Omega-3 Fatty Acids and Omega-3 Fatty Acids and ImmunityImmunity

By Jostelo GarcesBy Jostelo Garces

Sources of Omega-3 F.A. Sources of Omega-3 F.A.

Fish and seafood sourcesFish and seafood sources Nuts and SeedsNuts and Seeds Certain oils and spreadsCertain oils and spreads Eggs from hens fed with omega-3 Eggs from hens fed with omega-3

feedfeed

*There is no USRDA for Omega-3, but the *There is no USRDA for Omega-3, but the Canadian FDA recommends 1.0 - 1.5 Canadian FDA recommends 1.0 - 1.5 grams per day.grams per day.

Seafood sources of Seafood sources of Omega-3 Omega-3

Type of fish Grams of -3 per serving

Atlantic mackerel 2.6 Lake trout 2.0 Atlantic Salmon 1.9 Herring 1.8 Albacore tuna 1.5 Sardines, canned 1.4 Salmon, pink 1.0

Health Effects of Health Effects of -3 Fatty -3 Fatty AcidsAcids

Improves cardiovascular lipid Improves cardiovascular lipid profile profile CVD prevention CVD prevention

Prevents cancerPrevents cancer Decreases symptoms of some Decreases symptoms of some

mental disorders, i.e., Alzheimer’s mental disorders, i.e., Alzheimer’s DiseaseDisease

Improves immune function Improves immune function

Omega-3 Fatty AcidsOmega-3 Fatty Acids

Eicosapentaenoic acid (EPA)Eicosapentaenoic acid (EPA)

Docosahexaenoic acid (DHA) Docosahexaenoic acid (DHA)

EPA and DHA are two EPA and DHA are two -3 fatty acids that -3 fatty acids that are especially high in immune cells and are especially high in immune cells and are incorporated in the cell membrane are incorporated in the cell membrane where they can influence membrane where they can influence membrane fluidity, receptor function, enzyme activity, fluidity, receptor function, enzyme activity, and the production of eicosanoids. and the production of eicosanoids.

EicosanoidsEicosanoids

Lipid mediators of immune function. They Lipid mediators of immune function. They can yield positive and negative effects. can yield positive and negative effects.

Eicosanoids derived from arachidonic acid Eicosanoids derived from arachidonic acid (AA) (AA) most potent pro-inflammatory f/x most potent pro-inflammatory f/x effects on immune function effects on immune function

-3 PUFAs inhibit AA oxygenation synth of bad eicosanoids & pro-inflammatory f/x

PUFAs and EicosanoidsPUFAs and Eicosanoids

Suggested intake of PUFAs:Suggested intake of PUFAs:– High levels of High levels of -3 fatty acids, but -3 fatty acids, but

low levels of low levels of -6 fatty acids. -6 fatty acids.

-6 -6 AA AA 2 series of ‘bad’ 2 series of ‘bad’ prostaglandinsprostaglandins

and inflammatory leukotrienes VS.and inflammatory leukotrienes VS.

-3 -3 EPA EPA 3 series of ‘good’ 3 series of ‘good’ prostaglandins and less inflammatory prostaglandins and less inflammatory leukotrienes leukotrienes

PUFAs and ImmunityPUFAs and Immunity

Cells which perform immune Cells which perform immune functions are mediated by functions are mediated by membrane-associated activities, such membrane-associated activities, such as cytokine and antibody secretions as cytokine and antibody secretions and lymphocyte transformations. and lymphocyte transformations.

High PUFAs High PUFAs healthier cell healthier cell membrane membrane improved immune improved immune functionfunction

Clinical StudiesClinical Studies

Population of Greenland Eskimos Population of Greenland Eskimos compared with matched groups living in compared with matched groups living in Denmark. Denmark. – Low incidence of autoimmune and Low incidence of autoimmune and

inflammatory disorders, such as psoriasis, inflammatory disorders, such as psoriasis, asthma, and type-I diabetes. asthma, and type-I diabetes.

– These diseases display inappropriate T cell These diseases display inappropriate T cell activation & host tissue destruction w/ activation & host tissue destruction w/ macrophages & mediators produced by macrophages & mediators produced by cytokines, eicosanoids, and ROS. cytokines, eicosanoids, and ROS.

Clinical Studies (cont.)Clinical Studies (cont.)

3 month 3 month -3 supplementation -3 supplementation between groups of older and young between groups of older and young female subjects female subjects – Both groups increased showed an Both groups increased showed an

increase in EPA and DHA, but older increase in EPA and DHA, but older group had a greater increase. group had a greater increase.

– Older groups showed a decrease in AA, Older groups showed a decrease in AA, while younger groups showed no while younger groups showed no change. change.

Clinical Studies (cont.)Clinical Studies (cont.)

Graft rejection in transplants is caused Graft rejection in transplants is caused by a T-cell immune reaction to the by a T-cell immune reaction to the foreign material introduced into the foreign material introduced into the body. body.

Kidney transplant recipients received 6 g Kidney transplant recipients received 6 g fish oil/day for one year post-op fish oil/day for one year post-op

better kidney function and less better kidney function and less rejections when compared to those with rejections when compared to those with no supplementation. no supplementation.

Weaknesses Amongst Weaknesses Amongst StudiesStudies

Contradictory observations Contradictory observations between studies due to: between studies due to: – differences in the cell types useddifferences in the cell types used– differences in protocols used differences in protocols used – sample populations too smallsample populations too small– source of source of -3 was always fish oil, did -3 was always fish oil, did

not observe f/x with plant sources not observe f/x with plant sources

Safety AspectsSafety Aspects

Healthy subjects or those with Healthy subjects or those with compromised immune status yield compromised immune status yield undesirable effects due to excessive undesirable effects due to excessive reduction in cytokine or eicosanoid reduction in cytokine or eicosanoid production which impairs their normal production which impairs their normal host defenses or homeostasis.host defenses or homeostasis.

*Vitamin E supplements may *Vitamin E supplements may this side effect. this side effect.

Eat fish,Eat fish,

live longer. live longer.