Are fish oil and weight loss really connected? Scientists from the University of Brazil have uncovered evidence that ordinary fish oil supplements — the kind you can get for $10 online, such as Nature’s Bounty rapid release fish oil softgels ($9, Amazon) — may have hidden powers that’ll make your thyroid work better. And that’s very good news for folks who are struggling to get slim.

“Your thyroid is the gas pedal for your metabolism,” explains Richard Shames, MD, author of Thyroid Power ($10, Amazon). Fish oil primes this pedal, “allowing the body to use more fat for fuel,” and thereby shed pounds quickly.

The big question, of course, is how well does it work? To find out, we asked a group of dieters to start taking 2,000 mg of fish oil daily and report back on how their bodies responded. Every single one seemed thrilled. “I could eat carbs and still lose weight easily,” said Wisconsin reader JoAnne Custer, 58, who was down eight pounds in seven days. Minnesota mom Tonya Busall, 27, added: “I’ve struggled with my weight for years. But after one week of taking fish oil supplements and eating right, I lost 10 pounds. I wish someone had told me about this sooner!”

(Photo Credit: Getty Images)

Fish Oil and Weight Loss

Brazilian researchers actually set out to see if fish oil pills might lower cholesterol. Turns out, thyroid hormone helps regulate cholesterol — so they noticed signs that fish oil “was basically making thyroid hormone more effective at clearing away fat,” explains Baylor College of Medicine’s Ridha Arem, MD, author of The Thyroid Solution ($18, Amazon). Experts already knew that omega-3 fatty acids in fish seemed to boost thyroid function. Yet this new research, which is still in its early phases, hints that fish oil’s effect may be more powerful than previously thought. Dr. Arem and Dr. Shames agree there’s no need to wait for more studies to try fish oil supplements for weight loss. After all, fish oil is so safe that it’s often recommended for pregnant women.

(Photo Credit: Getty Images)

How to Take Fish Oil for Weight Loss

Here are some of the most frequently asked questions about taking fish oil for weight loss.

What’s the best dose? Andrew Weil, MD, recommends eating oily-fleshed, wild-caught, cold-water fish two to three times per week. If you choose to use fish oil supplements instead, Dr. Weil suggests taking a product that provides 700 to 1,000 mg of EPA and 500 mg of DHA daily.

Does it work without a diet? Fish oil can make pounds easier to shed, but you still need to take in fewer calories than you burn.

Does it supercharge any diet? Since starvation diets can damage the thyroid, experts recommend aiming for about 1,500 calories per day. Docs also note that a high-nutrient mix of fruit, vegetables, lean protein, good carbs, and good fat is healthiest for your thyroid and all body systems. See the sample meals below.

Can fish oil replace thyroid medication? No. If you have or suspect a thyroid problem, talk to your doctor and follow his or her advice. Fish oil may be part of the recommended treatment, but it doesn’t replace prescription meds.

What if my thyroid is already healthy? Fish oil can help keep it that way! Plus, supplements also offer other impressive benefits, such as improving your heart health.

Fish Oil Benefits for Women

Did you know that one of the top 10 leading causes of death in the United States is due to an omega-3 deficiency? A study conducted by researchers at Harvard Medical School found that omega fatty acids (fish oil in particular) are essential to our health.

It relieves arthritis symptoms. Getting plenty of †fish oil can help relieve symptoms of rheumatoid arthritis and decrease patients’ need for nonsteroidal anti-inflammatory drugs, according to the National Center for Complementary and Integrative Health (NCCIH).

It fights cancer. Scientists at the Fred Hutchinson Cancer Research Center say that taking fish oil regularly seems to reduce breast-cancer risk by about 30 percent.

It protects your ticker. Danish researchers found that premenopausal women who got plenty of omega-3s from †fish had a 90 percent lower risk of heart disease than women who avoided †fish.

It lifts your spirits. After taking 2,000 mg of †fish oil daily for eight weeks, 70 percent of depressed women reported improved mood, according to a study at Massachusetts General Hospital.

Hunger shrinks. One study found that fish oil shifts the balance of hunger hormones, dialing down the urge to eat. Omega-3s also enhance mood. “When you feel better, you’ll naturally crave less and eat less,” Arem promises.

Fat cells shut down. A Japanese study found that omega-3s in fish oil help block the excess calories we eat from being stuffed into fat cells. Explanation? Omega-3s may improve levels of insulin, a hormone in charge of storing excess calories, says Shames.

Fat becomes less stubborn! Omega-3s help soothe a type of internal inflammation that promotes weight gain, “so weight loss becomes easier,” Arem notes. Is fish oil right for you? Only you and your doctor can decide. But for many women, the answer will be yes. Shames says taking fish oil — which is also linked to stronger hearts, improved immunity, and sharper thinking — is simply “one of the best and healthiest” things most dieters can do.

(Photo Credit: Getty Images)

The Fish Oil Diet Meal Plan

Our nutrition team worked with top experts to develop no-fuss meals that promote thyroid health and accelerate weight loss. Consider it a quick-start guide to smart eating. You’ll get lots of nutrients and a nice balance of protein, good carbs, and good fat — all for a healthy 1,500 calories per day. Prefer to make your own menus? Go for it! See below for guidelines.

You can also substitute menus from any healthy diet — just choose one (such as the South Beach Diet or the Mayo Clinic Diet) that provides a nice mix of nutrients and about 1,500 calories a day. Drink as much water as you’d like. Add ultra-low-cal extras (spices, vinegar, Splenda) in moderation. Take between 1,000 mg and 2,000 mg of fish oil daily. Note: Always speak with your doctor before trying any new plan or supplement.

