By Craig Weatherby
People sometimes take fish oil hoping that it will help alleviate inflammation-related conditions such as arthritis or allergies.
A new epidemiological study supports this long-presumed benefit of seafood-source omega-3s ... whose credibility is bolstered by their proven biological effects.
We should note that, with regard to specific conditions, the precise inflammation-related powers of fish oil remain to be proven by high-quality clinical trials.
The encouraging findings also applied to glucosamine and chondroitin … two supplements used by people with osteoarthritis.
Before examining the new findings, we'll quickly review what's known about seafood-source omega-3s and inflammation.
Omega-3s and inflammation
Omega-3s (DHA and EPA) are the essential precursors to the inflammation-damping members of a family of key inflammation-regulating compounds called prostaglandins.
It’s wise to ensure ample intake of both omega-3s, by eating seafood frequently and/or taking fish, krill, or other marine-life oils.
Excess intake of omega-6 fats from the cheapest vegetable oils – which is typical of the American diet – promotes excessive production of pro-inflammatory prostaglandins, and a lack of inflammation moderating influence from omega-3s.
This “omega imbalance” is strongly associated with artery disease, cancer, depression, diabetes, and other major conditions.
And it was recently discovered that when we consume these omega-3s from fish they metabolize into compounds (resolvins and protectins) that end inappropriate, damaging inflammation.
As the authors of a recent evidence review wrote, “Dietary omega-3 fatty acids are associated with … lower levels of inflammation … in cardiovascular disease and other chronic and acute diseases.” (Rangel-Huerta OD et al. 2012).
For an overview of the inflammation-related effects of EPA and DHA see the “Long-chain omega-3s: Truly essential to life and health” section of our Omega-3 Facts & Sources page.
And to read relevant news coverage from our archive, see “Omega-3s May Fight Bodily Fire in New Way”, “Omega-3 Findings Point to Greater Cardiovascular Potential”, “Pain May be Relieved by Omega-3 Byproducts”, and “Fish Fat May Reduce Children’s Asthma Risk”.
Now, an analysis of data from America’s large, ongoing diet-health survey lends more weight to the idea that omega-3s from fish help keep inflammation under control.
This matters because most major health conditions – cancer, cardiovascular disease, Alzheimer’s, diabetes, arthritis, and more – are either promoted or exacerbated by chronic inflammation.
Analysis links fish oil to anti-inflammatory effect
The new epidemiological study was performed by researchers from the Fred Hutchinson Cancer Research Center and the University of Washington in Seattle (Kantor ED et al. 2012).
A team led by Elizabeth Kantor of the Hutchinson Center analyzed data from a nationally representative sample of 9,947 adults participating in the National Health and Nutrition Examination Survey (NHANES).
The people who reported regular use of fish oil supplements had 16 percent lower levels of a key inflammation marker called CRP (C-reactive protein).
In addition, those who reported regular use of glucosamine or chondroitin supplements had 17 percent and 22 percent lower levels of CRP, respectively.
As they wrote, “[Other] studies, plus our current study in a representative U.S. population, provide evidence for the anti-inflammatory effects of long-chain omega-3 PUFAs in humans …” (Kantor ED et al. 2012)
They followed that comment with key points about the practical meaning of their study’s findings (Kantor ED et al. 2012):
- “… and they support one of several mechanisms by which long-chain omega-3 PUFA intake may reduce the risk of cardiovascular disease, some cancers, and total mortality.”
- This study adds biologic plausibility to previous studies, which have shown beneficial effects of these supplements on chronic diseases.”
- “Given the number of diseases with which inflammation is associated, such as cancer and cardiovascular disease, there is a need to find safe and effective ways to reduce inflammation.”
- “Research suggests that these 3 supplements have excellent safety profiles, supporting their potential role in disease prevention. It is therefore important that the potential anti-inflammatory role of these supplements be further investigated.”
Interestingly, the Seattle team noted that the relatively low CRP levels seen in those who reported using fish oil, glucosamine, or chondroitin supplements matches the range of reductions seen with prescription statin drugs such as Lipitor and Crestor … and their antiinflammatory effects are believed to account for much of their cardiovascular health benefit.
Other supplements showed no effect
The Seattle-based scientists saw no impact on CRP levels among people who reported taking any of a range of other supplements, including MSM (methylsulfonylmethane), pycnogenol/POC, garlic, ginkgo, or saw palmetto.
These five were the only other supplements whose use was compared with inflammation levels. However, CRP is not the only marker for inflammation.
And as the Seattle group noted: “it is … possible that these supplements may affect inflammation downstream of CRP or that these supplements may not be associated with inflammation in humans.” (Kantor ED et al. 2012)
Unfortunately, they did not look for connections between consumption of supplemental curcumin – one of the most promising candidates for natural inflammation control – and CRP levels.
But that omission is understandable, given the relative novelty and rarity of curcumin supplements in drug and health retail chains in the U.S.
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