Omega-3 Fatty Acids and Immunity

1. Omega-3 Fatty Acids and Immunity By Jostelo Garces

2. Sources of Omega-3 F.A. • Fish and seafood sources • Nuts and Seeds • Certain oils and spreads • Eggs from hens fed with omega-3 feed *There is no USRDA for Omega-3, but the Canadian FDA recommends 1.0 - 1.5 grams per day.

3. Seafood sources of Omega-3

4. Health Effects of -3 Fatty Acids • Improves cardiovascular lipid profile  CVD prevention • Prevents cancer • Decreases symptoms of some mental disorders, i.e., Alzheimer’s Disease • Improves immune function

5. Omega-3 Fatty Acids Eicosapentaenoic acid (EPA) Docosahexaenoic acid (DHA) EPA and DHA are two -3 fatty acids that are especially high in immune cells and are incorporated in the cell membrane where they can influence membrane fluidity, receptor function, enzyme activity, and the production of eicosanoids.

6. Eicosanoids • Lipid mediators of immune function. They can yield positive and negative effects. • Eicosanoids derived from arachidonic acid (AA)  most potent pro-inflammatory f/x effects on immune function • -3 PUFAs inhibit AA oxygenation  synth of bad eicosanoids &  pro-inflammatory f/x

7. PUFAs and Eicosanoids • Suggested intake of PUFAs: • High levels of -3 fatty acids, but low levels of -6 fatty acids. -6  AA  2 series of ‘bad’ prostaglandins and inflammatory leukotrienes VS. -3  EPA  3 series of ‘good’ prostaglandins and less inflammatory leukotrienes

8. PUFAs and Immunity • Cells which perform immune functions are mediated by membrane-associated activities, such as cytokine and antibody secretions and lymphocyte transformations. • High PUFAs  healthier cell membrane  improved immune function

9. Clinical Studies • Population of Greenland Eskimos compared with matched groups living in Denmark. • Low incidence of autoimmune and inflammatory disorders, such as psoriasis, asthma, and type-I diabetes. • These diseases display inappropriate T cell activation & host tissue destruction w/ macrophages & mediators produced by cytokines, eicosanoids, and ROS.

10. Clinical Studies (cont.) • 3 month -3 supplementation between groups of older and young female subjects • Both groups increased showed an increase in EPA and DHA, but older group had a greater increase. • Older groups showed a decrease in AA, while younger groups showed no change.

11. Clinical Studies (cont.) • Graft rejection in transplants is caused by a T-cell immune reaction to the foreign material introduced into the body. Kidney transplant recipients received 6 g fish oil/day for one year post-op  better kidney function and less rejections when compared to those with no supplementation.

12. Weaknesses Amongst Studies • Contradictory observations between studies due to: • differences in the cell types used • differences in protocols used • sample populations too small • source of -3 was always fish oil, did not observe f/x with plant sources

13. Safety Aspects • Healthy subjects or those with compromised immune status yield undesirable effects due to excessive reduction in cytokine or eicosanoid production which impairs their normal host defenses or homeostasis. *Vitamin E supplements may  this side effect.

14. Eat fish, live longer.