Breakfast (choose one daily)

Option 1:

  • 1 whole-grain English muffin or pita, 2 Tbsp. lite cream cheese, 2 oz. smoked salmon or ham, 1 sliced tomato, fresh herbs to taste
  • 1 cup blueberries

Option 2:

  • 2 eggs, 1/2 cup spinach, 2 Tbsp. reduced-fat feta cheese scrambled in 1 tsp. olive oil
  • 1/2 whole-grain pita
  • 1 orange

Mid-Morning Snack (enjoy once daily)

  • 1 cup plain, fat-free Greek yogurt; 1/2 cup muesli or other whole-grain cereal; 2 tsp. honey; 1 cup berries or 1/2 cup sliced fruit

Lunch (choose one daily)

Option 1:

  • 1/2 cup hummus, 6 olives, 1/2 cup fresh veggies stuffed into 1 whole wheat pita, 1 piece of fresh fruit

Option 2:

  • Starbucks Chicken & Hummus Bistro Box, 1 piece of fruit

Option 3:

  • 4 oz. tuna or 2 chopped hard-boiled eggs, 1/4 cup each chickpeas and kidney beans, 1 tsp. olive oil, lemon juice and herbs to taste
  • 8 olives and 1/2 cup sliced veggies
  • 8 to 10 whole-grain crackers or 1 whole-grain pita

Option 4:

  • 4 oz. shrimp, 3 Tbsp. cocktail sauce, 1 1/2 cups reduced-sodium vegetable soup, 1/2 cup added vegetables, 4 to 6 whole-grain crackers

Dinner (choose one daily)

Option 1:

  • 4 oz. chicken breast (cooked), 1/2 cup crushed tomatoes, 1 Tbsp. olives, capers and seasoning to taste
  • 1/ 2 cup cooked whole-grain pasta
  • 1 cup green beans, 1 tsp. olive oil

Option 2:

  • 4 oz. broiled †fish, herbs to taste
  • 1 cup broccoli, 1 tsp. olive oil
  • 1/2 cup cooked brown rice, 1 Tbsp. walnuts

Option 3:

  • 4 oz. grilled chicken sausage
  • 2 cups kale or spinach cooked with garlic and 2 tsp. olive oil
  • 1 baked sweet potato

Snack (choose one daily)

Option 1:

  • 1 oz. dark chocolate

Option 2:

  • 1/4 cup hummus, 5 wheat crackers

Option 3:

  • 4 oz. wine
  • 8 almonds

This article originally appeared in our print magazine.

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‘Your product does not work,’ he complained. ‘I took your Omega-3 for a month and my belly fat didn’t go away.’

Exercise, portion control, and a diet that is low in sugar and refined grains are still the best reduce belly fat. Not fish oil.

The Crossfit fitness community has several followers who take large amounts of fish oil in hopes of losing weight and reducing exercise soreness.

I’ve written that fish oil does not reduce cholesterol. Let me add another item to the Does-Not-Do list: melt away belly fat.

Fish oil does not reduce belly fat.

There are fish oil brands that are sold as part of a weight loss program. Sure, combining exercise with fish oil helps support a healthy metabolism, but Omega-3 by itself will not make stubborn belly fat go away.*

Psst…want to know a REAL weight loss secret?


There are several reasons why people become obese. Overeating and laziness are usually blamed. These are not the #1 and 2 reasons.

Having helped many people shed pounds, I’d rank ‘what you eat’ as the #1 reason for obesity. In my experience, it’s slightly more important than ‘how much you eat,’ given you are consuming reasonable quantities of food.*

Back to insulin…

If you look at most successful, popular diets, regardless of how contrary they seem on the surface, they all help you lose weight by doing one thing: reduce insulin levels.

Atkins Diet
Zone Diet
Ornish Diet
Paleo Diet
South Beach Diet
Fuhrman Diet

All successful diets reduce your insulin level

How? By reducing or eliminating sugar and processed, refined carbohydrates.

Sugar, refined carbs and starches all get converted to the same things in the body – sugar.

Since the body is not capable of storing large volumes of sugar, you need to either burn it or store it as fat.

Eat a bagel? You’d better spend at least an hour on the treadmill after eating it or the carbs get broken down into sugar. And sugar will need to get stored.

Enter insulin. Your pancreas releases insulin to start the process of packing away sugar and starches as fat. This makes your fat cells bigger.

You cannot get fat without a big helping hand from insulin.

Eat pizza and beer? Well, your pancreas has to crank out a LOT of insulin to keep you from going into hyperglycemia, a dangerous situation. If you’re a teenager, your body can handle this. (Teens today have much higher insulin levels than a generation ago.) But if you’re not a teenager, well, keep reading…

As more sugar gets stuffed into storage as fat, you gain weight. The heavier you get, your body becomes less sensitive to insulin. In other words, your cells become deaf to the insulin trying to store fat. So the pancreas has to crank out even more insulin to get the cells to listen.

This is called insulin resistance. (Great technical details here.)

Insulin does two things that affect your weight:

  1. It helps pack away calories (as fat.)
  2. It keeps your stored fat from being burned. It keeps fats cells in lock-mode.

That second point is a real bummer.

This basically means that even if you’re starving, your stored fat reservers won’t be tapped for energy if your insulin level is high.

If you want to burn fat, you need to unlock your fat cells so its contents can be burned. If you have high blood insulin levels, that fat isn’t going anywhere. Fat cells remain locked and you will have a very hard time losing weight.

Cut out sugar, cut out refined and processed grains. Heck, why pull punches. Cut out grains altogether, especially wheat. Wheat is fantastic at raising your blood sugar and subsequently insulin.

Short video on Insulin Response with Dr. Peter Attia

A somewhat simpler explanation from ‘Fat Head’

How do you know what your insulin level is?

