Side Effects of Taking Fish Oil Supplements Every Day — Eat This Not That
What happens when you're told to go fish, but you don't have access to a fresh piece of salmon? Or if you simply don't like fish? Or if you don't have it in your budget to dine on halibut a few times a week?
You're not alone. Despite Dietary Guidelines recommending seafood as part of a healthy diet, "[seafood is] under-consumed in a typical American diet or eliminated from certain diets such as vegetarian or vegan diets," says Mastaneh Sharafi, PhD, RD, Vice President of Scientific and Clinical Affairs at Ritual.
"Most people do not consume enough fish on a daily basis to meet their requirements for essential omega 3 fatty acids, and many would prefer to take a supplement than eat fish daily or 3-4 times a week," says Alicia Galvin, RD, a registered dietitian for Sovereign Laboratories.
So when you can't go fish, supplements are your next best option—and a popular one, at that.
Fish oil supplements are the most commonly taken nonvitamin/nonmineral supplement in America, according to a National Health Interview Survey.
"Fish oil is known for its high content of omega-3 fatty acids. The body can't make omega-3s, so we must get them through the food we eat. For those who do not get optimal amounts of omega-3s from their diet, supplements can be useful and effective," says Danielle Gaffen, MS, RDN, a registered dietitian who specializes in autoimmune diseases.
Gaffen tells us that fish oil supplements contain two types of omega-3 fatty acids that occur naturally in fish and seafood: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). "Both are types of essential omega-3s that make unique and irreplaceable contributions to our body's function, like overall brain and nervous system functioning as well as lower inflammation," explains Gaffen.
There are many benefits of taking a fish oil supplement every day, but there are also some lesser-known negative side effects you should be aware of. So we asked experts about the side effects you can expect to experience when taking a fish oil supplement. Read on, and for more on healthy eating, don't miss 7 Healthiest Foods to Eat Right Now.
1 You may protect your brain
"When it comes to making a list of foods that boost brain power, omega-3 containing foods [like fish oil] are generally at the top. This is because roughly 60% of the brain is made of fat, and half that amount is omega-3 type fats," says Trista Best, MPH, RD, LD, a Registered Dietitian at Balance One Supplements. "It has been found that omega-3 rich foods can help prevent cognitive diseases like Alzheimer's and slow mental decline. The brain requires omega-3 fat to make nerve cells, which are vital to memory and one's ability to learn."
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2 You may notice lower levels of inflammation
"Fish oil also may help decrease inflammation. This is due to fish oils' anti-inflammatory properties. This results in reduced joint pain and stiffness," says Allison Gregg, RDN, LD/N, a registered dietitian and Nutritional Consultant at Mom Loves Best. The National Institutes of Health (NIH) notes that omega-3 fatty acids may help relieve symptoms of rheumatoid arthritis—an autoimmune disease characterized by chronic inflammation of the joints—but more research is still needed to confirm this.6254a4d1642c605c54bf1cab17d50f1e
Related: 14 Tips to Reduce Inflammation to Lose Weight Faster, According to RDs
3 You may start to see healthier hair and skin
"Having enough omega 3s is also important for skin and hair health, which can suffer if one is deficient in omega 3s," says Galvin.
4 You may experience some bad breath
"When you take fish oil every day, you may experience some fishy breath for a couple of hours after taking it. This is unpleasant for many people, but can be avoided if you switch to a flaxseed oil supplement," says Megan Byrd, RD, a registered dietitian with a food blog called The Oregon Dietitian.
Galvin explains that this aftertaste may be more prevalent if you have a poorly functioning gallbladder, as "having a 'fishy aftertaste can be a side effect due to a reduced ability to properly digest fats."
5 Men may experience improved fertility
"Men who take fish oil supplements every day may experience improved fertility. In a recent study published in JAMA Network Open, researchers found that fish oil supplements resulted in improved sperm count and fertility hormone levels," says Lauren Manaker MS, RDN, LD, registered dietitian and author of Fueling Male Fertility.
6 Pregnant women may support their developing child's brain development
"Omega-3s are essential for pregnant women because they're so important for a growing fetus' cognitive development," says Byrd.
7 Overdoing it may have a negative effect on your blood health
As is the case with any supplement you're taking every day, it is possible that you could be consuming too much fish oil. Experts say you should be wary of fish oil's blood-thinning effects:
"More than 3,000 milligrams per day of EPA/DHA may increase the risk for bleeding, bruising, and elevation in blood sugar. Also, much caution needs to be given to people on blood-thinning medications and those with diabetes," explains Gaffen.
