous bacterial toxins, preventing them from doing any damage in the body. One of the most lethal toxins is produced by a widely spread bacterium, Staphylococcus aureus, which is the cause of MRSA (Methicillin- resistant Staphylococcus aureus), a common hospital infection. This toxin can literally dissolve red blood cells. However, it does not work in the presence of LDL-cholesterol. People who fall prey to this toxin have low blood cholesterol. It has been recorded that people with high levels of cholesterol are protected from infections; they are four times less likely to contract AIDS, they rarely get common colds and they recover from infections more quickly than people with "normal" or low blood cholesterol. People with low blood cholesterol are prone to various infections, suffer from them longer and are more likely to die from an infection. A diet rich in cholesterol has been demonstrated to improve these people’s ability to recover from infections. So, any person suffering from an acute or chronic infection needs to eat high-cholesterol foods to recover. Cod liver oil, the richest source of cholesterol (after caviar), has long been prized as the best remedy for the immune system. Those familiar with old medical literature will tell you that until the discovery of antibiotics, a common cure for tuberculosis was a daily mixture of raw egg yolks and fresh cream. Varying Blood Cholesterol Levels The question is, why do some people have more cholesterol in their blood than others, and why can the same person have different levels of cholesterol at different times of the day? Why is our level of cholesterol different in different seasons of the year? In winter it goes up and in the summer it goes down. Why is it that blood cholesterol goes through the roof in people after any surgery? Why does blood cholesterol go up when we have an infection? Why does it go up after dental treatment? Why does it go up when we are under stress? And why does it become normal when we are relaxed and feel well? The answer to all these questions is this: cholesterol is a healing agent in the body. When the body has some healing jobs to do, it produces cholesterol and sends it to the site of the damage. Depending on the time of day, the weather, the season and our exposure to various environmental agents, the damage to various tissues in the body varies. As a result, the production of cholesterol in the body also varies. Since cholesterol is usually discussed in the context of disease and atherosclerosis, let us look at the blood vessels. Their inside walls are covered by a layer of cells called the endothelium. Any damaging agent we are exposed to will finish up in our bloodstream, whether it is a toxic chemical, an infectious organism, a free radical or anything else. Once such an agent is in the blood, what is it going to attack first? The endothelium, of course. The endothelium immediately sends a message to the liver. Whenever our liver receives a signal that a wound has been inflicted upon the endothelium somewhere in our vascular system, it gets into gear and sends cholesterol to the site of the damage in a shuttle, called LDL-cholesterol. Because this cholesterol travels from the liver to the wound in the form of LDL, our "science," in its wisdom calls LDL "bad" cholesterol. When the wound heals and the cholesterol is removed, it travels back to the liver in the form of HDLcholesterol (high-density lipoprotein cholesterol). Because this cholesterol travels away from the artery back to the liver, our misguided "science" calls it "good" cholesterol. This is like calling an ambulance travelling from the hospital to the patient a "bad ambulance," and the one travelling from the patient back to the hospital a "good ambulance." But the situation has gotten even more ridiculous. The latest thing that our science has "discovered" is that not all LDL-cholesterol is so bad. Most of it is actually good. So, now we are told to call that part of LDL the "good bad cholesterol" and the rest of it the "bad bad cholesterol." Marvelous Healing Agent Why does the liver send cholesterol to the site of the injury? Because the body cannot clear the infection, remove toxic elements or heal the wound without cholesterol and fats. Any healing involves the birth, growth and functioning of thousands of cells: immune cells, endothelial cells and many others. As these cells, to a considerable degree, are made out of cholesterol and fats, they cannot form and grow without a good supply of these substances. When the cells are damaged, they require cholesterol and fats to repair themselves. It is a scientific fact that any scar tissue in the body contains good amounts of cholesterol.4 Another scientific fact is that cholesterol acts as an antioxidant in the body, dealing with free radical damage.5 Any wound in the body contains plenty of free radicals because the immune cells use these highly reactive molecules for destroying microbes and toxins. Excess free radicals have to be neutralized, and cholesterol is one of the natural substances that accomplishes this function. When we have surgery, our tissues are cut and many small arteries, veins and capillaries get damaged. The liver receives a very strong signal from this damage, so it floods the body with LDL-cholesterol to clean and heal every little wound in our blood vessels. That is why blood cholesterol goes high after any surgical procedure. After dental treatment, in addition to the damage to the tissues, a lot of bacteria from the tooth and the gums finish up in the blood, attacking the inside walls of our blood vessels. Once again, the liver gets a strong signal from that damage and produces lots of healing cholesterol to deal with it, so the blood cholesterol goes up. The same thing happens when we have an infection: LDL-cholesterol goes up to deal with the bacterial or viral attack. Apart from the endothelium, our immune cells need cholesterol to function and to heal themselves after the fight with the infection. Our stress hormones are made out of cholesterol in the body. Stressful situations increase our blood cholesterol levels because cholesterol is being sent to the adrenal glands for stress hormone production. Apart from that, when we are under stress, a storm of free radicals and other damaging biochemical reactions occur in the blood. So the liver works hard to produce and send out as much cholesterol as possible to deal with the free radical attack. In situations like this, your blood cholesterol will test high. In short, when we have a high blood cholesterol level, it means that the body is dealing with some kind of damage. The last thing we should do is interfere with this process! When the