Cholesterol

   This past weekend, I went to a BBQ and we had hamburgers, chicken and of course all kinds of bread products to complement the meats. I saw several of my friends avoiding the hamburgers like the plague and going for the chicken and heap of bread. A friend told me that his doctor told him to avoid red meat at all cost because it would raise his cholesterol. I simply walked away with a loaded plate of hamburgers and a piece of chicken. The ugly word cholesterol shows up everywhere; folks are trying to keep their cholesterol down. Gary Taubes in his book, Good Calories Bad Calories talks about the Eisenhower paradox. I thought the story was really interesting and relevant to our cholesterol discussion, here is the gist of it.  President Dwight Eisenhower suffered his first heart attack at the age of sixty four in September 1955. Eisenhower's heart attack brought the coronary heart disease to the forefront of American radar. The Monday after the heart attack, Dr. Paul White, a cardiologist flown in from Harvard to consult on President's situation gave a very descriptive press conference describing the heart disease and an update on President's health. For the six subsequent weeks, two press conferences were held daily to update the American public on President's situation. By the time President returned back to his presidential duties, the middle-aged Americans were well versed in the evils of cholesterol and high fat diet. The cholesterol haters were born and that bandwagon was rolling. However, President Eisenhower saga was not done yet, it was only starting. Prior to the heart attack, President was very active, had quit smoking years ago, maintained his weight, had occasional high blood pressure, and had normal cholesterol level (165mg/dl). Then why did the President suffer a heart attack? After his illness, the President fanatically started to watch his food intake, and still continued to exercise. He was measuring his cholesterol ten times per year, had his food cooked in soy bean oil, watched his cholesterol intake by reducing fats in his diet, he ate newly developed healthy polyunsaturated margarine, but the more he dieted the worst his situation became. Once his weight crept up to 176 pounds, he gave up breakfast of oatmeals and skim milk, and switched to melba toast and fruit. When his weight refused to come down then he gave up breakfast altogether. Few years later after receiving some information about the benefits of corn oil, the President gave up cream, lard, butter, and margarine for corn oil. Despite all the precautionary measurements his cholesterol had reached up to 223 mg/dl and his doctors were lying and were telling him a smaller number (217mg/dl). Eisenhower, had practically renounced all types of fatty foods, and was living on few pieces of cheese, skim milk, cold cuts, fruit, and sanka. His last day in office, January 19, 1961, his measured cholesterol was 259 mg/dl, but he was told a lower number by the staff doctors. President Eisenhower, died in 1969 just 14 years after suffering his first heart attack. During the 14 years span he suffered 6 more heart attacks, while he remained fanatically obsessed with reducing his cholesterol and did everything in his power to reduce his fat and cholesterol intake. The experience of Eisenhower is shared by many others who take all necessary precautions to lower their cholesterol. These days the doctors play the statin game, and experiment with different dosage of statins to lower a patient's cholesterol. The doctors routinely advise their patients to reduce the fat and cholesterol intake, eat whole grains, and exercise more. The patients dutifully follow their doctors' advice, yet the sale of lipitor has reached a staggering $125 billion since 1996. Despite all the good intentions and numerous efforts, the heart disease still continues to climb and is the number one cause of death in the country and in most countries around the globe. When I speak with friends, a general phobia of fats and cholesterol is expressed. People have varying understanding of what fats and cholesterol do for our bodies, but no one seem to have the complete picture. I think it is only fair that if we are going to conquer this beast, let us at least understand and learn some of its behavior, and besides no paleo blog will be complete without some discussion of cholesterol.

                    Lipids_____Triglycerides (Fats and oils)
                             |                                          |___fatty acids
                             |                                                                |___Saturated
                             |                                                                |___Monounsaturated (MUFA)
                             |                                                                |___Polyunsaturated (PUFA)
                             |                                                                                       |____Omega 3
                             |                                                                                       |____Omega 6
                             |_____ Phospholipids
                             |                                |___Lecithin
                             |_____ Sterols
                                                   |____Cholesterol

   Cholesterol is a sterol and part of a nutrient class called lipids. Above is cholesterol's family tree. Sterols are found in many foods, but cholesterol can only be obtained from animal products: meats, eggs, dairy, fish, and poultry. Liver makes 800-1500 milligrams of cholesterol per day contributing much more to the body's total cholesterol than diet.  If cholesterol was such an evil thing as we have made it out to be, then why would nature produce it in large quantities on the daily basis. The fact is that cholesterol is really useful for our well being; cholesterol made by the liver is used for making bile acids, vitamin D, and various hormones like testosterone and cortisol. Cholesterol is responsible for creating the cell membranes, hence 90% of body's cholesterol is contained in the cells. If our cell membranes were not elastic enough, we would crumble like objects made out of sand, and if cholesterol did not act like a barrier, our cells will never take shape and would lose all their internal fluids. Brains of an animal contains a large amount of cholesterol. The myelin sheath around the nerves is basically made out of cholesterol and fats. Myelin sheath acts like an insulating outer wall of an electric wire. In the future if someone calls you a fat head, do't be offended, your head is actually made out of fat and cholesterol. A 4 oz. serving of beef brains contains about 2254 mg of cholesterol. An amount that will put a big frown on the faces of most cardiologists and the creators of the famous food pyramid.

