Confused About SATURATED Fats?
These nutrient-rich traditional fats have nourished healthy population groups for thousands of years:
- Beef and lamb tallow
- Chicken, goose and duck fat
- Coconut, palm and sesame oils
- Cold pressed olive oil
- Cold pressed flax oil
- Marine oils
These new-fangled fats can cause cancer, heart disease, immune system dysfunction, sterility, learning disabilities, growth problems and osteoporosis:
- All hydrogenated oils
- Soy, corn and safflower oils
- Cottonseed oil
- Canola oil
- All fats heated to very high temperatures in processing and frying.
SATURATED FAT: IMPORTANT FOR HEALTHY KIDNEYS
by Mary G. Enig, Ph.D.
One of the body’s most important organs is the kidney. Properly functioning kidneys are essential for maintaining proper blood volume and composition; for filtering and excreting or saving various chemical metabolites; and for helping to maintain proper blood pressure. Hypertension (high blood pressure) is known to result from improperly functioning kidneys. Research carried out during the last few years indicates that both saturated fat and cholesterol play important roles in maintaining kidney function, as do the omega-3 fatty acids.
The kidneys need stable fats both for their cushioning and as their en
A species of rat known to be prone to strokes and to spontaneously develop hypertension (high blood pressure) has been used to evaluate effects of different lipids such as plant sterols or cholesterol, and also fatty acids such as omega-3 or omega-6 fatty acids in the finely tuned functions of the kidney. These animals are very sensitive to dietary cholesterol manipulations and a deficiency of cholesterol in their membranes makes their membranes weak and fragile. When plant sterols found in vegetable oils are substituted for cholesterol in their diets, these animals have a shortened life span.2 Also, these animals are reported to need a proper omega-6 to omega-3 ratio in the kidney phospholipids. It was further reported that feeding oils high in omega-6 fatty acids without omega-3 fatty acids resulted in renal injury, and that feeding oils rich in the omega-3 fatty acids such as fish oil, perilla oil, and flaxseed oil prolonged the survival time of this animal.3
The omega-3 fatty acids are recognized as being important, and the conversion of the flax oil-type omega-3 fatty acid (alpha-linolenic acid) to the fish oil-type omega-3 fatty acids (EPA and DHA) is enhanced when the diet contains saturated fat such as coconut oil. This conversion is hindered when there is extra omega-6 oils in the diet.4 Injury to the kidney from immune dysfunction (IgA nephropathy) responds to omega-3 fats (both flax oil-type omega-3 and fish oil-type omega-3).5 As noted, adding the saturated fats, especially coconut oil, improves the body’s use of omega-3 fatty acids.
Another reason that coconut oil enhances kidney function is because it supplies myristic acid, the 14-carbon saturated fatty acid.6 Myristic acid is involved in the signalling from cell membrane receptors through G proteins and their attachment to membranes. These signalling proteins require a lipid such as myristic acid to be added to one end of the protein, a process called myristolation.7
Thus, the fats that we recommend for general good health, namely various saturated animal fats and tropical oils, along with a supplement of flax oil, are also specifically helpful for kidney function. Products containing high omega-6 oils and trans fatty acids should be avoided.
SATURATED FATS: IMPORTANT FOR LUNG HEALTH
Yes fat? No fat? High fat? Low fat? Wrong questions! A better question would be, how much of what kind of fat and why? Yes, we need added fat in our diets or we lose the synergistic effects from the natural fats in our foods. Such fats provide us with appropriate satiety signals; they ensure absorption of important fat-soluble vitamins, phytonutrients and important minerals; and they provide the raw material for skin health, hormone production and adequate energy storage.
The use of lowfat diets is increasingly recognized as counter productive. Without good quality fat in the diet to promote proper satiety signals, we tend to overeat those foods that are readily available. And since “readily available” foods are either high in simple carbohydrates or partially hydrogenated fats and oils or both, and since these foods promote insulin resistance, it is easy to head in the direction of obesity.
Saturated fats have gotten a bad rap. For 30 to 40 years, they have borne the brunt of an anti-fat campaign. This campaign was promoted by individuals in the fats and oils part of the food industry who had great influence over government agencies, consumer groups and the media.
Recommendations about fat in the diet made by government agencies such as the USDA, the FDA, the National Heart, Lung and Blood Institute, organizations such as the American Heart Association and consumer activist groups such as Center for Science in the Public Interest invariably paint saturated fat as the one bad actor in the diet that needs to be fired from the scene.
