But this controversy is more important when talking about saturated fats.
Arguments against saturated fatsThe American Heart Association says in a post on May 30, 2014 that “Eating foods that contain saturated fats raises the level of cholesterol in your blood. High levels of blood cholesterol increase your risk of heart disease and stroke. Be aware, too, that many foods high in saturated fats are also high in cholesterol – which raises your blood cholesterol even higher”. (8)
Dr. Galland says that “the impact of being a meat eater on your risk of coronary artery disease is pretty well established, it’s because of the saturated fat that raises cholesterol.” Also, “a high fat diet increases the flow of bile. Bile alters the gut micro flora because there are organisms that are killed by bile and bile acids and bile salts, and there are others that thrive in bile” (1). So Dr. Galland thinks that meat fat create a dysbiosis (unbalance in gut flora) and increases the risk of cardiovascular diseases.
Several studies have demonstrated that saturated fatty acids (SFAs) stimulate adipose tissue inflammation by a process that involves Toll-like receptor 4 (TLR4). SFAs also stimulate inflammatory molecules in macrophages. (3), (9)
Chang and his colleagues traced how saturated fats, particularly those from dairy, which are also present in many baked goods and processed foods, can change the composition of naturally harmless bacteria communities in the gut. As the balance of species shifts, it can trigger an immune response that results in inflammation and tissue damage. (10), (11).
Arguments in favour of saturated fatsNumerous doctors have changed their minds about saturated fats over time, and are currently in favor, as Dr Weil wrote in 2011: “You're correct that my thinking on saturated fat has evolved. One catalyst was a scientific analysis of 21 earlier studies, which showed "no significant evidence" that saturated fat in the diet is associated with an increased risk of coronary heart disease.” He is referring to studies such as one that was published in 2010 in the American Journal of Clinical Nutrition (7), where it is concluded that “A meta-analysis of prospective epidemiologic studies showed that there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD”
Now, a new study (4) indicates that a diet low in carbohydrates is also more effective than a diet low in fat in reducing in the blood and reducing markers of inflammation.
One possible explanation for this change of opinion is the consideration that not all animal fats are equal. Animal fats are more inflammatory when the animal has been fed with grain, so that the amount of omega-6 is more important. However, the fat of grass-fed animals contain other anti-inflammatory substances. (6)
Typically, in the studies that indicate an inflammatory effect of saturated fats, the type of food that is fed to the animals which the proteins used on in the study is not specified.
The laboratory studies often use refined products, not natural products. In studies where it is concluded that saturated fat is unhealthy, as published in Nature (10), “milk fat” is used, “a powdered substance that remains when fat has been separated from butter and dehydrated“. This fat is very different from the fat that exists naturally in milk, yogurt, or butter made from raw milk. The health effects of these fats can also be very different.
The cholesterol mythThe myth that high cholesterol foods cause heart disease is being rejected by numerous scientific studies. First of all, 75% of the body's cholesterol is synthesized in the liver, so only 25% comes from food intake. So there is not a direct correlation between dietary cholesterol and blood cholesterol. In fact, a study conducted in 1948, discovered that the correlation was actually reversed, meaning that, the more saturated fat one ate, the more cholesterol one ate, the more calories one ate, the lower the person's serum cholesterol. weighed the least and were the most physically active. (13)
By contrast, it has been shown that diets low in saturated fat are link with increased mortality involving cancer, suicide, cerebral haemorrhage and violence. (14)
Dr. Weston Price studied indigenous civilisations that maintained good health and high longevity, and found that the diet was very different. Some of them had fish as staple food, others were hunters, others were vegetarians with diary products, etc. But they had all in common a very high fat intake.(15)
Dr. Mercola says: “Remember that 75 percent of your cholesterol is produced by your liver, which is influenced by your insulin levels. Therefore, optimising the insulin level, cholesterol will be automatically optimise and risk of both diabetes and heart disease will be reduced. There is no magic pill to cure heart disease, as the underlying cause is insulin resistance caused by eating too many sugars, grains and especially fructose.” “Elevated triglycerides in the blood have been positively linked to proneness to heart disease, but these triglycerides do not come directly from dietary fats; they are made in the liver from any excess sugars that have not been used for energy” (12)
Animal and vegetable saturated fatsThe terms saturated fat and animal fat are often confused. All fats and oils, whether of vegetable or animal origin, are some combination of saturated fatty acids, monounsaturated fatty acids and polyunsaturated linoleic acid and linolenic acid. In general, animal fats such as butter, lard and tallow contain about 40-60% saturated fat and are solid at room temperature. They also contain 30-50% of monounsaturated fat and the rest is polyunsaturated. Interestingly, it is precisely the composition most similar to human milk fat: 48% saturated, 33% monounsaturated and 16% polyunsaturated, and this proportion is the human need for life in our food supply. (12) (2)
Coconut oil, for example, is 92% saturated. These fats are liquid in the tropics but hard as butter in northern climes. Of particular interest is lauric acid, found in large quantities in both coconut oil and in mother's milk. This fatty acid has strong anti-fungal and antimicrobial properties.
Fats and oils harmful to health are those who have undergone the following processes:
1 -. Vegetable oil extraction in processes that require heating, or using chemicals.
3 -. Homogenisation of fats, usually those in milk.
As a result, these processes produce fats with an inflammatory effect, such as trans fats from hydrogenated or partially hydrogenated oils, which are used in the food industry: baked goods (pastries, biscuits, muffins, cakes, pie crusts, doughnuts and cookies) and fried foods (French fries, fried chicken, breaded chicken nuggets and breaded fish), snack foods (popcorn, crackers), chocolate, ice-cream, mayonnaise and other foods made with partially hydrogenated vegetable oils, traditional vegetable shortening or stick margarin.
