Anti-inflammatory Studies:

Animal studies have shown that dietary fish oil results in altered lymphocyte function and in suppressed production of pro-inflammatory cytokines by macrophages. Supplementation of the diet of healthy human volunteers with fish oil-derived n-3 PUFA results in decreased monocyte and neutrophil chemotaxis and decreased production of proinflammatory cytokines. Fish oil feeding has been shown to ameliorate the symptoms of some animal models of autoimmune disease. Clinical studies have reported that fish oil supplementation has beneficial effects in rheumatoid arthritis, inflammatory bowel disease, and among some asthmatics, supporting the idea that the n-3 PUFA in fish oil are anti-inflammatory and immunomodulatory.

[Lipids. 2001 Sep;36(9):1007-24. Polyunsaturated fatty acids, inflammation, and immunity. Calder PC1.]

This study suggests that dietary (n-3) fatty acids are associated with levels of these biomarkers reflecting lower levels of inflammation and endothelial activation, which might explain in part the effect of these fatty acids in preventing cardiovascular disease.

2. [Lopez-Garcia, E., Schulze, M. B., Manson, J. E., et al. Consumption of (n-3) fatty acids is related to plasma biomarkers of inflammation and endothelial activation in women. J Nutr. 2004;134(7):1806–1811]

A total of 88% of men and 91% of women reported fish consumption at least once a month. Compared to non-fish consumers, those who consumed >300 g of fish per week had on average 33% lower CRP, 33% lower IL-6, 21% lower TNF-alpha, 28% lower SAA levels, and 4% lower WBC counts (all p < 0.05). Significant results were also observed when lower quantities (150 to 300 g/week) of fish were consumed. All associations remained significant after various adjustments were made.

3. [Zampelas, A., Panagiotakos, D. B., Pitsavos, C., et al. Fish consumption among healthy adults is associated with decreased levels of inflammatory markers related to cardiovascular disease: the ATTICA study. J Am Coll Cardiol. 2005;46(1):120–124.]

The present review explores the presence of dose-related effects of long-chain n-3 PUFA supplementation on immune markers and differences between healthy subjects and those with inflammatory conditions, because of the important implications for the transfer of information gained from studies with healthy subjects to patient populations, e.g. for establishing dose levels for specific applications. The effects of long-chain n-3 PUFA supplementation on ex vivo lymphocyte proliferation and cytokine production by lymphocytes and monocytes in healthy subjects have been studied in twenty-seven, twenty-five and forty-six treatment cohorts respectively, at intake levels ranging from 0.2 g EPA+DHA/d to 7.0 g EPA+DHA/d. Most studies, particularly those with the highest quality study design, have found no effects on these immune markers. Significant effects on lymphocyte proliferation are decreased responses in seven of eight cohorts, particularly in older subjects. The direction of the significant changes in cytokine production by lymphocytes is inconsistent and only found at supplementation levels > or =2.0 g EPA+DHA/d. Significant changes in inflammatory cytokine production by monocytes are decreases in their production in all instances. Overall, these studies fail to reveal strong dose-response effects of EPA+DHA on the outcomes measured and suggest that healthy subjects are relatively insensitive to immunomodulation with long-chain n-3 PUFA, even at intake levels that substantially raise their concentrations in phospholipids of immune cells. In patients with inflammatory conditions cytokine concentrations or production are influenced by EPA+DHA supplementation in a relatively large number of studies. Some of these studies suggest that local effects at the site of inflammation might be more pronounced than systemic effects and disease-related markers are more sensitive to the immunomodulatory effects, indicating that the presence of inflamed tissue or ‘sensitised’ immune cells in inflammatory disorders might increase sensitivity to the immunomodulatory effects of long-chain n-3 PUFA. In a substantial number of these studies clinical benefits related to the inflammatory state of the condition have been observed in the absence of significant effects on immune markers of inflammation. This finding suggests that condition-specific clinical end points might be more sensitive markers of modulation by EPA+DHA than cytokines. In general, the direction of immunomodulation in healthy subjects (if any) and in inflammatory conditions is the same, which indicates that studies in healthy subjects are a useful tool to describe the general principles of immunomodulation by n-3 PUFA. However, the extent of the effect might be very different in inflammatory conditions, indicating that studies in healthy subjects are not particularly suitable for establishing dose levels for specific applications in inflammatory conditions. The reviewed studies provide no indications that the immunomodulatory effects of long-chain n-3 PUFA impair immune function or infectious disease resistance. In contrast, in some conditions the immunomodulatory effects of EPA+DHA might improve immune function.

5. [Sijben JW, Calder PC. Differential immunomodulation with long-chain n-3 PUFA in health and chronic disease. Proc Nutr Soc. 2007 May;66(2):237-59.]

Excessive amounts of omega-6 polyunsaturated fatty acids (PUFA) and a very high omega-6/omega-3 ratio, as is found in today’s Western diets, promote the pathogenesis of many diseases, including cardiovascular disease, cancer, and inflammatory and autoimmune diseases, whereas increased levels of omega-3 PUFA (a lower omega-6/omega-3 ratio), exert suppressive effects. In the secondary prevention of cardiovascular disease, a ratio of 4/1 was associated with a 70% decrease in total mortality. A ratio of 2.5/1 reduced rectal cell proliferation in patients with colorectal cancer, whereas a ratio of 4/1 with the same amount of omega-3 PUFA had no effect. The lower omega-6/omega-3 ratio in women with breast cancer was associated with decreased risk. A ratio of 2-3/1 suppressed inflammation in patients with rheumatoid arthritis, and a ratio of 5/1 had a beneficial effect on patients with asthma, whereas a ratio of 10/1 had adverse consequences.