The spokespersons from these organizations don’t understand the effects of the saturated fatty acids found in the diet and they don’t understand how much and where saturated fatty acids are normally found in the human body. Everything these organizations report about fat is based on what they perceive to be the effects of saturated fatty acids on serum cholesterol levels.
So when a particular fat raises the level of the body’s repair substance, which is what cholesterol is, the question that really should be asked is whether this is good because the body will now get the repair substance it needs, or whether it could be bad if getting more of the repair substance triggers the need for repair. The former makes sense, the latter does not. A well-known New York pathologist, Meyer Texon, MD, noted that accusing fat and cholesterol of causing the injury that led to the atheroma is akin to accusing the white blood cells of causing infection; they are both there to help repair.
We need natural saturated fat in our diets. The important phospholipids that form the membranes in all of our cells are made of mostly (half or more) saturated fatty acids. This is especially true for parts of our brains where more than 80 percent of the phospholipids carry half of their fatty acids as saturated fatty acids.
When it comes to our lungs, the very important phospholipid class called lung surfactant is a special phospholipid with 100 percent saturated fatty acids. It is called dipalmitoyl phosphatidylcholine and there are two saturated palmitic acid molecules attached to it. When people consume a lot of partially hydrogenated fats and oils, the trans fatty acids are put into the phospholipids where the body normally wants to have saturated fatty acids and the lungsmay not work effectively. Some research has suggested that trans fatty acids are causing asthma in children.
Recent research shows that having enough saturated fat prevents stroke; and to protect our kidneys from disease, research shows we need certain kinds of saturated fatty acids, which are found only in the natural fats such as animal fats and coconut and palm kernel oils.
Mary G. Enig, PhD is the author of Know Your Fats: The Complete Primer for Understanding the Nutrition of Fats, Oils, and Cholesterol, Bethesda Press, May 2000.
THE HUMAN DIET
from: The Lipid Hypothesis of Atherogenesis
by: William E Stehbens, M.D.
Homo sapiens is essentially omnivorous and individual diets have largely been dependent on geographic, socioeconomic and cultural characteristics. Animal food products have been a basic ingredient in the human diet for millennia and humans in the absence of metabolic diseases generally cope with the ingestion of animal fats far better than rabbits. With more pervasive affluence the consumption of animal food products increased but milk, eggs and meat remain the major source of high quality protein. These commodities in association with fruit and vegetables have been considered the basis of good nutrition, greater body size, immunity and brain development. Poor nutrition on the other hand, seen for the most part in communities with poor access to animal protein, is associated with poor physical and mental development, apathy, susceptibility to infectious diseases and a shortened life span. Fat, consumed in many varieties of food, provides a good source of energy. In general it satiates the appetite better than carbohydrate which traditionally has often been used as a filling agent but few can eat much fat at any one sitting and its consumption tends to be self limiting. Much fat is lost in cooking and often meat and sausages cook in their own fat which adds flavor and moistness. There are anecdotal tales about the need for a high fat diet by the Inuit and Arctic fisherman who, sustaining very adverse climatic conditions, need a high fat intake to cope with hard labor and to maintain health. This observation could provoke an interesting scientific investigation.
The consumption of eggs, milk, cream, butter and cheese has been actively discouraged for some time. Because there has been emphasis on cholesterol and fat in meat, this too has suffered a bad press although some softening of this attitude is becoming apparent and portions of lean meat are now permissible. The acknowledged absence of demonstrable effect of these cholesterol containing foods in the diet on serum cholesterol levels in individuals and the evidence that some have a hypocholesterolemic effect indicate that the current dietary recommendations are based on superstition and an ecological fallacy rather than science. With the implementation of current dietary recommendations of the lipid protagonists across the spectrum of the human population concern must be expressed regarding the adequacy of the diet. Common sense is not proving to be as common as is necessary, e.g., (a) It is usually not possible to reduce the intake of a major dietary constituent such as fat (more specifically animal fat) without provoking secondary effects on the adequacy of intake of animal protein, vitamins, calcium and iron in readily assimilable forms. Low fat milk is a case in point.
(b) The emphasis on carbohydrate in particular may contribute indirectly to an increased incidence of obesity in the community.