damage has been dealt with, the blood cholesterol will naturally go down. If we have an ongoing disease in the body that constantly inflicts damage, then the blood cholesterol will be permanently high. So, when a doctor finds high cholesterol in a patient, what this doctor should do is to look for the reason. The doctor should ask, "What is damaging the body so that the liver has to produce all that cholesterol to deal with the damage?" Unfortunately, instead of this sensible procedure, our doctors are trained to attack the cholesterol. Many natural herbs, antioxidants and vitamins have an ability to reduce our blood cholesterol. How do they do that? By helping the body remove the damaging agents, be they free radicals, bacteria, viruses or toxins. As a result, the liver does not have to produce so much cholesterol to deal with the damage. At the same time, vitamins, minerals, antioxidants, herbs and other natural remedies help to heal the wound. When the wound heals there is no need for high levels of cholesterol anymore, so the body removes it in the form of HDL-cholesterol or so-called "good" cholesterol. That is why herbs, vitamins, antioxidants and other natural remedies increase the level of HDL-cholesterol in the blood. In conclusion, cholesterol is one of the most important substances in the body. We cannot live without it, let alone function well. The pernicious diet-heart hypothesis has vilified this essential substance. Unfortunately, this hypothesis has served many commercial and political interests far too well, so they ensure its long survival. However, the life of the diet-heart hypothesis is coming to an end as we become aware that cholesterol has been mistakenly blamed for the crime just because it was found at the scene. Dietary Sources Of Cholesterol Caviar is the richest source; it provides 588 mg of cholesterol per 100 grams. Obviously, this is not a common food for the majority of us, so let us have a look at the next item on the list. Cod liver oil follows closely with 570 mg of cholesterol per 100 grams. There is no doubt that the cholesterol element of cod liver oil plays an important role in all the well-known health benefits of this time-honored health food. Fresh egg yolk takes third place, with 424 mg of cholesterol per 100 gram. I would like to repeat: fresh egg yolk, not chemically mutilated egg powders (they contain chemically mutilated cholesterol)! Butter provides a good 218 mg of cholesterol per 100 gram. We are talking about natural butter, not butter substitutes. Cold-water fish and shellfish, such as salmon, sardines, mackerel and shrimps, provide good amounts of cholesterol, ranging from 173 mg to 81 mg per 100 gram. The proponents of low-cholesterol diets tell you to replace meats with fish. Obviously, they are not aware of the fact that fish is almost twice as rich in cholesterol as meat. Lard provides 94 mg of cholesterol per 100 gram. Other animal fats follow. Vitamin D Deficiency What does it mean for our bodies to be deficient in vitamin D? A long list of suffering: Diabetes, as vitamin D is essential for blood sugar control Heart disease Mental illness Auto-immune illness, such as rheumatoid arthritis, lupus, inflammatory bowel disease and multiple sclerosis Obesity Osteoarthritis Rickets and osteomalacia Muscle weakness and poor neuro-muscular coordination High blood pressure Cancer Chronic pain Poor immunity and susceptibility to infections Hyperparathyroidism, which manifests itself as osteoporosis, kidney stones, depression, aches and pains, chronic fatigue, muscle weakness and digestive abnormalities References Strauss E. One-eyed animals implicate cholesterol in development. Science. 1998 Jun 5;280(5369):1528-9. Chavarro JI and others. A prospective study of dairy foods intake and anovulatory infertility. Human Reproduction, Issue 28, Feb 2007. According to one theory, trans fats interfere in the metabolism of omega-3 fats, making them ineffective in producing their derivative eicosanoids, which leads to many types of cancers, including skin cancer. Trans fats also interfere with enzyme systems that help protect the body against cancer. References for the relationship of trans fats to skin cancer include: Alberts et al. Molecular Biology of the Cell: fourth edition, NY: Garland Science, 2002; _An estimate of premature cancer mortality in the U.S. due to inadequate doses of solar ultraviolet-B radiation._ (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=11920550) Cancer. 2002 Mar 15;94(6):1867-75; _Beneficial effects of sun exposure on cancer mortality._ (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=8475009) Prev Med. 1993 Jan;22(1):132-40. Review; Berg JM, Tymoczko JL and Stryer L. Biochemistry, 2006; _Does sunlight prevent cancer? A systematic review._ (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16904314) Eur J Cancer. 2006 Sep;42(14):2222-32. Epub 2006 Aug 10. Review; _Does sunlight have a beneficial influence on certain cancers?_ (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16595142) Prog Biophys Mol Biol. 2006 Sep;92(1):132-9. Epub 2006 Feb 28. Revew; _Ecologic studies of solar UVB radiation and cancer mortality rates._ (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=1 2899536) Recent Results Cancer Res. 2003;164:371-7. Review; _Geographic patterns of prostate cancer mortality. Evidence for a protective effect of ultraviolet radiation._ (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=1451068) Cancer. 1992 Dec 15;70(12):2861-9; Skrabanek P, McCormick J. Follies and fallacies in medicine. Tarragon Press, Glasgow, 1989; _Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease._ (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_ui ds=15585788) Am J Clin Nutr. 2004 Dec;80(6 Suppl):1678S-88S. Review; _UV radiation and cancer prevention: what is the evidence?_ (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16886 683) Anticancer Res. 2006 Jul–Aug;26(4A):2723-7. Review; _Vitamin D and cancer._ (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=AbstractPlus&list_uids=16886659) Anticancer Res. 2006 Jul-Aug;26(4A):2515-24. Review; Epstein SS. Unreasonable risk. 2001. Published by Environmental Toxicology, PO Box 11170, Chicago, USA. Pfohl M and others. Upregulation of cholesterol synthesis after acute myocardial infarction--is cholesterol a positive acute phase reactant? Atherosclerosis. 1999 Feb;142(2):389-93. Enig, MG. Know Your Fats: The Complete Primer for Understanding the Nutrition of Fats, Oils and Cholesterol. Bethesda Press, Silver Spring, MD, 2000. This article appeared in Wise Traditions in Food, Farming and the Healing Arts, the quarterly magazine of the Weston A. Price Foundation, Fall 2007.

