Omega 3 Fatty Acids in Parenteral Nutrition

Erin Buehler Lauryn Whitfield

Background

• Most patients, especially critically ill, experience inflammation due to trauma or disease

• When oral intake or enteral feeding is not tolerated, patients may be placed on parenteral nutrition

• Currently, the majority or parenteral solutions use safflower/soybean oil as a source of lipids, both containing high amounts of omega-6 polyunsaturated fatty acids

Lipids in Parenteral Nutrition

Disadvantages

• Elevate triglycerides: bypasses the lymphatic system

Advantages

• Provide energy and cellular building blocks

• Decreases risk of hyperglycemia

• Provides fat soluble vitamins

• Precursors to metabolically pertinent prostaglandins and eicosanoids

Omega 6 vs. Omega 3 Fatty Acids

Omega- 6 PUFA

• Pro-inflammatory• Precursors of inflammatory

mediators: leukotrienes and prostaglandins

Omega-3 PUFA

• Anti-inflammatory• Promote hemodynamic

stability• Quickly incorporated into

immune cell membranes• Increase stability and fluidity

of the cell membrane• Less thrombogenic effects• Better T-cell immune

function

Critically Ill

• May decrease length of hospital stay• Does not decrease mortality rates• In a study with an omega-3 to omega-6 ratio

of 1:2, no statistically significant differences between length of stay, nosocomial infections, duration of mechanical ventilation, and inflammatory markers

Colorectal Cancer

• Decreases tumor protein synthesis and inhibits tumor growth

• In one study, a statistically significant decrease in interleukin-6 and TNF-alpha levels were found

• Some studies do not show the same effects in all cancers

Parenteral Nutrition Associated Liver Disease

• Ectopic fat deposits are common with long term use of parenteral nutrition

• Omega-3 fatty acids can prevent or correct these complications

• The appropriate ratio is still undetermined• Decreases liver availability of fatty acids for

VLDL synthesis and secretion

Other Conditions

Spinal Cord Injuries

• Mouse study• Less cell death in the spinal

cord• Improved locomotor

performance during recovery time

• Arachidonic acid is detrimental after injury, but omega-3 fatty acids can inhibit the action of AA

General Surgery

• Inflammation post surgery is partly due to proinflammatory mediators (leukotrienes and prostaglandins)

• Omega-3 fatty acids counteract these effects

• Decreases mortality rates

Conclusions

• General consensus among studies that use of omega-3 FA in PN produces no harmful effects

• Use has shown to be beneficial in various disease states/conditions

• Currently, there is no appropriate ratio determined

• Should FDA approve use of omega-3 FA in PN?

Areas for Future Research

• More randomized controlled trials with larger samples and longer durations should be conducted to determine the appropriate ratio of omega-3:omega-6 FA

• More research on the efficacy of omega-3 in PN in the critically ill