If you are experiencing any similar side effects, consult with your physician or dietitian.
8 You may lower levels of triglycerides
Triglycerides are a type of fat found in the blood. Excessive levels of triglycerides may raise the risk of heart disease, but fish oil omega-3 supplements may help.
"Fish oil may help reduce elevated blood pressure, reduce high blood triglyceride levels, and improve HDL, 'good' cholesterol," says Gregg.
The NIH reports that high doses of omega-3s have been shown to reduce levels of triglycerides. To manage high triglyceride levels, the American Heart Association (AHA) suggests that 4,000 milligrams of prescription omega-3s (containing EPA plus DHA or EPA only) per day can help lower triglyceride levels when used alone or as adjuncts to other lipid-lowering medications.
9 You may consume more vitamin A than you need
Omega-3s aren't the only thing you'll find in some fish oil pills. "Many omega-3 supplements contain vitamin A, which, if taken in high doses, can lead to vitamin A overdose and toxicity. Some symptoms include joint pain, nausea, and rash or skin irritation. It could even lead to liver damage over time. It's important to pay attention to how much vitamin A is in your omega-3 supplement, as well as any other supplements you're taking to make sure you're not overdoing it," says Byrd. For example, some cod liver oil supplements may contain as much as 90% DV vitamin A.
Speaking of overdoing it, why don't you take a look at these Ugly Side Effects of Drinking Too Much Coffee, According to Science.
[Top 5] Benefits Of Fish Oil For Hair According To Science
Benefits of Taking Fish Oil for Hair + Side Effects & Precautions
Fish oil is one of the most easily available natural things that can make your hair lustrous again!
Have you also felt envious of luscious bell-like curls of Harry Styles or that butt length braid of Beyonce?
Well, there’s a guaranteed way to get such rich-looking hair.
Trust me when I say this, for me, one of the most striking facts of consuming fish oil is the benefits of omega 3 fatty acids for hair.
Most people, even though people don’t like the smell of fish oil, frequently add it in their diet because of its overall health benefits.
Apart from being great for heart and mental health, benefits of fish oil for hair are unmissable.
If you are still confused, let me make it clear for you.
Fish oil contains omega-3 fatty acid which is not naturally produced by the human body. Hence, people take supplements for it.
Not only fish oil is good for hair loss, the presence of omega-3 fatty acids makes it beneficial in improving the symptoms of depression as well.
And when it comes to fish oil benefits for men, fish oil supplements even boost sexual health and fertility.
Well, these are just some of the generalized overall fish oil benefits.
And if you want to use this amazing oil for hair, wait till you get to know some scientifically-backed omega 3 effect on hair.
Jaw-Dropping Benefits Of Taking Fish Oil For Hair
Enriched with protein, fish oil is a 100% hair-friendly nutrient. Because of its specific ability to fight inflammation symptoms, it aids in hair growth.
Moreover, fish oil provides a stronger omega 3 effect on hair, which acts as a catalyst and provides a safe environment for active nourishment of the hair.
In summary, the following are some of the unbelievable benefits of fish oil for hair.
#1. Stimulates Hair Growth
Using fish oil for hair growth is one of its true benefits.
As per scientific evidence, Omega-3s found in fish oil provides a suitable environment for the growth of hair fibers by hydrating the dry scalp.
Not only this, but it also minimizes other scalp-related issues like itchiness, dandruff, scaling, and flakiness.
By controlling these issues, it precludes hair thinning and boosts hair growth.
Moreover, the presence of essential proteins, fatty acids, and other vitamins strengthens the hair roots and fibers leading to the prevention of hair loss.
Henceforth, if you’re dealing with excessive hair fall, you can definitely use fish oil for hair thickness.
#2. Minimizes Inflammation
If you are dealing with patchy hair loss on your scalp, beard areas, eyebrows, eyelashes, and armpits, consuming fish oil might be of some good.
It is to be noted that inflammation is the major reason behind hair loss and serious hair problems like alopecia.
And, because of the presence of fatty acids, fish oil benefits include anti-inflammation properties.
Moreover, it enhances hair health by feeding the hair follicles and nourishing the hair strands.
As a result, using fish oil for hair loss can help you treat alopecia as it lowers the breakage and promotes hair growth.
#3. Improves Scalp Health
It’s more common sense that a healthy scalp is much needed for healthy hair. This is the reason why it’s often recommended to oil hair with a gentle massage.
Moreover, fish oil is not only beneficial for healthy skin but also for your scalp.
The benefits of fish oil for hair include improved blood circulation in the scalp.