Liver saving saturated fats

Liver saving saturated fats

August 2, 2012 by principleintopractice

As my last post started to explore, different types of dietary fats have different effects on the progression of alcoholic liver disease. This post will further explore the protective effects of saturated fats in the liver.

For many, the phrase “heart healthy whole grains” rolls off the tongue just as easily as “artery clogging saturated fats”. Yet where is the evidence for these claims? In the past few decades saturated fats have been demonized, without significant evidence to suggest that natural saturated fats cause disease (outside of a few well touted epidemiological studies). Indeed, most of the hypothesis-driven science behind the demonization of saturated fats is flawed by the conflation of saturated fats with artificial trans fats (a la partially hydrogenated soybean oil).

In the face of a lack of any significant scientific evidence that clearly shows that unadulterated-saturated fats play a significant role in heart disease (and without a reasonable mechanism suggesting why they might), I think the fear-mongering “artery clogging” accusations against saturated fats should be dropped. On the contrary, there is significant evidence that saturated fats are actually a health promoting dietary agent- all be it in another (though incredibly important) organ.

Again (from my last post), here is a quick primer on lipids (skip it if you’re already a pro). For the purpose of this post, there are two important ways to classify fatty acids. The first is length. Here I will discuss both medium chain fatty acids (MCFA), which are 6-12 carbons long, and long chain fatty acids (LCFA), which are greater than 12 carbons in length (usually 14-22; most have 18). Secondly, fatty acids can have varying amounts of saturation (how many hydrogens are bound to the carbons). A fatty acid that has the maximal number of hydrogens is a saturated fatty acid (SAFA), while one lacking two of this full complement, has a single double bond and is called monounsaturated (MUFA) while one lacking more (four, six, eight etc.) has more double bonds (two, three, four, etc.) and is called a polyunsaturated fatty acid (PUFA).

Next time you eat a good fatty (preferably grass-fed) steak, or relish something cooked in coconut or palm oil, I hope you will feel good about the benefits you are giving your liver, rather than some ill-placed guilt about what others say you are doing to your arteries. From now on, I hope you think of saturated fats as “liver saving (and also intestine preserving) lipids”. Here’s why:
In 1985, a multi-national study showed that increased SAFA consumption was inversely correlated with the development of liver cirrhosis, while PUFA consumption was positively correlated with cirrhosis [1]. You might think it is a bit rich that I blasted the epidemiological SAFA-heart disease connection and then embrace the SAFA-liver love connection, but the proof is in the pudding- or in this case the experiments that first recreated this phenomena in the lab, and then offered evidence for a mechanism (or in this case many mechanisms) for the benefits of SAFA.

