Omega-3 Fatty Acids: What They Do and How Much You Need

Reviewed by Precious, One Life Health Consultant — Updated July 2026

Omega-3s come up in almost every health conversation at our counter, and for good reason — they're one of the few supplements with genuinely solid evidence behind them. Here's the honest, no-hype version of what they do, who tends to need them, and how to choose a decent one.

What omega-3s actually are

Omega-3 fatty acids are essential fats — your body can't make them, so you have to get them from food or a supplement. There are three main types:

• ALA — from plant sources like flaxseed, chia and walnuts. Your body has to convert it to EPA and DHA to use it fully, and that conversion is inefficient (roughly 5–15%), so plant sources alone often aren't enough on their own.
• EPA — found in fatty fish and fish oil, generally associated with supporting a healthy inflammatory response and mood balance.
• DHA — also from fatty fish or algae, and a major structural building block of the brain and retina. It's especially important during pregnancy and early childhood.

How much do you actually need?

Most health bodies suggest a general daily intake of around 250–500mg combined EPA and DHA for maintenance. The South African Heart and Stroke Foundation recommends eating fatty fish at least twice a week to support heart health. If you have a specific health concern, talk to your doctor about what dose makes sense for you rather than guessing at a higher number.

What we'd suggest omega-3s for

• Heart health — omega-3s are well studied for supporting healthy triglyceride levels and normal blood pressure, and for helping maintain flexible blood vessels. Pairing them with a generally heart-conscious diet is the sensible approach.
• Brain function — DHA makes up around 40% of the polyunsaturated fat in the brain, so it's a genuinely foundational nutrient for cognitive health across life stages, from pregnancy through to older age.
• General inflammatory balance — EPA and DHA support the body's normal inflammatory response, which is why people managing joint stiffness or general aches often ask us about fish oil alongside their usual care.
• Mood support — there's a reasonable body of research linking adequate omega-3 intake to general mood balance. We'd frame this as support for everyday emotional wellbeing, not a treatment for depression or anxiety — if you're struggling, please see your doctor first.
• Skin comfort — omega-3s help maintain the skin's natural barrier, which can support hydration and general skin comfort. If you're dealing with a diagnosed skin condition like eczema or psoriasis, omega-3s can sit alongside your dermatologist's plan, not replace it.
• Eye comfort — DHA is a structural part of the retina, and omega-3s are also commonly used to support tear film quality for people who get dry, tired eyes from screen time.

Food sources worth knowing

For EPA and DHA:

• Fatty fish — salmon, sardines, mackerel, herring, and South African pilchards (an affordable, easy local option)
• Shellfish — mussels, oysters, crab
• Algae — the main option for vegetarians and vegans
• Omega-3 enriched eggs, widely available locally

For ALA (plant-based): flaxseed and flaxseed oil, chia seeds, hemp seeds, walnuts, edamame and soybeans.

Choosing a decent supplement

• Look at the EPA + DHA number, not just the total fish oil weight — that's what actually matters.
• Check for purity testing — look for products tested for heavy metals and contaminants.
• Triglyceride form tends to absorb better than ethyl ester. Algae-based options are a good fishy-aftertaste-free alternative for vegans.
• Store it properly — cool, dark place or the fridge, to stop it going rancid.
• Take it with a meal that has some fat in it for better absorption.

Who tends to need it most

• Pregnant and breastfeeding women — DHA supports foetal brain and eye development.
• Older adults, for general cognitive, heart and joint support.
• Active people, since omega-3s support normal post-exercise recovery.
• People with a family history of heart disease.
• Vegetarians and vegans — an algae-based supplement is usually the practical choice.

Worth knowing before you start

Omega-3s are generally well tolerated. High doses can increase bleeding risk, especially if you're on blood thinners like warfarin — so check with your doctor first if that applies to you. The most common niggles are a fishy aftertaste, mild nausea or stomach upset, usually eased by taking the supplement with food or switching to an enteric-coated capsule.

Our honest bottom line

Omega-3s are one of the few supplements we'd call a genuine foundational nutrient — most South African diets don't include oily fish twice a week, so a decent fish oil or algae supplement is a reasonable, low-risk way to close that gap. It's not a cure-all, and if you're managing a diagnosed condition, it works alongside your treatment plan, not instead of it.

Not sure which omega-3 is right for you? WhatsApp our consultants — free, no pressure, no upsell. Or pop into Centurion, Glen Village or Edenvale.

By Precious, One Life Health Consultant

Shop this at One Life Health

• NATROCEUTICS® SA - Omega 3 Pure & Wild 60 Capsules — A pure, wild-sourced fish oil with a strong EPA and DHA number.
• BIOMAX® - Purest Omega 3 - 60 Capsules — A well-tested omega-3 for daily heart, brain and joint support.
• NOW® - Ultra Omega-3 Fish Oil (Bovine Gelatin) - 90 Softgels — A concentrated fish oil that keeps the EPA and DHA high per softgel.
• SOLGAR - Omega-3 Double Strength – 60 Softgels — A double-strength option to reach a maintenance dose in fewer capsules.
• WILLOW - Omega 3 Marine Salmon Oil - 90 Softgels — A salmon-oil omega-3 as a good-value everyday choice.

From the apothecary shelf

A few products we'd hand a customer asking for a starting point. Not a paid placement — these are what we actually take, recommend, or keep at the front of the shelf.