To elaborate, omega-3 fats in fish oil provide essential nutrients to the scalp cells by leveling up the blood circulation.
This act of good circulation leads to extended hair follicles and better production of hair cells.
#4. Moisturizing And Conditioning
Consuming fish oil/cod liver oil for hair growth has numerous accumulated benefits.
Adding fish oil supplements every day into your diet nourishes your scalp cells, keeps them hydrated, and minimizes conditions like flaky skin, dandruff, and dry scalp.
The use of essential nutrients conditions the scalp and hair strands by providing enough moisture and balancing the content of oil on your scalp.
Adding to this, because of the anti-bacterial properties of fish oil, it promotes wound healing and protects scalp skin from aging and dermatitis as well.
#5. Hair Thickness
Be it a man or a woman, one cannot deny their desire for thick and luscious hair. It makes you attractive, beautiful, and confident.
Undoubtedly, you can expect these same effective results by using fish oil for hair thickness.
Loaded with omega-3s and other vital nutrients, fish oil improves the density and volume of hair and, thus, promotes hair thickness.
Hence, the ultimate result of using fish oil for hair is voluminous, long, strong, and shiny hair.
These very many benefits of fish oil on hair are scientifically proven.
Furthermore, while not all of the research and findings have been promising, there are certain studies that show the benefits of omega 3 fatty acids for hair from fish oil and other foods. Let’s have a look at some.
Fish Oil And Hair Growth – What Does Study On Fish Oil Benefits Show?
Below we have discussed some of the scientific studies showing the link between fish oil and hair-related benefits. Let’s check out the benefits of fish oil for hair according to science!
#1. Study 1
Double-blind, placebo-controlled study evaluating the ability of extra-strength marine protein supplements to promote hair growth and decrease shedding.
Timing: 3 months of a randomized study.
Method: Adult women with thinning hair because of poor diet, stress, hormonal influences, or abnormal menstrual cycles were randomized to take MPS (Marine Protein Supplement) twice daily for 90 days to assess its ability to promote hair growth.
Result: Women suffering from self-perceived temporary hair thinning experienced hair growth and decreased hair loss without any reported adverse events.
#2. Study 2
Mackerel-Derived Fermented Fish Oil Promotes Hair Growth by Anagen-Stimulating Pathways.
#2.1: Fermented Fish Oil (FFO) elongated the hair-fiber length of cultured rat vibrissae follicles.
Timing: 14 days
Method: Rat Vibrissae Follicles were cultured and maintained for 14 days in medium supplemented with FFO or minoxidil extract.
Result: FFO extract offered a 175.1% increase in the length of hair fiber as compared to 153.1% from minoxidil.
#2.2: Stimulation of Telogen-to-Anagen transition of the hair cycle in mice.
Timing: 35 days treatment with FFO extract on a mouse model.
Method: Topical application of FFO extract daily for 35 days on mice after depilation.
Result: FFO extract stimulated the transition to anagen and hair growth was observed in all mice.
#2.3: FFO extract increased the proliferation of Dermal Papilla Cells.
Timing: 72 h.
Method: Proliferation of cultured DPC investigated for 72 h in media containing FFO extract.
Result: Hair –growth was witnessed by increasing the proliferation of DPCs through the cell cycle progression.
#3. Study 3
Effects on hair loss of a nutritional supplement (specifically with omega 3 & 6) on women.
Timing: 6 months
Method: 120 healthy women subjects were supplemented for 6-months for randomized and comparative study.
Result: Reduction in telogen percentage and improvement in hair density after a 6-month supplementation with omega 3&6 and antioxidants.
These scientific studies are worth noting for the potential benefits of adding a fish oil supplement in your diet for hair growth.
In fact, according to science, Omega 3 fatty acid benefits for hair are so effective that fish oil supplement has become a part of many Americans’ diet plans.
However, it’s a fact that omega-3 fats are not naturally produced by the human body. Hence, people have to depend on external sources because of their benefits.
And even though they bring a whole wide range of health benefits, certain precautions are to be taken while consuming fish oil.
Possible Side Effects Of Taking Fish Oil | Precautions You Need To Take
There are numerous fish oil benefits for skin, hair, and overall health in general.
However, certain side effects might be witnessed after consuming fish oil.
Hence, one needs to be cautious of these factors when adding fish oil pills to their diet.
#1. Possibility of upset stomach and loose stool.
#2. Feeling of nausea and acid reflux.
#3. Insomnia.
#4. Offensive fishy breath when taken by mouth.
#5. Increased levels of blood sugar in diabetic people.