6. [Simopoulos AP. The importance of the omega-6/omega-3 fatty acid ratio in cardiovascular disease and other chronic diseases. Exp Biol Med (Maywood). 2008 Jun;233(6):674-88.]

Animal experiments and clinical intervention studies indicate that omega-3 fatty acids have anti-inflammatory properties and, therefore, might be useful in the management of inflammatory and autoimmune diseases. Coronary heart disease, major depression, aging and cancer are characterized by an increased level of interleukin 1 (IL-1), a proinflammatory cytokine. Similarly, arthritis, Crohn’s disease, ulcerative colitis and lupus erythematosis are autoimmune diseases characterized by a high level of IL-1 and the proinflammatory leukotriene LTB(4) produced by omega-6 fatty acids. There have been a number of clinical trials assessing the benefits of dietary supplementation with fish oils in several inflammatory and autoimmune diseases in humans, including rheumatoid arthritis, Crohn’s disease, ulcerative colitis, psoriasis, lupus erythematosus, multiple sclerosis and migraine headaches. Many of the placebo-controlled trials of fish oil in chronic inflammatory diseases reveal significant benefit, including decreased disease activity and a lowered use of anti-inflammatory drugs.

7. [Simopoulos AP. Omega-3 fatty acids in inflammation and autoimmune diseases. J Am Coll Nutr. 2002 Dec;21(6):495-505.]

Low intakes of long-chain n-3 fatty acids (fish oils) enhance certain immune functions, whereas high intakes are inhibitory on a wide range of functions, e.g., antigen presentation, adhesion molecule expression, Th1 and Th2 responses, proinflammatory cytokine and eicosanoid production, and they induce lymphocyte apoptosis. Vitamin E has a demonstrable critical role in long-chain n-3 PUFA interactions with immune functions, often reversing the effects of fish oil. The effect of dietary fatty acids on animal autoimmune disease models depends on both the autoimmune model and the amount and type of fatty acids fed. Diets low in fat, essential fatty acid deficient (EFAD), or high in long-chain n-3 PUFA from fish oils increase survival and reduce disease severity in spontaneous autoantibody-mediated disease, whereas high-fat LA-rich diets increase disease severity. In experimentally induced T cell-mediated autoimmune disease, EFAD diets or diets supplemented with long-chain n-3 PUFA augment disease, whereas n-6 PUFA prevent or reduce the severity. In contrast, in both T cell- and antibody-mediated autoimmune disease, the desaturated/elongated metabolites of LA are protective. PUFA of both the n-6 and n-3 families are clinically useful in human autoimmune-inflammatory disorders, but the precise mechanisms by which these fatty acids exert their clinical effects are not well understood. Finally, the view that all n-6 PUFA are proinflammatory requires revision, in part, and their essential regulatory and developmental role in the immune system warrants appreciation.

9. [Harbige LS. Fatty acids, the immune response, and autoimmunity: a question of n-6 essentiality and the balance between n-6 and n-3. Lipids. 2003 Apr;38(4):323-41.]

Current intakes of very long chain omega-3 fatty acids, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are low in most individuals living in Western countries. A good natural source of these fatty acids is seafood, especially oily fish. Fish oil capsules contain these fatty acids too. Very long chain omega-3 fatty acids are readily incorporated from capsules into transport, functional, and storage pools. This incorporation is dose-dependent and follows a kinetic pattern that is characteristic for each pool. At sufficient levels of incorporation, EPA and DHA influence the physical nature of cell membranes and membrane protein-mediated responses, eicosanoid generation, cell signaling and gene expression in many different cell types. Through these mechanisms, EPA and DHA influence cell and tissue physiology, and the way cells and tissues respond to external signals. In most cases, the effects seen are compatible with improvements in disease biomarker profiles or in health-related outcomes. As a result, very long chain omega-3 fatty acids play a role in achieving optimal health and in protection against disease. Long chain omega-3 fatty acids protect against cardiovascular morbidity and mortality, and might be beneficial in rheumatoid arthritis, inflammatory bowel diseases, childhood learning, and behavior, and adult psychiatric and neurodegenerative illnesses. DHA has an important structural role in the eye and brain, and its supply early in life is known to be of vital importance. On the basis of the recognized health improvements brought about by long chain omega-3 fatty acids, recommendations have been made to increase their intake.

10. [Calder PC, Yaqoob P. Omega-3 polyunsaturated fatty acids and human health outcomes. Biofactors. 2009 May-Jun;35(3):266-72.]

11. The International Fish Oil Standards Program. Fact Sheet: Fish Oil Contaminants & Your Health. 2012.

12. Kimberly Warner, Ph.D., et al. Oceana Study Reveals Seafood Fraud Nationwide. Oceana Consumer Advocacy Group. February 2013.

(http://oceana.org/sites/default/files/National_Seafood_Fraud_Testing_Results_FINAL.pdf)

The transient rise in plasma triacylglycerol fatty acids after single-dose ingestion of fish oil as triacylglycerols, free acids, or ethyl esters with linseed oil as an absorption standard was used to determine the relative absorption of fish oil fatty acids in eight men. As free acids, the fish oil fatty acids were well absorbed (greater than or equal to 95%). As triacylglycerols, eicosapentaenoic acid (1.00 g) and docosahexaenoic acid (0.67 g) were absorbed only 68% and 57% as well as the free acids. The ethyl esters were absorbed only 20% and 21% as well as the free acids. The incomplete absorption of eicosapentaenoic and docosahexaenoic acids from fish oil triacylglycerols correlates well with known in vitro pancreatic lipase activity.

13. [Lawson LD, Hughes BG. Human absorption of fish oil fatty acids as triacylglycerols, free acids, or ethyl esters. Biochem Biophys Res Commun. 1988 Apr 15;152(1):328-35.]

