It’s true that omega-3 fatty acids, particularly those contained in fish oil supplements, are best absorbed by the body when taken alongside a high-fat meal (1). It’s also better to take them at the start of the meal, to prevent any potential gastric problems.
A lipid-rich meal stimulates the production of bile acids: produced by the liver, these help to emulsify essential long-chain fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These are the main omega-3 fatty acids found in the various omega-3 supplements available (fish oil, krill oil, calanus oil...).
Once emulsified in this way, the long-chain fatty acids are easier to digest by lipases, pancreatic enzymes which act at the upper level of the intestine (2) and which facilitate their absorption.
Some marine-source omega-3 supplements can produce adverse effects such as burping, acid reflux, bad breath, and a fishy after-taste … Such effects are mainly due to undue oxidation (3) of the fatty acids. To some degree, oxidation is normal, but it can become excessive during the various production and preservation stages of fish oil-based supplements.
To avoid these effects, be sure to choose supplements of EPA and DHA fatty acids in their natural form (triglycerides). It’s more expensive than the synthetic form (ethylic esters), but studies show that it’s easier to digest (there’s no release of ethanol) and twice as bioavailable. It’s a good idea to choose supplements that contain antioxidants too, especially tocopherols (ie, vitamin E), to minimise oxidation and maximise preservation.
In addition, taking these supplements at the start of a meal reduces the time they take to pass through the stomach and thus minimises the risk of unwelcome gastric effects.
EPA and DHA have proven beneficial effects:
In the case of therapeutic use, it’s essential to seek advice from your pharmacist in order to take the right dose for your particular situation.