#6. Low blood pressure.
#7. Bleeding gums and nose bleeds.
#8. Impact on the clotting mechanism and possibility of a stroke.
#9. Skin irritation and rashes.
#10. Reduced immunity function.
Plus, there are some people who should definitely stay away from fish oil.
Who Should Not Take Fish Oil?
Considering its side effects, it becomes vital to know who should not consume fish oil or need to take special precautions while consuming it.
#1. Children
Young children must not consume more than 2 ounces of fish oil per week.
Adding to this, consuming fish oil from dietary sources could possibly be unsafe because it contains toxins like mercury.
Frequent eating of contaminated fish can cause seizures, mental retardation, brain damage, and even blindness in children.
#2. Pregnant Women
Pregnant women and nursing mothers must avoid eating fish with high mercury content, such as shark, king mackerel, tilefish, and swordfish.
Also, limit the consumption of other fish to 12 ounces per week.
#3. People Dealing with Certain Health Issues
An increase in the symptoms of certain health conditions, such as bipolar disorder, depression, high blood pressure, diabetes, HIV AIDS, and other conditions of the immune system can be seen.
Therefore, people with such health issues must consult their doctor before taking fish oil.
Additionally, fish oil supplements are available in both non-prescription and prescription varieties.
While the former variety of fish oil pills are a part of a multivitamin regime for many people, the latter, as the name suggests, needs to be medically prescribed because of its ability to interact with other medications.
Warning: Fish Oil Supplements May Interact With Medications. The degrading environment and increasing health issues have led to an upsurge in the consumption of prescribed medication and supplements. In order to stay healthier, people are indulging themselves in bigger risks by mixing supplements with drugs without any medical consultation. It is to be noted that these risks could cause permanent damage and can be life-threatening as well.
Mentioned below are some of the fish oil drug interactions you should take care of before you think about taking a fish oil supplement.
Drugs Category Possible Interaction 1. Blood Pressure Decreases blood pressure (problematic for people suffering from low BP) 2. Vitamin E Decreases vitamin E levels 3. Contraceptive Pills May interfere in lowering the effectiveness of triglyceride levels 4. Anticoagulants and Antiplatelet Increased Bleeding risk
Now that we are through all that, it’s time we go over how you can actually take a fish oil supplement if you do choose to do so.
What Is The Best Form Of Fish Oil And How To Take It?
When it comes to fish oil and omega -3 fatty acids, there are different ways to consume them. Following are some of the common ones:
#1. Fish oil supplements
#2. Cod liver oil supplements (fish liver oil supplement)
#3. Fish and other Seafood (salmon, cod, sardines, mackerel, oysters, and cold water fatty fish)
#4. Nuts, seeds, and plant oils (flax seeds, chia seeds, soya bean oil, and canola oil)
#5. Seaweed and algae
Now, talking about the best form of fish oil to reap maximum benefits, go for whole fish.
However, if you can’t bear the fishy smell for longer, you can go for fish oil supplements as well.
Adding to this, even though fish oil supplements are a part of the diet of many people, they still don’t know the right dosage.
Here’s how much fish oil you should take every day.
How Many Fish Oils Can I Take A Day?
There is no prescribed quantity of how much omega-3 per day is good for hair growth.
However, a dosage of 200-500 mg of omega-3 fatty acids every day could be considered good along with a balanced diet.
Not to mention, the requirement of dosage may vary from person to person depending upon the needs.
To clarify, a healthy individual, pregnant women, and an infant, all require different dosages.
All in all, Omega 3 fatty acid benefits for hair and overall health could be overwhelming.
Therefore, we are here with some of your most frequently asked questions related to fish oil.
Q&As
Check out the following questions to get the answers to the rest of your queries.
QUES 1: Is it good to take fish oil everyday?
ANS: Fish oil contains omega-3, and, as per scientists, its consumption for a longer period can reduce immunity because of omega-3s ability to lower the body’s inflammation.
QUES 2: How long does fish oil take to work?
ANS: After having the supplement, it takes 3-4 hours for the omega 3 fatty acids to read the blood, but studies show that it takes 3-6 months to show a significant change.
QUES 3: Does fish oil make you gain weight?
ANS: Fish oil consists of omega-3 fatty acids, which makes it logical to wonder whether it makes you gain weight.
However, contrary to the rumors, this supplement actually promotes weight loss by the proliferation of cells.
Adding to this, it helps reduce one of the major contributors to obesity, inflammation.
Also, it boosts metabolism and stimulates thermogenesis.
