For the last, year Paul Greenberg has eaten fish for breakfast, lunch, and dinner every. Single. Day. The author and casual fisherman was on a mission to find out if eating a diet rich in omega-3 fatty acids would really benefit his health, and debuted his fishy journey in a documentary with Frontline on April 25.
Unfortunately for Greenberg, his year of eating fish did absolutely nothing for his health. He started the year with high blood pressure, cholesterol issues, depression, and problems sleeping, he said in a video promoting the documentary. He checked in with his doctor before the year of fish began, and again once it was over.
At the end of the year, Greenberg still had high blood pressure, cholesterol issues, depression, and sleep problems, BuzzFeed reports. And he had elevated mercury levels to boot, which eating excessive amounts fish can do.
Ingesting organic mercury every day can cause symptoms such as uncontrollable shaking, vision loss, and memory problems over time, according to the National Institutes of Health (NIH).
Because all fish carry at least small traces of mercury — though some types carry more than others — the FDA recommends no more than 12 ounces of fish per week, which translates into about two servings. If Greenberg was eating a true serving of fish at every meal, he had about 21 servings every week.
But Greenberg's disappointing results shouldn't turn you off of fish forever, or give you an excuse to never again think about omega-3s.
Although Greenberg told BuzzFeed that if you're only eating fish for the omega-3s, "the jury is out," his personal experiment isn't enough to counter-act decades of science-backed reasons for why omega-3s should be on your radar.
"I don't think it would be responsible to say that one man's experiment on himself should completely overrule quite a robust body of past research," Willow Jarosh, MS, RD, registered dietitian and co-owner of C&J Nutrition, told Refinery29. "[We'd] need to know way more about what changed and stayed the same with regard to this man's lifestyle over the course of the year he ate fish."
Although the research on omega-3 supplements can be unclear, it's still a good idea to get the recommended amount of omega-3s. These are essential fats, according to Harvard Health, and important for things like heart health. Since your body doesn't make any of these fats on its own, you need to get omega-3s through food sources — like fish.
But eating fish is also beneficial for other reasons, Jarosh said. "[Fish is] a lean protein source that is fast to prepare (you can cook it straight from frozen or use canned)," she said.
It's also one of the richest sources of selenium, which is "a nutrient that may play an important role in thyroid hormone metabolism and overall protection of cells from oxidative damage," as well as choline, which is important for metabolism.
Still, we wouldn't recommend an experiment like Greenberg's. It's safe to stick with the recommended two servings a week.