Whether you’ve been taking fish oil for years or are just now considering an omega-3 supplement, there are—of course—a few things you’ll want to keep in mind. From the benefits you can reap (think cardiovascular wellness, joint health, and cognitive function) to precautions you should take note of, here’s what you should know about fish oil’s potential side effects—and how to make your supplement a winning part of your healthy routine.* For these reasons (among others) a quality fish oil supplement can be incredibly helpful—especially if you don’t eat fatty fish like salmon or tuna at least two to three times a week, says Kelly. The American Heart Association echoes this two-fish-serving baseline and then recommends a higher daily dose of these marine omega-3s—1,000 milligrams per day—for optimizing heart health.* Meanwhile, research1 indicates that pregnant women need 650 milligrams of omega-3s per day, with at least 300 milligrams of that coming from DHA (a must-have for baby’s brain, eye, and neural development), specifically.* That said, clinical research indicates that up to 10,000 milligrams (aka a whopping 10 grams) of EPA and DHA can be taken safely without adverse effects. In fact, you’re probably more likely to run into issues eating tons of fish than taking high amounts of fish oil, according to Andrea Paul, M.D. “The more likely negative health outcome is exposure to high levels of environmental toxins like mercury through very high levels of fish consumption,” she says. Since quality supplement brands purify and test their products for contamination for things like heavy metals, you would actually face greater risk by eating lots of tuna than by taking a high-quality supplement for a concentrated dose of omega-3s.* But as Ashley Jordan Ferira, Ph.D., RDN, mbg’s in-house nutrition scientist, warns: “A negative GI experience with an omega-3 supplement is more commonly tied to poor-quality ingredients, in other words, lower-quality fish oil or fish oil that’s been allowed to oxidize and become rancid.” So, it’s of utmost importance to consider these “fishy” factors. Ferira says this potential side effect has been blown out of proportion. “Way too much of any good thing, even water, can have potentially negative effects on our health. But in this case, a textbook physiological mechanism, that omega-3s can impact platelets, has been used to broadly fearmonger against completely safe doses of omega-3s found in supplements.” She goes on to say that, “In reality, the blood-thinning effect of fish oil actually occurs at absurdly high levels of EPA plus DHA, 10 grams plus, which by the way, no supplement even comes close to containing. Omega-3 supplements are playing in the 200- to 1,800-milligram range of EPA plus DHA 99% of the time.” Ferira explains that the scientific case for omega-3s’ safety is a strong one. “I’m talking about 80-plus research studies demonstrating the safety of low, medium, and high levels of daily EPA + DHA consumption. It’s time somebody debunked this myth that is genuinely scaring people away from using a truly helpful tool (i.e., fish oil supplementation) for whole-body health.”* Ferira shares that, “to be clear, omega-3 supplementation research has been shown to be highly effective for promoting a healthy profile of lipids, with particular benefit to triglyceride levels. That same research has found a modest beneficial trend for glucose, insulin, and HbA1c measures of glucose control5, while other studies have reached statistical significance, demonstrating omega-3s’ ability to improve insulin sensitivity6.”* For most people, this means that omega-3s are actually helpful for your blood sugar balance, but Ferira explains, “For those with true hypoglycemia considerations, partner with your doctor to optimize your omega-3 supplement approach.” One teaspoon of cod liver oil, she says, contains 4,500 I.U. of vitamin A7—so if you take multiple teaspoons per day (which some people might), you may exceed the recommended maximum (i.e., tolerable upper intake level) of 10,000 I.U. for vitamin A. A few signs of too much vitamin A8 may include dizziness, queasiness, or even joint discomfort. Ferira shares that, “the fact that omega-3s have been shown in a large number of research studies to promote healthy blood pressure levels is compelling, so compelling that a couple of years ago, the FDA issued a claim10 for omega-3 food and supplement products containing at least 800 mg of EPA plus DHA per serving, saying those products may reduce blood pressure and the risk of hypertension, which is, in turn, a major risk factor for coronary heart disease."† Ferira concludes that “these case studies are informative, but n-of-1 reports are not something to base population info on. In fact, recent clinical trial research in healthy young adults found omega-3 supplements to be helpful13 for sleep architecture and efficiency13.”* As Ferira alluded to before, the FDA believes the science collectively supports omega-3-rich supplements’ ability (i.e., at least 800 milligrams of EPA plus DHA per serving) to help reduce coronary heart disease risk.† Ferira concludes, “If omega-3s were not top of mind for musculoskeletal health, they should be. The science is exciting and growing.”* Ferira shares, “Indeed, these omega-3s are literally intrinsic to the cellular membranes of cells throughout our central nervous system, from our brain and retina to neurons throughout the body. They are ensuring healthy neuronal signaling via synaptic transmission, which translates practically into mental acuity, memory, vision, and more.”* She caveats these potential benefits with an important message: “These central nervous system benefits are all predicated on the assumption that, of course, you are regularly consuming a meaningful amount of omega-3s EPA and DHA in the first place.”* “Given omega-3s’ extensive neuroprotective roles in the body, it’s not surprising that they have been linked to mood balance and health,”* concludes Ferira. Explaining the science a bit more, Ferira shares that, “We know DHA supports functioning & regeneration of rhodopsin, a visual pigment that plays a critical role in the visual system that converts light into visual images. In other words, DHA helps you see25, that’s pretty important stuff!”*
