Stop Wasting Your Money: 6 Truths About Fish Oil Revealed by a Kinesiology PhD

As we age, we inevitably enter a phase where we start paying closer attention to our health. The most direct and simple approach is often taking supplements, with fish oil being one of the most popular choices.

However, a quick search on any major e-commerce platform reveals a market flooded with various fish oil products, ranging in price from ten dollars to hundreds. Is fish oil just a gimmick? Are its benefits exaggerated? With so many brands out there, what criteria should you use to choose?

A video by a vlogger I’ve followed for a long time answered these questions perfectly. Below, I have synthesized his content with other information found online to summarize 6 truths about fish oil:

The Basics: What Exactly is Fish Oil?

First, we must understand that the core value of fish oil lies in its polyunsaturated fatty acids: DHA and EPA.

• DHA: Can cross the blood-brain barrier; its primary function is to promote brain development and improve cognition.
• EPA: Its main role is lowering blood lipids and suppressing inflammation in the body.

Myth 1: The Omega-6 to Omega-3 Ratio Must be 1:1

For a long time, many influencers have emphasized that the ratio of vegetable oil (Omega-6) to fish oil (Omega-3) intake must reach 1:1. However, in modern diets, achieving this ratio is almost impossible.

The Truth: Literature from 2009 found that the ratio itself does not directly dictate cardiovascular health. The only metric that truly matters is the total intake of DHA and EPA.

If your intake of fish oil is sufficient, the ratio doesn’t matter; conversely, if your intake is insufficient, a perfect ratio won’t help.

Myth 2: Taking DHA Alone Guarantees Improved Cognition?

Many people believe that taking fish oil makes you smarter. However, research shows that high concentrations of DHA do not significantly improve mental state if there is a deficiency in B vitamins.

The Truth: B vitamins are essential for facilitating the effective transport of DHA across the blood-brain barrier. Therefore, it is recommended to take fish oil alongside B vitamins to achieve a synergistic “1+1>2” effect.

Myth 3: Buying Fish Oil Based Only on DHA and EPA Content?

While content is important, the absorption rate and purity are the real “traps.”

• Absorption Rate: Fish oil on the market comes in three forms: TG, rTG, and EE. The absorption rates of TG and rTG forms are significantly higher than the EE form. When shopping, try to avoid the EE form.
• Certification: Look for the IFOS (International Fish Oil Standards) report. You must personally verify on their official website that the specific model is actually certified, rather than just trusting the merchant’s marketing (some manufacturers claim certification but sell uncertified batches).
• Source: Try to choose fish oil extracted from small fish (such as anchovies or sardines) to minimize microplastics and heavy metal residue.

Myth 4: Fish Oil is Only for the Elderly and Children?

If you think fish oil is just a general health supplement for the weak, you are mistaken. It provides amazing benefits for fitness enthusiasts and hardcore trainees as well.

The Truth: Components in fish oil can promote Brain-Derived Neurotrophic Factor (BDNF), enhancing neural transmission and, consequently, muscle contraction force. Research has found that under a caloric deficit, a daily intake of 2 grams of fish oil can sustain leg strength. Additionally, it offers effective joint protection.

Myth 5: You Can Take Fish Oil Anytime, Any Way Without Side Effects?

Although Omega-3 is very safe, that doesn’t mean it can be taken indiscriminately.

• Immunity Issues: Long-term high-dose intake (over 3-5 grams daily) may lead to excessive anti-inflammatory effects, which can actually lower immunity. For the average person, 500-1000 mg daily is sufficient.
• Avoid Pre-Workout: Fish oil lowers cortisol and has a certain sedative effect. This might reduce the “aggression” or drive needed during training, so it is not recommended to take it before a workout.
• Suggested Protocol: If you train in the afternoon, take it with lunch; if you train in the morning or at noon, take it with dinner.

Myth 6: Seal Oil is Superior to Fish Oil?

This is an absolute scam.

The Truth: Experiments show that seal oil offers no significant advantage in improving cholesterol or triglycerides. Worse yet, seals are at the top of the food chain, meaning they accumulate far more harmful substances in their bodies than small fish. Furthermore, the market lacks strict regulation, making quality hard to guarantee. Therefore, purchasing seal oil is highly discouraged.

Summary & Recommendations:

If you want to get the most out of fish oil:

1. Ensure your intake meets the standard.
2. Combine it with B vitamins.
3. Choose supplements made from small fish in rTG or TG form.
4. Avoid taking it before strength training.

