Immune Modulation by Parenteral Lipids

Immune Modulation by Omega-3 Versus Omega-6 Based Parenteral Lipids in Healthy Volunteers

Immune modulating properties of parenteral lipid emulsions seem to contribute to the increased risk for infections which remains associated with the use of total parenteral nutrition. Emulsions based on soy bean oil (SO) are the oldest and still most widely used lipid source in TPN formulations but their high content of omega-6 polyunsaturated fatty acids (PUFAs) may be a drawback. Fish oil-based lipid emulsions (FO), rich in omega-3 PUFAs, has been approved for parenteral nutrition in many countries. Mainly retrospective studies on clinical outcomes in septic and postoperative patients have suggested clinical benefits with the inclusion of FO in parenteral nutrition regimens. The exact mechanisms behind the beneficial immunological effects of parenteral FO have, however, not yet been elucidated.

Objective:

To evaluate the effects of intravenous infusion of a FO-based lipid emulsion and a SO-based emulsion on immune function as evidenced by effects on peripheral blood leukocyte counts and functions and on the susceptibility to oxidative stress.

Study design:

Randomized placebo controlled cross-over pilot study with healthy volunteers.

Inclusion Criteria:

• Adult (>18 yrs of age)
• Healthy
• Willingness to give written informed consent

Exclusion Criteria:

• Smoking > 5 cigarettes/day
• Diet with > 2 portions of fatty fish per day
• Use of oral fish oil or vitamin substrates
• History of metabolic disorder (especially diabetes or lipid disorders)
• History of allergic, inflammatory of immunological disease
• History of pulmonary, cardiovascular, renal or hematological disease
• Medication use