Abstract

BACKGROUND:

Dietary fish oil supplements are increasingly used as an alternative to prescription-grade omega-3 fatty acids (P-OM3) for the treatment of hypertriglyceridemia. The content of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in these supplement products varies widely and may result in a suboptimal response. The aim of this study was to review marketed fish oil supplements and to develop a reference for clinicians to compare products.

METHODS:

The National Library of Medicine Herbal Supplement Database was systematically searched using fish oil, EPA, DHA, and omega-3 fatty acid as search terms. Daily doses needed to achieve the Food and Drug Administration (FDA)-approved dose (RxDose) (3,360 mg of combined EPA and DHA) were calculated from the milligrams of EPA and DHA per serving, and suggested retail prices were used to calculate monthly cost of each product. A “usage criteria” was set to highlight products at the RxDose with a monthly cost of <$50, daily servings <8, daily amount of vitamins A and D less than or equal to the U.S. Dietary Reference Intake upper limit defined as 10,000 and 4,000 IU, respectively, and if the product was U.S. Pharmacopeia verified.

RESULTS:

A total of 163 products were identified, and 102 nonliquid and liquid products met our entry criteria. The median amount of EPA and DHA per serving in the nonliquid products was 216 mg and 200 mg, respectively, and the median number of servings at the RxDose was 11.2 at a median monthly cost of $63.49. The median amount of EPA (460 mg) and DHA (400 mg) per serving in the liquid products was higher than the nonliquid products. Thus, the median number of servings at the RxDose was only 3.6 teaspoons and the median monthly cost of $13.60. Only 22% of products met our “usage criteria.”

CONCLUSIONS:

The amount of EPA and DHA per recommended serving in these products was highly variable. Clinicians should heighten their scrutiny in terms of selection of the appropriate product.

14. [Zargar A, Ito MK. Long chain omega-3 dietary supplements: a review of the National Library of Medicine Herbal Supplement Database. Metab Syndr Relat Disord. 2011 Aug;9(4):255-71.]

15. Opperman M, Marais de W, Spinnler Benade AJ. Analysis of omega-3 fatty acid content of South African fish oil supplements. Cardiovasc J Afr. 2011 Nov-Dec;22(6):324-9.

 

Fish Oil /Omega-3 Fatty Acid Supplements

Fish Oil & Antidepressants — (5/10/2016) Several studies suggest that fish oil can help people suffering from major depression. A new study indicates that it can have additive benefit for people already taking a prescription antidepressant. The amount and type of omega-3’s seem to make a difference. Get the details in the “What It Does Section” of the Fish Oil Supplements Review >>

How Fish Oil May Help With Depression — (4/16/2016) Studies have shown that fish oil can help some people suffering from major depression. A recent study suggests how it may work. For details, see the ”What It Does” section of the Fish Oil Supplements Review >>

Fish Oil and Blood Pressure — (2/16/2016) As explained in our Fish Oil Review, fish oil supplements may not provide overall cardiovascular benefits — eating fish is better. However, a recent analysis found that a certain kind of fish oil may help people with high systolic blood pressure. For details, see the Fish Oil and Omega-3 Fatty Acids Supplements Review >>

Sale of GMO Salmon Halted — (2/10/2016) Although genetically engineered salmon has been approved for sale by the FDA, the agency recently announced sale of the salmon will not be permitted just yet. Get the details in the Fish Oil and Omega-3 Fatty Acids Supplements Review >>

Fish Oil Helps in Schizophrenia — (1/26/2016) A study found that concentrated fish oil greatly reduced symptoms in more people who had recently experienced a first episode of schizophrenia than did a placebo. The greatest effect was on depressive symptoms, which is consistent with other studies which have shown fish oil to reduce depression, particularly in people who do not regularly eat fish.

This impact on depression has also been suggested as one reason why fish oil has shown some benefit in people with cognitive decline. Details about the studies and products used, including our tests and reviews of similar fish oil supplements, are found in the Fish Oil and Omega-3 Fatty Acid Supplements Review >>

Omega-3’s and Cognition — (1/17/2016) Studies in older individuals have shown that omega-3 fatty acid intake from fish oil may improve certain areas of mental functioning and reduce age-related cognitive decline. Benefits have also been found in younger individuals.

A study has been underway which evaluates the effects of krill oil in adolescents with lower educational performance. It was recently reported that baseline testing (before starting krill) of the students showed a positive association between levels of EPA + DHA in their blood and performance on some, but not all, measures of cognitive performance. Get the details in the Fish Oil and Omega-3 Fatty Acid Supplements Review (Including Krill, Algae, Calamari, Green-lipped Mussel Oil) >>

Genetically-engineered Salmon: How it Compares — (11/21/2015) This week the FDA approved a genetically-engineered, farmed salmon as safe for consumption — but how do amounts of omega-3s and hormones compare with non-genetically engineered salmon? Get the details in the update to the Fish Oil and Omega-3 Fatty Acid Supplements Review (Including Krill, Algae, Calamari, Green-lipped Mussel Oil) 

Fish Oil Freshness — (11/11/2015) 50% of omega-3 fatty acid supplements recently purchased by researchers in Canada failed tests for freshness, exceeding limits for oxidation. Although the study raises some important issues, it also had significant shortcomings. Get the details in the Fish Oil and Omega-3 Fatty Acid Supplements Review (Including Krill, Algae, Calamari, Green-lipped Mussel Oil) 

Fish Oil for Depression — (10/3/2015) A small study found that taking EPA and DHA daily significantly reduced depression in young men and women. Get the details, including dosage, plus our tests of popular products, in the Fish Oil and Omega-3 Supplements Review 