You’ll be surprised to know that fish oil is consumed by many athletes and bodybuilders before their competition to preserve and energize their muscles.
QUES 4: Can I take fish oil at night?
ANS: There’s no perfect time to take fish oil. You can consume it at any time of the day.
However, splitting the supplement into two doses, day and night can reduce acid reflux and might make it easier for you to get out of bed the next morning.
Not to mention, to avail of maximum fish oil benefits, it’s recommended to consume it with high-fat variety food for better absorption.
QUES 5: Does fish oil improve memory?
ANS: Yes, because fish oil contains omega-3 fatty acid, which is good for brain health.
It supports the functioning of the brain and promotes better development of thinking and memory skills.
QUES 6: Can I take fish oil with water?
ANS: Yes, people can take fish oil with 8 oz (one cup) of water during a meal with enough fat for better results.
QUES 7: Can I take fish oil with biotin?
ANS: Consumption of fish oil and biotin for hair growth is normal.
However, whether you can take fish oil with biotin is debatable.
Even though there are no interactions found, it’s better to consult your doctor before taking both of these together.
QUES 8: Can you take fish oil with blood pressure medications?
ANS: Omega-3 fatty acid found in fish oil tends to lower blood pressure.
Therefore, people taking blood pressure-lowering medications are strictly recommended to consult their doctor before adding fish oil to their diet.
Fish oil with blood pressure medications also increases the risk of bleeding.
With that, Let’s wrap things up!
Summary
Being rich in omega-3 fatty acids, fish oil is an essential nutrient that needs to get adequately included in your diet.
And while hair loss after a certain age is inevitable, you can definitely slow down the process and enjoy healthy-looking hair for longer by taking fish oil supplements and applying fish oil topically.
However, it’s more effective to consume fish oil by adding it to your daily diet through food or by taking supplements.
Also, cod liver oil benefits for hair are scientifically proven; however, people dealing with certain underlying issues need to take proper precautions and consult a doctor before adding it to their diet.
Hair loss is the most terrifying thing.
Once it starts, it seems uncontrollable.
And just like me, if you’re getting a nightmare that you’ve gone bald, it’s time to take things in your hands by reaping the benefits of fish oil for hair.
Therapeutic Goods Administration (TGA)
This issue of Medicines Safety Update was published in the April 2010 issue of Australian Prescriber.
On this page: ACSOM membership announced | Safety of fish oil and omega-3 fatty acids | What to report
ACSOM membership announced
On 2 February 2010 Mark Butler, the Parliamentary Secretary for Health, announced the membership of the new Advisory Committee on the Safety of Medicines (ACSOM) for 2010-13. ACSOM replaces the Adverse Drug Reactions Advisory Committee (ADRAC) as the key advisory committee to the Therapeutic Goods Administration (TGA) on medicines safety.
The Committee will be chaired by Professor Emily Banks, a pharmacoepidemiologist and senior research fellow at the National Centre for Epidemiology and Population Health. Professor Banks has extensive experience in quantitative evaluation of the benefits and risks of medicines.
The Committee comprises medical experts, a pharmacist and a health consumer expert. The members are: Associate Professor Christopher Beer, Professor Nick Buckley, Associate Professor Danny Liew, Dr Kristine Macartney, Ms Alison Marcus, Dr Jane Robertson, Associate Professor Simone Strasser and Professor Duncan Topliss.
Once again the TGA thanks the past and outgoing ADRAC members for their contribution to the monitoring of medicines safety in Australia and looks forward to working with the members of ACSOM.
ACSOM recommendations will be published on the TGA website.
Safety of fish oil and omega-3 fatty acids
In this section: Introduction | Summary of the literature | Consumer use of fish oil and omega-3 fatty acids | Regulation | Summary | Conclusion | References
Introduction
The anticoagulant properties of fish oil products and the consequent risk of bleeding tendency have led to safety concerns, in particular concerning the risk of postoperative bleeding. Anecdotally, it is understood that some surgeons and anaesthetists may delay procedures if their patients are taking fish oil and, while there is no specific clinical guideline to support this, there is some support in the medical literature. Thomas et al (2008) has reported epistaxis and easy bruising with the use of fish oils and suggested that these may potentiate the action of warfarin and present a risk to haemophiliacs.1
Fish oil contains the omega-3 fatty acids, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). There is good evidence indicating that DHA and EPA in the form of fish oil supplements have beneficial cardiovascular effects. This is presented in a comprehensive review undertaken by Colquhoun et al for the Australian National Heart Foundation (NHF), published in 2008.2
The most commonly proposed mechanism for the anticoagulant activity of fish oils relates to changes in the ratio of phospholipids in platelet membranes. In vitro, fish oils competitively inhibit cyclo-oxygenase which decreases synthesis of thromboxane A 2 from arachidonic acid (ARA) in platelets. The cyclo-oxygenase mediated generation of thromboxane A 2 from ARA in platelets plays an important role in blood coagulation. Consumption of fish-rich diets or fish oil supplements may reduce platelet aggregation through reduction of platelet ARA concentration and cyclo-oxygenase mediated generation of thromboxane A 2 from EPA.
