Feeding laying hens linseed oil at 2.5% in their diet increases the omega-3 fatty acid content in their egg yolks by 13.6% and lowers the omega-6 to omega-3 ratio from 4.95 to 1.01, changing the fat...

We analyzed the available evidence and found that adding linseed oil to chicken feed appears to change the fat profile of egg yolks. Specifically, when laying hens were fed linseed oil at 2.5% of their diet, the omega-3 fatty acid content in their egg yolks increased by 13.6%, and the balance between omega-6 and omega-3 fats shifted from 4.95 to 1.01 [1]. This change happened without affecting how many eggs the hens laid. All 17 studies or assertions we reviewed supported this outcome, and none contradicted it. The shift in the omega-6 to omega-3 ratio means the eggs contain relatively more omega-3s and fewer omega-6s compared to eggs from hens not fed linseed oil. Omega-3s are a type of fat linked to heart and brain health, while omega-6s are also essential but often consumed in excess in modern diets. By altering the hens’ feed, the fat composition of the eggs changes in a way that may make them more similar to what some people look for in a healthier dietary profile. We don’t know if this change leads to measurable health benefits in people who eat these eggs, because that wasn’t part of what we reviewed. We also don’t know how long the effect lasts, or if different amounts of linseed oil would produce stronger or weaker results. But based on what we’ve found so far, feeding linseed oil to hens consistently changes the fat content of their eggs in a predictable way. If you’re looking to get more omega-3s from eggs, choosing eggs from hens fed linseed oil may be one way to do it — but it’s just one part of a larger diet.