Does Fish Oil Slow Cognitive Decline? — (8/29/2015) Results of a large U.S. study suggest that taking fish oil does not slow cognitive decline in the elderly. Before you nix fish oil for this purpose, be aware of an important caveat about the people in the study. Get the details about this and other studies of omega-3 fatty acids, as well as our tests of popular products, in the Fish Oil and Omega-3 Fatty Acid Supplements Review 

Fish Oil and Alzheimer’s Disease — (7/4/2015) The evidence is mixed on whether fish oil can help people with Alzheimer’s disease. A benefit was seen in a study reported last year, but a recently reported study found no benefit with fish oil combined with antioxidants. More details are found in the “What It Does” section of the Fish Oil and Omega-3 Fatty Acid Supplements Review 

Problem with Too Much Krill Oil — (6/24/2015) Researchers recently gave overweight men a very large daily amount of krill oil (with a smaller amount of fish oil) with the hope it would improve their insulin sensitivity. Unfortunately, the opposite happened, suggesting that the oil could increase the risk of diabetes and cardiovascular disease. Details about the study, including dosage, are found in the “Concerns and Cautions” section of the Fish Oil and Omega-3 Fatty Acid Supplements Review (Including Krill, Algae, Calamari, Green-lipped Mussel Oil) 

Fish Oil for Dry Eye — (6/24/2015) A large study of computer-using young men and women experiencing dry eye found that fish oil significantly improved symptoms. Benefits have also been reported in postmenopausal women with dry eye. Details, including dosage, are found in the “What It Does” section of the Fish Oil Supplements Review 

Fish Oil Increases Muscle/Strength — (5/24/2015) Last week we reported that vitamin D could help increase strength — this week it’s fish oil. A recent study found that taking a high dose of fish oil led to increases in muscle and strength in older individuals — without additional exercise. As reported earlier, a lower of dose of fish oil may improve results of exercise. For the details, including specifics about the fish oil used, see the Fish Oil Supplements Review 

Treating ADHD with Omega-3s? — (5/13/2015) A new study giving boys omega-3 fatty acids (EPA and DHA) showed modest improvement in an important aspect of Attention Deficit/Hyperactivity Disorder. For details about this and other studies with omega-3 fatty acid supplements, as well as our tests of products, see the Fish Oil and Omega-3 Fatty Acid Supplements Review

Fish Intake and Breast Cancer Risk — (5/13/2015) Women with breast cancer who consumed the most fish had a lower risk of death compared to women who did not eat fish, a new study reports. Get the details, plus evidence for the use of fish oil supplements to reduce the risk of breast and prostate cancer, and our tests of popular products in the Fish Oil and Omega-3 Fatty Acids Supplements Review 

Avoid Fish Oil When Getting Chemotherapy — (4/8/2015) A series of studies in mice and people suggest that fish oil from supplements, and consumed from certain fish, can interfere with chemotherapy. More details are in the Fish Oil Supplements Review 

Green Lipped Mussel Oil Reduces Pain and Inflammation After Exercise — (3/6/2015) Green-lipped mussel oil (a source of omega-3 fatty acids EPA and DHA) significantly reduced pain and inflammation days after exercise in young healthy men, compared to a placebo, according to a new study. For details, and ConsumerLab.com tests of the product used in the study, see the Fish Oil and Omega-3 Fatty Acid Supplements Review 

Lower-dose Fish Oil Helps with Epilepsy — (9/24/2014) A small, but well-controlled study of people with drug-resistant epilepsy found that a modest dose of fish oil significantly reduced the frequency of seizures while a higher dose did not. The researchers note a possible explanation why the lower dose was more effective than the higher dose. Find out the details, including the dose and exact type of fish oil used, in the update to the Fish Oil Supplements Review 

Fish Oil May Prevent Cognitive Decline — (7/16/2014) A study of older individuals found that cognitive function and brain volume (size) were better preserved among those who reported using fish oil supplements than those who did not. The effect, however, was only seen in certain groups of people. For more about the study, and our tests and comparisons of fish oil supplements, see the updated Fish Oil and Omega-3 Fatty Acid Supplements Review (Including Krill, Algae, Calamari, Green-lipped Mussel Oil) 

DHA for Periodontitis (Inflammation Around Teeth) — (7/16/2014) A new study found that giving DHA (from algal oil) along with low-dose aspirin led to greater reductions in local inflammation and pocketing around teeth than aspirin plus placebo. For more about the study, including dosage, and our tests and comparisons of algal oil supplements, see the Fish Oil and Omega-3 Fatty Acid Supplements Review (Including Krill, Algae, Calamari, Green-lipped Mussel Oil) 

Don’t Be Fooled by “Good Source of Omega-3s” Claim — (7/10/2014) Over the years, ConsumerLab.com has pointed out that products sometimes claim to provide a percentage of the Daily Value (DV) of omega-3 or -6 fatty acids, even though no such Daily Value has been established. Now, the FDA has prohibited certain related statements on omega-3 supplement and food labels that could mislead consumers into thinking a product provides some percentage of this imaginary amount. Get the details, including what to watch out for on labels, plus our tests of fish oil and other omega-3 fatty acid supplements, in the updated Fish Oil and Omega-3 Fatty Acid Supplements Review (Including Krill, Algae, Calamari, Green-lipped Mussel Oil) 

Fish Oil May Reduce Risk of Blood Clots — (6/7/2014) A study of more than 20,000 people found that those who ate fish several times per week had a reduced risk of venous blood clots, and that getting additional fish oil from supplements reduced the risk even further. Get the details, including our tests of fish oil and other omega-3 supplements in the Fish Oil and Omega-3 Fatty Acid Supplements Review (Including Krill, Algae, Calamari, Green-lipped Mussel Oil) 

