Omega-3 Fatty Acids: What They Do and How to Use Them
Omega-3 fatty acids are essential fats your body can’t make well on its own. They play a role in heart health, brain function, inflammation control, and eye health. You get them from food or supplements. This page gives clear, practical advice on what to eat, how much to take, and what to watch for.
There are three main types: ALA (from plants), and EPA plus DHA (from fish and algae). ALA is in flaxseed, chia, and walnuts. EPA and DHA come from oily fish like salmon, mackerel, sardines, and from algae oils for vegans. For most benefits people focus on EPA and DHA.
How much should you take?
For generally healthy adults, 250–500 mg combined EPA and DHA per day is a reasonable target. If you have high triglycerides, doctors often recommend 2–4 grams per day under medical supervision. Pregnant and breastfeeding people usually aim for about 200–300 mg DHA daily for fetal brain development. Don’t exceed very high doses without a doctor’s OK — above 3 grams per day may increase bleeding risk.
Choosing a supplement and safety tips
Pick supplements that list EPA and DHA amounts on the label. Look for third-party testing (USP, NSF, or ConsumerLab) to avoid rancid or contaminated products. If you are vegetarian, choose algae-based DHA/EPA. Take fish oil with a meal to reduce fishy burps and to help absorption. Store capsules in a cool, dark place; liquid oils can go rancid faster.
Watch for interactions. Omega-3s can thin the blood slightly. If you take blood thinners like warfarin, aspirin, or clopidogrel, talk to your clinician before starting supplements. People with seafood allergies should choose algae or plant sources. Side effects are usually mild: fishy aftertaste, mild stomach upset, or loose stools at high doses.
What about diet first? Whole food sources offer other nutrients. Aim for two servings of oily fish per week to boost EPA and DHA naturally. For plant-based diets, use ground flaxseed, chia, and walnuts to get ALA, but expect lower conversion to EPA/DHA. Consider testing or asking your doctor about blood omega-3 levels if you rely only on ALA sources.
Do they prevent heart attacks? Large studies show consistent benefits for lowering triglycerides and modest benefits for heart health, especially in people with high triglycerides. Results vary by dose and population. Use supplements to fill gaps or for specific medical goals, not as a cure-all.
Quick checklist: check EPA/DHA amounts, prefer third-party tested brands, take with food, tell your doctor about blood thinners, choose algae oil for vegans, and aim for food-first when possible. If you have a specific condition, get personalized advice from a healthcare professional.
If you’re taking prescription medications, bring your supplement bottle to appointments. Some trials used high-dose omega-3s for specific conditions, so your doctor can advise if a prescription-strength product makes sense. Small changes in diet plus correct supplement choice often give the best results over time. Start simple, track effects weekly, adjust.
