Omega-3 fatty acids are a type of fat – a good type. This fat may help lower inflammation and prevent heart disease, cancer, Alzheimer’s, and a host of other diseases (1).
There are three types of omega-3 fatty acids: DHA, EPA, and ALA. DHA and EPA come from marine sources (algae, marine fish, shellfish). ALA comes from plant sources (walnuts, chia seeds, flax seeds, etc). We need all three types.
Our bodies can convert ALA from walnuts and other plants into DHA and EPA… but we aren’t very good at it. It’s estimated that only 8-40% of ALA is converted into DHA and EPA, based on our genetic disposition, overall health, gender, and lifestyle & food consumption habits. Vegans and vegetarians convert more ALA into DHA and EPA – probably because they aren’t getting it from their seafood-free diets (2).
Long story short: It’s more efficient for us to get DHA and EPA from seafood.
This is why we need seafood. It is our most efficient source of the critical omega-3 fatty acids.
The more our population grows, the more fish we’ll need to reap from the seas to give us that omega-3.
That’s bad news for fish stocks.
(1) Saini RK & Keum YS. 2018. Omega-3 and omega-6 polyunsaturated fatty acids: Dietary sources, metabolism, and significance – A review. Life Sciences, 203, 255-267. https://www.sciencedirect.com/science/article/abs/pii/S0024320518302303
(2) Welch AA, et al. 2010. “Dietary intake and status of n-3 polyunsaturated fatty acids in a population of fish-eating and non-fish-eating meat-eaters, vegetarians, and vegans and the precursor-product ratio of {alpha}-linolenic acid to long-chain n-3 polyunsaturated fatty acids: results from the EPIC-Norfolk cohort.” American Journal of Clinical Nutrition, 92(5), 1040-1051. https://www.ncbi.nlm.nih.gov/pubmed/20861171
Fish By The Pounds 