Help for Acne from Omega-3 & -6 Oils — (6/7/2014) A small clinical study found daily supplementation with either omega-3 fatty acids or an omega-6 fatty acid from borage oil significantly reduced the number and severity of acne outbreaks. Get the details, including dosage, and our tests of supplements containing omega-3 and omega-6 fatty acids, in the Fish Oil and Omega-3 Fatty Acid Supplements Review  and the Flaxseed Oil, Evening Primrose, Borage and Seed Oil Supplements Review 

Does Fish Oil Help During Pregnancy? — (5/3/2014) A recent study shows that, at age 4, children born to women given DHA-rich fish oil during pregnancy do not fare better cognitively than other children. Other positive effects around the time of birth, however, suggest that supplementation may be worthwhile. For details, as well as our tests of fish oil supplements, see the Fish Oil and Omega-3 Fatty Acid Supplements Review (Including Krill, Algae, Calamari, Green-lipped Mussel Oil) 

Fish Oil Lowers Blood Pressure — (3/28/2014) Fatty acids from fish and fish oil may reduce blood pressure, particularly in those with high blood pressure, according to a recently published review. For details, information about other uses of fish oil, and our tests of fish oil supplements, see the updated Fish Oil and Omega-3 Fatty Acid Supplements Review  

Fish Oil Study Finds No Heart Benefit — (3/23/2014) Findings of a large study reported this week showed that a daily fish oil supplement did not reduce the risk of cardiovascular disease in elderly people. So what’s the bottom line for fish oil and heart disease? See the update to the Fish Oil Supplements Review, which includes the latest information about potential uses of fish oil and our tests of popular fish oil supplements.

Fish Oil / Alpha-Lipoic Acid for Alzheimer’s — (1/31/2014) A new study found that fish oil and alpha-lipoic acid can slow cognitive and functional decline in people with Alzheimer’s disease. Get the details in the Fish/Marine Oil Supplements Review  and the Alpha-Lipoic Acid Supplements Review 

Too Much Fish Oil May Cause Adverse Effects — (11/3/2013) Recent animal studies using EPA and DHA from fish oil suggest that very high intakes may dampen immunity. Might you be getting too much? Find out in the update to the Fish Oil and Omega-3 Fatty Acid Supplements Review

Fish Oil and Arthritis — (9/21/2013) A study of several thousand women found those who consumed at least a moderate of amount omega-3 fatty acids (EPA and DHA) from fish in their diets had just half the risk of developing rheumatoid arthritis over the course of the study than did women with lower intakes.  For details about the amount of omega-3’s and fish consumption associated with preventing arthritis, other uses of omega-3’s, and tests of fish/marine oil supplements, see the Fish/Marine Oil Supplements Review

Fish Oil Linked to Prostate Cancer? — (7/14/2013) Headlines this week about a study showing an association between the fatty acids in fish oil and the development of prostate cancer have stirred concerns about consuming fish and fish oil supplements. For details about this study and studies of other effects of fish oil and omega-3 fatty acids, as well as test results and comparisons for 74 fish and other marine oil supplements, see the updated Fish/Marine Oil (Omega-3) Supplements Review 

Fish Oil for Brain Function — (7/7/2013) Healthy people, ages 50 to 75, given a specific fish oil supplement for 6 months experienced significant gains in their performance on visual tasks, reading, and verbal fluency in a recent placebo-controlled study. Brain scans also showed significant gains in the structure and volume of tissue in several areas of the brain. For details about the type and dose of fish oil taken, as well as test results and comparisons for 74 fish and other marine oil supplements, see the updated Fish/Marine Oil (Omega-3) Supplements Review 

Fish Oil and Stress — (6/16/2013) A new study shows that fish oil may slightly blunt some of the effects of mental stress. Get the details, plus our quality ratings of 74 supplements, in the updated Fish Oil and Omega-3 Fatty Acid Supplements Review 

Fish Oil No Help for Heart Disease? — (5/19/2013) A new study found that taking a fish oil supplement did not reduce the risk of heart attack or stroke in people with multiple risk factors for heart disease. But this doesn’t tell the whole story. Get the bottom line on fish oil for heart disease and test results for over 70 fish oil supplements, in the updated Fish Oil and Omega-3 Fatty Acid Supplements Review 

Omega-3s Linked to Less Heart Disease and Longer Life — (4/7/2013) A study among older individuals who did not use fish oil supplements showed that those with higher levels of omega-3 fatty acids in their blood were far less likely to have a heart attack or arrhythmia and were 27% less likely to die during the 14-year study. The researchers calculated how much EPA and DHA a person should consume to reach this higher blood level and noted that further increases yield little additional benefit. Get the details, as well as how to get omega-3s from foods, in the updated Fish Oil Supplements Review

What You Need to Know About Fish Oil — (3/10/2013) Most fish oil in supplements is not natural, but is a semi-synthetic form. This affects how much you absorb and new research is revealing other differences. Time to throw out what you take, or switch brands? Probably not, but if you use fish oil, it’s worth knowing about these differences. Get the details in the update to the Fish Oil and Omega-3 Fatty Acid Supplements Review (Including Krill, Algae, and Calamari Oil) 

Stroke and Fish Oil — (11/18/2012) An analysis of 38 studies concluded that eating fish regularly is associated with fewer strokes, but fish oil supplements do not seem to help. Interestingly, the type of fish and how it is prepared seem to make all the difference. For details, including what fish oil supplements can or cannot do, see the updated Fish Oil & Marine Oil (Omega-3) Supplements Review. More 

Fish Oil Helps Memory — (10/28/2012) A small study of healthy young women and men found that those with the highest levels of the omega-3 fatty acid DHA in their red blood cells scored better on a memory test than those with lower levels. After six months of supplementation with a certain fish oil supplement, scores improved — particularly among those whose DHA levels had been lowest. See the Fish Oil (Omega-3) Supplements Review for details about this study, the particular supplement used, what fish oil can and cannot do, and our quality ratings of products. More 

