You've probably heard some buzz about "omega-3" fatty acids promising all sorts of health benefits. It's the kind of buzz that led 18.8 million American adults to take omega-3 fish oil supplements in 2012, and helped created a global omega-3 industry worth more than $30 billion.
But for the average person, what's the real outcome of boosting omega-3 levels by gorging on seafood or taking supplements?
Author Paul Greenberg set out to find answers, and documenting his year of eating fish every day in a new Frontline documentary, The Fish on My Plate, which airs Tuesday.
The short answer — spoiler alert — nothing much happened.
To measure his progress, Greenberg saw his doctor before and after his experiment. "I've got slightly elevated blood pressure. I've got cholesterol issues. I have depression issues. I have sleep issues, and I don’t like it," he said at the start of the film. "So I started to listen to the soft purr of the omega-3 industry: This is everything they’re supposed to fix." But more than 700 fish meals later, Greenberg's doctor delivered the disappointing results about these measurements: "I'd say virtually the same. Unchanged."
His cholesterol ratio was the same, his triglyceride level (a fat in the blood) was the same, and his blood pressure even went up "a tiny bit," possibly due to increased salt intake. But a side effect of consuming seafood daily rather than the recommended two times per week: elevated mercury levels, which was "actually slowing your thinking and hurting your memory," a biologist told him.
"If you’re only thinking about omega-3s the jury is out," Greenberg told BuzzFeed News. Although he argued that from environmental point of view, eating "any kind of fish is better than a land animal."
Of course, Greenberg is just one man with his own lifestyle and a unique set of genetics.
"The totality of research suggests that omega-3 intake is positively linked to a healthy heart," according to the trade group Global Organization of EPA and DHA Omega-3s, or GOED, whose members include agribusiness giants like BASF, Cargill and Dow AgroSciences. "Omega-3 intake is positively linked to a healthy brain, healthy eyes, and a healthy baby."
Asked about the results of Greenberg's experiment, a GOED spokesperson told BuzzFeed News: "Every individual is different and these clinical endpoints — cholesterol, blood pressure, and triglycerides — are impacted by many lifestyle factors, including diet, exercise, stress, etc. That’s why large population-based studies are so important to determine cause and effect because they can actually detect the impact of one factor like omega-3 consumption."
The health and medical establishment still have not drawn hard conclusions about the benefits of omega-3s.
The US Food and Drug Administration has not set a recommended daily value for omega-3 fatty acids nor has it authorized any nutrient content claims for omega-3 fatty acids in general. It prohibits food companies from labeling foods as being "high in" “rich in” or “excellent source of” the fatty acids DHA or EPA.
The American Heart Association said this year that while there might be benefits for people who recently had a heart attack, for the general population there is an "absence of scientific data that shows any benefit of [omega-3 fish oil] supplements in preventing heart attacks, stroke, heart failure or death for people who do not have a diagnosis of cardiovascular disease.”
Bottom line, according to the National Institutes of Health's Office of Dietary Supplements, "consuming omega-3s by eating fish and other seafood is beneficial. Although omega-3 supplements do have a few demonstrated health benefits, overall, their effects are less clear."
Some 5,000 scientific reports have "omega-3" in their title, according to PubMed, the massive database of biomedical studies. Yet Frontline points out that none of the thousands of studies on omega-3s and health "have revealed anything unequivocal."
Jörn Dyerberg, who kicked off the omega-3 movement with research on Inuits in Greenland in the 1970s, told Greenberg in the next few years three major studies including thousands of patients are set to come out "with the results that we have to believe in."