The first significant piece of support for SAFA consumption came in 1989, when it was shown in a rat model that animals that were fed an alcohol-containing diet with 25% of the calories from tallow (beef fat, which by their analysis is 78.9% SAFA, 20% MUFA, and 1% PUFA) developed none of the features of alcoholic liver disease, while those fed an alcohol-containing diet with 25% of the calories from corn oil (which by their analysis is 19.6% SAFA, 23.6% MUFA, and 56.9% PUFA) developed severe fatty liver disease [2].

More recent studies have somewhat complicated the picture by feeding a saturated fatty-acid diet that combines beef tallow with MCT (medium chain triglycerides- the triglyceride version of MCFAs). This creates a diet that is more highly saturated than a diet reliant on pure-tallow, but it complicates the picture as MCFA are significantly different from LCFA in how they are absorbed and metabolized. MCFA also lead to different cellular responses (such as altered gene transcription and protein translation). Nonetheless, these diets are useful for those further exploring the role of dietary SAFA in health and disease.

These more recent studies continue to show the protective effects of SAFA, as well as offer evidence for the mechanisms by which SAFA are protective.

Before we explore the mechanisms, here is a bit more evidence that SAFAs are ‘liver saving’.
A 2004 paper by Ronis et al confirmed that increased SAFA content in the diet decreased the pathology of fatty liver disease in rats, including decreased steatosis (fat accumulation), decreased inflammation, and decreased necrosis. Increasing dietary SAFA also protected against increased serum ALT (alanine transaminase), an enzymatic marker of liver damage that is seen with alcohol consumption [3]. These findings were confirmed in a 2012 paper studying alcohol-fed mice. Furthermore, these researchers showed that SAFA consumption protected against an alcohol-induced increase in liver triglycerides [4]. Impressively, dietary SAFA (this time as MCT or palm-oil) can even reverse inflammatory and fibrotic changes in rat livers in the face of continued alcohol consumption [5].

But how does this all happen?
Before I can explain how SAFA protect against alcoholic liver disease, it is important to understand the pathogenesis of ALD. Alas, as I briefly discussed in my last post, there are a number of mechanisms by which disease occurs, and the relative importance of each mechanism varies based on factors such as the style of consumption (binge or chronic) and confounding dietary and environmental factors (and in animals models, the mechanism of dosing). SAFA is protective against a number of mechanisms of disease progression- I’ll expound on those that are currently known.
In my opinion, the most interesting (and perhaps most important) aspect of this story starts outside the liver, in the intestines.

In a perfect (healthy) world, the cells of the intestine are held together by a number of proteins that together make sure that what’s inside the intestines stays in the lumen of the intestine, with nutrients and minerals making their way into the blood by passing through the cells instead of around them. Unfortunately, this is not a perfect world, and many factors have been shown to cause a dysfunction of the proteins gluing the cells together, leading to the infamous “leaky gut”. (I feel it is only fair to admit that when I first heard about “leaky gut” my response was “hah- yeah right”. Needless to say, mountains of peer-reviewed evidence have made me believe this is a very real phenomenon).
Intestinal permeability can be assessed in a number of ways. One way is to administer a pair of molecular probes (there are a number of types, but usually a monosaccharide and a disaccharide), one which is normally absorbed across the intestinal lining and one that is not. In a healthy gut, you would only see the urinary excretion of the absorbable probe, while in a leaky gut you would see both [6]. Alternatively, you can look in the blood for compounds such as lipopolysaccharide (LPS-a product of the bacteria that live in the intestine) in the blood. (Personally, I would love to see some test for intestinal permeation become a diagnostic test available to clinicians.)

Increased levels of LPS have been found in patients with different stages of alcoholic disease, and are also seen in animal models of alcoholic liver disease. Increased levels of this compound have been associated with an increased inflammatory reaction that leads to disease progression. Experimental models that combine alcohol consumption and PUFA show a marked increase in plasma LPS, while diets high in SAFA do not.