(c) The greatest concern must be for the adequacy of protein intake and animal products remain the best and most convenient source. There is already evidence of nutritional deprivation and dwarfism. Children deprived in early life of adequate protein-caloric intake develop hypogammaglobulinemia and even agammaglobulinemia. Immunological deficiency can persist after the institution of adequate nutrition.
(d) The adequacy of iron and calcium intake particularly in women must be a cause for concern and reduction in animal fat and protein could be accompanied by vitamin deficiencies.
(e) The adverse effects of trans fatty acids, other commercial modifications and substitute foods and preserving agents are unknown but the evidence is that some may be distinctly unhealthy”.
Food is to be enjoyed and tasty: nutritious food can be a source of immense pleasure. This observation does not condone gluttony and as with all things prudence will avoid a lot of problems. Currently the advice that should be given to the population is to eat a varied diet in moderation, preferably fresh natural foods with a minimum of food additives or preservatives. Animal foods are highly nutritious and can provide considerable variation in gustatory pleasures in contrast with the unpalatable monotony of some currently recommended diets.
Milk, eggs and meat remain the major source of high quality protein and these commodities in association with fruit and vegetables should constitute the basis of what we call good nutrition. Emphasis should be on the ingestion of animal protein, fresh natural foods, an adequate source of vitamins and minerals and variety. These recommendations rely to a large extent on common sense and are made with the realization that additional rations of salt and iodine are needed according to geographical and environmental conditions in the same way that fluid intake should be adequate.
It is widely believed and sedulously promulgated that diets high in cholesterol and saturated animal fats and low in polyunsaturated fats tend to raise the plasma cholesterol levels by 10% to 20% in some individuals” and are therefore assumed to be atherogenic. In other words an effect on blood cholesterol levels is assumed to have a similar effect on the severity of atherosclerosis. This is a common but fallacious extrapolation that pervades CHD epidemiological studies of lipids (“substitution game”). In many animal species, the feeding of large amounts of cholesterol results in severe hypercholesterolemia This is particularly well seen in rabbits, chickens and even some primates. Some animals require thyroidectomy or thyroid suppression to facilitate the rise in plasma cholesterol concentrations. In humans only small rises in cholesterol concentration can be induced by dietary means. Rats can absorb large quantities of cholesterol yet are remarkably resistant to hypercholesterolemia. Some humans may be responders and others may not be Just as in pigeons for there is considerable heterogeneity of response.
Preoccupation with lipids has occasioned a preponderance of dietary studies related to fat intake but evidence incriminating diets high in animal fat is essentially circumstantial or indirect. Short-term experimentation may elevate serum cholesterol levels in some individuals. Biological adaptation in the long-term may minimize the effect. More to the point, mild elevation of plasma cholesterol is not necessarily atherogenic and there is no scientific evidence that this is so in man. Evidence for the alleged role of dietary animal fat and cholesterol is primarily based on correlations of the per capita fat available for human consumption with CHD mortality rates for countries where vital statistics are available and incorrectly assumed to be sufficiently accurate for epidemiological use. Nevertheless the plausibility of the epidemiological evidence and the validity of estimates of the food consumed are in question and much contradictory evidence exists regarding the role of animal fats in atherogenesis.
In the USA, from 1909 to 1965, when the national mortality rates for CHD allegedly rose, there was a fall of 7% in the animal fat available for consumption and a rapid increase (181%) in vegetable polyunsaturated fat. This does not suggest that the ingestion of animal fats is responsible for the allegedly increased national CHD mortality rate, nor does the dietary intake of polyunsaturated fats correlate with CHD mortality rates. Epidemiologists have ignored this evidence for an increasing intake of vegetable fats and oils. In the UK, Trenchard reviewed fat consumption and claimed that on the available evidence and after reappraisal of past estimates, animal fat consumption had probably remained constant from 1909-1913 to 1975 except for wartime and shortage periods. This evidence is not strong but basically no weaker than other epidemiological evidence of its type. Besides, the estimated total dietary animal fat does not correlate with the severity of atherosclerosis at autopsy.
Segall, comparing milk consumption and the incidence of CHD for 43 countries, found that milk consumption gave the strongest correlation with total caloric intake, meat intake, fats, oils and proteins. Such correlations tend to negate causality because of their very nonspecificity. However, rather than raising serum cholesterol levels, milk has a hypocholesterolemic effect as has yogurt. In African pastoral tribes the high intake of calories and fat (mainly as milk) is associated with a lower serum cholesterol level and a low CHD mortality rate.