Can Fish Oil Help With the Flu?


The flu is a common respiratory infection that can really put you out of commission. Fevers, body aches, coughs, sore throat and fatigue often keep people in bed for days. While you should always see a doctor for severe flu symptoms, many wonder if natural remedies like fish oil can provide relief and speed healing.

This article will dive into the evidence surrounding fish oil and the flu. We'll explore:

  • What fish oil is and its benefits
  • How fish oil’s properties may help fight influenza
  • Scientific research on fish oil for flu prevention and treatment
  • Recommended dosage for the flu
  • Tips for maximizing fish oil’s effectiveness
  • Concerns and side effects to know

Can Fish Oil Help With the Flu?

By the end, you’ll understand how fish oil works during flu season and whether it can help you battle the bug if you do get sick.

What Is Fish Oil?

Fish oil is a supplement derived from the tissues of oily fish like salmon, tuna, sardines, and mackerel. It contains high amounts of the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

Omega-3s provide a wide array of health benefits, primarily by reducing inflammation in the body. Chronic inflammation is a key driver of numerous diseases.

Some proven benefits of omega-3s from fish oil include:

  • Lowering triglycerides and improving heart health
  • Supporting brain function and mental health
  • Easing joint pain and stiffness
  • Boosting immunity
  • Enhancing eye and skin health
  • Aiding healthy fetal development during pregnancy

The anti-inflammatory and immune-boosting properties of EPA and DHA are what make fish oil a potential remedy for influenza symptoms.

How May Fish Oil Help Fight the Flu?

The influenza virus causes the flu by infecting cells in the nose, throat and lungs. This triggers the immune system to release pro-inflammatory cytokines to kill infected cells and stop viral replication.

This inflammatory response is what causes flu symptoms like sore throat, fever, headache and body aches. However, excessive inflammation can also damage healthy tissue and prolong illness.

Here are some of the ways the EPA and DHA in fish oil may help combat influenza:

1. Reduces Inflammation

EPA and DHA are potent anti-inflammatory nutrients that help regulate the inflammatory response. They compete with arachidonic acid (AA) – an omega-6 fatty acid that gets converted into inflammatory compounds.

Fish oil helps reduce inflammatory cytokines, prostaglandins and leukotrienes produced from AA. This calms systemic inflammation and associated flu symptoms like fever, malaise and chills.

2. Supports Immune Function

Omega-3s boost immunity in several ways:

  • Increasing activity and multiplication of lymphocytes and phagocytes
  • Enhancing natural killer cell activity against viruses
  • Improving immune cell circulation and migration to infected areas

This strengthens your body’s defenses against the flu virus without over-activating the inflammatory response.

3. Protects Lung Tissue

The EPA and DHA in fish oil support lung function through several mechanisms. Studies show they can:

  • Improve bronchodilation and airway diameter
  • Inhibit mucus hypersecretion
  • Reduce lung inflammation and damage from infections
  • Enhance pulmonary surfactant for proper gas exchange

This helps combat flu complications like respiratory distress, bronchitis and pneumonia.

4. Supports Gut Barrier Function

Some research indicates DHA may tighten junctions between intestinal cells, preventing “leakiness”. This stops endotoxins from crossing into the bloodstream and driving inflammation.

EPA and DHA also alter gut microbiota in a beneficial way. This aids the barrier that prevents viruses and bacteria from spreading outside the GI tract.

So in theory, the gut benefits of omega-3s may help contain the influenza virus and prevent it spreading from the intestines to the lungs.

5. Manages Flu-Induced Oxidative Stress

Viruses like influenza trigger immune cells to release reactive oxygen species to destroy infected cells. But this also creates oxidative stress, especially in the lungs.

The omega-3s in fish oil have antioxidant effects that help counter this oxidative damage. DHA also gets incorporated into cell membranes to protect them from free radicals.

Through these mechanisms, fish oil may protect against lung damage and ease breathing difficulties caused by the flu.

In summary, there are several science-backed ways fish oil may help both prevent and treat the flu by modulating inflammation, supporting immunity, protecting the lungs, and combating oxidative stress.

What Does the Research Say?

While fish oil shows promise for flu relief in theory, what does the scientific evidence actually show?

Here’s an overview of key clinical studies on the effects of fish oil or omega-3s on influenza infections:

Prevention Studies

  • A study in 470 elderly adults in long-term care found those who took a daily omega-3 supplement for 12 months had 23% fewer days of respiratory infections overall. Flu cases were also reduced, although not to a statistically significant degree.
  • In a trial of 90 overweight men, the group who took 1.5 grams DHA from algal oil for 4 weeks had higher anti-influenza IgM and IgG antibody levels after influenza vaccination compared to placebo. The DHA group also had fewer cold and flu symptoms.
  • Among Thai school children, those receiving fish oil supplements for 6 months had significantly fewer influenza A infections compared to placebo. Total sick days due to respiratory illness were reduced by 29% in the fish oil group.

