Omega-3 (EPA/DHA)

What it is

Omega-3 refers to the long-chain fatty acids EPA and DHA, obtained mainly from oily fish or fish oil. They are incorporated into cell membranes and shift the balance of the signalling molecules made from membrane fats, which lowers triglyceride production in the liver and dampens inflammatory signalling. They are used to help manage triglycerides and cholesterol, and are taken for joints and for cognition.

Used for

• Cholesterol
• Joints
• Cognition

What to know while taking it

These are fat-soluble, so absorption is markedly better when taken with a meal that contains some fat. Because they mildly reduce platelet aggregation, bleeding risk rises, and this matters most alongside anticoagulants and antiplatelets: warfarin, acetylsalicylic acid and clopidogrel. Triglycerides are the lab value that tracks the effect and is worth following. The oil oxidises with heat and light, which is why it is stored cool and dark; a strongly rancid smell means the capsules are past use.

When to see a doctor

Unusual bruising, nosebleeds, bleeding gums, blood in the stool or urine, or bleeding that is slow to stop, are reasons to see a doctor, especially alongside warfarin, aspirin or clopidogrel. Planned surgery or a dental procedure is also worth mentioning to a doctor beforehand.

Worth knowing

• Absorbed better with fat
• Raises bleeding risk
• Store cool and dark

Markers to watch

• Triglycerides