Think of this like your body’s hormonal environment: if your primary metrics (like total intake) aren’t met, chasing minor adjustments in ratios is missing the forest for the trees. Only when the foundation is solid can optimizing the details truly make a difference.

Warning

Note: In the content above, it is mentioned that 500-1000 mg of fish oil daily is sufficient for the average person. However, for specific groups (such as pregnant women, breastfeeding mothers, or patients with cardiovascular disease), higher doses may be required. Please adjust under the guidance of a doctor.

Based on the American Heart Association (AHA) and the latest clinical studies (such as the REDUCE-IT trial), here are recommendations for different scenarios:

1. Core Principle: Therapeutic Dose vs. Maintenance Dose

A standard fish oil capsule on the market usually contains only about 300mg of Omega-3 (EPA+DHA). This is a “maintenance dose.”

For people with diagnosed cardiovascular or cerebrovascular diseases, a “therapeutic dose” is usually required. This often necessitates high-purity fish oil or prescription-grade fish oil.

2. Recommended Intake for Different Conditions

A. Patients with Coronary Heart Disease (CHD)

• Recommendation: Approximately 1 gram (1000 mg) of EPA + DHA per day.
• Goal: To reduce the risk of cardiovascular death and recurrence.
• Note: Can be taken via supplements under medical supervision. If taking standard low-purity fish oil (300mg Omega-3 per capsule), you might need 3-4 capsules to reach this target; with high-purity (rTG) fish oil, 1-2 capsules may suffice.

B. High Triglycerides (Hypertriglyceridemia)

• Recommendation: 2 grams ~ 4 grams of EPA + DHA per day.
• Goal: Clinical evidence confirms this dose can significantly lower triglyceride levels (by 20%-30%).
• Note: This is a very high dose. It is difficult to achieve this with standard fish oil (you might need to swallow a dozen pills a day), which would also involve ingesting too much impurity fat. Therefore, doctors usually prescribe high-purity prescription fish oil (such as Icosapent Ethyl, a pure EPA preparation) for this condition.

C. Stroke

• Recommendation: There is no unified recommended dose for “stroke prevention,” though some studies support high doses (pure EPA).
• Latest Findings: The effectiveness of standard fish oil (EPA+DHA mix) in preventing stroke recurrence is still debated in the academic community (some studies show no effect). However, large-scale clinical trials (REDUCE-IT) found that 4 grams of high-purity EPA daily can significantly reduce the risk of ischemic stroke.
• Critical Warning: Fish oil targets ischemic stroke (clots/thrombosis). If you have a history of hemorrhagic stroke (brain bleed), taking high-dose fish oil increases bleeding risk and must be strictly managed by a doctor.

3. Three Major Warnings (Must Read)

• Atrial Fibrillation (AFib) Risk:

Multiple recent studies indicate that long-term use of high-dose fish oil (>1 gram daily) increases the risk of atrial fibrillation. If you already have heart rhythm issues (arrhythmia), do not blindly increase your dosage. Consult a cardiologist.

• Bleeding Risk:

Cardiovascular patients often take anticoagulants (blood thinners like Aspirin, Warfarin, Plavix, etc.). Fish oil also has an anticoagulant effect. Taking both together can stack bleeding risks (e.g., bleeding gums, easy bruising). If you are on anticoagulants, daily fish oil intake is generally recommended to be kept under 3 grams, with coagulation markers monitored.

• Read the Label (EPA vs DHA):

For cardiovascular protection, EPA is generally ranked higher than DHA. If your goal is lipid lowering and heart protection, prioritize products with high EPA content (an ideal EPA:DHA ratio is about 2:1 or higher, or even pure EPA).

Summary Advice

• General Heart Maintenance: Aim for 1 gram of EPA+DHA daily (calculate based on the nutrition facts label, not the total weight of the capsule).
• Lowering Triglycerides/High-Risk Groups: Requires 2-4 grams, but this falls under medical treatment. Please seek a prescription (e.g., Vascepa) from a doctor. Do not try to reach this by eating dozens of cheap supplements; it strains the liver and isn’t cost-effective.
• Check Before Use: If you have existing conditions, ask your doctor one question before starting: “I am taking anticoagulants/I have an AFib risk; is this dose of fish oil safe for me?”