There's no mercury to worry about, and flaxseed oil does contain omega-3 fats...but not the best kind.
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.
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FAQs
The bottom line on flaxseed oil
Who should avoid flaxseed oil? ›
Avoid use of flaxseed and flaxseed oil during pregnancy. Occasionally, using flaxseed or flaxseed oil causes an allergic reaction. Don't eat raw or unripe flaxseeds. Because flaxseed oil might decrease blood clotting, stop using flaxseed oil two weeks before having elective surgery.
What happens if you take flaxseed oil every day? ›
When taken by mouth: Flaxseed oil is likely safe for most adults. Supplements containing 2 grams of flaxseed oil daily have been used safely for up to 6 months. Higher doses of up to 24 grams daily have also been used safely for up to 7 weeks. These larger doses can cause side effects such as loose stools and diarrhea.
Is flaxseed oil hard on the kidneys? ›
Because flax seeds and chia seeds are low in sodium, potassium, and phosphorus, they are healthy for all the following kidney conditions and treatments: CKD/Transplant. Hemodialysis (3 times/week) Daily Home and Nocturnal Hemodialysis/Peritoneal Dialysis.
What is the biggest disadvantage of flax? ›
Adding flaxseed to the diet might increase the number of bowel movements each day. It might also cause side effects such as bloating, gas, stomachache, and nausea. Higher doses are likely to cause more side effects.
What is a safe amount of flaxseed oil per day? ›
There is no single recommended dose of flaxseed. But a daily intake of 1-2 tablespoons of ground flaxseed can be a healthy amount. Up to 1 tablespoon of flaxseed oil daily is thought to be a safe and healthy amount. Ask your doctor for advice about how much is right for you.
What medications should not be taken with flaxseed oil? ›
Some drugs that may interact with this product include: drugs for diabetes (including metformin, sulfonylureas such as glipizide, glitazones such as pioglitazone), medications/other herbal products that may increase your risk of bleeding (including "blood thinners" such as warfarin and heparin, anti-platelet drugs such ...
Does flaxseed oil increase inflammation? ›
Accumulating studies have shown that flaxseed oil protects against inflammation [24] and via suppressing inflammation can accelerate wound healing [19, 25].
Why can't you cook with flaxseed oil? ›
You can also add one serving (one tablespoon or 15 ml) into smoothies or shakes to add some flaxseed oil into your diet with minimal effort. Keep in mind that flaxseed oil should not be used for cooking, as it does not have a high smoke point and can form harmful compounds when exposed to high heat ( 25 ).
Does flaxseed oil burn belly fat? ›
Foods that are rich in fiber, protein and healthy fats, like flaxseeds, contribute to satiety and regulate hunger, making them good for weight loss. A meta-analysis of 45 studies cites that eating flaxseeds as part of a healthy diet may decrease body weight and waist size.
Dosage. Flaxseed oil has most often been used in 1,000mg to 2,000mg doses for up to six months. The recommended daily intake of ALA is 1,100mg for women and 1,600mg for men. 13 This recommendation is based on the overall intake of the nutrient, not specifically on supplement dosage.
Which is healthier, flaxseed oil or olive oil? ›
Bottom Line. While both oils contain predominately healthy unsaturated fats, extra virgin olive oil is far superior when it comes to health benefits, as well as being the more well researched, stable, and versatile of the two oils.
Are there any negative effects of flaxseed? ›
Side effects of flaxseed include: allergic reactions. diarrhea (oil) intestinal obstruction.
Which is healthier, flaxseed or chia seeds? ›
Both seeds are very nutritious. If you're looking for more omega-3s, pick flax seeds. If you're seeking higher amounts of fiber and bone-strengthening minerals, opt for chia seeds.
Is flaxseed good for arthritis? ›
Flaxseed oil, which can be bought over the counter in capsule form, is rich in ALA. This fatty acid can help in reducing joint inflammation. Limited evidence suggests that flaxseed oil isn't effective in the treatment of rheumatoid arthritis and we don't yet know how safe it is.
Does flaxseed oil affect liver? ›
Flaxseed favorably altered liver lipid composition and this change correlated with reduced ALT, AST, and lower hepatic cholesterol/triglyceride levels, indicating decreased liver damage. Further studies may be warranted to dissect molecular mechanisms and to explore different chemical components of flaxseed.
Is it okay to take flaxseed every day? ›
While there are no specific recommendations for flaxseed intake, 1-2 tablespoons a day is considered a healthy amount. One tablespoon of ground flaxseed contains 37 calories, 2 grams of polyunsaturated fat (includes the omega-3 fatty acids), 0.5 gram of monounsaturated fat and 2 grams of dietary fiber.
Is flaxseed oil inflammatory? ›
Found in all forms of flaxseed, flavonoids are well known anti-inflammatories and may play a role in reducing the low-grade inflammation that triggers many chronic diseases, including autoimmune arthritis.
