Essential fatty acid assessment

Physical examination should focus on assessment of lean body mass (LBM) and physical findings of vitamin, trace element, and essential fatty acid deficiencies. 

Biochemical assessment of trace element, vitamin, and essential fatty acid deficiencies should be based on the nutrient s function, but few practical... 

Holman, R. T., Caster, W. O. and Wiese, H, F. 1964. The essential fatty acid requirement of infants and the assessment of their dietary intake of linoleate by serum fatty acid analysis. Am. J. Clin. Nutr. 14, 70-75. 

Special techniques have been developed to induce deficiencies and assess requirements. A multigeneration deficiency is induced where a severe deficiency in a particular nutrient cannot be induced in the life span of the animal. This technique is also used to study the effect on the neonatal or young aiumal. The muJtigcnera-tion deficiency has been used in studies of taurine (Sturman et ai 1955), essential fatty acids (Tinoco et ah. 1978), and fluoride (Tao and Suttie, 1976). 

Erosion of the fibrous cap, 360 Enicic add, 6S3 Erythroblasts, 513 Erythnopoiesis, 755 Erythropoietin, 755 EscfiericJfl fplr, in the gut, 148 Essential amino acids, 22-23 Essentiai fatty acid deflciertcy, 650-653 Essential fatty acids (EfAs), 493,638-639 assessment of status, 650. deficiency, 650-655 dsesaturation, 638-639,641-643 fish oils, 643... 

In EFA deficiency, oleic acid can be dehydrogenated to yield polyunsaturated fatty acids (PUFAs) that are nonessential and do not substitute for the essential fatty acids. One suchPUFA is 5,8,11-eicosatrienoic acid, which occurs in significant amounts in heart, liver, adipose tissue, and erythrocytes of animals fed diets deficient in EFAs but decreases after supplementation with linoleic or linolenic acids. Its appearance in tissues and plasma has been used in the assessment of EFA deficiency. 

The nutrition-focused physical examination consists of an assessment of lean body mass (LBM) and the physical findings of vitamin deficiency, trace element deficiency, and essential fatty acid deficiency. The assessment should characterize the presence and degree of muscle wasting, edema, loss of subcutaneous fat, dermatitis, glossitis, cheilosis, and/or jaundice (Table 135-2). 

A comprehensive nutrition assessment must include an evaluation of possible trace element, vitamin, and essential fatty acid deficiencies. Because of their key role in metabolic processes (as coenzymes and cofactors), a deficiency of any of these nutrients may result in altered metabolism and cell dysfunction, and may interfere with metabolic processes necessary for nutritional repletion. The evaluation of single-nutrient-deficiency states includes an accurate history to identify symptoms and risk factors that may indicate deficiency or predispose the patient to developing a deficiency state. A focused physical examination for signs of deficiencies and biochemical assessment to confirm a suspected diagnosis also should be done. Ideally, biochemical assessment would be based on the nutrient s function (e.g., metalloenzyme activity) rather than simply measuring the nutrient s serum concentration. Unfortunately, few practical methods to assess micronutrient function are available currently, and most assays measure serum concentrations of the individual nutrient. 

Lipids. Fasting plasma triglyceride levels provide some indication of fat metabolism, but arc again affected by a variety of metabolic priKcsscs. Essential fatty acid levels may be measured if specific deficiencies are suspected. Faecal fat may be measured both qualitatively and quantitatively in the assessment of malabsorption (pp. 104-105). 

As with the male rat, the early reports that erucic acid somehow interfered with reproduction in the female rat are difficult to assess because the diets that were used may have been low in essential fatty acids (Carroll and Noble, 1957). Decreased numbers of pregnancies, resorption, and pseudopregnancies were observed in female rats fed diets supplemented with either erucic or oleic acids. Somewhat more plausible are the reports that the ovarian cholesterol content is increased in rats fed a HEAR oil containing diet (Carroll and Noble, 1952). When rats were fed ethyl erucate mixed with corn oil which is high in essential fatty acids, there were no noticeable reproductive abnormalities in the females (Walker eta/., 1972). As in the adrenal gland, the erucic acid in the ovaries accumulated as the cholesterol ester. Also, the cholesterol esters of 20 4 n-6, 22 4 n-6, and 24 1 n-9 were increased in the ovaries from these rats. An interesting observation by these authors was that rats fed an olive oil containing diet with no erucic acid accumulated appreciable quantities of esterified erucic acid, i.e., 3.1% of the cholesterol ester fraction and 1.4% of the phospholipid fraction. It was... 

The measurements of the total amount of various essential fatty acids as co-3 fatty acids in plasma, serum, or erythrocyte membrane phospholipids have been indicated as useful markers of essential polyunsaturated fatty adds. Essential fatty acid deficiency is a clinical condition that derives from inadequate status of co-3 and co-6 fatty acids however, the symptoms are nonspecific and may not present prior to marginal essential fatty acid status. Widely used biomarkers for bicx hemi( essai-tial fatty acid deficiency are mead acid and the triene/tetraene ratio. Howcvct, the total plasma triene/tetraene ratio has been considered the gold standard for essential fatty acid deficiency. Mead acid, or 5,8,11-eicosatrienoic acid (5,8,11-20 3 co-9) is synthesized from endogenous oleic acid and is increased when there is insufficient concentrations of linoleic and a-linolenic acid to meet the needs of polyunsaturated fatty acids. Under normal conditions only trace amounts of mead acid are found in plasma. EPA and DHA inhibit mead acid synthesis. Mead acid measurement is an indicator of essential fatty acid deficiency state, while essential fatty add depletion is associated with a decrease in plasma hnoleate and arachidonate percentages. Assessment of long-term essential fatty acid intake is measured in adipose tissue, and it is considered the best indicator because of its slow tumover. - Cutoff values for the assessment of essential fatty adds and to-3 fatty acid status in erythrocytes have been reported. Proposed cutoff values for children older than 0.2 years are 0.46 mol% 20 3 co-9 (mead acid) for early suspicion of essential fatty acid defidency, 0.068 mol/mol docosapentaenoic/arachidonic acid... 

Sauberlich, H.E., Essential fatty acids deficiencies, in Assessment of Nutritional Status, Sauberlich, H.E., Ed., CRC Press, Boca Raton, EL, 1999, pp. 471 77. 

The fats and oils standards aim to provide protection in terms of authenticity of the products covered and contain descriptions of each. They also recognize that the fatty acid composition is one of the main ways of identifying and distinguishing one oil/fat from another. Fatty acid specifications for each oil/fat are included as essential composition and quality factors and are reproduced in Tables 8.6 and 8.7. For vegetable oils, it is also recognized that other compositional factors may be used to assist in assessing authenticity—iodine... 

Other carbonyl compounds, including propanal, pentanal, decadienal, etc., are also used for evaluating lipid oxidation in foods. For instance, propanal is a recommended indicator for lipid oxidation in foods that are high in 0)3 fatty acids, such as marine oils (67, 68). In general, it is essential to use appropriate indicators when assessing the oxidative deterioration of different food systems. 

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