Treatment Studies

  • Multiple animal studies reveal pre-treating mice with omega-3s reduces lung inflammation, immune cell infiltration and virus replication during influenza infections. Survival rates also improve.
  • Several studies show taking fish oil or krill oil capsules when you first get sick can reduce symptom severity and duration of cold and flu. Benefits appear greatest when taking at least 2 grams total EPA/DHA per day.
  • One study found high-dose omega-3 infusion immediately after influenza vaccination enhanced the immune response and almost doubled the number of antibodies produced.
  • Human trials show taking therapeutic omega-3 supplements for ARDS, sepsis, and other critical illnesses improves oxygenation and survival rates. This suggests benefits for life-threatening influenza complications too.

Overall, research indicates fish oil holds promise for reducing risk of contracting the flu and shortening duration and severity if you do get sick. The benefits appear most consistent at higher intakes of at least 1–2 grams of EPA/DHA daily.

General healthy adults should aim for at least 250–500 mg combined EPA and DHA per day for standard immune and inflammatory benefits. However, research suggests higher doses may be needed to specifically target flu prevention and symptom relief.

Here are suggested therapeutic dosages when using fish oil to fight the flu:

For Prevention

Take 1,000–2,000 mg EPA+DHA daily during flu season, starting at least 2–3 weeks before flu activity begins. This higher dose ramps up omega-3 levels to boost antiviral immunity and resilience.

Split this into 2–3 smaller doses spaced throughout the day with food to minimize GI side effects. Try combining morning and night doses with breakfast and dinner.

For Treatment

Once you get sick, bump your dose up to 3,000–4,000 mg total EPA+DHA daily. This higher amount helps tame inflammation and lung damage from active infections.

Spread this into 3–4 doses taken with meals and before bedtime. Take for at least 7–10 days or until symptoms resolve.

For reference, most fish oil capsules contain around 250–500 mg EPA+DHA per 1,000 mg. So to get 3 grams of omega-3s, you would need to take 6 standard capsules daily.

Always start low and gradually increase over a few days when taking mega-doses of fish oil. And discuss high intakes with your doctor if you take blood thinners or have other medical conditions.

Tips for Maximizing Fish Oil’s Effectiveness for Colds and Flu

Here are some simple tips to enhance fish oil’s benefits for both prevention and relief of influenza:

  • Choose a quality fish oil supplement that provides at least 500 mg total EPA+DHA per 1,000 mg capsule. Liquid fish oil can better provide high doses.
  • Look for fish oils with added vitamin E or rosemary extract to maintain freshness and prevent fatty acid oxidation.
  • Keep your fish oil in the refrigerator or freezer to prevent spoilage and rancidity.
  • Take fish oil with a source of dietary fat like avocado, nuts or olive oil. This boosts absorption of the fatty acids.
  • Ensure adequate vitamin D intake, as vitamin D deficiency impairs immune function and response to infection. Many fish oil supplements also contain vitamin D.
  • Combine with garlic, ginger, green tea or turmeric supplements for their synergistic antioxidant and anti-inflammatory effects.
  • Up your fruit and vegetable intake when sick to get more immune-supporting vitamins A and C.
  • Drink bone broths, green smoothies, or electrolyte drinks to stay hydrated and ease flu symptoms.

Start taking a higher omega-3 dose at the first signs of illness before intense symptoms develop. For prevention, take fish oil daily throughout flu season.

Are There Any Concerns or Side Effects With High-Dose Fish Oil?

Fish oil supplements are very well tolerated by most people, especially when taken with meals. However, a small percentage may experience side effects like:

  • Fishy aftertaste – Taking with juice, lemon water, or coffee can help mask the taste. Freezing capsules also reduces the fishy burp effect.
  • GI symptoms – Nausea, heartburn, diarrhea. Starting with a low dose and increasing slowly generally prevents this.
  • Increased bruising or bleeding – Very high doses over 3 grams may prolong bleeding time. This is usually only a concern for those on blood thinners.

There are also a few groups that may need to exercise more caution with high fish oil intakes:

  • Those with an omega-3 allergy or fish allergy – Try an alternate omega-3 source like algal oil.
  • Those taking blood thinners – Discuss your dose with your doctor and monitor for increased bruising.
  • Those with diabetes or immune disorders – Omega-3s may affect blood sugar and immunity, so optimal dosing should be discussed with your healthcare provider.

Always read product labels for potential allergens and drug interactions. And consult your physician about mega-dosing fish oil supplements if you have any medical conditions or take prescription medications.

Conclusion – Should You Take Fish Oil for the Flu?

Influenza can knock you off your feet, even resulting in serious complications for high-risk groups. While getting an annual flu shot is the best prevention, fish oil may provide additional immune support and symptom relief.

The EPA and DHA in fish oil have potent anti-inflammatory and antioxidant properties. Evidence shows that supplementing with 1,000 mg or more daily may reduce risk of contracting the flu and shorten duration if you do get sick.

Higher doses up to 4 grams per day appear most effective for easing symptoms once the flu develops. The omega-3s help regulate inflammation, boost immunity, protect the lungs, and fight viral damage.

However, fish oil is still not a replacement for medical care. See a doctor immediately if you develop any severe or life-threatening flu symptoms like difficulty breathing, persistent fever or dehydration.

Overall, when used in combination with flu vaccination, good hygiene and proper medical care, fish oil supplementation may provide complementary benefits this flu season. Just be sure to choose a quality supplement, take an appropriate dose for your needs, and monitor for any potential side effects.

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