What Really Happens When You Take A Fish Oil Supplement Every Day
Fish oil, omega-3 supplements: Is eating fish every day healthy?
Paul Greenberg makes a mean plate of spaghetti and fish balls.
The journalist spent a year eating seafood at every single meal, enjoying it grilled, broiled, fried, smoked and packed in olive oil, with the recipes becoming more “inventive” as he went along. His daily fish feast injected his diet with an abundance of fish oil — a rich source of omega-3 fatty acids.
How would all that goodness affect Greenberg’s body? He was a one-man experiment in a world crazy about omega-3s, a type of healthy fat humans must get from food. Greenberg explored the obsession and its impact on the environment in his latest book, “The Omega Principle: Seafood and the Quest for a Long Life and a Healthier Planet.”
With claims that omega-3s may boost heart and brain health, Americans are paying attention: Fish oil is the most popular non-vitamin dietary supplement taken by U.S. adults. Over 18 million people reported they had taken a fish oil supplement in the previous month, according to the National Health Interview Survey.
Why are omega-3s so special? Greenberg shared the answers with TODAY. The following interview was condensed and edited for clarity.
How did eating seafood at every meal for a year affect your body?
Sadly, I didn’t really see any of the typical markers of cardiovascular health change. I didn’t see any marked change in cholesterol, either good or bad. Triglycerides — no change. Heart rate and blood pressure were all pretty much the same.
But I had around 11 percent omega-3 levels in my blood — most Americans are below 5 percent. A finding above 8 percent is desirable. Somebody said to me that I had the blood of a Sicilian fisherman circa the 1890s.
My mercury levels went up. My readings were such that an Alaskan health professional said: “If we had readings as high as yours come in from one of our citizens, we would probably send somebody out to your village and tell you to stop eating so much whale blubber.”
Once I started going back to two to three portions of seafood per week, my mercury issues disappeared.
Why do you call omega-3 the “Forrest Gump molecule”?
You know how Forrest just kind of seems to show up at these very important moments? You’re never quite sure: Is Forrest actually making the moment, or is he just there when the important moment happens?
Omega-3 is just present in a lot of things. Sperm cells and egg cells have really high levels of omega-3, so it’s there for sex. It’s really high in our brains, so it’s there for thinking. It seems to be implicated in cardiovascular disease.
Omega-3s seem to play a large part in having more supple and more active cell membranes. They also seem to help us with inflammation and with resolution from inflammation.
Something like 10 percent of the human brain is DHA omega-3 fatty acid by weight. So even if you just looked at it from raw quantity, you’d have to admit it was playing a vital role there.
Do omega-3s boost health?
I do believe having omega-3s in our diet is critical.
The jury is out on heart health. In terms of the body of evidence and just the very fact that there’s so much omega-3s as part of our brains, that leads me to believe the neurological effect may be more important. There are some people who believe omega-3s and mental health are linked.
Can you have an omega-3 deficiency?
The people who are in “omega world” believe there’s a chronic omega-3 deficiency in the American diet. It stems from the fact that we have switched over to a diet that’s largely omega-6 based — which is corn- and soy-fed beef, pork and chicken; corn and soy oil in our foods — and that we eat very little seafood and very few leafy greens.
The omega-3 people say we need to have a balance of omega-3s and omega-6s in our bodies. Their argument is that we’re so tilted against omega-3 in our regular eating patterns that we have to supplement our bodies in order come up to parity.
Is it worth taking fish oil supplements?
Rather than trying to supplement our way out of the situation, what we really need to address is our overconsumption of industrial animal products and industrial corn and soy products, and to try to boost the levels of omega-3s in our bodies through sustainable seafood.
People might want to look at getting their omega-3 blood levels tested. If they are super low, they might consider getting them up to levels their physicians recommend. My first choice would be to try and do it through diet. But if you can’t do it through diet, I suppose you could try the supplements.
Which fish are the best to eat to boost omega-3 levels?
Salmon is certainly very high in omega-3s. I always try to push people towards wild Alaskan sockeye salmon. It has very low levels of mercury and other toxins.
Beyond that, herring and anchovies are really great ways to get omega-3s into your life.
Sardines — all these little silvery fish are all really great sources of omega-3 and they also tend to be lower in mercury.
How often should we eat fish?
A pescaterian diet did very, very well for health outcomes. In the Mediterranean way of eating, you’re only supposed to have animal protein a couple or three times a week. In the pescaterian diet, you’re making a large portion of those small amounts of animal protein coming from fish.
Do you take fish oil supplements?
I do not.
