Aging

ALA deficiency has been found in patients on long-term gastric tube-feeding that included large amounts of skim milk without ALA supplementation. These patients, who were in nursing homes,

Table 9 Effects of polyunsaturated fatty acids on several genes encoding enzyme proteins involved in cell growth, early gene expression, adhesion molecules, inflammation, /-oxidation, and growth factors3

Function and gene Linoleic acid a-Linolenic acid Arachidonic acid Eicosapentaenoic acid Docosahexaenoic acid

Cell growth and early gene expression c-fos — — " # #

Adhesion molecules

Inflammation

/3-oxidation

Acyl-CoA oxidased " " " " ""

Growth factors

aVCAM, vascular cell adhesion molecule; IL, interleukin: PDGF, platelet-derived growth factor. # suppresses or decreases, " induces or increases.

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

cEicosapentachoic acid has no effect by itself but enhances the effect of docosahexachoic acid (DHA) dMONOs also induce acyl-CoA oxidase mRNA

Source: Modified from Simopoulos AP. The role of fatty acids in gene expression: Health implications. Ann Nutr Metab 1996, 40: 303-311. With permission.

Table 10 Adequate intake (AI) for adults

Fatty acid Grams/day % Energy

(2000 kcal diet)

Table 10 Adequate intake (AI) for adults

Fatty acid Grams/day % Energy

(2000 kcal diet)

LA

4.44

2.0

(upper limit)a

6.67

3.0

ALA

2.22

1.0

DHA+EPA

0.65

0.3

DHA to be at leastb

0.22

0.1

EPA to be at least

0.22

0.1

TRANS-FA

(upper limit)c

2.00

1.0

SAT

(upper limit)d

-

<8.0

MONOse

-

-

aAlthough the recommendation is for AI, the Working Group felt that there is enough scientific evidence to also state an upper limit (UL) for LA of 6.67 gday-1 based on a 2000kcal diet or of 3.0% of energy.

bFor pregnant and lactating women, ensure 300 mgday-1 of DHA. cExcept for dairy products, other foods under natural conditions do not contain trans-FA. Therefore, the Working Group does not recommend trans-FA to be in the food supply as a result of hydrogenation of unsaturated fatty acids or high-temperature cooking (reused frying oils).

dSaturated fats should not comprise more than 8% of energy. eThe Working Group recommended that the majority of fatty acids are obtained from monounsaturates. The total amount of fat in the diet is determined by the culture and dietary habits of people around the world (total fat ranges from 15% to 40% of energy) but with special attention to the importance of weight control and reduction of obesity.

If sufficient scientific evidence is not available to calculate an estimated average requirement, a reference intake called an adequate intake is used instead of a recommended dietary allowance. The AI is a value based on experimentally derived intake levels or approximations of observed mean nutrient intakes by a group (or groups) of healthy people. The AI for children and adults is expected to meet or exceed the amount needed to maintain a defined nutritional state or criterion of adequacy in essentially all members of a specific healthy population. LA, linoleic acid; ALA, a-linolenic acid; DHA, docosahexaenoic acid; EPA, eicosapentaenoic acid; TRANS-FA, trans-fatty acids; SAT, saturated fatty acids; MONOs, monounsaturated fatty acids. Reproduced with permission from Simopoulos AP, Leaf A, and Salem N Jr (1999) Essentiality of and recommended dietary intakes for omega-6 and omega-3 fatty acids. Annals of Nutrition and Metabolism 43: 127-130.

Table 11 Adequate intake (AI) for infant formula/diet

Fatty acid Per cent of fatty acids

LAa 10.00

ALA 1.50

AAb 0.50

DHA 0.35 EPAc

®The Working Group recognizes that in countries like Japan the breast milk content of LA is 6-10% of fatty acids and the DHA is higher, about 0.6%. The formula/diet composition described here is patterned on infant formula studies in Western countries. bThe Working Group endorsed the addition of the principal long-chain polyunsaturates, AA and DHA, to all infant formulas. cEPA is a natural constituent of breast milk, but in amounts more than 0.1% in infant formula may antagonize AA and interfere with infant growth.

If sufficient scientific evidence is not available to calculate an estimated average requirement, a reference intake called an adequate intake is used instead of a recommended dietary allowance. The AI is a value based on experimentally derived intake levels or approximations of observed mean nutrient intakes by a group (or groups) of healthy people. The AI for children and adults is expected to meet or exceed the amount needed to maintain a defined nutritional state or criterion of adequacy in essentially all members of a specific healthy population. LA, linoleic acid; ALA, a-linolenic acid; AA, arachidonic acid; DHA, docosahexaenoic acid; EPA, eicosapentaenoic acid; TRANS-FA, trans-fatty acids; SAT, saturated fatty acids; MONOs, monounsaturated fatty acids.

Reproduced with permission from Simopoulos AP, Leaf A, and Salem N Jr (1999) Essentiality of and recommended dietary intakes for omega-6 and omega-3 fatty acids. Annals of Nutrition and Metabolism 43: 127-130.

symptoms, along with the biochemical determinations, provides additional support for the diagnosis. To verify the diagnosis, it is essential that the clinical symptoms disappear upon supplementation of the deficient diet with n-3 fatty acids.

With the increase in the number of elderly persons in the population, and the proliferation of nursing homes, particular attention must be given to the nutritional requirements of the elderly, especially those who are fed enterally or parenterally.

developed skin lesions diagnosed as scaly dermatitis, which disappeared with ALA supplementation. A number of other patients were reported to have n-3 fatty acid deficiency, again patients on long-term gastric tube-feeding or prolonged total parenteral nutrition because of chronic illnesses. If a deficiency of total n-3 fatty acid intake is suspected, its concentration in plasma should be measured. A decrease in the concentration of 20:5n-3, 22:5n-3, and particularly 22:6n-3 in plasma or erythrocyte phospholipids indicates that the dietary intake of n-3 fatty acids has been low. The presence of clinical

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