Recommended intakes

The Ministry of Health recommends that an adequate intake is 90mg of long-chain omega-3 per day for women and 160mg for men. Men are bigger than women so they have a higher requirement.

But that's a baseline, for "healthy" people.

To help reduce the risk of chronic disease (especially heart disease), it recommends 430mg per day for women and 610mg per day for men. 

Excessive amounts (>3000mg/day) could increase the risk of bleeding. People taking blood thinners, such as daily aspirin or warfarin, should check with their doctor before taking supplements or eating lots of omega-3 fortified foods.

Real food

You can't beat real food for getting your daily intake of omega-3s.

Seafood is one of the main dietary sources of omega-3. The omega-3 content varies widely between and within different species depending on factors such as age, environment, season and the tissue being tested.

Oily fish such as salmon have the highest levels. Just eating one 150g piece of salmon per week can give you 4700mg of omega-3 - that's even more than a man's weekly suggested dietary target.

Packaged and pre-prepared fish and seafood products, including canned and packaged salmon, sardines and herrings range from 358 to 9200mgs per 100g.

Not a seafood fan? You can now buy bread, milk and dairy products with added omega-3s (see table above).

Past concerns with omega-3 fortified foods were that the oils could become oxidised, making the food taste and smell rancid. As a result, the food industry has developed a new way to protect the oil. The omega-3s are now microencapsulated in protective edible proteins or carbohydrates, which prevents the oils oxidising and the taste and smell changing.

Mercury concerns

Mercury occurs naturally in the environment and most seafood contains a small amount of mercury.

Some species (such as shark, swordfish, and fresh tuna) have higher levels of mercury.

Pregnant women need to take particular care, because their developing foetus is potentially more sensitive to the effects of mercury - so they should limit their intake of these species to one serving per week.

Fish oil products and supplements aren't a major source of mercury, and there's no health reason for restricting intake.