A growing body of evidence links omega-3 fatty acids (found mostly in seafood, eggs, seeds and nuts) to better heart and brain health. In particular, the omega-3s DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) appear to lower blood pressure, reduce inflammation and, ultimately, help prevent atherosclerosis—the hardening and thickening of blood vessel walls that can cause a heart attack or stroke. But we still don’t know exactly why DHA and EPA have this effect, only that people who consume lots of them seem to have better “outcomes” (lower pressure readings, fewer strokes, etc.), on average, than people who don’t.
Finally, the basic science is beginning to catch up to these population-based studies. In a study published this month, researchers have used a mutant strain of mice that are especially susceptible to atherosclerosis to show that omega-3 fats replace saturated fats in the diet when it comes to regulating levels of cholesterol and inflammatory molecules in the blood.1 This effect in turn leads to slowed progression of their atherosclerosis.
Unsurprisingly, mice that were fed a diet high in omega-3s and low in saturated fats, the bad fats, did best—they had the lowest cholesterol and inflammation, and the least damage to their blood vessels. But, importantly, even mice that were fed high levels of saturated fats with only low omega-3 supplementation still fared much better than their counterparts who received no omega-3 supplement at all.
Of course these are experimental findings, and what happens in mutant rodents can’t necessarily be applied to humans. But they strongly suggest an explanation for the effects we’ve seen Omega-3s have in people—and the possibility to use omega-3s more effectively for disease prevention in the future. Specifically, it looks like “every little bit” really does help when it comes to Omega-3 intake. So rather than focusing our energy on cutting saturated fat from our diets, it may be much more efficient to simply add omega-3 fats instead. Our bodies seem to be very capable of telling the difference.
Chang CL, Torrejon C, Jung UJ, Graf K, Deckelbaum RJ. Incremental replacement of saturated fats by n-3 fatty acids in high-fat, high-cholesterol diets reduces elevated plasma lipid levels and arterial lipoprotein lipase, macrophages and atherosclerosis in LDLR-/- mice. Atherosclerosis. 2014;234(2):401-9. doi: 10.1016/j.atherosclerosis.2014.03.022. PMID: 24747115.
About the Author
Emilie Croisier is a writer and editor based in Austin, TX. She has a PhD in Neuroscience from Imperial College London, and bachelor’s degree in Chemistry, with a minor in Brain and Cognitive Science, from the Massachusetts Institute of Technology. When she’s not counting cars at the intersection of science and natural health, you can find her in her garden or at emilieilime.com.