DHA has the potential to influence platelet aggregation by competing with ARA for membrane incorporation in platelets and thereby reducing available ARA for thromboxane A 2 generation. Other mechanisms such as decreasing platelet growth and clotting factors are also postulated to play a role.3,4
There is some evidence for other benefits of fish oil. These include use for infant eye/brain development, inflammation, nutrition (in gastrointestinal disorders), mental health disorders, Alzheimer's disease and rheumatoid arthritis. While fish oil products are widely used, this suggests the potential for more extensive applications.5
Summary of the literature
A literature search identified only three case reports presenting bleeding events or changes in laboratory results in patients taking fish oil and anticoagulant medication.6-8 Evidence from several randomised placebo-controlled trials and reviews is presented below.
Leaf et al (1994) undertook a randomised controlled trial in 551 candidates for percutaneous intraluminal coronary angioplasty to investigate whether omega-3 fatty acids prevented restenosis. Subjects were randomised to receive high doses of EPA and DHA or placebo for 14 days before, and six months after, angioplasty. All patients also received 325 mg of aspirin for six months post angioplasty. While the intervention did not prevent restenosis, there was no statistically significant difference in bleeding time between groups.9
The safety of postoperative fish oil was evaluated by Heller et al (2002) in a randomised, double-blind, placebo-controlled trial of 44 patients administered high doses of omega-3 fatty acids in parenteral nutrition after major abdominal surgery. No significant between-group difference was seen in bleeding events.10
Commentary by Lichtenstein (2005) on clinical data concerning dietary supplements affecting antithrombotic therapy included the conclusion on safety from an evidence-based review on the effects of omega-3 fatty acids on cardiovascular disease, prepared for the US Agency for Healthcare Research and Quality in 2004. It was noted that while clinical bleeding was a theoretical concern, in the studies reviewed there was no difference in the overall number of bleeding events between supplement and control groups. It was concluded that adverse events related to consumption of fish oil appeared to be minor.11
Harris (2007) reviewed 19 clinical trials of candidates for vascular surgery or femoral artery puncture who were administered omega-3 fatty acids in addition to anticoagulant medications. In 14 of these trials, the fatty acids were administered one and 42 days prior to surgery, and in 5 studies, postoperatively, at doses varying from 1.4 to 21 g/day. It was concluded that clinically significant bleeding events were 'virtually non-existent'.12
The effects of prescription omega-3 acids (POM) and aspirin, alone and in combination, on platelet function in 10 healthy subjects were investigated by Larson et al (2008). This was an open-label four-week sequential therapy trial with each subject their own control. It was found that while platelet aggregation was not affected by POM alone, it was affected by aspirin and by aspirin with POM.13
Tavazzi et al (2008) published the results of a randomised, double-blind, placebo-controlled trial looking at the effect of n-3 polyunsaturated fatty acids (PUFA) in patients with chronic heart failure (New York Heart Association class II-IV). Participants were assigned to n-3 PUFA 1 g/day (n=3494) or placebo (n=3481). Analysis of those discontinuing the study due to adverse events was undertaken, and showed no significant difference between the treatment and placebo groups.14
Watson et al (2009) undertook a retrospective record review of 182 subjects treated with high-dose fish oil, aspirin and clopidogrel and 182 controls on aspirin and clopidogrel alone, with a mean follow-up period of 33 months. One major bleed was seen in the treatment group (a patient with rectal cancer requiring transfusion) and none in the control group (p=1.0). There were more minor bleeds in the control group compared to the treatment group but the difference was not statistically significant. It was concluded that high-dose fish oil is safe in combination with aspirin and clopidogrel, and does not increase the risk of bleeding compared with that seen with aspirin and clopidogrel alone.15
Consumer use of fish oil and omega-3 fatty acids
Research shows that the popularity of complementary medicine (CM) use, and particularly fish oil, is worldwide and likely increasing.
