Your heart and brain functions depend on omega-3 fatty acids including DHA. These nutrients help prevent or lessen the effects of hypertension, arthritis, some cancers and other chronic diseases of the body and mind.
How often do you eat foods rich in omega-3’s? Salmon, herring, lake trout, mackerel, sardines, albacore tuna and seaweed are all known for their health benefits and are rich in omega-3 fatty acids. Lesser-known foods that also contain these fatty acids are rapeseed oil, flaxseed and walnuts. A Harvard professor recommends at least one serving of these each day.
The sky is the limit
One serving per day seems easy, yet most Western diets (American & European) don’t include this essential nutrient daily.
Even if we usually get enough fatty acids in our diet, there is no apparent harm in consuming more. I’m usually a fan of moderation but this is one instance where there seems to be little downside to ensuring that you include omega-3’s in your daily diet. Depending on your source of these fatty acids, there are no known side effects besides the possibility of fishy taste! 
Even better, eggs and milk, which are staple food that many of us consume daily are now available with more omega-3’s. A milk genomics article says it best (the same theory applies to eggs): “Cows from organic milk producers are not purposely supplemented with omega-3s, but they consume more omega-3s and less omega-6s as a result of increased access to pasture (where they consume grasses and legumes) and decreased consumption of grains, particularly corn.”
Additionally, some milk producers have also begun to include an additional supplement of algal DHA in their milk. For example, Horizon Organic plus DHA Omega-3 milk can be found in most supermarkets. http://www.horizondairy.com/store-locator/ Since there’s no apparent harm in extra DHA, we may as well ensure that it’s in our system when we drink milk!
Critical impact for babies
A serving per day of omega-3’s is especially important if you are pregnant or breastfeeding due to baby’s needs for such nutrients in their critical period of neural pathway and retinal development. And yet, many such women avoid or limit fish consumption and therefore provide even less of this essential nutrient to their babies! This seems like a public policy failure because the FDA/EPA recommend limiting seafood consumption (with good reason) yet does not adequately publicize the benefits and alternative sources of omega-3’s.  This is despite studies that show that even small amounts of omega-3 fatty acids could be of benefit during pregnancy. These agencies do recommend fish oil supplements, but again the contents of supplements are not regulated or enforced in the United States (link to post).
As a result, it is vital for pregnant women to understand what to consume throughout their pregnancies and lactation periods to provide omega-3’s to their babies. This nutrient is so essential and it is proven to be essential to the point where even most formulas contain DHA, yet few breastfeeding moms realize the importance of including it in their own daily intake.
Indeed, the benefits of fatty acids are so great for anyone that we should all know about them and consume them daily. In fact, I would recommend including fatty acid content on the Nutrition Facts label system so people can consciously include an adequate amount in their daily diets.