Do omega-3 (fish oil) supplements benefit my heart?
Fish oil reliably lowers triglycerides and can slightly reduce the risk of a heart attack in people with existing heart disease or high risk, but it does not demonstrably lower the overall risk of death. Always discuss its use with your doctor if you have a condition or are on medication.
Fish oil reliably lowers blood fats (triglycerides) by around 15%. That is its most robust benefit. For the heart itself, the picture is more nuanced, and if you have a heart condition, always discuss it with your doctor.
Want to try it for your heart? In research, people took around 1 g of EPA+DHA per day for at least 12 months, preferably for years. Check the label for 'EPA + DHA', for example 1 g per capsule. A pooled analysis of 29 studies involving more than 117,000 participants shows that fish oil slightly lowers the chance of dying from a cardiac cause. The risk of a heart attack also falls slightly: on average, 272 people need to be treated to prevent one additional heart attack. For stroke, no demonstrable effect has been found. The overall risk of death barely changes, as shown by 45 studies involving 143,000 participants. The effect is therefore modest.
For elevated triglycerides, people in research took 2 to 4 g of EPA+DHA per day, long term, for as long as levels remain elevated. Discuss dose and duration with your doctor. Higher doses, above 3 g per day, increase the risk of atrial fibrillation. The exact formulation on the label need not matter: EPA+DHA as ethyl esters or as triglycerides both work, provided you take ethyl esters with a fatty meal for better absorption.
People who already have heart disease or are at high risk are more likely to benefit than someone who is healthy. The American Heart Association concludes that the evidence for people with existing heart disease, diabetes, or high risk is considerably stronger than for the general population. Plant-based omega-3, such as that found in flaxseed, shows no measurable effect on cardiovascular mortality. Two studies did find a possible lower risk of heart rhythm disorders, but that evidence is thin.
An important caveat: earlier positive studies had weaker designs. Once only the stronger studies are examined, the benefits become smaller or disappear. For healthy people without elevated risk, fish oil is therefore of little value for the heart.
Claims are based on multiple large systematic reviews and meta-analyses of RCTs (up to 143,693 participants). One claim regarding the Omega-3 Index is observational.
Do omega-3s help against heart rhythm disorders?
Omega-3 supplements do not help against heart rhythm disorders and at higher doses actually increase the risk of atrial fibrillation. Eating fish regularly appears to be a different story, but always discuss rhythm problems with your doctor first.
Does taking omega-3 help you stay healthy for longer?
Omega-3 reliably lowers blood fats, but the evidence that it helps you live longer or stay healthier is limited. If you already have heart disease, discuss with your doctor whether omega-3 is a worthwhile addition to your treatment.
Are calcium supplements bad for your heart?
Calcium supplements may be associated with an increased heart risk, but not all studies confirm this. It is best to get calcium from your diet, and discuss with your doctor whether a supplement is truly necessary for you.
Is the Mediterranean diet really good for your heart, and why?
For people at increased heart risk, the Mediterranean diet is the best-supported dietary choice currently available. Both large studies in people and dozens of population studies confirm a lower risk of heart attack and stroke.
Does omega-3 from fish oil help with chronic inflammation?
Omega-3 from fish oil lowers inflammation markers in the blood and has the strongest evidence in rheumatoid arthritis. The effect varies by condition and by person; if you have a joint condition, talking to your doctor is the logical first step.
Does omega-3 (fish oil) have an effect on bone strength?
Omega-3 does not improve bone density in healthy older adults; for bone maintenance you are better off ensuring adequate calcium and vitamin D, ideally in consultation with your doctor.