The results from a Canadian National Population Health Survey undertaken in 2000-01 including 11,424 adults were published by Singh et al. These showed the prevalence of use of natural health products within the two days preceding was 9.3%, with fish oils the fourth most common product.16
An analysis of data by Elmer et al, collected as part of the Cardiovascular Health Study cohort study of risk factors for coronary heart disease (CHD) and stroke in adults 65 years and older, aimed to determine the prevalence of CM use concurrent with prescription and over-the-counter (OTC) medications and assess the risk for adverse interactions.17 Fish or cod liver oil was the fourth most common CM, with 2.28% of study participants using it over the four periods. Its use was categorised as a possible or theoretical risk for bleeding adverse events, rather than a significant risk.
Ramsay et al published the results of a retrospective analysis of pharmaceutical care plans for patients starting warfarin, who attended an anticoagulation clinic in 2003, to ascertain their CM use.18 Of the 631 plans analysed it was found that 170 (26.9%) patients were taking some form of CM. Approximately 60% of these were taking a CM that could interact with warfarin. Overall, more than 10% of the patients were taking fish or cod liver oil.
Regulation
Currently in Australia, fish oil ingredients derived from whole body and liver of fish are permitted for use in complementary and some OTC (listed) medicines. There is also a recognised component name, 'omega-3 marine triglycerides'. There are no quantity restrictions for any of the ingredients or the components in the ingredients, and the use of these substances does not attract any advisory statements for labelling purposes.
Information from adverse event reports with omega-3 fatty acids and fish oil in the TGA adverse drug reaction database showed that to February 2010, there had been a total of 92 reports, dating back to 1987, with 11 of these describing bleeding. These products were the sole suspect medication in only three (3.2%) cases. This finding is consistent with reports in international databases.
Notwithstanding the limitations of spontaneous adverse event reporting, these data suggest that there are relatively few reported bleeding-related adverse events with fish oil preparations, and that only a small proportion may be solely attributed to these products.
Health Canada permits a number of health claims for fish oil including the maintenance of good health, cardioprotection, assistance in reduction of serum triglycerides, and promotion of healthy mood balance. A June 2009 fish oil monograph indicates that no statements are required in relation to cautions, warnings, contraindications, and known adverse reactions.19
In 2004, the US Food and Drug Administration endorsed a qualified health claim indicating that, 'Supportive but not conclusive research shows that consumption of EPA and DHA omega-3 fatty acids may reduce the risk of coronary heart disease'. It states that, 'Dietary supplements should not recommend or suggest in their labelling a daily intake exceeding 2 grams of EPA and DHA'.20
Included in the Australian NHF 2008 review were recommendations for consumption of combined DHA and EPA through use of omega-3 fatty acids or fish oil, or fish intake. These were for:
all adult Australians to lower their risk of CHD
women who are planning pregnancy, pregnant or breastfeeding
children
adult Australians with documented CHD
Australians with lipid abnormalities.2
The NHF review did not consider fish oils to have a significant effect on haemostasis and did not include a cautionary statement.2
Similar recommendations have been made by the American Heart Association. These are qualified with statements to indicate that patients taking high dose omega-3 fatty acids should be under the care of a physician, and that high intake could cause bleeding in some people.21
In its information sheet on fats and oils, the British Heart Foundation supports intake of omega-3 fatty acids for cardioprotection. This indicates that patients taking warfarin and fish oil supplements concomitantly should consult with their medical practitioner because of the possibility of bleeding risk.22
Summary
Current evidence and recommendations for usage support fish oil for cardioprotection in patients with or without diagnosed CHD, decreasing triglycerides, and in women who are planning pregnancy, pregnant or breastfeeding, and children.
There are multiple proposed additional uses for fish oil.
It is likely that the use of fish oil will significantly increase.
Regulatory agencies consider that fish oil and omega-3 fatty acid containing products are safe with some requiring warnings about the theoretical possibility of bleeding events and drug interactions in their product information.
Evidence in relation to the safety concern about possible bleeding indicates that the theoretical possibility of increased bleeding tendency is not reflected functionally in results of human studies.
Conclusion
Healthcare practitioners should ensure they are aware of all medications - including prescription, over-the-counter and complementary products - being taken by their patients.
Despite the lack of evidence of a systematic safety concern, it would appear reasonable to be mindful of the theoretical risk of bleeding with fish oil when monitoring patients treated with fish oils and anticoagulants.
