Dietary fatty acids and coronary heart disease

The effects of dietary fats have been established in epidemiological and intervention studies and through relationship to risk factors for development of coronary heart disease (CHD). During a period where the impressive effects of hydroxymethylglutaryl-CoA reductase inhibitors on the mortality of CHD dominate the medical journals, it is important to realize the major effects of dietary fatty acids on a series of events included in the multifactorial disorder of CHD.     

Fatty acid monoesters of l-ascorbic and d-isoascorbic acids as antioxidants for fats and oils

Summary 1. The fatty acid monoesters of l-ascorbic and d-isoascorbic acids have been tested for antioxygenic activity in different fats and oils under various conditions and in combination with other inhibitors. 2. Traces of soap were found to have a deleterious effect on the stability of fats. This deleterious effect can be counteracted by the use of fat-soluble ascorbyl monoesters. 3. The ascorbyl monoesters used in combination with either α-tocopherol or phospholipids, or both, show a marked synergistic antioxidant effect. 4. Possible explanations are given for certain synergistic phenomena that have been observed.     

Fatty acids from pulp mill wastes

This paper discusses the new fatty acid-containing product “Tall Oil.” which is derived from the waste liquors of the paper industry. The method of preparation, some thoughts on chemical composition, uses, and available supplies are discussed.     

Fatty acids and Schizophrenia

In a controlled study of red cell membrane fatty acids in patients with schizophrenia, substantial depletions of fatty acids from both the n-6 and n-3 series were demonstrated. Arachidonic acid and docosahexaenoic acid were particularly depleted. In a separate study, dietary analysis revealed no deficiency of fatty acid intake in this patient group, but greater intake of n-3 fatty acids was associated with less severe symptomatology. Dietary supplementation for six weeks with 10 g per day of concentrated fish oil (MaxEPA) led to significant improvement in schizophrenic symptoms. This clinical improvement was related to the increased level of n-3 fatty acids in red cell membranes. These findings form part of a growing body of research data suggestive of an abnormality in cell membrane fatty acid composition in schizophrenia. The preliminary evidence for clinically effective dietary manipulation to correct such an abnormality opens up novel and exciting therapeutic possibilities.     

Fatty acids and sterols in oils from canola screenings

One sample of canola seed (variety Tower) and five samples of screenings were commercially processed to yield first an “expeller oil” and subsequently an “extractor oil” by the hexane extraction of the residue. The screening samples contained 25–50% intact or broken canola seed. The balance included 21–31% weed seeds (especially lambsquarter and stinkweed), hulls, fragments of the embryo, and chaff. All the oil samples were analyzed for sterol and fatty acid composition. The extractor screening samples had slightly higher sterol contents than the corresponding expeller samples, while the Tower samples gave the lowest values. The averages (in mg/g oil or extract) for the extractor screening samples were: brassicasterol, 1.0; campesterol, 4.1; and β-sitosterol, 7.3. For expeller screening samples the average were: 0.9, 3.6 and 6.2 and for the Tower oils they were, respectively, 0.9, 3.8, 5.3 and 0.9, 3.5, 4.7. The fatty acid compositions of the screening samples for both extractor and expeller oils were similar to that of the Tower oil except for the higher proportions of docosenoic acid (22:1) and eicosenoic acid (20:1) and the more obvious presence of three C₁₈ conjugated dienes totalling up to 0.6% of one screening oil sample. The docosenoic acid level (mainly erucic acid) ranged from 3.0 to 7.0% for the extractor oils and from 2.5 to 8.0% for the expeller samples, compared to 0.1% for the two Tower oils. The oil contents of the screenings ranged from 20 to 30%, and the fatty acids and sterols appear to be nutritionally useful and innocuous in all respects. Presented in part at the ISF/AOCS World Congress, New York, April–May 1980.     