Well, you need a blood test.

But there is a simpler way to predict what it’s going to be. Measure the blood sugar that is going to trigger insulin release.

Measuring blood sugar is easy. Go down to the corner drug store and ask the pharmacist to help you choose a blood sugar test kit. A little pin-prick and you measure the sugar level in your blood an hour and two hours after each meal or after that 100-calorie light snack of ‘healthy whole grain’ goodness.

If your blood sugar is higher than 120 after 1 and 2 horus, then chances are your insulin levels are high. If it is over 140, talk to your doctor, you may be diabetic or pre-diabetic, in which case, you have bigger problems.

This is a really, really easy way to find out what you can and cannot eat. Cut out whatever jacks up your blood sugar.

My guess: this technique will rule out most sugary, starchy, carby stuff. Chances are, non-starchy vegetables, meats, seafood, eggs, nuts, healthy fats like olive oil, coconut oil and butter will not budge your blood glucose levels much.

If you do this, your fat cells will get ‘unlocked’ and fat that you’ve been storing for a long, long time will finally be able to be released and burned for energy.

Don’t be shocked if you lose a LOT of weight this way.

Losing weight is nice.

So back to our caller who said OmegaVia did not reduce his belly fat.

Want to reduce belly fat?

Cut out sugar and grains and in its place, add healthy fats and protein.

A little Omega-3 doesn’t hurt, but fish oil by itself won’t get rid of belly fat.

Parting shot…

Image credit: Geo Cristian

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Fish vs. Fish Oil: Which Is Better?

A diet rich in fatty fish provides a wealth of healthy benefits. But if you’re one of those people who can’t bear the smell – or even the sight – of seafood, maybe a fish oil supplement can reel in the important omega-3s you need.

Omega-3s are polyunsaturated fatty acids that are essential for a healthy diet. They play a crucial role in how the body’s cells function and can help reduce cardiovascular risks and much more.

“Omega-3s have been shown to reduce inflammation in the body and can decrease symptoms associated with arthritis and chronic disease,” says Jill Dodson, a Virtua dietitian. “If you have a family history of heart disease or high cholesterol, then omega-3s can help reduce your risk of developing arrhythmia or artery-clogging plaque.”

Because your body cannot produce omega-3 fatty acids on its own, you must obtain them from food, most notably fish. Omega-3 fatty acids can be acquired by eating cold water fish such as:

  • Tuna
  • Salmon
  • Halibut
  • Mackerel
  • Sardines
  • Herring
  • Anchovies
  • Rainbow trout

“The American Heart Association (AHA) recommends eating a three-ounce serving of oily fish at least two times a week to get the heart-healthy benefits from omega-3s,” says Dodson.

Fish oil supplements can be an alternative

While eating fish is a great source of omega-3 fatty acids, not everyone is a seafood fan. If you don’t like fish, have a fish allergy, or you’re a vegetarian or pregnant, then try taking fish oil supplements. One fish oil capsule contains about 1,000 milligrams of omega-3s, which is comparable to one three-ounce serving of fatty fish.

“In general, people don’t eat enough fish because it’s too costly, they don’t enjoy it or they’re worried about mercury levels,” says Dodson. “But we need those omega-3s in our diet. Fish oil supplements are good alternatives because they provide healthy benefits from omega-3s.”

When choosing a fish oil supplement, Dodson says to make sure it contains EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), two essential omega-3 fatty acids that are proven to reduce blood pressure, cholesterol and inflammation.

“If you’re a vegetarian who doesn’t want to consume anything that is associated with fish,” says Dodson, “then you can purchase an algae-based DHA supplement as an option.”

Dodson adds you should take one fish oil capsule a day, but it’s always important to follow your doctor’s instructions.

The fish vs. fish oil battle royal winner is …

According to the AHA, if you want the full omega-3 fatty acid health benefits, then fish reigns supreme.

“Studies have shown that fish, in addition to providing cardiovascular benefits, is loaded with healthy vitamins and minerals as well as protein that you just can’t get from fish oil supplements,” says Dodson. “But taking a fish oil supplement, especially if you don’t like fish or can’t get enough in your diet, is a great backup plan.”

Updated December 29, 2017

Okay, back to regular programming! Apologies for the long delay since my last update—things were a little crazy in the aftermath of New York. Seeing the chaos first-hand was sobering, and I hope any readers affected by Sandy are getting their lives back to normal.

Just wanted to give a quick heads-up about a new review on the links between fish oil and strokes in the British Medical Journal (journal article freely available here; press release here; news article here). It’s a systematic review of previous studies, covering a total of about 800,000 subjects. In brief, the findings are:

  • Eating fish twice a week lowers your risk of stroke by about 6%; eating five servings a week lowers risk by 12%. That’s a relatively small but significant effect.
  • Taking omega-3 fatty acid supplements (the substance in fish usually thought to provide big health benefits) doesn’t show any significant benefit against strokes, at least in the controlled trials reviewed here.

So what’s the deal? The researchers suggest a few possible explanations. One is that the health benefits of fish may be due to the whole package of different nutrients in fish, rather the omega-3s alone:

“For example, fish are also a good source of vitamins D and B complex, which have been linked to inverse cerebrovascular risk. In addition, essential amino acids and trace elements in fish (for example, taurine, arginine, selenium, calcium, magnesium, potassium, and iodine) may have potentially favourable vascular effects.”

Another possibility is that eating fish means that you’re eating less of other “foods detrimental to cerebrovascular health, such as red meat.” Taking supplements, on the other hand, doesn’t displace any other foods.