   So, if cholesterol is useful, then how did it become evil? The answer lies with few of the proteins our bodies makes to transport cholesterol and other lipids around the body. Cholesterol must first enter the lymphatic system before it can be absorbed by the cells. The body makes four types of proteins to transport most of the fats and cholesterol around the body. Collectively, these proteins are called lipoproteins. Lipoproteins basically solve the problem of transporting fats through the watery blood stream. Below is the function of each lipoprotein described in detail:

   Chylomicrons are the first type of lipoproteins responsible for carrying triglycerides and mostly diet derived lipids to cells around the body. As chylomicrons move about the body, various cells remove fats, so in about 10-14 hours the chylomicrons get smaller and smaller and little is left of them other than protein remnants. Special protein receptors on the liver cells sense the depleted chylomicrons and remove them from the blood circulation. The liver cells dismantle the chylomicrons to make new triglycerides.

   VLDL (Very-Low-Density Lipoproteins). While chylomicrons are busy delivering fats to cells in the body, the liver is busy making cholesterol from other chylomicrons remnants, carbohydrates, proteins, and alcohol. The excessive carbs in combination with high fats are a sure recipe for disaster. If the body is not able to expend the excessive dietary carbs, then it ends up converting them to fats for future use. The caveat is that it requires a lot more energy to convert carbs into fat for storage then to convert fats into triglycerides for storage. A diet high in fat is an optimal diet for the reason that body has to do less work in converting the fatty acids to triglycerides for storage and energy usage. Most cells prefer to use fats as their energy source and little fat ends up going a long way because of the high amount of calories available in fats. It boils down to less work for the liver, an optimal diet is high in fats, moderate in proteins, and moderate in carbohydrates; other words, paleo diet. The cholesterol and triglycerides created in liver are packaged with VLDLs and shipped throughout the body for delivery to the cells. As VLDLs move through the body, the cells remove triglycerides and cholesterol causing VLDL to get progressively smaller. Since fat molecules are removed, the VLDL protein package gets more dense.

   The VLDL eventually becomes LDL (Low-Density Lipoproteins) and continues to circulate the body making cholesterol available to cell membranes and tissues. The cholesterol rich LDL is rushing towards the cells to provide a bandage for abrasions and tears in the cell lining. After all the cell membranes are made out of cholesterol. This is where cholesterol gets its bad name. LDL rich in cholesterol and low in triglycerides and due to systemic inflammation caused by most grains, the LDL gets stuck in the arteries and causes plaque that eventually leads to coronary disease. When cardiologists open up a heart patient, they consistently find deposits of LDL stuck in arteries, so naturally the blame goes to the cholesterol responsible for the heart attack. Of course all the blame goes to the dietary cholesterol obtained from eggs, red meats, and saturated fats. No one even mentions the systemic inflammation caused by the grains, that caused the arteries to constrict in the first place. Instead of calling LDL the bad cholesterol, the doctors and nutritionists should really be pointing out the inflamed arteries to the patients.

  On different occasions, the fat cells release their fatty acids and glycerol molecules back in the blood stream, the liver makes another type of lipoprotein called HDL (High-Density Lipoproteins). HDL is responsible for carrying the cholesterol and other lipids from cells to the liver for recycling and disposal. HDL is called a good cholesterol, because it is responsible for removing excessive cholesterol from the blood stream. Here is a graphic depiction of each lipoprotein:

   As you can see from the above table that LDL contains the most amount of cholesterol and this is the cholesterol that ends up getting stuck in the arteries and ultimately causes heart disease. As I mentioned earlier, that the reason why cholesterol gets stuck is due to the inflammation of the arteries. The inflammation is caused by the proteins in the grains. In a normal healthy body the cholesterol has no reason to get stuck. The lipoproteins carrying cholesterol and fats are designed to move about the lymphatic system freely to deliver energy and repair/rebuild cell membranes. If you have a splinter in your hand, the body responds by inflaming the area to fight the foreign object. This inflammation is good and this is how a healthy immune system works. Now if you poked the infected area constantly, the inflammation will never go down. This is exactly what bad proteins in grains do to our bodies. The lectins end up escaping into the body and the immune system launches an attack by inflaming the area. Since grain products containing lectins and glutens are consumed frequently, the inflammation never goes down. It is like poking the inflamed area over and over again. The cholesterol rushes to various parts of the body to repair the cell tissues and build cell membranes, but due to systemic inflammation, ends up getting stuck in the constricted arteries causing build up of plaque. Yes, a high cholesterol and fat diet with grains is really bad and will eventually give you a coronary. But if you eliminate the grains and eat fats, proteins, and carbs from vegetables and fruits, then the systemic inflammation goes away. The constricted arteries return to their normal state and the cholesterol and fats run through the lymphatic system without ever getting stuck. If you are on paleo and your cholesterol goes up, there is no need for panic; most likely your HDL will go up as well. The ratio to watch for is triglycerides to HDL. If this ratio is less than 2 then you have good foamy LDL that will not get stuck in the arteries. It may take few months or up to a year for the  body to repair the damages caused by prolonged grains consumption. Eventually the body will recover and will return to its normal state. There are no guarantees that eating melba toast and skim milk will lower your cholesterol, as President Eisenhower learned the hard way. 

   To lower your cholesterol, a diet must be formulated with at least 50% fats, 30% proteins, and 20% carbs (from vegetables, fruits, nuts, and seeds). The grains, soy, legumes, sugars, and dairy must be eliminated from the diet. These types of foods only became available when we adopted the agrarian life style and our health has been declining since then. The modern processing makes these foods even more dangerous; that is why there is an obesity epidemic out there. If grains are such a good source of energy then why do they have to be fortified. The fats, meats, and healthy carbs make an optimal diet. If you want to beat the heart disease then check out this article from one of the paleo experts, Chris Kresser.