S14

SCD1 SCD2 ACC ME Glycolysis G6PD GK PK

Mature adiposités Glucose transport GLUT4 GLUT1

Clarke and Jump (1996) Clarke and Jump (1993) Clarke et al. (1990) Clarke et al. (1977) Clarke and Jump (1996) Clarke and Jump (1993) Clarke et al. (1990) Clarke et al. (1977) Ntambi (1991) DeWillie and Farmer (1993) Clarke and Jump (1996) Clarke and Jump (1996)

Jump and Clarke (1994) Jump and Clarke (1994) Liimaatta et al. (1994)

| = suppresses or decreases; f = induces or increases.

IQ (Lucas et al., 1992; Eurocat Working Group, 1991), motor development is very much dependent on intermediary metabolism and on overall normal metabolism, both of which are influenced by fatty acid biosynthesis and carbohydrate metabolism.

The amounts of PUFA found in breast milk in mothers fed diets consistent with our evolution should serve as a guide to determine omega-6 and omega-3 fatty acid requirements during pregnancy, lactation, and infant feeding. Of interest is the fact that saturated, monounsaturated, and trans fatty acids do not exert any suppressive action on lipogenic or glycolytic gene expression, which is consistent with their high content in human milk serving primarily as sources of energy. Because nutrients influence gene expression and many chronic diseases begin in utero or in infancy, proper dietary intake of PUFA, even prior to pregnancy may be essential, as shown for folate deficiency in the development of neural tube defects (Eurocat Working Group, 1991).

A balance between the omega-6 and omega-3 fatty acids is a more physiologic state in terms of gene expression (Simopoulos, 1996), prostaglandin and leukotriene metabolism, and interleukin-1 (IL-1) production (Simopoulos, 1991). The current recommendation to substitute vegetable oils (omega-6) for saturated fats leads to increases in IL-1,

Table 14

Effects of Polyunsaturated Fatty Acids on Several Genes

Encoding Enzyme Proteins Involved in Cell Growth, Early Gene Expression,

Adhesion Molecules, Inflammation, ß-Oxidation, and Growth Factors

Function and gene

Ref.

leic lenic acid acid

Arachi- Eicosa- Docosa-donic penta- hexaenoic acid enoic acid acid

Cell growth and early gene expression c-fos Egr-1 Adhesion molecules VCAM-1 mRNAa Inflammation

IL-1p p-oxidation

Acyl-CoA oxidasec Growth factors PDGF

Note: VCAM, vascular cell adhesion molecule; IL, interleukin; PDGF, platelet-derived growth factor. | suppresses or decreases, f induces or increases.

aMonounsaturated fatty acids (MONOs) also suppress VCAM1 mRNA, but to a lesser degree than does DHA. AA also suppresses to a lesser extent than DHA.

Eicosapentaenoic acid has no effect by itself but enhances the effect of docosahexaenoic acid (DHA). cMONOs also induce acyl-CoA oxidase mRNA.

prostaglandins, and leukotrienes, is not consistent with human evolution, and may lead to maladaptation in those genetically predisposed.

The time has come to return the omega-3 fatty acids into the food supply. Progress in this regard is being made (Simopoulos, 1998a; Simopoulos, 1999b; Simopoulos and Robinson, 1999). In the past, industry focused on improvements in food production and processing, whereas now and in the future, the focus will be on the role of nutrition in product development and its effect on health and disease (Simopoulos, 1998c).

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