Now, I should emphasize that this study is only looking at stroke reduction. There’s actually pretty good evidence that omega-3 fatty acids, even in supplement form, do help lower your risk of heart disease. But this study suggests (yet again) that you don’t get all the benefits from a healthy food when you replace it with a supplement. This is a topic I’ve blogged about (some would say ranted about) before, and I think it’s a pretty important one. As the researchers conclude:

“Our findings are in line with current dietary guidelines (that is, to encourage fish consumption for all; and intake of fish oils, preferably from oily fish, to people with pre-existing or at high risk of coronary heart disease) and favour propositions that the future nutritional guidelines should be principally ‘food based.'”

(Photo credit: mdalmuld/Flickr)

Pledge your support and become a member to enjoy the freshest fish in BC!

Registered Holistic Nutritionist, and Skipper Otto’s member, Melissa Evanson continues her series of nutrition-focused blog posts tackling the issue of the nutritional value of fish vs fish oil.

Like many trends in nutrition, fish oil is still enjoying its time in the limelight. This is because the omega-3 fatty acids in fish oil have been linked to prevention of heart disease and dementia, to name a few. So for those who may not have access to, or enjoy, wild fish and seafood, popping a pill every morning can seem like a viable option to help ward off disease.

But while early research on fish oil was promising, many studies are now showing mixed outcomes, with many not showing any significant impact on health at all. So why is the data so confounding? And why might eating whole fish on a regular basis be the best way to address health and disease prevention?

So you want to make a fish oil supplement. First you’ve got to catch the fish. Then you need to transport it to a processing plant and turn it into fish meal. Next you have to refine, purify and clean the oil. Finally you have you package it and distribute it to the store where it will remain until purchased. Each one of these stages can compromise product quality. And quality control is especially important for fish oil because it is chemically unstable and highly prone to oxidation. Studies have shown 50-83% of the fish oils tested exceeded at least one of the measures of acceptable oxidation. Once oxidized, fish oil can have a “fishy” flavour and odour, reduced shelf life, and lower levels of omega-3s than the labels claim. There is also some evidence that oxidized fish oil may increase risk factors of disease like inflammation. Even so, the effect of oxidized fish oil on human health hasn’t been well studied.

This difference in fish oil quality, and the fact that most clinical trials don’t test the oxidative state of the fish oils, may explain inconsistencies in study results. A study published in 2013 showed that fish oil quality (oxidative state) had significant impacts on heart disease markers (triglyceride and cholesterol levels). In that study, fish oil capsules with lower levels of oxidation showed improved heart disease markers compared to highly oxidized omega-3 capsules, which had a negative effect on cholesterol levels. All this to say, unless you are purchasing omega-3 supplements from a reputable manufacturer that tests for oxidative stability, the benefits of taking omega-3 supplements may be questionable.

Omega-3 fish oil supplements contain EPA and DHA, the primary anti-inflammatory fats. But, unlike whole fish and seafood, omega-3 supplements typically don’t contain other micronutrients like vitamin D, selenium, iodine and B vitamins. B vitamins, are especially important because they work with omega-3s to support brain function reducing the likelihood of dementia. The greatest benefit of eating whole fish then, is because it offers a whole range of micronutrients that not only support a broad range of our nutritional needs but also are designed to work together to optimize their use in the body.

Our bodies are designed in a way that efficiently takes and uses nutrients from whole foods. Studies comparing fish to fish oil have shown that omega-3 supplements aren’t used as well by our bodies as those in food form. This may be because of the larger amount of overall fat in whole fish, which can better activate fat absorption in the body. This difference in absorption might explain why eating even low or moderate amounts of fish (1-4 servings/week), can be protective against cardiovascular disease.

BOTTOM LINE: For most of us, eating whole fish, like wild BC salmon and salmon roe (my favourite!), several times a week will provide us with all the protective omega-3 fatty acids our body needs with no ‘fishy’ burps!

Have questions about seafood and nutrition? Email us at with your questions and Melissa will be happy to answer them!

Sonia – April 11, 2018

Back to blog

Here’s how fish oil can help burn those extra kilos around your belly

A new report has brought to light that fish oil is beneficial in losing extra weight. But before talking about the research, here are some facts that you should know about fish oil.

Also read: From weight loss to clearing up your skin, 6 benefits of drinking sugarcane juice

You can obtain fish oil by eating fish or by taking supplements. Tuna, Salmon, Mackerel, Mullet, Trout are some of the fishes that are rich in omega-3 fatty acid.

Fish oil supplements often contain small amounts of vitamin E to prevent spoilage. They might also be combined with calcium, iron or vitamins A, B1, B2, B3, C, or D.

Also read: Learn these 5 Iyengar yoga asanas for weight loss

Fish oil is also used for conditions related to the heart and blood system. Some people use fish oil to lower blood pressure or triglyceride levels (fats related to cholesterol), but it should be taken in recommended amounts.

According to the recent research, a group of mice was fed fatty food while another group of mice was given fatty food with fish oil additives. They observed that mice that ate food with fish oil gained five to ten per cent less weight and 15-25 per cent less fat compared to those that did not consume the oil.

Here is the full study:

Fish oil when consumed activates receptors in the digestive tract, shoots the sympathetic nervous system and induces storage cells to metabolise fat.

Also read: These 5 amazing benefits of eating almonds will make you go nuts!

But the fat tissues does not store all the fat. The so-called “white” cells store fat in order to maintain energy supply while “brown” cells metabolise fat to maintain a stable body temperature.

Brown cells are abundant in babies, but decrease in number with maturity.

A third type of fat cell called “beige” cells –have recently been found in humans and mice, and have shown to function much like brown cells.

Beige cells also reduce in number as people approach middle-age and without these metabolising cells, fat continues to accumulate for decades, without ever being used.

