The Health Benefits of Omega-3

People are becoming hip to the health benefits of omega-3 fatty acids. It's one of the reasons people are eating more fish, the main source of omega-3s. But while food sources of omega-3s are considered superior, omega-3 supplements have also gained popularity.

If you like to eat salmon, tuna, and many other sources, you likely get enough of this nutrient in your diet. But many people who don't like seafood wonder if they don't need to eat fish for omega-3 benefits.

Omega-3 fatty acids are what are known as essential fats. That means the body can't make them and you need to consume them in your diet. In many other ways, omega-3s are essential to your body.

For example, omega-3s are an integral component of the membranes that surround each cell in your body, with levels of one type of omega-3 especially high in the eye, brain, and sperm. Omega-3s also have many functions in the heart, blood vessels, lungs, immune system, and endocrine system, which governs the production of the hormones that regulate everything from metabolism to mood.

It's likely due to these effects that omega-3s have been shown to provide health benefits, most notably as a way to help prevent heart disease and stroke—the conditions for which there's the strongest evidence.

Indeed, a large body of scientific research suggests that higher dietary omega-3 intakes are associated with a reduction in the risk of heart diseases. That's why the American Heart Association (AHA) recommends that all adults eat at least two weekly servings of fish, particularly oily fish like salmon, tuna, and anchovies, the types richest in omega-3s.

Not everyone wants to eat fish. So, roughly eight percent—or about 19 million Americans—take some kind of over-the-counter (OTC) fish oil supplement, according to figures from the National Institutes of Health.

These supplements, which mostly contain EPA and DHA, the two types of omega-3s found in fish, are by far the most popular in America. Note that OTC supplements are different from prescription fish oil supplements like Lovaza (omega-3 ethyl esters), Vascepa (icosapent ethyl), and Epanova (omega-3-carboxylic acids), which are primarily used for people with very high triglycerides.

Despite their popularity, taking fish oil supplements might only be beneficial for certain people, not the general public. While research continues on both dietary sources of omega-3s and supplements, there are a number of studies showing that fish oil supplements don't get into your body or blood nearly as well as fish in food form. This isn't surprising, as our bodies are much better at taking in the nutrients from real food.

So far, the direct evidence that fish oil supplements improve heart health is underwhelming. A study published in the New England Journal of Medicine found that fish oil supplements did nothing to reduce heart attacks, strokes, or deaths from heart disease in people with risk factors for heart disease.

Another study that reviewed 10 prior studies reported only a small effect for those who already had heart disease or a heart attack: Fish oil supplements reduced the risk of death by seven percent in these patients and the risk of nonfatal heart attack by three percent—not enough to be considered significant, according to the study, which was published in the journal JAMA Cardiology.

The bottom line, according to the AHA, which issued an advisory about the benefits of fish oil supplements: They may slightly lower the risk of dying of heart failure or after a recent heart attack, but there's no good evidence that they prevent heart disease.

In addition to heart disease, fish oil supplements are often touted for a host of other conditions, including:

Alzheimer's Disease

Low DHA levels may be a risk factor for Alzheimer's disease and other types of dementia, but it's not yet known whether fish oil supplements can help prevent or treat these cognitive disorders.

Breast Cancer

Researchers have hypothesized that higher intakes of omega-3s from either foods or supplements might reduce the risk of cancer due to their anti-inflammatory effects and potential to inhibit cell growth factors. The evidence is increasing that higher intakes of dietary and supplemental omega-3s are associated with a lower risk of breast cancer. In one study, women who took supplements had a 32 percent lower risk of breast cancer than those who didn't take them. While promising, more research is needed to confirm that fish oil supplements can reduce the risk of breast cancer.

Dry Eye

Research using fish oil supplementation has had mixed results in reducing the symptoms of dry eye, which occurs when the quantity and/or quality of tears fails to keep the surface of the eye adequately lubricated. 

Rheumatoid Arthritis

Study results vary, but the types of omega-3s found in seafood and fish oil may be modestly helpful in relieving symptoms of rheumatoid arthritis and decreasing the need for nonsteroidal anti-inflammatory drugs. 

According to the National Institutes of Health, higher doses of omega-3s are sometimes prescribed for people who need to lower their triglycerides. However, these doses could cause bleeding problems and possibly affect immune function, according to the source. They recommend that you be under the care of a healthcare provider if you take higher than the recommended dose.

For most people, however, taking the recommended dose, side effects are usually mild. They may include an unpleasant taste in the mouth, bad breath, heartburn, nausea, stomach discomfort, diarrhea, headache, and smelly sweat.

The NIH states that there is no recommended daily dose for omega-3s, except for ALA (alpha-linoleic acid) which your body can convert into EPA and DHA in limited amounts. The amount of ALA that you need depends on your age and gender. Adult men need 1.6 grams and adult women need 1.1 grams.

Plants provide alpha-linoleic acid. The best plant sources of omega-3 fatty acids include:

• Nuts, such as walnuts and almonds
• Seeds, such as flaxseeds, chia seeds, pumpkin seeds, hemp seeds, and pine nuts
• Edamame
• Canola oil
• Navy beans

It's easy to add plant sources of omega-3s to your diet. You can sprinkle pumpkin seeds to a salad, cook with canola oil, and snack on walnuts.

If you consume fish to get your omega-3s, look for cold water fatty fish such as salmon, mackerel, tuna, herring, and sardines.

If you don't eat fish, it's likely that plant sources alone may not provide enough omega-3s. If that's the case, talk to your health care provider about taking a supplement to fill in the gaps. This is particularly important if you're pregnant, since expecting women typically don't eat enough fish (only 27 percent did in one study), and omega-3s are required for the development of the growing baby's brain.

Fish oil supplements are generally safe, as long as you don't have a reason to avoid them and you follow the label directions. Keep in mind, too, that because nutritional supplements aren't highly regulated in the United States, it's important to purchase a product from a reputable source.

The NIH suggests that you look for a supplement that contains a seal of approval from a third party organization that provides quality testing. These organizations include U.S. Pharmacopeia, ConsumerLab.com, and NSF International. A seal of approval from one of these organizations does not guarantee the product's safety or effectiveness but it does provide assurance that the product was properly manufactured, contains the ingredients listed on the label, and does not contain harmful levels of contaminants.

Once you choose a product, you should also look for a Supplement Facts label on the product that you buy. This label will contain vital information including the amount of active ingredients per serving, and other added ingredients (like fillers, binders, and flavorings).