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Saturated fat
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Saturated fat is fat that consists of triglycerides containing only saturated fatty acid radicals. There are several kinds of naturally occurring saturated fatty acids, which differ by the number of carbon atoms - from 1 to 24. Saturated fatty acids have no double bonds between the carbon atoms of the fatty acid chain and are thus fully saturated with hydrogen atoms.
Fat that occurs naturally in living matter contains varying proportions of saturated and unsaturated fat.
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Encyclopedia
Saturated fat is fat that consists of triglycerides containing only saturated fatty acid radicals. There are several kinds of naturally occurring saturated fatty acids, which differ by the number of carbon atoms - from 1 to 24. Saturated fatty acids have no double bonds between the carbon atoms of the fatty acid chain and are thus fully saturated with hydrogen atoms.
Fat that occurs naturally in living matter contains varying proportions of saturated and unsaturated fat. Examples of foods containing a high proportion of saturated fat include dairy products (especially cream and cheese but also butter and ghee), animal fats such as suet, tallow, lard and fatty meat, coconut oil, cottonseed oil, palm kernel oil, chocolate, and some prepared foods.
Fat profiles
While nutrition labels usually lump them together, the saturated fatty acids appear in different proportions among food groups. Lauric and myristic acid radicals are most commonly found in "tropical" oils (e.g. palm kernel, coconut) and dairy products. The saturated fat in meat, eggs, chocolate and nuts is primarily the triglycerides of palmitic and stearic acid.
Saturated fat profile of common foods (Esterified fatty acids as percentage of total fat )| Food | Lauric acid | Myristic acid | Palmitic acid | Stearic acid | | Coconut oil | 47% | 18% | 9% | 3% | | Butter | 3% | 11% | 29% | 13% | | Ground beef | 0% | 4% | 26% | 15% | | Dark chocolate | 0% | 0% | 34% | 43% | | Salmon | 0% | 1% | 29% | 3% | | Eggs | 0% | 0% | 27% | 10% | | Cashews | 2% | 1% | 10% | 7% | | Soybean oil | 0% | 0% | 11% | 4% | |
Examples of saturated fatty acids
Some common examples of fatty acids are:
Related diseases
Cardiovascular diseases
Diets high in saturated fat are correlated with an increased incidence of atherosclerosis and coronary heart disease according to a number of studies, both in African green monkeys and humans, such as a study of infant diets , 22 hypercholesterolemic men Some studies have suggested that diets high in saturated fat increase the risk of heart disease and stroke. Epidemiological studies have found that those whose diets are high in saturated fatty acids, including lauric, myristic, palmitic, and stearic acid, had a higher prevalence of coronary heart disease. Additionally, controlled experimental studies have found that people consuming high saturated fat diets experience negative cholesterol profile changes. A 2003 meta-analysis published in the American Journal of Clinical Nutrition concluded that diets high in saturated fat might adversely affect cholesterol profiles.
Experiments in which subjects were randomly assigned to either Mediterranean or a control diet (which replaces saturated fat with mono and polyunsaturated fat) showed that subjects assigned to a Mediterranean diet exhibited a significantly decreased likelihood of suffering a second heart attack, cardiac death, heart failure or stroke.
An evaluation of data from Harvard Nurses' Health Study found that "diets lower in carbohydrate and higher in protein and fat are not associated with increased risk of coronary heart disease in women. When vegetable sources of fat and protein are chosen, these diets may moderately reduce the risk of coronary heart disease."
Fatty acid specificity
Epidemiological studies of heart disease have implicated the four major saturated fatty acids to varying degrees. The World Health Organization has determined that there is "convincing" evidence that myristic and palmitic acid intake increases the probability, "possible" risk from lauric acid, and no increased risk at all from stearic acid consumption.
Cancer
Breast cancer
There is one theorized association between saturated fatty acids intake and increased breast cancer risk.
Prostate cancer
Myristic and palmitic saturated fatty acids are associated with prostate cancer. However it's still unclear whether this association is a cause or consequence of the disease.
Dietary recommendations
A 2004 statement released by the Centers for Disease Control (CDC) determined that "Americans need to continue working to reduce saturated fat intake..." Additionally, reviews by the American Heart Association led the Association to recommend reducing saturated fat intake to less than 7% of total calories according to its 2006 recommendations. This concurs with similar conclusions made by the World Health Organization (WHO) and the US Department of Health and Human Services, both of which determined that reduction in saturated fat consumption would positively affect health and reduce the prevalence of heart disease.
The World Health Organization (WHO) has concluded that saturated fats negatively affect cholesterol profiles, predisposing individuals to heart disease, and recommends avoiding saturated fats in order to reduce the risk of a cardiovascular disease.
Another confounding issue may be the formation of exogenous (outside the body) advanced glycation endproducts (AGEs) and oxidation products generated during cooking, which it appears some of the studies have not controlled for. It has been suggested that, "given the prominence of this type of food in the human diet, the deleterious effects of high-(saturated)fat foods may be in part due to the high content in glycotoxins, above and beyond those due to oxidized fatty acid derivatives." The glycotoxins, as he called them, are more commonly called AGEs
Contrary research
- A 3-year study of 235 postmenopausal women conducted by Mozaffarian et al was released in 2004. The study subjects all had established coronary artery disease. Most were hypertensive and many had diabetes (19–31%). Their body mass index ranged from 29 to 30 and their lipid profile indicated combined hyperlipidemia. These combined characteristics are consistent with metabolic syndrome. Coronary angiography was employed to examine 2,243 coronary artery segments; once at the start of the study and once more at its conclusion. The study concluded that "in postmenopausal women with relatively low total fat intake, a greater saturated fat intake is associated with less progression of coronary atherosclerosis." The same study revealed similarly surprising results when it was disclosed that a greater consumption of polyunsaturated oils "was also associated with greater progression of atherosclerosis".
- A study of 297 acute myocardial infarction (MI) cases in Portuguese males, published in February 2007, concluded that, "Total fat intake, lauric acid, palmitic acid, and oleic acid were inversely associated with acute MI" and that, "Low intake of total fat and lauric acid from dairy products was related to acute MI". The researchers also stated, in revealing the results of this study, that "some prospective studies show that replacing saturated fat with unsaturated fat is more effective in lowering CHD risk than reducing total fat consumption".
- Fulani of northern Nigeria get around 25% of energy from saturated fat, yet their lipid profile is indicative of a low risk of cardiovascular disease. This finding is likely due to their high activity level and their low total energy intake.
- A 2004 article in The American Journal of Clinical Nutrition raised the possibility that the supposed causal relationship between saturated fats and heart disease may actually be a statistical mistake because of the greater precision with which saturated fats have been measured.
Molecular description
See also
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