What’s the Best Omega-3 for Depression? — (10/14/2012) Recent studies suggest the relative amounts of EPA and DHA in a supplement help determine whether or not it will improve symptoms of depression. Get the details, as well as our tests of 63 omega-3 supplements, in the updated Fish Oil and Omega-3 Fatty Acid Supplements Review (Including Krill, Algae, and Calamari Oil). More 

Fish Oil Benefit Questioned — (9/16/2012) There are many potential benefits from supplementing with the omega-3 fatty acids found in fish oil, but the most widely-touted benefits — reducing the risks of heart disease and stroke — are now in doubt. Read about the latest studies in the update to the Fish Oil (EPA & DHA) Supplements Review, which includes our product tests and quality ratings. More 

Fish Oil for Strokes and Heart Attacks? — (6/24/2012) A recent study with fish oil supplements found no reduction in strokes and heart attacks among people with diabetes and poor glucose control. Does this mean fish oil doesn’t help with cardiovascular disease? Not necessarily. See the updated Fish Oil (Omega-3) Supplements Review. More 

Heart Benefits of Fish Oil Supplements in Doubt — (4/22/2012) A review of the latest studies finds no conclusive evidence that fish oil supplements help people hoping to prevent another heart attack or stroke. It also remains unclear if fish oil provides cardiovascular benefits for healthy individuals. Find out what people concerned about heart disease should do, the other potential benefits of fish oil supplements, and our tests of supplements on the market in the updated Fish Oil Supplements Review. More 

Fish Oil Tested for Multiple Sclerosis — (4/22/2012) Fish oil supplements are often taken by multiple sclerosis patients with the hope that omega-3 fatty acids can improve their condition, but a new study suggests fish oil supplements may not provide benefit. For details, including the dose used, see the updated information in the Fish Oil Supplements Review. More 

Fish Oil During Pregnancy Reduces Allergy in Infants — (2/5/2012) Last year we reported important findings from a study of fish oil given to pregnant women. A further analysis of that study shows another benefit of daily fish oil for pregnant women — their babies have nearly a 40% lower risk of egg allergies. A lower risk of eczema was also found, although this association did not hold after adjusting the data for certain factors. See the update to the Fish Oil Supplements Review, which includes details on this study, the type and amount of fish oil taken, and our latest product tests.

Fish Oil for Strength — (1/15/2012) A recent study of women in their 60’s suggests that taking fish oil when strength-training leads to greater improvements in strength than training alone. Women who took fish oil were not only stronger but had a greater functional capacity, such as being able to rise faster from a chair. For the type and dose of fish oil taken, and more details, see the update to the Fish Oil Supplements Review, which includes the latest product tests.

Algal Oil vs. Fish Oil — (12/20/2011) Fish get their omega-3’s from algae and many people are now doing the same by taking algal oil, but how does it compare to fish oil? Experts recently reviewed studies of algal oil and concluded that it boosts (“good”) cholesterol but it also increases LDL cholesterol — which is often thought of as “bad” cholesterol. But there’s more to the story. Get the details in the recently updated Fish/Marine Oil Supplements Review, which includes our test results for algal, krill, and fish oil supplements.

Concern with Rancid Fish Oil — (12/13/2011) As our tests have shown, some fish oils are spoiled by the time you buy them. Spoilage produces a variety of compounds. You can smell and taste some of these (if you take the oil directly by spoon, for example) but others you cannot. An expert panel recently reported on the safety of consuming rancid fish oil. See their conclusions in the Fish/Marine Oil Supplements Review, which includes our test results.

Fish Oil’s Impact on Cognitive Decline — (10/4/2011) Cognitive decline may be a normal part of aging, but a new study suggests that high-dose fish oil particularly rich in DHA may provide some benefit. In people over age 65 with mild cognitive impairment, fish oil was associated with improved verbal skill. Perhaps as important, fish oil also reduced depressive symptoms, which can be a risk factor in the progression to dementia. Get the details, including how much DHA and EPA was used in the study, in the Fish Oil and Omega-3 Fatty Acid Supplement Review. More 

Suicide and Omega-3 — (8/31/2011) A new study found the risk of suicide was 62% higher among people with low levels of the omega-3 fatty acid DHA in their blood as compared to those with higher levels. An update to the Fish Oil Supplements Review includes the details. More 

Fish Oil and Anxiety — (8/7/2011) A study using a specially concentrated fish oil supplement showed a 20% reduction in anxiety symptoms compared to placebo. An update to the Fish Oil Supplements Review includes the dose and type of fish oil used. More 

DHA in Pregnancy — (8/7/2011) The omega-3 fatty acid, DHA, is known to be important to fetal development and is recommended for pregnant woman. A new study suggests that DHA during pregnancy may reduce early colds in some infants. An update to the Fish Oil Supplements Review includes the dose and type of DHA used. More 

Fish Oil Helps Treat Depression — (5/22/2011) A recent study showed that fish oil taken daily was associated with a remission of depression in 41% of people taking the supplement. The patients were women in a nursing home setting. The dose given was fairly high but treatment was well tolerated. The amounts of EPA and DHA taken daily and more information are found in our Product Review of Fish Oil Supplements. More 

Did you hear that DHA (an omega-3 fatty acid in fish oil) might raise the risk of prostate cancer? — (5/9/2011) This was recently in the news. Higher levels of DHA in the blood were associated with increased risk of high-grade prostate cancer. However, the findings do not mean that you should stop taking fish oil or eating fish. We talked with the researcher of this study and learned more. Get the facts in our Fish Oil Supplements Review. More 

