Omega-3 Fatty Acids Come From Green Plants

The food indus­try has been urg­ing me to eat fish. The sup­ple­ment com­pa­nies have been urg­ing me to take fish oil sup­ple­ments. They claim that omega-3 fat­ty acids pre­vent heart attacks. Some peo­ple even claim that a baby can­not devel­op a nor­mal brain unless its moth­er ate fish or took fish oil sup­ple­ments. In con­trast, nutri­tion sci­en­tists tell me that green plants are an excel­lent source of the only omega-3 fat­ty acid that is essen­tial in human nutri­tion. This could explain why pop­u­la­tions that rarely if ever eat fish can have healthy hearts and healthy brains. In fact, the health­i­est pop­u­la­tions are the ones that eat very lit­tle fat of any kind and lots of veg­eta­bles.

All of the omega-3 fat­ty acids in the food sup­ply came orig­i­nal­ly from the green plants and blue-green algae (cyanobac­te­ria) that are at the bot­tom of the food chain. An omega-3 fat­ty acid called alpha-linolenic acid is an impor­tant part of the thy­lakoid mem­branes that are involved in pho­to­syn­the­sis. No ani­mal can make an omega-3 fat­ty acid. Ani­mals do not have the enzymes that would be need­ed to put a dou­ble-bond in the omega-3 posi­tion in the hydro­car­bon chain of a fat­ty acid. How­ev­er, ani­mals can length­en the car­bon chain of an omega-3 fat­ty acid. Thus, fish and oth­er ani­mals (includ­ing human beings) can con­vert alpha-linolenic acid to longer-chain omega-3 fat­ty acids, such as eicos­apen­taenoic acid (EPA) and docosa­hexaenoic acid (DHA). For this rea­son, you can find EPA and DHA in fish but not in ordi­nary plant-source foods.

Accord­ing to the Food and Nutri­tion Board of the Nation­al Acad­e­my of Sci­ences, there is only one omega-3 fat­ty acid that is essen­tial in human nutri­tion. It is the alpha-linolenic acid that is found in thy­lakoid mem­branes of the chloro­plas­ts of green plants. For this rea­son, you can get this omega-3 fat­ty acid from eat­ing green veg­eta­bles. Flaxseeds, hempseed, and wal­nuts are also good sources of alpha-linolenic acid.

You need only a lit­tle bit of alpha-linolenic acid from your food. The dietary require­ment for the two essen­tial fat­ty acids (alpha-linolenic acid and an omega 6 fat­ty acid called linole­ic acid) was dis­cov­ered only after hos­pi­tal­ized patients start­ed being fed fat-free solu­tions for an extend­ed peri­od. Yet even their need for these essen­tial fat­ty acids could be met by rub­bing a lit­tle bit of veg­etable oil on the skin.

For years, many peo­ple have been urg­ing the pub­lic to eat fish or take fish oil sup­ple­ments, to reduce the risk of heart attack. Pop­u­la­tions that eat a lot of omega-3 acids, from cold-water fish, do have a some­what low­er-than-expect­ed rate of fatal heart attacks. How­ev­er, this is prob­a­bly because of the blood-thin­ning effects of omega-3 fat­ty acids, which could also lead to more deaths from major bleed­ing. If you real­ly want to make your­self heart-attack-proof, eat a low-fat, plant-based diet to keep your total cho­les­terol below 150 mg/dL.

Some man­u­fac­tur­ers of baby for­mu­la have been adding DHA so that the for­mu­la will have a DHA con­tent sim­i­lar to that of breast milk. Yet whether the addi­tion­al DHA pro­vides real ben­e­fits to the baby is still unclear. How­ev­er, these stud­ies do raise con­cerns about giv­ing too much long-chain omega-3 fat­ty acid with­out also pro­vid­ing a sup­ple­ment of arachi­don­ic acid.

I do not know whether any veg­ans (such as preg­nant women or the elder­ly) would ben­e­fit from sup­ple­men­ta­tion with the longer-chain omega-3 fat­ty acids. If these sup­ple­ments are ben­e­fi­cial, it would be best for them to come from a plant source. Plants are less like­ly to be con­t­a­m­i­nat­ed by the pol­lu­tants that build up in ani­mal tis­sue.

Pho­to by albert­straub