Fatty acids in phospholipids isolated from human red cells

Total lipids of packed erythrocytes from healthy men 22 to 25 years old were extracted with chloroform-methanol mixture. Phospholipid classes were separated from neutral lipids and pigments on a silicic acid column. Phosphatidyl inositol (PI) was freed of its contaminants phosphatidyl ethanolamine (PE) and phosphatidyl serine (PS) on an aluminum oxide column. Additional silicic acid columns with modified solvent systems were needed for complete separation of other overlapped phospholipid classes. The identification of phospholipids in each eluted fraction was accomplished by TLC, using the appropriate spray tests and reference compounds, and confirmed on each of the isolated phospholipids by IR spectrophotometry. The total content of phospholipids as determined by phosphorus analysis was found to be 2.63 mg/ml of packed cells. These phospholipids were found to have the following composition (in per cent of total phospholipid): PI, 2.3; PE, 13.4; ethanolamine plasmalogen (EP), 14.5; PS, 3.9; lecithin (L), 34.2; choline plasmalogen (CP), 1.4; sphingomyelin (Sph), 28.4 and lysolecithin (LL), 1.7. The fatty acid composition of each phospholipid was determined by GLC. The average number of double bonds per fatty acid in the isolated phospholipids was found to be as follows: PI, 1.5; PE, 1.9; EP, 3.6; PS, 2.1; L, 1.0; CP, 2.0; Sph, 0.2 and LL, 0.5. The positional distribution of fatty acids in both L and PE was ascertained by selective enzymatic hydrolysis with phospholipase A. Saturated fatty acids of L were esterified predominantly in the α′-position, whereas in PE only 63.9 mole per cent of the saturated fatty acids were found in this position. Presented in part at the AOCS Meeting in Los Angeles, April 1966. Dept. of Health, Education and Welfare, USPHS.     

Inhibition of malonaldehyde formation by antioxidants from ω3 polyunsaturated fatty acids

The inhibitory effect of α-tocopherol, β-carotene, 2″-O-glycosyl isovitexin (2″-O-GIV), and butylated hydroxytoluene (BHT) on malonaldehyde (MA) formation from ω3 polyunsaturated fatty acids (PUFA) was determined by gas chromatography. The levels of MA formed from 1 mg each of octadecatetraenoic acid (ODTA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) upon oxidation with Fenton's reagent were 29.8±1.5, 17.2±1.5, and 22.0±0.7 nmol, respectively. BHT was most effective toward protecting all three ω3 PUFA, whereas β-carotene did not exhibit any inhibitory effect. 2″-O-GIV inhibited MA formation from EPA and DHA by 56 and 43%, respectively, showing the second greatest inhibitory activity after BHT. α-Tocopherol inhibited MA formation from ODTA and DHA by 67 and 28%, respectively, but it did not show any activity toward EPA oxidation. The naturally occurring antioxidant, 2″-O-GIV, may be useful to prevent oxidation of ω3 PUFA.     

Fatty acids from the scent glands of the Louisiana muskrat

1. The mixture of fatty acids from muskrat scent glands has been analyzed by the ester fractionation method.
2. The esters of myristic, palmitic, hexadecenoic, oleic, and linoleic acids were found present as major components in these glands. Unsaturated acids of the C₂₄ and C₂₆ series are also present to the extent of 8.5% of the total fatty acids. Acids present to less than 1% each include decanoic, dodecanoic, stearic, tetracosanoic, dodecenoic, and tetradecenoic acids.
3. Application of determinants for the solution of simultaneous equations has been presented as a method which greatly simplifies and facilitates the calculations necessary to this type of work.
4. The possible relationship existing between fatty acids and macrocyclic carbinols has been considered and possible mechanisms for such transformations have been presented.

     

Fatty acids from grain fed and grass fed beef in South Africa

Regular consumption of red meat is often considered detrimental to human health due, among other factors, to a perceived unhealthy fatty acid profile. With production systems intensifying globally, grain‐fed beef from feedlots are dominating market shelves within westernized countries. Although grass fed beef is considered to be a healthier alternative due to a lower total fat content and more desirable fatty acid composition, no studies have been performed to quantify such differences in South Africa. The current study evaluated the fatty acid profile of the different beef offerings available on the market, and expressed the data per edible portion to effectively guide future dietary recommendations. Notable differences were found in the quantity and quality of different fatty acids between the different production systems. Due to the unique classification system dictating the characteristics of fresh meat the result indicated distinctive differences between South African red meat and international produce.     

