by Craig Weatherby
The “marine” omega-3s abundant only in fish and fish oil display anti-inflammatory effects in animal, clinical, and cell studies.
Researchers at several German universities have reported findings suggesting that omega-3s may bring benefits to people undergoing surgery.
Over the past decade, they've published the remarkably positive results of trials designed to test the post-operative effects of dietary or intravenous omega-3s in surgery patients.
Story began with premature babies
We first came across this area of research via media reports last summer concerning the life-saving benefits of omega-3s among premature babies, many of whom must receive intravenous nutrition (see “Fish Oil Saves “Premie” Babies' Livers and Lives”).
As we reported, premature infants and adults with serious intestinal dysfunctions must receive liquid nutrition formulas via intravenous lines: a kind of intervention called total parenteral nutrition or TPN (“Parenteral” means “outside the intestines”).
However, TPN formulas used in the US contain only one of the two kinds of essential fatty acids: omega-6 fatty acids, which predominate in grain-fed meats and poultry and common vegetable oils, and tend to promote inflammation and fatty infiltration of the liver.
For no good reason, and to patients' probably detriment, these formulas lack any omega-3 essential fatty acids.
Because current TPN formulas used in the US contain only omega-6 fatty acids, they promote liver failure when used for extended periods. This is why a German company developed Omegaven, a fish-oil based formula that's used in Europe for adults on TPN.
Pediatricians in Boston received permission to try the Omegaven formula in premature infants facing liver failure, thereby improving or saving the lives of more than a dozen children. Unfortunately, Omegaven's maker hasn't marketed Omegaven here, for commercial reasons, so its use remains restricted to experimental, last-resort uses approved by the FDA on a case-by-case basis.
But the results of several clinical trials suggest that the benefits of intravenous omega-3s extend beyond premature infants to adult cancer-surgery patients, and that oral omega-3s offer similar post-operative advantages.
We only became aware of the existence of these studies recently, and thought our readers should know about them, for two reasons:
Omega-3s curb post-op inflammation and infection, enhance organ function
The research conducted to date involved patients in German hospitals and clinics who needed surgery for colorectal cancer or to remove tumors in the abdomen or upper gastrointestinal tract.
The publication last year of a literature review alerted us to this area of research (Stehr SN, Heller AR 2006).
As the review's German authors concluded, “In patients undergoing tumor resection surgery we observed improvement of liver and pancreas biochemical indices when omega-3 fatty acids were administered.”
Now, another clinical trial affirms the apparent benefits of omega-3s in certain cancer-surgery contexts (Senkal M et al 2007 2007).
The authors enrolled 40 patients scheduled for colorectal surgery at St. Josef Hospital in Bochum, Germany, all of whom were likely to require intravenous feeding post-operatively.
In this double-blind, randomized study, some of the participating colorectal surgery patients received a standard, omega-6-fortified parenteral formula administered intravenously, while others received an omega-3-supplemented intravenous formula.
While seven patients in the omega-6-fortified formula group suffered postoperative infectious complications, only four patients in the omega-3-formula group had such problems.
The doctors also found that the omega-3-fortified formula raised patients' tissue levels of omega-3s (EPA and DHA), with beneficial anti-inflammatory effects.
As the authors concluded, “Omega-3-fatty-acids-supplemented fat emulsions for parenteral administration are safe and very well tolerated … Thus, postoperative parenteral administration of omega-3-PUFA-enriched lipid emulsions could have an impact on the postoperative inflammatory response after abdominal surgery and could be used in standard postoperative care...”
Prior German trials find organ and inflammation benefits
It's worth reviewing the results of two of the earlier trials covered by the 2006 literature review, because they highlight the reasons why omega-3s seem to contribute to good post-surgical outcomes.
Dresden trial reveals better organ outcomes
In 2004, a team at University Hospital Carl Gustav Carus in Dresden, Germany performed a randomized, double-blinded clinical trial in 44 patients undergoing major abdominal surgery to remove solid tumors.
They reported that liver and pancreas function test results in the patients who received the omega-3-fortified formula were significantly healthier than the results among the omega-6-fortified formula group (Heller AR et al 2004).
In addition, patients in the omega-3 group who were found at increased risk of infection showed a tendency to shorter stays in the intensive care unit, (ICU) versus similarly situated patients in the omega-6 group.
And unlike some patients in the omega-6 group, none of the patients in the omega-3 group suffered weight loss.
The authors came to this encouraging conclusion: “After major abdominal tumor surgery, FO [fish oil] supplementation improved liver and pancreas function, which might have contributed to the faster recovery of patients.”
Passau and Bochum trials affirm anti-inflammatory effects
The benefits of omega-3 nutrition in surgery patients may stem in part from the anti-inflammatory effects of these fatty acids from fish.
Studies performed in surgical patients at St. Josef Hospital in Bochum, Germany and at the Clinical Centre in Passau, Germany revealed that intravenous administration of omega-3s raised tissue levels of omega-3s and reduced markers of inflammation.
Researchers in Bochum gave surgery patients oral fish oil supplements rich in omega-3s, and the outcome led them to this conclusion (Senkal M et al 2005): “…preoperative administration of oral PUFA-enriched diets could have an impact on the postoperative inflammatory response after major abdominal surgery.”
The Passau Clinic team performed a similar, double-blind trial, testing a standard omega-6-fortified formula (made with soy oil) against a formula with increased amounts of omega-3s and monounsaturated fatty acids (as in olive oil).
Their results showed similar anti-inflammatory effects (Grimm H et al 2006): “Treatment with the new emulsion … is well tolerated and modulates FA [fatty acid] and leukotriene patterns, suggesting favorable anti-inflammatory effects and further clinical benefits.”
Note: leukotrienes (loo-kuh-treens) are chemical messengers sent by immune system cells. Patients who received the omega-3 formula enjoyed reduced levels of pro-inflammatory leukotrienes, versus patients who received the standard omega-6 (soy oil) formula.
Wake up call awaits an answer
The positive results of these small but well-controlled studies warrant follow up in larger trials.
But why should patients need to wait for the wheels of medicine to turn?
Given the demonstrated safety and benefits of supplemental omega-3s and intravenous formulas containing omega-3s, it seems irresponsible to not to include them in intravenous formulas for surgery patients and premature infants, instead of omega-6 fatty acids with demonstrable down sides.