Intake Recommendations for Omega 3 Fatty Acids
Omega-3 fatty acids are macronutrients, and as such are not assigned a recommended daily allowance (RDA). Instead, they are given AI (Acceptable Intake) and AMDR (Acceptable Macronutrient Distribution Range) values.
The acceptable intake for alpha-linolenic acid (ALA) is 1.6 grams/day for men and 1.1 grams/day for women (excluding those who are pregnant or lactating), whilst the acceptable macronutrient distribution range is 0.6-1.2% of total energy; that is, people are recommended to consume at least 0.6-1.2% of their total daily calories as omega-3 fats.
It is recommended that eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) can contribute up to 10% of the acceptable intake for ALA. For example, the UK Department of Health recommend an intake of 0.2 g/day of EPA and DHA, whilst the British Nutrition Foundation Task Force recommend a higher intake of these two omega 3 fatty acids: 1.0-1.5 g/day.
Omega 3 Consumption Advice
Meeting the recommended acceptable intake for omega 3 fatty acids can be accomplished in a number of ways, such as the inclusion of oily fish into the diet at least twice a week, and the addition of oils and foods rich in alpha-linolenic acid (e.g flaxseed, soya beans and walnuts). For example, a 4 ounce piece of salmon contains 1.5 grams of omega 3 fats, whilst 2 tablespoons of flaxseeds contain 3.5 grams of omega 3 fats.
There have recently been concerns regarding mercury levels in fish, and whilst most people's consumption of fish poses no health concern, certain groups (such as children or pregnant/lactating women) are advised to eat fish that are lower in mercury. This includes salmon, tuna, pollock and catfish.
Vegetarians that rely on ALA as their only source of omega-3 fatty acids should increase their consumption of ALA-rich foods to ensure sufficient production of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).
It is not advisable to take more than 3 grams of omega-3 fatty acids from supplements (unless recommended to do so by a doctor) as high intakes can cause excessive bleeding in some people.