Fatty acids of sphingomyelin from amniotic fluid of normal and diabetic pregnancies

Amniotic fluid collected from 14 normal and 11 diabetic patients was analyzed for phospholipids, and separated sphingomyelin and lecithin fractions were further studied for their fatty acid composition by gas liquid chromatography. Notable differences in percent fatty acid composition of sphingomyelin were observed for palmitic (16∶0; diabetic < normal), oleic (18∶1; diabetic > normal), behenic (22∶0; diabetic < normal) and arachidic acid (20∶0; absent in diabetics) in the specimens studied. Notable differences were not observed in fatty acids from lecithin fraction. Fatty acid composition of sphingomyelin from amniotic fluid is similar to fatty acid distribution in sphingomyelin from serum and erythrocyte and suggests maternal origin of the lipid. Presented in part at the 67th annual meeting of the Federation of American Societies for Experimental Biology, Chicago, IL 1983. Abstracted from dissertation written by one of the authors (Vicki Brooks) in partial fulfillment for Master of Science degree in Clinical Chemistry, Department of Pathology, LSU Medical Center.     

Balance between polyunsaturated fatty acids and antioxidants in nutrition

It is recommended that humans increase their consumption of omega‐3 polyunsaturated fatty acids (PUFA) because of many nutritional advantages. However, the oxidative instability of these fatty acids poses a problem regarding the sensory and nutritional quality of foods. It is clear that antioxidants need to be added to stabilize these lipids during food processing and storage, as well as to provide the body with enough antioxidant power to counteract any oxidative stress resulting from the increased intake of PUFA. However, we need more knowledge regarding the levels of antioxidant required for food stability and nutritional adequacy as well as the nature of antioxidant oxidation products and their toxicological significance.     

Fatty acids and sterols ofCronartium fusiforme basidiospores

The hydrocarbons, fatty acids, and sterols ofCronartium fusiforme basidiospores were examined by gas chromatography and mass spectrometry. Trace quantities of aliphatic hydrocarbons were detected, but these were probably not fungal products. Principal nonsubstituted fatty acids were palmitic (11.7%), linoleic (17.2%), and linolenic (16.1%) acids; the predominant acid was 9,10-cis-epoxyoctadecanoic acid (40.7%). Four sterols were detected, three of which were identified as stigmast-7-enol (57.6%), stigmasta-5,7-dienol (22.7%), and ergost-7-enol (16.0%). The fourth sterol (4%) is a C₂₈ diene. Lipids of the aeciospores and basidiospores ofC. fusiforme are compared.     

Fatty acid composition of meat from ruminants, with special emphasis on trans fatty acids

The fatty acid composition was determined in 39 samples of beef, 20 samples of veal, and 34 samples of lamb, representative of the supply of ruminant meat in Denmark. Five cuts of beef and veal and three cuts of lamb with increasing fat content were selected, and analysis of the fatty acid methyl esters was performed by gas-liquid chromatography (GLC) on a polar 50-m capillary column CP Sil 88 with flame-ionization detection. Lamb had the highest content of saturated fatty acids (52.8±1.8 g/100 g fatty acids), higher than beef and veal (45.3±3.1 and 45.4±0.8 g/100 g fatty acids, respectively). Cis monounsaturated fatty acids were 49.2±3.1, 44.9±1.8, and 37.7±1.7, and polyunsaturated fatty acids were 3.3±0.7, 5.8±2.0, and 5.0±0.1 g/100 g fatty acids in beef, veal, and lamb, respectively. Beef contained 2.1±0.8 g trans C_18:1 per 100 g fatty acids, about half that found in veal (4.0±1.2 g/100 g fatty acids) and lamb (4.5±0.6 g/100 g fatty acids). Trans C_16:1 was 0.24±0.01, 0.14±0.02, and 0.79±0.02 g/100 g fatty acids in beef, veal, and lamb, respectively. Only small variations in trans and other fatty acids could be demonstrated between cuts. The overlap between cis and trans C_18:1 by capillary GLC was verified by argentation-thin-layer chromatography followed by GLC, on three samples of veal and three samples of lamb. In veal 1.0 g, and in lamb 1.4 g trans C_18:1 per 100 g fatty acids were hidden under the cis C_18:1 peak. The mean intake of trans fatty acids from ruminant meat is estimated at 0.2 g/d.     

