Cedars-Sinai Blog

Fish Oil Supplements, CoQ10 and Your Heart

Fish oil and C0Q10 supplements.

Fish oil. CoQ10. These are just two of the supplements Americans spend billions of dollars on each year, hoping to up their health game and prevent or treat medical conditions. Do these natural aids do any good? More importantly, can they do harm?

The answer to both questions is a qualified yes. Fish oil and CoQ10 do provide benefits, but if you take too much of them or combine them with other drugs, you may actually increase your risk of problems. Let's have a closer look at them.

"Taking more than one gram of fish oil per day is something you should only do following your doctor's advice."

Fish oil: The good, the bad and the doctor's advice

Thank goodness for fatty fish, chia seeds and algae. All three contain omega-3 fatty acid, which our bodies can't produce—even though we need it to survive.

From muscle activity to cell growth, omega-3 is essential. It's also associated with heart health because it may help lower triglycerides—unhealthy fats in your blood—and improve blood pressure. But there's no solid evidence that it lowers your risk of heart disease, and it's not clear if fish oil supplements provide the same benefit as getting your fatty acid straight from the swimming source.

There's another problem: Not only are the benefits of fish oil supplements not well established, but there are also risks associated with taking high doses of fish oil. In a meta-analysis that reviewed the results of multiple scientific studies, Dr. Christine M. Albert found that fish oil supplements were associated with an increase in atrial fibrillation—an irregular and often very rapid heart rhythm that can lead to blood clots in the heart and result in death.

The study is important because meta-analysis is more reliable than individual studies. "With a meta-analysis, you can see if there are effects not detected in a single trial," says Dr. Albert, the Lee and Harold Kapelovitz Distinguished Chair in Cardiology and chair of the Department of Cardiology in the Smidt Heart Institute at Cedars-Sinai.

Christine M. Albert, MD, MPH

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In a review of more than 81,000 patients enrolled in seven clinical trials, Dr. Albert and her team found that patients who took more than 1000 mg (equal to 1 g) per day of omega-3 fatty acid had a 49% increased risk of developing atrial fibrillation—compared to just 12% for patients who took 1000 mg or less of the supplement per day.

Does that mean you should stop taking omega-3? Not necessarily. If the supplement was prescribed, discuss any concerns with your doctor. That supplement could be keeping dangerous triglycerides under control.

For everyone else, there may be benefits to taking fish oil supplements, but it's wise to stay in the safe zone of less than one gram per day. "Taking more than one gram of fish oil per day is something you should only do following your doctor's advice," Dr. Albert concludes.

CoQ10: Proceed, but with caution

You've probably seen CoQ10 in the vitamin aisle. It's one of the bestselling supplements in the world. But unlike fish oil, it's not obvious what CoQ10 means, so it can cause more confusion than the many other jars that line our store shelves. The debate on its benefits may be equally confusing. Who's right: Those who say it's a miracle or those who say it's bunk? The truth lies somewhere in between.

A powerful antioxidant, CoQ10 (which stands for coenzyme Q10) is an enzyme that your body naturally produces in small amounts. It's found in higher levels in foods such as sardines, liver, chicken and broccoli. As you age, your body's ability to make CoQ10 drops, which may cause your levels of good cholesterol to fall, as well. Supplements can help bring those levels back up.

If you have a heart-related condition, CoQ10 may help due to its antioxidant properties. It may also improve energy production in cells and prevent blood clots. A multicenter randomized study of 420 patients found that taking CoQ10 in addition to standard therapies helped reduce mortality in patients with severe heart failure. Another clinical study suggested that people who took CoQ10 within three days of a heart attack were less likely to have another one and were less likely to die of heart disease than those who didn’t take the supplement.

CoQ10 is also a popular treatment for the side effects of statins, a widely prescribed class of drugs that lower cholesterol. Statins can reduce the amount of CoQ10 the body makes on its own, which may be the reason they're linked to muscle aches and pains. Unfortunately, there is no solid evidence that CoQ10 supplements help, although some people who take them report feeling better. If you are taking statins and experiencing pain, ask your doctor if switching to a different statin may help.

If you do want to try CoQ10, it's important that you consult your doctor first. The supplement could make certain drugs, including the blood thinner warfarin, less effective. There is also some concern it could interfere with certain chemotherapies. Even if those issues aren’t relevant to you, there could be other risks particular to your situation, so don't skip the consultation.

While they may have a place in protecting heart health, fish oil and CoQ10 underscore the importance of treating supplements like you would any other medication. They are advertised as natural, and they're not regulated by the Food and Drug Administration, but that doesn't mean they are risk-free. So, before you start taking any supplement, follow Dr. Albert's advice: "Think of it like taking a drug, and talk to your doctor about whether it's right for you."