“We knew from previous research that fish oil has tremendous health benefits, including the prevention of fat accumulation. We tested whether fish oil and an increase in beige cells could be related,” said senior author Teruo Kawada.

Also read: 4 Fool-proof weight loss tips to follow before going to bed

The team fed a group of mice fatty food, and other groups fatty food with fish oil additives.

The mice that ate food with fish oil, they found, gained five-ten per cent less weight and 15-25 per cent less fat compared to those that did not consume the oil.

The team also found that beige cells formed from white fat cells when the sympathetic nervous system was activated, meaning that certain fat storage cells acquired the ability to metabolise.

“People have long said that food from Japan and the Mediterranean contribute to longevity, but why these cuisines are beneficial was up for debate. Now, we have better insight into why that may be,” explained Kawada in a paper that appeared in the journal, Scientific Reports.

(With inputs from IANS)

Does Fish Oil Make You Fat?

Q: I have been taking fish oil supplements every day, but now I’ve noticed that they have a lot of calories. Since I’m trying to lose weight, should I be concerned about the extra calories from the fish oil?

A: Because fish oil supplements contain omega-3 fatty acids, a form of fat, some people do worry that the extra fat calories might contribute to problems with weight control. On the other hand, earlier research suggested that one of the metabolic benefits of omega-3s might be to promote weight loss. Latest findings: A new study published in The American Journal of Clinical Nutrition showed that supplementing with fish oil did not affect weight either way—it neither helped nor hindered weight loss.

Bottom line: Fish oil typically contains about 10 to 15 calories per capsule. There is no standard dosage, so it is best to follow your doctor’s recommendations. But even if you take as many as five capsules per day, you are probably getting no more than 50 to 75 extra calories daily. The health benefits far outweigh those calories—because omega-3s promote cardiovascular health, reducing blood pressure, triglycerides (fats related to cholesterol) and heart attack risk… may fight arthritis due to their anti-inflammatory effects… and may help protect against psychiatric and cognitive problems. Of course: It also is wise to get fish oil naturally by regularly eating fish, such as anchovies, herring, mackerel, mullet, salmon and sardines.

Why not flaxseed oil?

There’s no mercury to worry about, and flaxseed oil does contain omega-3 fats…but not the best kind.

Updated: July 29, 2019Published: October, 2006

Troll the medical literature, and you’ll come up with study after study showing that fish and fish oil are good for us, especially for our hearts but maybe also for our moods and immune systems. Various epidemiologic investigations have found that people who eat fish regularly are less likely to have heart attacks, suffer strokes, or die from sudden cardiac arrest. The definition of “regularly” varies, but it usually means at least a couple of times a week, although eating fish even once a month has been shown to make a difference.

Fish, and especially fish oil, have also been the subject of dozens of randomized clinical trials, most involving people with existing heart conditions. In large amounts (several grams a day), fish oil has been shown to nudge various cardiac risk factors (“good” HDL cholesterol, triglycerides, blood pressure) in the right direction.

Something fishy

Getting fish oil into your diet can be difficult. Eating fish will certainly do it — if you feast on salmon, trout, mackerel, and other oily species. A three-ounce serving of those fish supplies about a gram’s worth. But you’d need to eat more than a pound of farmed catfish to get that much fish oil. Or 12 ounces of light tuna canned in water.

There’s also mercury contamination to think about. Mercury accumulates in the food chain, so some of the heaviest concentrations are found in long-lived predatory species that are also some of the most desirable from the standpoint of fish-oil consumption.

The third omega-3

The health benefits of fish oil are believed to derive principally from two omega-3 fats, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Flaxseed oil contains a third, plant-based omega-3, alpha-linolenic acid (ALA). Other foods (especially walnuts) and oils (canola and soybean, for example) contain ALA. But at about 7 grams per tablespoon, flaxseed oil is by far the richest source.

The main problem with ALA is that to have the good effects attributed to omega-3s, it must be converted by a limited supply of enzymes into EPA and DHA. As a result, only a small fraction of it has omega-3’s effects — 10%–15%, maybe less. The remaining 85%–90% gets burned up as energy or metabolized in other ways. So in terms of omega-3 “power,” a tablespoon of flaxseed oil is worth about 700 milligrams (mg) of EPA and DHA. That’s still more than the 300 mg of EPA and DHA in many 1-gram fish oil capsules, but far less than what the 7 grams listed on the label might imply.

The bottom line on flaxseed oil

Flaxseed oil will give your diet a nice little omega-3 boost in the form of alpha-linolenic acid. You might try adding flaxseed oil to your salad dressing. But flaxseed oils a backup, not a substitute, for the omega-3s in fish and fish oil because of the conversion factor. If you’re in need of omega-3s but are concerned about mercury, salmon, pollock, and catfish are all low in mercury. And canned light tuna tends to be lower in mercury than albacore (“white”) tuna.

Image: © Xanya69/Getty Images

As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.

All essential fatty acids are not created equal-get the inside scoop on the important differences between fish and flax oils.

Unless you’ve been living under a rock, you probably already know how great omega-3 fats are for you. These “wellness molecules” are associated with healthier brains and hearts, improved mood, lowered inflammation, fewer cardiac arrhythmias, reduced joint pain, lowered triglycerides, and healthier skin and hair. What’s not to like?

You probably already know that the best sources of omega-3s are fish oil and flaxseed oil. But you might be wondering, which is better?

Let’s start at the beginning. It’s entirely true that omega-3s are found in both flaxseed oil and fish oil. But omega-3s are a category (with three members), like the (much larger) category of professional basketball players. And while all professional ballplayers are pretty darn good (especially compared to you and me), not all of them are Kobe Bryant. And so it is with omega-3s.