Fish Oil and the Eye — (4/10/2011) A study of over 30,000 women showed that the risk of developing age-related macular degeneration (AMD) was reduced by up to 42% among those consuming the most fish and highest amounts of omega-3 fatty acids DHA and EPA. Find out the specific types and amounts of fish and the amounts of DHA and EPA associated with the greatest reductions in the risk of AMD. See the Fish Oil Supplements Review for more 

Fish Oil Helps in Chemotherapy — (3/9/2011) A recent study in lung cancer patients showed that those using fish oil supplementation during initial chemotherapy tended to maintain their muscle and total weight while those who did not lost 5 lbs of weight on average (2.2 lbs of which was muscle). See the Fish Oil (Omega-3) Product Review for more details, including the dosage used. More 

16. [ConsumerLab Independent Testing Group. Contamination and Other Problems Found in Fish Oil Supplements. Auguts 22, 2012. (http://www.consumerlab.com/news/Review%20of%20Fish%20Oil%20and%20Omega-3%20Supplments%20by%20ConsumerLab.com/8_22_2012/)]

Abstract

AIMS/HYPOTHESIS:

Intake of n-3 polyunsaturated fatty acids reduces adipose tissue mass, preferentially in the abdomen. The more pronounced effect of marine-derived eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids on adiposity, compared with their precursor alpha-linolenic acid, may be mediated by changes in gene expression and metabolism in white fat.

METHODS:

The effects of EPA/DHA concentrate (6% EPA, 51% DHA) admixed to form two types of high-fat diet were studied in C57BL/6J mice. Oligonucleotide microarrays, cDNA PCR subtraction and quantitative real-time RT-PCR were used to characterise gene expression. Mitochondrial proteins were quantified using immunoblots. Fatty acid oxidation and synthesis were measured in adipose tissue fragments.

RESULTS:

Expression screens revealed upregulation of genes for mitochondrial proteins, predominantly in epididymal fat when EPA/DHA concentrate was admixed to a semisynthetic high-fat diet rich in alpha-linolenic acid. This was associated with a three-fold stimulation of the expression of genes encoding regulatory factors for mitochondrial biogenesis and oxidative metabolism (peroxisome proliferator-activated receptor gamma coactivator 1 alpha [Ppargc1a, also known as Pgc1alpha] and nuclear respiratory factor-1 [Nrf1] respectively). Expression of genes for carnitine palmitoyltransferase 1A and fatty acid oxidation was increased in epididymal but not subcutaneous fat. In the former depot, lipogenesis was depressed. Similar changes in adipose gene expression were detected after replacement of as little as 15% of lipids in the composite high-fat diet with EPA/DHA concentrate, while the development of obesity was reduced. The expression of Ppargc1a and Nrf1 was also stimulated by n-3 polyunsaturated fatty acids in 3T3-L1 cells.

CONCLUSIONS/INTERPRETATION:

The anti-adipogenic effect of EPA/DHA may involve a metabolic switch in adipocytes that includes enhancement of beta-oxidation and upregulation of mitochondrial biogenesis.

17. [Flachs P, et al. Polyunsaturated fatty acids of marine origin upregulate mitochondrial biogenesis and induce beta-oxidation in white fat. Diabetologia. 2005 Nov;48(11):2365-75.]

Abstract

BACKGROUND:

Docosahexaenoic acid (DHA) is important for brain function, and its status is dependent on dietary intakes. Therefore, individuals who consume diets low in omega-3 (n-3) polyunsaturated fatty acids may cognitively benefit from DHA supplementation. Sex and apolipoprotein E genotype (APOE) affect cognition and may modulate the response to DHA supplementation.

OBJECTIVES:

We investigated whether a DHA supplement improves cognitive performance in healthy young adults and whether sex and APOE modulate the response.

DESIGN:

Healthy adults (n = 176; age range: 18-45 y; nonsmoking and with a low intake of DHA) completed a 6-mo randomized, placebo-controlled, double-blind intervention in which they consumed 1.16 g DHA/d or a placebo. Cognitive performance was assessed by using a computerized cognitive test battery. For all tests, z scores were calculated and clustered into cognitive domains as follows: episodic and working memory, attention, reaction time (RT) of episodic and working memory, and attention and processing speed. ANCOVA was conducted with sex and APOE as independent variables.

RESULTS:

RTs of episodic and working memory improved with DHA compared with placebo [mean difference (95% CI): -0.18 SD (-0.33, -0.03 SD) (P = 0.02) and -0.36 SD (-0.58, -0.14 SD) (P = 0.002), respectively]. Sex × treatment interactions occurred for episodic memory (P = 0.006) and the RT of working memory (P = 0.03). Compared with the placebo, DHA improved episodic memory in women [0.28 SD (0.08, 0.48 SD); P = 0.006] and RTs of working memory in men [-0.60 SD (-0.95, -0.25 SD); P = 0.001]. APOE did not affect cognitive function, but there were some indications of APOE × sex × treatment interactions.

CONCLUSIONS:

DHA supplementation improved memory and the RT of memory in healthy, young adults whose habitual diets were low in DHA. The response was modulated by sex. This trial was registered at the New Zealand Clinical Trials Registry (http://www.anzctr.org.au/default.aspx) as ACTRN12610000212055.

18. [Stonehouse W, et al. DHA supplementation improved both memory and reaction time in healthy young adults: a randomized controlled trial. Am J Clin Nutr. 2013 May;97(5):1134-43.]

Abstract

AIMS/HYPOTHESIS:

Diets rich in n-3 polyunsaturated fatty acids, namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), protect against insulin resistance and obesity in rodents and increase insulin sensitivity in healthy humans. We tested whether the anti-diabetic effects of EPA and DHA involve enhanced production of the endogenous insulin sensitiser, adiponectin.

