A new lab study looking at underlying mechanisms of action for omega-3s compared eight different types of omega-3s and discovered DHA in particular inhibits inflammatory biochemical pathways in the body.
Researchers at the University of Houston found DHA, and oleic acid to a lesser extent, inhibited the prostaglandin E2 pathway—the major cellular means of causing inflammation “that is directly related to the pathological processes of pain, vascular diseases, and cancer cell growth,” wrote the researchers. (Read the full study [PDF])
DHA has the ability to both interfere with prostaglandin E2 creation as well as inhibit it from binding to its receptor and therefore reduce the inflammatory signaling.
“The study has provided important evidence that fish oil and one of its major ingredients, DHA, have the ability to inhibit PGE2 signaling, which highlights the benefit of taking fish oil as a supplement for health, including preventing inflammation, cancers and heart disease,” wrote the researchers.
The other oils studied showed varying levels of interference with inflammation but only DHA worked to a statistically significant degree. The oils studied included olive oil, canola oil and sesame oil, and corresponded to the major omega-3s in the oils: arachidonic acid, linolenic acid, linoleic acid, EPA and DHA.
Counteracting the negative meta-analysis
In addition, the researchers calculated that an average 150 lb person should consume between 500mg and 1,000mg of fish oil daily. The researchers did not get into different concentrations and ratios of DHA in the fish oil solution, leaving one to assume they used the standard 120mg DHA in a 1,000mg fish oil solution.
The original research study stands in contrast to the recent meta-analysis—that is, a review of previously conducted trials—that asserted omega-3 fish oil has no effect on cardiovascular disease.
With more than 16,000 original research studies on fish oil specifically related to cardiovascular disease, and the controversial meta-analysis picking a selection of just 20 of them, it's no wonder there was much industry push-back to the view that fish oil health benefits are overstated.