Free radicals, oxidative stress, and antioxidants in human health and disease

Free radicals and other reactive oxygen species (ROS) are constantly formed in the human body. Free-radical mechanisms have been implicated in the pathology of several human diseases, including cancer, atherosclerosis, malaria, and rheumatoid arthritis and neurodegenerative diseases. For example, the superoxide radical (O ₂ ^·− ) and hydrogen peroxide (H₂O₂) are known to be generated in the brain and nervous system in vivo, and several areas of the human brain are rich in iron, which appears to be easily mobilizable in a form that can stimulate free-radical reactions. Antioxidant defenses to remove O ₂ ^·− and H₂O₂ exist. Superoxide dismutases (SOD) remove O ₂ ^·− by greatly accelerating its conversion to H₂O₂. Catalases in peroxisomes convert H₂O₂ into water and O₂ and help to dispose of H₂O₂ generated by the action of the oxidase enzymes that are located in these organelles. Other important H₂O₂-removing enzymes in human cells are the glutathione peroxidases. When produced in excess, ROS can cause tissue injury. However, tissue injury can itself cause ROS generation (e.g., by causing activation of phagocytes or releasing transition metal ions from damaged cells), which may (or may not, depending on the situation) contribute to a worsening of the injury. Assessment of oxidative damage to biomolecules by means of emerging technologies based on products of oxidative damage to DNA (e.g., 8-hydroxydeoxyguanosine), lipids (e.g., isoprostanes), and proteins (altered amino acids) would not only advance our understanding of the underlying mechanisms but also facilitate supplementation and intervention studies designed and conducted to test antioxidant efficacy in human health and disease.     

Fatty acids recovery from vegetable oil wet sludge by supercritical alcoholysis

In the last decade the production of soybean and sunflower oil has greatly increased worldwide. Together with it, the market of the oil refining by-products, phospholipids sludge (wet gum) and distillates of the deodorizer (DDEO) is rapidly changing. In this work, we performed the direct alcoholysis of the phospholipids and oil enclosed in the wet gum using supercritical ethanol. A statistical design of experiments was carried out to determine the effect of temperature (280–320 °C), ethanol concentration (50–80 wt%), reaction time (20–50 min) and water content (51–2.4 wt%). In all the cases a complete conversion of the lipids was observed. After removal of volatile compounds, the reaction product contained a hexane insoluble solid substrate (around 25%) and an oily phase with more than 50 wt% of fatty esters.     

Oxygen absorption of methyl esters of fat acids,and the effect of antioxidants

Summary The oxygen absorption of methyl linolenate, methyl linoleate, methyl oleate, methyl stearate, the distilled methyl esters of lard, and various mixtures of the four individual methyl esters were measured at 100° C. in the Barcroft-Warburg apparatus. Mixtures of methyl esters absorbed oxygen at a rate which could be approximately predicted from the rate of oxygen absorption of each component and the percentage of each present. The antioxidants nordihydroguaiaretic acid (NDGA), propyl gallate, benzylhydroquinone, α-tocopherol, and their synergistic combinations with citric acid, d-isoascorbyl palmitate, and lecithin were tested with the substrates methyl linoleate, methyl oleate, methyl stearate, and the distilled methyl esters of lard. Citric acid showed marked synergism with each antioxidant. The two most effective were the combinations of citric acid with nordihydroguaiaretic acid and with propyl gallate. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, United States Department of Agriculture.     

Intake of ruminant versus industrial trans fatty acids and risk of coronary heart disease – what is the evidence?

Several studies have reported a positive association between intake of trans fatty acids and risk of heart disease. It has been suggested that trans fatty acids from ruminant sources are less detrimental than trans fatty acids from industrial sources. Legislation or advice on limiting trans fatty acids has, in some instances, been restricted to trans fatty acids from industrial sources. However, comparisons of ruminant and industrial trans fatty acids have been based on few studies using relative intake data (e.g. quintiles of intakes). Therefore, we have reviewed data describing the associations between absolute intake (g eaten per day) of ruminant and industrial trans fatty acids and risk of coronary heart disease, and examined the associations graphically. Where direct comparison is possible, there are no differences in risk of coronary heart disease between total, ruminant and industrial trans fatty acids for intakes up to 2.5 g/d. At higher intakes (more than 3 g/d) total and industrial trans fatty acids are associated with an increased risk of coronary heart disease but there is insufficient data available on ruminant trans fatty acids at this level of intake. The scarce data do not support discrimination between ruminant and industrial trans fatty acids in dietary recommendations or legislation.