The dirty little secret about omega-3s is that the two found in fish and the one found in flax are quite different and may be anything but equal in their effects on human health. The two omega-3s in fish oil are like Kobe Bryant and Shaquille O’Neal-the one in flaxseed oil is a very talented young fellow who may or may not grow up to be a star.


Fish oils last longer when stored in a cool, dark place-keep them away from the m crowave, stove, windowsill, etc. Always refrigerate liquid fish oils after opening.

ALA (alpha-linolenic acid)

Flaxseeds and flaxseed oil contain a particular omega-3 fat called ALA (alpha-linolenic acid). Fish and fish oil contain two very different omega-3s, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). The vast majority of the research on the health benefits of omega-3s has been done on DHA and EPA. They are the true superstars of the small omega-3 kingdom. The health benefits of ALA (found in flaxseed) are less clear. (Currently, a large randomized dietary intervention study called the Alpha Omega Trial is testing the relative effects of ALA and EPA/DHA on heart disease, but the results won’t be in till late 2010.)

To give you an idea of the controversy, consider the following: Recently, the European Union instituted new labeling rules that established levels at which omega-3s must be present in food for them to bear the legend “source of omega-3s” or “high in omega-3s.” These new labeling rules drew stern criticism from a prominent group of scientists studying omega-3s. Why? Because the scientists feared that food manufacturers would take advantage of the fact that most people couldn’t distinguish among the various omega-3s. They feared that manufacturers would add plant-based ALA to products such as energy bars and cereals, allowing them to legally claim these products were “high in omega-3s.” But scientists feared that this would be misleading to the public, since the benefits of ALA are not as well documented as the benefits of EPA and DHA.

Now don’t get me wrong-it’s not that flaxseed oil-with its high concentration of ALA isn’t a good fat-it most certainly is. And it’s not that there aren’t huge differences in quality among flaxseed oils. It’s simply that the omega-3 in flaxseed oil, ALA, hasn’t been convincingly shown in research to be as powerful a health modulator as the two omega-3s found in fish.

Proponents of flaxseed oil like to point out-quite correctly, I might add-that the body can actually take the ALA found in flaxseed and convert it into the more “valuable” fatty acids, DHA and EPA. It does this by the action of enzymes known as elongases and desaturases, and the end result is that some of that ALA you consume in flaxseed oil actually does get converted to EPA and DHA.

The big question is how much actually gets converted. And the answer is-not so much. There’s a range of figures shown in various studies on conversion, but the consensus is that it’s never higher than 9 percent and usually considerably less. Truth be told, the actual percentage is a little squishy. Some studies have shown that consuming a lot of ALA does indeed boost blood levels of EPA, but hardly moves blood levels of DHA. This is important, because DHA is one of the most important fats for the brain. Both EPA and DHA keep cell membranes nice and fluid, which is one of the reasons that fish oil, which contains both EPA and DHA right out of the box, is so protective of the heart.

Omega 6 Fats in Vegetable Oils

One thing that works against the conversion of ALA into DHA and EPA is, believe it or not, vegetable oil. Omega-6 fats-which are predominant in most vegetable oils (such as corn, cottonseed, soybean, safflower, and sunflower oils)-actually work to prevent the conversion of ALA into DHA and EPA. Interestingly, saturated fat does not seem to have this dampening effect. One study on ALA conversion concluded that with “a background diet high in saturated fat, conversion … is approximately 6 percent for EPA and 3.8 percent for DHA, with a diet rich in omega-6, conversion is reduced by 40 to 50 percent.”

This can be a real dilemma for the average vegan or vegetarian, who is extremely unlikely to be consuming a “background diet high in saturated fat” and very likely to be consuming a ton of omega-6s from vegetable oils in her diet. A vegan or vegetarian who is getting all her omega-3s from plant foods or flaxseed oil should be very careful to reduce the amount of omega-6 fats in her diet while boosting the amount of flaxseed oil consumed. The ideal ratio of omega-6s to omega-3s in the human diet is somewhere between 4:1 and 1:1. Most Americans consume a ratio of around 20:1. Since omega-6s are pro-inflammatory and omega-3s are anti-inflammatory, this ratio isn’t healthy-whether you’re a vegetarian or not.

Should You Use Flaxseed Oil or Fish Oil?

So if you put a gun to my head and asked me to choose between flaxseed oil and fish oil, I’d have to go with the fish oil. The research on DHA and EPA is too compelling, and the research on ALA alone-while it does exist-is just not as strong and clear.

That said, flaxseed oil still has valuable properties of its own. Flax contains plant chemicals called lignans, which have profound anticancer effects. Oils such as Barlean’s Highest Lignan Flax Oil provide these lignans in addition to ALA, and products like Barlean’s Forti-Flax contain a trifecta of valuable compounds: lignans, omega-3s, and fiber to boot!

All things considered, it seems to me fish oil is the better choice for nonvegetarians. But vegetarians can get a great deal of value from flaxseed oil, provided they use it correctly. Forget about one or two capsules; take at least 1 to 3 tablespoons. That way you’ll be sure to get at least 0.5 gram of EPA and DHA. And cut back on the vegetable oils high in omega-6s. Which, come to think of it, is a good idea for everyone-vegetarian or not.

Omega 3, Fish Oil, and Flaxseed Oil Products

EuroPharma Vectomega (Whole Food Omega-3 DHA/EPA Complex) features salmon extracted via a patented chemical-free process. One to two tablets daily is all you need.

Barlean’s Total Omega 3-6-9 Swirl in Orange Cream tastes just like the popular ice cream treat and provides a balanced ratio of fish, flax, and borage oils.