One thing you have to remember is humans existed for a couple of hundred thousand years without omega-3 supplements in their lives. A lot of it is just eating real food.
Follow A. Pawlowski on Facebook, Instagram and Twitter.
Omega-3 Fatty Acids
This is a reader-friendly overview of Omega-3 Fatty Acids. For more details, see our health professional fact sheet on Omega-3 Fatty Acids.
What are omega-3 fatty acids and what do they do?
Omega-3 fatty acids are found in foods, such as fish and flaxseed, and in dietary supplements, such as fish oil.
The three main omega-3 fatty acids are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). ALA is found mainly in plant oils such as flaxseed, soybean, and canola oils. DHA and EPA are found in fish and other seafood.
ALA is an essential fatty acid, meaning that your body can’t make it, so you must get it from the foods and beverages you consume. Your body can convert some ALA into EPA and then to DHA, but only in very small amounts. Therefore, getting EPA and DHA from foods (and dietary supplements if you take them) is the only practical way to increase levels of these omega-3 fatty acids in your body.
Omega-3s are important components of the membranes that surround each cell in your body. DHA levels are especially high in retina (eye), brain, and sperm cells. Omega-3s also provide calories to give your body energy and have many functions in your heart, blood vessels, lungs, immune system, and endocrine system (the network of hormone-producing glands).
How much omega-3s do I need?
Experts have not established recommended amounts for omega-3 fatty acids, except for ALA. Average daily recommended amounts for ALA are listed below in grams (g). The amount you need depends on your age and sex.
Life Stage Recommended Amount of ALA Birth to 12 months* 0.5 g Children 1–3 years 0.7 g Children 4–8 years 0.9 g Boys 9–13 years 1.2 g Girls 9–13 years 1.0 g Teen boys 14–18 years 1.6 g Teen girls 14–18 years 1.1 g Men 1.6 g Women 1.1 g Pregnant teens and women 1.4 g Breastfeeding teens and women 1.3 g
*As total omega-3s. All other values are for ALA alone.
What foods provide omega-3s?
Omega-3s are found naturally in some foods and are added to some fortified foods. You can get adequate amounts of omega-3s by eating a variety of foods, including the following:
Fish and other seafood (especially cold-water fatty fish, such as salmon, mackerel, tuna, herring, and sardines)
Nuts and seeds (such as flaxseed, chia seeds, and walnuts)
Plant oils (such as flaxseed oil, soybean oil, and canola oil)
Fortified foods (such as certain brands of eggs, yogurt, juices, milk, soy beverages, and infant formulas)
What kinds of omega-3 dietary supplements are available?
Omega-3 dietary supplements include fish oil, krill oil, cod liver oil, and algal oil (a vegetarian source that comes from algae). They provide a wide range of doses and forms of omega-3s.
Am I getting enough omega-3s?
Most people in the United States get enough ALA from the foods they eat. They also get small amounts of EPA and DHA. Recommended amounts of EPA and DHA have not been established.
What happens if I don't get enough omega-3s?
A deficiency of omega-3s can cause rough, scaly skin and a red, swollen, itchy rash. Omega-3 deficiency is very rare in the United States.
What are some effects of omega-3s on health?
Scientists are studying omega-3s to understand how they affect health. People who eat fish and other seafood have a lower risk of several chronic diseases. But it is not clear whether these health benefits come from simply eating these foods or from the omega-3s in these foods. Here are some examples of what the research has shown.
Cardiovascular disease
Many studies show that eating fatty fish and other types of seafood as part of a healthy eating pattern helps keep your heart healthy and helps protect you from some heart problems. Getting more EPA and DHA from foods or dietary supplements lowers triglyceride levels, for example.
The American Heart Association (AHA) recommends eating one to two servings of seafood per week to reduce your risk of some heart problems, especially if you consume the seafood in place of less healthy foods. For people with heart disease, the AHA recommends consuming about 1 g per day EPA plus DHA, preferably from oily fish, but supplements are an option under the guidance of a healthcare provider. The AHA does not recommend omega-3 supplements for people who do not have a high risk of cardiovascular disease.
Infant health and development
During pregnancy and breastfeeding, eating 8 to 12 ounces per week of fish and other seafood may improve your baby’s health. However, it is important to choose fish that are higher in EPA and DHA and lower in mercury. Examples are salmon, herring, sardines, and trout. It is not clear whether taking dietary supplements containing EPA and DHA during pregnancy or breastfeeding affects a baby’s health or development. However, some studies show that taking these supplements may slightly increase a baby’s weight at birth and the length of time the baby is in the womb, both of which may be beneficial. Breast milk contains DHA. Most commercial infant formulas also contain DHA.