This damaged or oxidised cholesterol seems to promote both injury to the arterial cells as well as a pathological buildup of plaque in the arteries. Damaged cholesterol is found in powdered eggs, in powdered milk (added to reduced-fat milks to give them body) and in meats and fats that have been heated to high temperatures in frying and other high-temperature processes.
Functions of saturated fat in the bodyEvery cell of every organ in our body contains cholesterol in its structure. In many cells, almost half its membrane comprises of cholesterol.
Saturated fat is required for the brain, eyes, production of hormones, cortisol, vitamin D, and bile salts. In the nervous system, for example, myelin is a substance that covers the entire cell and nerve fibre. The myelin is composed 20% of cholesterol. The synapses, or connections between neurones needed for memory, also need cholesterol.
Saturated fats also play many other important functions in the body:
1.- It transports fat soluble vitamins: A, D, E and K
2.- They are necessary for the functioning of the immune system
3.- They slow down digestion, so they give a feeling of fullness after eating that lasts for a long time, which prevents the need to eat frequently
4.- They withstand the conversion of carotene into retinol, the vitamin A that will be used, for example, in the eyes and in all epithelial cells
5.- They contribute to the binding of calcium in the bones
6.- They protect the liver from alcohol and other toxic substances
7.- They protect the walls of the digestive system
8.- They Intervene in the reparation of the damaged tissues of the body
9.- They are an antioxidant against free radicals
The role of the liver and pancreasThe liver produces bile which emulsifies fats and dietary lipids. But if the liver is not working properly due to toxic overload, it can not perform this function. Therefore fats are not digested properly, and then fats feed undesirable intestinal bacteria, which proliferate and produce more toxins, increasing the toxic load of the liver. It is an endless cycle.
It can also occur, that there is a deficiency of lipase produced by the pancreas, an enzyme responsible for digesting lipids. The cause of this dysfunction is, according to Dr. Campbell-McBride (2), intestinal bacterial dysbiosis which also infects the organs and prevents proper functioning. In the end, as a result of maldigestion of lipids, fatty acid deficiency in the body occurs, which leads to malfunction in various parts of the body: brain and nervous system, eye, hormones, cardiovascular system, etc..
To know if one is suffering from a problem of this type, it is enough to observe whether the faeces float on water or sink. If it is the first case, it is a good indicator that there is not a proper digestion and absorption of lipids.
Thus, in the case in which fats can not be digested, it will be harmful to health, although the lack of them will also involve multiple deficiencies. So, do not try to avoid fats in food, but to repair the body, mainly the liver and pancreas so that fats can be tolerated and can nourish the body.
InterestsI will not go into detail; on the Internet you can find lots of information about the interests of the pharmaceutical industry to sell drugs statins to lower cholesterol level, and of the food industry to sell margarine.
ConclusionThe problem of protein and fat depends mainly on the type of animal from which it originates; if it is of good quality meat, meaning that, the animals are grass-fed and outdoors, or are raised in factories.
Industrial fats or fats that are under processes that denature them, are also harmful.
Perhaps the main problem is not whether to eat fats or not, but rather if the body is able to digest and absorb these fats and address to the needs of the organism. When the liver or the pancreas does not secrete enough bile and pancreatic juice, problems with digestion of fats and other nutrients appear, resulting in cardiovascular disease, hormonal, inflammatory, gastroenterology, cancer, etc..
Then, it is necessary to undergo a treatment that will allow it to regain function.
(1) Conférence Future of Nutrition http://futureofnutritionconference.com/conference/future-of-nutrition/?_ga=1.99153630.1319473935.1388612888
(2) « Put your Heart in Your Mouth », Dr. Natasha Campbell-McBride MD
(3) « Modulation of obesity-induced inflammation by dietary fats: mechanisms and clinical evidence » http://www.nutritionj.com/content/13/1/12
(4) « Low-carb Diet Reduces Inflammation And Blood Saturated Fat In Metabolic Syndrome » http://www.sciencedaily.com/releases/2007/12/071203091236.htm
(6) « What Causes Inflammation? A Comprehensive Look At The Causes and Effects Of Inflammation » http://www.thedoctorweighsin.com/what-causes-inflammation-a-comprehensive-look-at-the-causes-and-effects-of-inflammation-part-2/
(7) « Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease » http://ajcn.nutrition.org/content/early/2010/01/13/ajcn.2009.27725.abstract
(8) « Saturated Fats Q&A », http://www.heart.org/HEARTORG/GettingHealthy/FatsAndOils/Fats101/Saturated-Fats_UCM_301110_Article.jsp
(9) « Saturated Fatty Acids and Inflammation: Who Pays the Toll? » http://atvb.ahajournals.org/content/30/4/692.full
(10) « Dietary-fat-induced taurocholic acid promotes pathobiont expansion and colitis in Il10−/− mice », http://www.nature.com/nature/journal/v487/n7405/full/nature11225.html
(11) « Western diet changes gut bacteria and triggers colitis in those at risk » http://www.uchospitals.edu/news/2012/20120613-milkfat.html
(12) « The Cholesterol Myths that May be Harming Your Health » http://articles.mercola.com/sites/articles/archive/2011/10/22/debunking-the-science-behind-lowering-cholesterol-levels.aspx
(13) « The Framingham Heart Study: The Town That Changed America's Heart » http://www.framingham.com/heart/backgrnd.htm
(15) « Nutrition and Physical Degeneration », Weston A. Price, MS., D.D.S., F.A.G.D.