Country Life Omega-3 1000 mg Fish Body Oils with marine-source EPA and DHA omega-3s are purity tested for PCBs and other toxins.

ReNew Life Norwegian Gold Ultimate Fish Oils Super Critical Omega have 1,025 mg of omega-3s per gelcap and vitamin D3 for maximum strength omega-3 support.

By David H. Rahm, M.D.

Q: I’ve heard about the benefits of taking Omega-3s but I’m not really sure if I should take flax seed oil or fish oil. Or, if I should take both supplements?

Flax seed oil and fish oil belong to a class of supplements called Omega-3s. Taking an Omega-3 supplement can correct imbalances or deficiencies in your diet but fish oil confers different health benefits than flax seed oil. Understanding these differences will help you to determine which or both of these Omega-3s to add to your diet.

Before we talk about the benefits of taking fish oil vs flaxseed oil, let’s make sure that you understand what Omega-3s are and how they benefit your brain, heart, skin and every other organ in your body.

What are Omega-3s, Omega-6s & Omega-9s?

We all need essential nutrients for optimal health and wellness. And, believe it or not, an essential macronutrient we require is fat! But, not just any type of fat. The fats associated with cardiovascular and other disease are saturated and trans-fats. The fats that play a dominant role in our health are unsaturated fats.

Unsaturated fats are classified according to their molecular structure including Omega-3, Omega-6 and Omega-9.

Avocados, peanut butter and olive oil are popular foods that are a good source of the monounsaturated family of Omega-9s. The Mediterranean diet helped to popularize olive oil which is associated with longevity and good health.

Many of the oils widely available in our food supply are derived from beans and seeds such as soybean, corn, sunflower and safflower. These polyunsaturated oils are a good source of Omega-6 fats and in their natural state (without commercial refinement) are part of a health promoting diet.

Finding Omega-3 polyunsaturated fats is more of a challenge because these health-promoting oils are not widely available in the food supply. Excellent sources include flax seeds, chia seeds, walnuts, and deep cold water fish. You can also find foods enhanced with Omega-3s such as DHA eggs.

What are Essential Fats?

Our bodies require two essential fats (EFAs) for normal cell structure and body function. Just like vitamins and minerals, we need to obtain these EFAs through diet or supplementation. One of these essential fatty acids belongs to the Omega-6 family (linoleic acid or LA) and the other belongs to the Omega-3 family (alpha linolenic acid or ALA).

What are Conditionally Essential Fats?

Within the Omega-3 family are two other fats (Eicosapentaenoic acid or EPA and Docosahexaenoic acid or DHA) that are regarded as conditionally essential. While our bodies can manufacture these super polyunsaturated fats from ALA, our diet and lifestyle greatly influence this process, making EPA and DHA essential under certain conditions.

What Omega-3 Supplements Should I Take? Download our Guidelines

Should I Supplement With Omega-6s?

Given the wide range of foods that contain Omega-6s, most of us don’t need to supplement our diets with the essential Omega-6 fat LA. In fact, most Americans get way too much of Omega-6 oils which have negative implications for our health. Based on this, there is no reason to take an Omega-6 supplement.

Should I Supplement With Omega-9s?

Oleic acid is the Omega-9 fatty acid that is found in olive oil. This monounsaturated fat is associated with elevating HDL or “good” cholesterol levels. The best way to obtain this health-promoting fat is by replacing salad oils (which are predominantly Omega-6s) with olive oil. You can also cook with olive oil but keep in mind that you should only use with low to moderate heat. For cooking that requires high heat (e.g., stir fry), you’ll want to use an oil with a higher smoke point. Good examples include sesame oil or canola oil. For a great reference, download Spectrum Oil’s Kitchen Guide to oils here.

Should I Supplement With Omega-3s?

Due to the short shelf-life of Omega-3 fats, only a limited number of packaged foods contain them. Manufacturers prefer more highly processed seed oils like partially-hydrogenated soybean oil which last longer but are associated with health problems. Combined with the limited number of foods that naturally contain Omega-3s, most of us fall short of ALA, making supplementation with this essential fat necessary. Overconsumption of Omega-6 fats puts a strain on our bodies to synthesize EPA and DHA, so supplementing with these two Omega-3 fats is also warranted.

What’s the Daily Requirement for Omega-3s?

Although Daily Reference Values are established for total fat and saturated fat, they have not been established for Omega-3s. Instead, an Acceptable Intake (AI) has been assigned. In men, the AI for Omega-3s is 1.6 grams a day; in women it is 1.1 grams a day.

How Much Omega-3s Are in Flax Seed Oil & Fish Oil Capsules?

A typical flax seed oil or fish oil capsule is about 1 gram (or 1,000 mg). However, this amount just indicates the total contents of the capsule. It is important to examine the Supplement Facts Panel to determine what proportion of the capsule comprises Omega-3s.

For example, a flax seed oil capsule contains around 570 mg of the Omega-3 alpha-linolenic acid (ALA). The remaining 430 mg are a combination of Omega-6s (180 mg), Omega-9s (160 mg) and even saturated fat (90 mg).

Fish oil capsules vary greatly in terms of their Omega-3 content. To complicate matters, some fish oil capsules contain EPA only or DHA only or a combination of both, with the levels varying widely.

A brand like Whole Foods typically delivers 300 mg of Omega-3s per fish oil capsule (180 mg of EPA and 120 mg of DHA). In comparison, each 1 gram softgel of VitaMedica’s Super EPA/DHA Fish Oil provides 750 mg of Omega-3s (500 mg of EPA and 250 mg of DHA), requiring fewer softgels to reach daily requirements.

What are the Health Benefits of Taking Omega-3s?