Cancer prevention
Some studies suggest that people who get more omega-3s from foods and dietary supplements may have a lower risk of breast cancer and perhaps colorectal cancer. But a large clinical trial found that omega-3 supplements did not reduce the overall risk of cancer, or the risk of breast, prostate, or colorectal cancers. Other clinical trials in progress will help clarify whether omega-3s affect cancer risk.
Alzheimer’s disease, dementia, and cognitive function
Some—but not all—research shows that people who consume more omega-3s from food such as fish may have a lower risk of developing Alzheimer's disease, dementia, and other problems with cognitive function. More study of the effects of omega-3s on the brain is needed.
Age-related macular degeneration (AMD)
AMD is a major cause of vision loss among older adults. Studies suggest that people who get higher amounts of omega-3s from the foods they eat may have a lower risk of developing AMD. But once someone has AMD, taking omega-3 supplements does not keep the disease from getting worse or slow down vision loss.
Dry eye disease
Dry eye disease occurs when tears don’t provide enough moisture, causing eye discomfort and vision problems. Some studies show that getting more omega-3s from foods or supplements—mainly EPA and DHA—helps relieve symptoms of dry eye disease. But a large, recent study found that the symptoms of people with dry eye disease who took fish oil supplements of 2,000 mg EPA plus 1,000 mg DHA daily for 1 year did not improve any more than those who took a placebo (a dummy pill). Another study in healthy people found that daily supplements of 460 mg EPA plus 380 mg DHA for 5.3 years did not affect the risk of getting dry eye disease. More research on the effects of omega-3s on dry eye disease is needed.
Rheumatoid arthritis (RA)
RA causes chronic pain, swelling, stiffness, and loss of function in the joints. Some clinical trials have shown that taking omega-3 supplements may help manage RA when taken together with standard RA medications and other treatments. For example, people with RA who take omega-3 supplements may need less pain-relief medication, but it is not clear if the supplements reduce joint pain, swelling, or morning stiffness.
Other conditions
Researchers are studying whether taking omega-3 dietary supplements may help lessen some of the symptoms of attention-deficit/hyperactivity disorder, childhood allergies, and cystic fibrosis. But more research is needed to fully understand the potential benefits of omega-3s for these and other conditions.
Can omega-3s be harmful?
The U.S. Food and Drug Administration recommends consuming no more than 5 g/day of EPA and DHA combined from dietary supplements. Any side effects from taking omega-3 supplements are usually mild. They include an unpleasant taste in the mouth, bad breath, heartburn, nausea, stomach discomfort, diarrhea, headache, and smelly sweat.
Do omega-3s interact with medications or other dietary supplements?
Omega-3 dietary supplements may interact with the medications you take. For example, high doses of omega-3s may cause bleeding problems when taken with warfarin (Coumadin®) or other anticoagulant medicines.
Talk with your healthcare provider about possible interactions between omega-3 supplements and your medications.
Omega-3s and healthful eating
People should get most of their nutrients from food and beverages, according to the federal government’s Dietary Guidelines for Americans. Foods contain vitamins, minerals, dietary fiber, and other components that benefit health. In some cases, fortified foods and dietary supplements are useful when it is not possible to meet needs for one or more nutrients (for example, during specific life stages such as pregnancy). For more information about building a healthy dietary pattern, see the Dietary Guidelines for Americans and the U.S. Department of Agriculture’s MyPlate.
Where can I find out more about omega-3s?
What Really Happens When You Take A Fish Oil Supplement Every Day
What Really Happens When You Take A Fish Oil Supplement Every Day
When it comes to dietary supplements, fish oil is one of the most popular. That's because fish oil is a great source of omega-3 fatty acids — specifically, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). According to the National Institutes of Health (NIH), more than seven percent of adults regularly take a supplement that contains fish oil, omega-3s, or EPA and DHA. Because most people don't consume enough fatty fish to get significant amounts of EPA and DHA from their diet, adding fish oil supplements can help. Health officials recommend healthy adults get between 250 and 500 mg of EPA and DHA each day.
According to WebMD, fish oil supplements come in two forms: over-the-counter dietary supplements and prescription medications, which contain much higher levels of EPA and DHA. While individuals taking prescription-strength fish oil may be instructed to take up to 15 grams a day for certain medical conditions, people taking OTC fish oil usually take much lower doses. Although fish oil is commonly seen as safe, it can have negative interactions with certain medications, such as birth control pills and drugs used to control high blood pressure. It's always best to speak with your doctor before beginning any dietary supplement.
