Saturated fatty acids dietary sources

Dairy products provide a source of dietary saturated fatty acids. Generally, saturated fatty acids have been reported in the literature to increase LDL-cholesterol (Katan et al., 1994), a risk factor for CHD (Lamarche... 

Jerusalem artichoke tubers contain little or no starch, virtually no fat, and have a relatively low calorific value. Of the small amount of fat present, trace amounts of monounsaturated and polyunsaturated fatty acids have been reported, but no saturated fatty acids (Whitney and Rolfes, 1999). The polyunsaturated fatty acids linoleic (18 2 cis, cis n-6) and a-linoleic acid (18 3 n-3) have been recorded as present at 24 mg and 36 mg-100 g 1 of raw tuber, respectively (Fineli, 2004). The tubers are a good source of dietary fiber, because of the presence of inulin. 

CLA refers to a mixture of positional and geometric isomers of linoleic acid (cis-9, cis-12 octadecadienoic acid) with a conjugated double bond system. The structure of two CLA isomers is contrasted with linoleic and vaccenic acids in Figure 3.1. The presence of CLA isomers in ruminant fat is related to the biohydrogenation of polyunsaturated fatty acids (PUFAs) in the rumen. Ruminant fats are relatively more saturated than most plant oils and this is also a consequence of biohydrogenation of dietary PUFAs by rumen bacteria. Increases in saturated fatty acids are considered undesirable, but consumption of CLA has been shown to be associated with many health benefits, and food products derived from ruminants are the major dietary source of CLA for humans. The interest in health benefits of CLA has its genesis in the research by Pariza and associates who first demonstrated that... 

The current interest in dietary fat, however, stems primarily from its implication in the origin of several chronic diseases. Interest has centered on both the amount and type of dietary fat in the development of cardiovascular disease, cancer, hypertension, and obesity. As a result, dietary recommendations in many countries call for a reduction in total fat intake, to 30% of energy, and in saturated fat intake, to less than 10% of energy. In addition, some nutrition recommendations specify recommended levels of n-6 and n-3 fatty acids in the diets. Hence, the source of fat in the diet has assumed considerable importance over the past few years. Interest in the nutritional properties of canola oil developed because of its fatty acid composition (Table 2). Canola oil is characterized by a low level of saturated fatty acids, a relatively high level of monounsaturated fatty acids, and an appreciable amount of the n-3 fatty acid ot-linolenic acid (18 3 n-3). 

One common feature of the mediterranean dietary habit is the use of olive oil as fat source in place of animal fat typical of Northern European and USA diets. As compared to other vegetable oils, olive oil is charaeterized by the peculiar composition of the tryglieeride fraction and by the phenolic and volatile constituents which affect the organolectic properties. Olive oil is rich in monounsaturated fat (56-84% of oleic acid), contains 3-21% of the essential linoleic aeid [3], is low in tocopherols [4,5] and therefore the presence of phenols is important to mantain the anti-oxidative stability. Several articles [1,2,6] reviewed the reasons why olive oil should be preferable to other dietary fat, paying particular attention to the fatty acid composition. Oleic acid is antithrombotic compared to saturated fatty acids [7]. Monounsaturated and polyunsaturated fats reduced low density lipoproteins (LDL) levels. 

Organisms such as plants and bacteria can synthesize all the fatty acids they require from acetyl-CoA (Chapter 10). Mammals obtain most of their fatty acids from dietary sources. However, these organisms can synthesize saturated fatty acids and some monounsaturated fatty acids. They can also modify some dietary... 

Previously, low fat intakes were traditionally reeommended in the prevention of cardiovascular disease (CVD) as a component of a health promoting diet, without much attention to the quality of fat. However, current dietary guidelines generally put more emphasis on the quality of fat [1-4]. Imbalances in the amounts of individual fatty acids in the diet may have an impact on the occurrence of dyslipidemia, atherosclerosis, thrombosis, hypertension and obesity. Saturated fatty acids (SFA) have shown to be particularly important for development of the above mentioned diseases. However, in spite of an increasing body of new data, the role of individual dietary SFA in metabolic diseases is not fully clarified (Micha 2010). The reaches dietary sources of SFA include fast foods, processed foods, high-fat dairy products, red meats, and pork [1,5]. 

The composition of avocado, in tenns of macronutrients, has been widely studied and is compiled in different tables of food composition. According to the United States Department of Agriculture (USDA) National Nutrient Database for Standard Reference [83], 100 g of avocado are an important source of energy (160 kcal) and contain 73.23 g of water, 2 g of proteins, 14.66 g of total fat (67% monounsaturated, 12% polyunsaturated, and 14% saturated fatty acids), and 8.53 g of carbohydrates, of which 6.70 g are total dietary fiber and 0.66 g are sugars. As it can be seen, one of the main components of avocado is the fat, and thus it is not surprising that it is also known as butter fruit. Besides, some of the principal health benefits of avocado have been attributed to its high monounsaturated fatty acid content. These facts make lipids one of the most studied families of compounds in avocado. 

EFAs are present in all the body s cells, and especially concentrated in the brain and central nervous system. Properties attributed to EFAs include regulation of cholesterol metabolism and inflammatory processes. Table 8.1 lists some of the main dietary sources of EFAs. The quality of these dietary sources depends not only on the levels of the essential fatty acids, but also on their ratios. Many vegetable oils contain moderate levels of saturated fatty acids such as palmitic acid—they too provide therapeutic benefits. 

Many of the trials conducted concentrated on the substitution of polyunsaturated vegetable oils for saturated fat from animal sources and on decreasing the amount of dietary cholesterol. These studies followed the reasoning that fats rich in saturated fatty acids (SFA) raised plasma cholesterol mainly by... 

On a global basis for all species, oils produced in the tropics are more completely saturated and have the highest melting points, with melting points decreasing with distance from the equator (in north and south latitudes). Many dietary fatty acids are transposed from plant or plankton feed sources to body tissues, and fish oils from the Arctic and Antarctic species generally melt at lower temperatures than those... 

Enrichment of the dietary fat with PLs or TAGs may or may not affect fecal excretion of fat and minerals and may increase or decrease saturated fat absorption depending on the PL and TAG source (83). Long-chain polyunsaturated fatty acids were better absorbed in preterm infants when fed as PLs than as TAGs (84). Feeding long-chain polyunsaturates as PLs or TAGs influences the distribution of these fatty acids in plasma lipoprotein fractions, affects their content in different plasma... 

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