Are Fish Supplements Actually Good for You?

Back in 2015, The Washington Post ran the headline: “This is America’s favorite dietary supplement, even though the benefits aren’t proven.”

The article was about fish oil, which, at the time, had turned into a $1 billion industry. In the years since, that valuation practically doubled, to $1.9 billion in 2019. And by 2027, the market for fish oil is expected to balloon up to $2.8 billion, in lockstep with the rest of the surging supplements space.

What happened? How did America go from loving fish oil to really loving fish oil? Did researchers finally prove those purported benefits?

The opposite has happened, actually — as The Atlantic charted in a recent profile. The science has long been murky on fish oil; derived from the tissues of oily fish, and comprised of that nutritional buzzword — omega-3 fatty acids — fish oil was once hailed as a magical panacea. In the 1970s, Danish researchers studying indigenous peoples in Greenland concluded that regular consumption of fatty fish kept heart disease at bay.

But the maelstrom that these findings fueled in the decades since (which has only intensified over the last five years, as DTC supplement brands have become ubiquitous), has left a series of pertinent questions unanswered. For instance:

Which type of omega-3 (there are two) is responsible for the cardiovascular benefits of fish oil?
Do you have to eat the entire fish to reap these benefits?
Perhaps it’s less about the fish and more about the fact that you’re not eat a cheeseburger?

Fish oil has coasted on correlation for a while, but causation has eluded researchers. The Atlantic digs into the nuances of one study where scientists thought they might’ve cracked the code (it was called REDUCE-IT, and was conducted to support a “fish oil-based heart drug” called Vascepa), but in a bizarre, uncharacteristically dramatic twist for the buttoned-up world of double-blind testing, the placebo was faulty. It increased the volunteers’ risk of heart attack or stroke, which made the real drug look fantastic in comparison.

This disturbing saga is still unfolding, and in the meantime, the drug’s parent company, Amarin, has sold $100 million worth of Vascepa. (Yeah. Not great.) It’s a rather on-the-nose representation of how misleading the industry has become. That applies to casual (non FDA-approved) iterations of fish oil, too.

You can find thousands of articles online that will corroborate your hopes for fish oil — lowers blood pressure, this, flushes out plaque in your arteries, that — but the truth is we can’t say anything for sure. Your money is better served buying fresh fish from a market a couple times a week. Chances are, those healthy Inuit weren’t ordering fish oil on a monthly subscription model 50 years ago.