Bays (2007), in an article entitled 'Safety considerations with omega-3 fatty acid therapy', suggests:
discontinuing high-dose fish oil consumption or supplementation during an acute bleeding illness, such as during and immediately after a haemorrhagic stroke, or in patients with or at high risk for haemorrhagic stroke
discontinuing fish oil therapy 4-7 days before elective procedures with a high risk for bleeding complications, as often occurs with aspirin, warfarin, and clopidogrel, even though infusion of fish oils after major abdominal surgery through parenteral nutrition does not appear to result in clinically significant bleeding and has been suggested to be safe with specific regard to coagulation and platelet function
considering the potential antithrombotic and cardiovascular benefits of restarting fish oil therapies postoperatively, given that thrombotic and cardiovascular events may occur following major surgery.3
The author would like to thank colleagues from the TGA's Office of Complementary Medicines for their contribution.
References
Thomas AM, Gambert SR. Hazards from the health food store - Part II. Clin Geriatr 2008;16:34-40. Heart Foundation. Position statement: Fish, fish oils, n-3 polyunsaturated fatty acids and cardiovascular health. Melbourne: NHF; 2008. Bays HE. Safety considerations with omega-3 fatty acid therapy. Am J Cardiol 2007;99:35C-43C. Lien EL. Toxicology and safety of DHA. Prostaglandins, leukotrienes, and essential fatty acids. Prostaglandins Leukot Essent Fatty Acids 2009;81:125-32. Medline Plus. Drugs, supplements, and herbal information. [cited 2010 Mar 12] Buckley MS, Goff AD, Knapp WE. Fish oil interaction with warfarin. Ann Pharmacother 2004;38:50-2. McClasky EM, Landrum Michalets E. Subdural hematoma after a fall in an elderly patient taking high-dose omega-3 fatty acids with warfarin and aspirin: case report and review of the literature. Pharmacotherapy 2007;27:152-60. Jalili M, Dehpour AR. Extremely prolonged INR associated with warfarin in combination with both trazodone and omega-3 fatty acids. Arch Med Res 2007;38:901-4. Leaf A, Jorgensen MB, Jacobs AK, Cote G, Schoenfeld DA, Scheer J, et al. Do fish oils prevent restenosis after coronary angioplasty? Circulation 1994;90:2248-57. Heller AR, Fischer S, Rossel T, Geiger S, Siegert G, Ragaller M, et al. Impact of n-3 fatty acid supplemented parenteral nutrition on haemostasis patterns after major abdominal surgery. Br J Nutr 2002;87(Suppl 1):S95-S101. Lichtenstein AH. Remarks on clinical data concerning dietary supplements that affect antithrombotic activity. Thromb Res 2005;117:71-3. Harris WS. Expert opinion: omega-3 fatty acids and bleeding - cause for concern? Am J Cardiol 2007;99:44C-46C. Larson MK, Ashmore JH, Harris KA, Vogelaar JL, Pottala JV, Sprehe M, et al. Effects of omega-3 acid ethyl esters and aspirin, alone and in combination, on platelet function in healthy subjects. Thromb Haemost 2008;100:634-41. Tavazzi L, Maggioni AP, Marchioli R, Barlera S, Franzosi MG, Latini R, et al; Gissi-HF Investigators. Effect of n-3 polyunsaturated fatty acids in patients with chronic heart failure (the GISSI-HF trial): a randomised, double-blind, placebo-controlled trial. Lancet 2008;372:1223-30. Watson P, Joy P, Nkonde C, Hessen S, Karalis D. Comparison of bleeding complications with omega-3 fatty acids and aspirin and clopidogrel versus aspirin and clopidogrel in patients with cardiovascular disease. Am J Cardiol 2009;104:1052-4. Singh SR, Levine M. Potential interactions between pharmaceuticals and natural health products in Canada. J Clin Pharmacol 2007;47:249-58. Elmer GW, Lafferty WE, Tyree PT, Lind BK. Potential interactions between complementary/alternative products and conventional medicines in a Medicare population. Ann Pharmacother 2007;41:1617-24. Ramsay NA, Kenny MW, Davies G, Patel JP. Complementary and alternative medicine use among patients starting warfarin. Br J Haematol 2005;130:777-80. Health Canada. Natural health product monograph: Fish oil. 2009 Jun 22. [cited 2010 Mar 12] US Food and Drug Administration. Letter responding to health claim petition dated June 23, 2003 (Wellness petition): omega-3 fatty acids and reduced risk of coronary heart disease (Docket No. 2003Q-0401). 2004 Sep 8. [cited 2010 Mar 12] American Heart Association. Fish and omega-3 fatty acids. [cited 2010 Mar 12] British Heart Foundation. Information sheet: Fats and oils. 2008. [cited 2010 Mar 12]
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