METHODS:

We studied the effects, in an obesity-promoting high-fat diet, of partial replacement of vegetable oils by EPA/DHA concentrate (6% EPA, 51% DHA) over a 5-week period in adult male C57BL/6J mice that either had free access to food or had their food intake restricted by 30%. At the end of the treatment, systemic markers of lipid and glucose metabolism and full-length adiponectin and leptin were measured. Adiponectin (Adipoq) and leptin (Lep) gene expression in dorsolumbar and epididymal white adipose tissue (WAT) and isolated adipocytes was quantified and adipokine production from WAT explants evaluated.

RESULTS:

In mice with free access to food, plasma triacylglycerols, NEFA, and insulin levels were lower in the presence of EPA/DHA, while glucose and leptin levels were not significantly altered. Food restriction decreased plasma triacylglycerols, glucose, insulin and leptin, but not adiponectin. EPA/DHA increased plasma adiponectin levels, independent of food intake, reflecting the stimulation of Adipoq expression in adipocytes and the release of adiponectin from WAT, particularly from epididymal fat. Expression of Lep and the release of leptin from WAT, while being extremely sensitive to caloric restriction, was unaltered by EPA/DHA.

CONCLUSIONS/INTERPRETATION:

Intake of diets rich in EPA and DHA leads to elevated systemic concentrations of adiponectin, largely independent of food intake or adiposity and explain, to some extent, their anti-diabetic effects.

19. [Flachs P, et al. Polyunsaturated fatty acids of marine origin induce adiponectin in mice fed a high-fat diet. Diabetologia. 2006 Feb;49(2):394-7.]

A number of studies have investigated the effects of fish oil on the production of pro-inflammatory cytokines using peripheral blood mononuclear cell models. The majority of these studies have employed heterogeneous blends of long-chain n-3 polyunsaturated fatty acids (PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which preclude examination of the individual effects of LC n-3 PUFA. This study investigated the differential effects of pure EPA and DHA on cytokine expression and nuclear factor kappaB (NF-kappaB) activation in human THP-1 monocyte-derived macrophages. Pretreatment with 100 microM EPA and DHA significantly decreased lipopolysaccharide (LPS)-stimulated THP-1 macrophage tumor necrosis factor (TNF) alpha, interleukin (IL) 1beta and IL-6 production (P<.02), compared to control cells. Both EPA and DHA reduced TNF-alpha, IL-1beta and IL-6 mRNA expression. In all cases, the effect of DHA was significantly more potent than that of EPA (P<.01). Furthermore, a low dose (25 microM) of DHA had a greater inhibitory effect than that of EPA on macrophage IL-1beta (P<.01 and P<.04, respectively) and IL-6 (P<.003 and P<.003, respectively) production following 0.01 and 0.1 microg/ml LPS stimulation. Both EPA and DHA down-regulated LPS-induced NF-kappaB/DNA binding in THP-1 macrophages by approximately 13% (P< or =.03). DHA significantly decreased macrophage nuclear p65 expression (P< or =.05) and increased cytoplasmic IkappaBalpha expression (P< or =.05). Although similar trends were observed with EPA, they were not significant. Our findings suggest that DHA may be more effective than EPA in alleviating LPS-induced pro-inflammatory cytokine production in macrophages – an effect that may be partly mediated by NF-kappaB. Further work is required to elucidate additional divergent mechanisms to account for apparent differences between EPA and DHA.

23. [Weldon SM, et al. Docosahexaenoic acid induces an anti-inflammatory profile in lipopolysaccharide-stimulated human THP-1 macrophages more effectively than eicosapentaenoic acid. J Nutr Biochem. 2007 Apr;18(4):250-8.]

Abstract

BACKGROUND:

Hypertriglyceridemia is a risk factor for coronary artery disease (CAD). The American Heart Association recommends 1000 mg of omega-3 fatty acids, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), daily for cardioprotection and higher doses for triglyceride-lowering in patients with CAD.

METHODS:

This was a prospective, randomized, double-blind study comparing DHA to DHA + EPA in patients with CAD and triglycerides greater than 200 mg/dL. Subjects were randomized to either 1000 mg of DHA or 1252 mg of DHA + EPA for eight weeks. Baseline and eight-week laboratories were drawn to assess changes in the fasting lipid profile. The primary objective was to evaluate the change in triglycerides between the two groups at eight weeks.

RESULTS:

A total of 116 subjects were enrolled; 57 in the DHA group and 59 in the DHA + EPA group. Baseline characteristics were similar between groups. The mean age was 69.4 +/- 9.1 years and 70.7% were male. Triglycerides decreased by an average of 21.8% in the DHA group (p < 0.001) and 18.3% in the DHA + EPA group (p < 0.001). The difference between groups was not significant. A greater proportion of subjects in the DHA group achieved triglyceride goal (less than 150 mg/dL) compared to the DHA + EPA group (24.6% versus 10.2%, p < 0.05).

CONCLUSIONS:

Our results indicate that the American Heart Association recommended cardioprotective dose of omega-3 fatty acids can also significantly lower triglycerides in patients with CAD. There do not appear to be significant differences in triglyceride-lowering between DHA only and DHA + EPA combination products when dosing is based on DHA.

24. [Schwellenbach LJ, et al. The triglyceride-lowering effects of a modest dose of docosahexaenoic acid alone versus in combination with low dose eicosapentaenoic acid in patients with coronary artery disease and elevated triglycerides. J Am Coll Nutr. 2006 Dec;25(6):480-5.]

Our present results indicate that DHA may be more efficacious than EPA in improving the plasma lipid profile.

25. Buckley R, et al. Circulating triacylglycerol and apoE levels in response to EPA and docosahexaenoic acid supplementation in adult human subjects. Br J Nutr. 2004 Sep;92(3):477-83.

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† These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure or prevent any disease.