But why? (Warning- things get increasingly “sciencey” at this point. For those less interested in the nitty-gritty, please skip forward to my conclusions)

Cells from the small intestine of mice maintained on a diet high in SAFA, in comparison to those maintained on a diet high in PUFA, have significantly higher levels of mRNA coding for a number of the proteins that are important for intestinal integrity such as Tight Junction Protein ZO-1, Intestine Claudin 1, and Intestine Occludin. Furthermore, alcohol consumption further decreases the mRNA levels of most of these genes in animals fed a high-PUFA containing diet, while alcohol has no effect on levels in SAFA-fed animals. Changes in mRNA level do not necessarily mean changes in protein levels, however the same study showed an increase in intestinal permeability in mice fed PUFA and ethanol in comparison to control when measured by an ex-vivo fluorescent assay. This shows that PUFA alone can disturb the expression of proteins that maintain gut integrity, and that alcohol further diminishes integrity. In combination with a SAFA diet, however, alcohol does not affect intestinal permeability [4].

Improved gut integrity is no doubt a key aspect of the protective effects of SAFA. Increased gut integrity leads to decreased inflammatory compounds in the blood, which in turn means there will be decreased inflammatory interactions in the liver. Indeed, in comparison to animals fed alcohol and PUFA, animals fed alcohol with a SAFA diet had significantly lower levels of the inflammatory cytokine TNF-a and the marker of macrophage infiltration MCP-1 [4]. Decreased inflammation, both systemically and in the liver, is undoubtedly a key element of the protective effects of dietary SAFA.
This post is already becoming dangerously long, so without going into too much detail, it is worth mentioning that there are other mechanisms by which SAFA appear to protect against alcoholic liver disease. Increased SAFA appear to increase liver membrane resistance to oxidative stress, and also reduces fatty acid synthesis while increasing fatty acid oxidation [3]. Also, a diet high in SAFA is associated with reduced lipid peroxidation, which in turn decreases a number of elements of inflammatory cascades [5]. Finally- and this is something I will expand on in a future post- MCFAs (which are also SAFA) have a number of unique protective elements.

I realize that this post has gotten rather lengthy and has brought up a number of complex mechanisms likely well beyond the level of interest of most of my readers…

If all else fails- please consider this:
The “evidence” that saturated fats are detrimental to cardiac health is largely based on epidemiological and experimental studies that combined saturated fats with truly-problematic artificial trans-fats. Despite the permeation of the phrase “artery clogging saturated fats”, I have yet to see the evidence nor be convinced of a proposed mechanism by which saturated fats could lead to decreased coronary health.

ON THE CONTRARY…
There is significant evidence, founded in epidemiological observations, confirmed in the lab, and explored in great detail that shows that saturated fats are protective for the liver. While I have focused here on the protective effects when SAFA are combined with alcohol, they offer protection to the liver under other circumstances, such as when combined with the particularly liver-toxic pain-killer Acetaminophen [7].

Next time you eat a steak, chow down on coconut oil, or perhaps most importantly turn up your nose at all things associated with “vegetable oils” (cottonseed? soybean? Those are “vegetables”?), know that your liver appreciates your efforts!

1. Nanji, A.A. and S.W. French, Dietary factors and alcoholic cirrhosis. Alcohol Clin Exp Res, 1986. 10(3): p. 271-3.
2. Nanji, A.A., C.L. Mendenhall, and S.W. French, Beef fat prevents alcoholic liver disease in the rat. Alcohol Clin Exp Res, 1989. 13(1): p. 15-9.
3. Ronis, M.J., S. Korourian, M. Zipperman, R. Hakkak, and T.M. Badger, Dietary saturated fat reduces alcoholic hepatotoxicity in rats by altering fatty acid metabolism and membrane composition. J Nutr, 2004. 134(4): p. 904-12.
4. Kirpich, I.A., W. Feng, Y. Wang, Y. Liu, D.F. Barker, S.S. Barve, and C.J. McClain, The type of dietary fat modulates intestinal tight junction integrity, gut permeability, and hepatic toll-like receptor expression in a mouse model of alcoholic liver disease. Alcohol Clin Exp Res, 2012. 36(5): p. 835-46.
5. Nanji, A.A., K. Jokelainen, G.L. Tipoe, A. Rahemtulla, and A.J. Dannenberg, Dietary saturated fatty acids reverse inflammatory and fibrotic changes in rat liver despite continued ethanol administration. J Pharmacol Exp Ther, 2001. 299(2): p. 638-44.
6. DeMeo, M.T., E.A. Mutlu, A. Keshavarzian, and M.C. Tobin, Intestinal permeation and gastrointestinal disease. J Clin Gastroenterol, 2002. 34(4): p. 385-96.
7. Hwang, J., Y.H. Chang, J.H. Park, S.Y. Kim, H. Chung, E. Shim, and H.J. Hwang, Dietary saturated and monounsaturated fats protect against acute acetaminophen hepatotoxicity by altering fatty acid composition of liver microsomal membrane in rats. Lipids Health Dis, 2011. 10: p. 184.
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