As mentioned above, given the widespread use of Omega-6 oils in our food supply, most Americans consume far too much of these fats. However, most of us fall short of the Omega-3 requirements.

In fact, it is estimated that the ratio of Omega-6 to Omega-3 fats that we consume is 20:1. Instead, we should be targeting a ratio of 4:1 or four times the amount of Omega-6 fats to Omega-3s fats (example: 4 grams of Omega-6s to 1 gram of Omega-3s).

Why is this important? Because the excessive consumption of Omega-6 oils promotes the production of inflammatory compounds called prostaglandins. These hormone-like compounds regulate a wide range of body functions from inflammation, pain & swelling and blood pressure to kidney function and fluid balance. Over time, these pro-inflammatory compounds promote silent inflammation which is associated with many chronic conditions including cardiovascular disease and even aging.

Taking an Omega-3 supplement promotes the development of non-inflammatory prostaglandins thereby reducing silent inflammation and helps to bring your body back in balance.

Best Omega-3 Supplements: What to Look For

What are the Benefits of Flax Seed Oil?

Aside from the anti-inflammatory benefits, a key reason for taking a flax seed oil supplement is to ensure that you’re obtaining sufficient quantities of the essential Omega-3 fatty acid alpha linolenic acid (ALA).

The integrity and structure of cell membranes is dependent upon an ample supply of essential fatty acids like ALA. Without them, you’ll have dry skin, cracked nails, dry, lifeless hair, aching joints and even fatigue.

VitaMedica’s Anti-Aging Formula provides 1 softgel of high-quality organic flax seed oil in the evening packet to promote lustrous hair and soft, supple skin.

Omega-3s and Skin Health

What About Taking a Flax Seed Supplement?

Flax seeds are small, flat oval shaped seeds that are very hard. In order to obtain just a gram of Omega-3 oils, you would need to consume a large quantity of these seeds. The primary reason for taking ground flax seed is not to obtain Omega-3s but to increase your fiber intake. Ground flax seed is much more palatable than psyllium (e.g., Metamucil). Plus, flax seeds contain lignans, a phytoestrogen which has shown promise in vitro for halting breast cancer cell development.

What are the Benefits of Fish Oil?

From flax seed oil, our bodies can synthesize two other fats: EPA and DHA. However, our ability to make these fats is marginalized with a diet high in Omega-6 fats. Fish oil supplements provide an excellent source of these two important fats.

More than 8,000 studies published over the past 35 years have consistently shown that EPA and DHA are important to health throughout every stage of life. However, EPA is associated with heart health whereas DHA is associated with brain health.

The American Heart Association agrees that Omega-3 EPA and DHA are essential to a healthy cardiovascular system. Specifically, it recognizes the following benefits from these two good-for-you fats:

  • Reduced risk of heart attacks and strokes
  • Reduction in blood thickness (viscosity)
  • Relaxation of blood vessels (vasodilation)
  • Lowering of blood pressure
  • Reduced risk of blood clots in coronary arteries (thrombosis)
  • Protection against heartbeat abnormalities (arrhythmia, ventricular tachycardia, fibrillation)
  • Reduction of triglycerides (blood fat levels)
  • Protection against hardening of the arteries (atherosclerosis)
  • Protection against plaque rupture
  • Good overall heart health

Supplementing with fish oil ensures that you obtain sufficient amounts of these Omega-3 nutrients to support cardiovascular health.

Your brain is one of the vital organs that require Omega-3s to perform optimally. In fact, 60% of your brain is made up of structural fat (a large part of which is DHA), and it requires a regular intake of good fats, such as Omega-3, to function properly. Research suggests that DHA may reduce the risk of the following conditions:

  • Memory problems, including Alzheimer’s disease and other types of dementia
  • Attention Deficit Hyperactivity Disorder (ADHD) and other behavioral problems
  • Mental health conditions, including aggression, bipolar disorder, borderline personality disorder, depression, and schizophrenia

Supplementing with fish oil ensures that you obtain sufficient amounts of these Omega-3 nutrients to support brain health.

What About Cod Liver Oil?

Like other fish oils, cod liver oil contains Omega-3s. However, the Omega-3 content can vary significantly and is often lower than a traditional fish oil supplement. For example, Nordic Naturals’ Arctic Cod Liver Oil provides just 202 mg of Omega-3s per softgel (82 mg EPA; 120 mg DHA). While the liquid forms tend to be higher in Omega-3s, many people find this form unpalatable, even if flavored. Cod liver oil is known for its modest vitamin D and high vitamin A content. Postmenopausal women should limit their vitamin A intake as osteoporotic hip fractures are associated with higher vitamin A intake.

What About Taking Krill Oil vs Fish Oil?

Krill, like other crustaceans and wild salmon, have a naturally occurring red pigment called astaxanthin. Astaxanthin is a type of carotenoid, a fat-soluble compound that works as an antioxidant to protect against oxidative damage. While krill oil is a good source astaxanthins plus vitamins A and D, it does not provide appreciable amounts of either EPA or DHA. For example, NatureMade’s Krill Oil supplement contains just 90 mg of Omega-3s per softgel (50 mg EPA; 24 mg DHA). Due to the lower Omega-3 content and higher cost, taking a Krill oil supplement is one of the most expensive ways to obtain Omega-3s.

David H. Rahm, M.D. is the founder and medical director of The Wellness Center, a medical clinic located in Long Beach, CA. Dr. Rahm is also president and medical director of VitaMedica. Dr. Rahm is one of a select group of conventional medical doctors who have education and expertise in functional medicine and nutritional science. Over the past 20 years, Dr. Rahm has published articles in the plastic surgery literature and educated physicians about the importance of good peri-operative nutrition.

Fish oil vs fish

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