To maintain healthy levels of EPA and DHA Omega-3s, the American Heart Association recommends an absolute minimum of 2 servings of oily, coldwater fish per week. Although it may seem simple to meet this guideline reliably and consistently, often it is not, primarily for three reasons:
Safety: Mercury and organic toxin levels in fish have been rising steadily over the past three decades. No long-term studies have proven that prolonged intake of trace levels of these impurities is safe.
Difficulty: The key to sound nutrition is consistency. Many people find it difficult to eat two servings of oily coldwater fish each week without fail.
Dietary choices: Many people do not eat fish, simply because they don.t like the taste.
Plant sources of Omega-3s, such as walnuts and flaxseed oil, do not contain any EPA or DHA, but instead contain ALA. In order for ALA to be used by the body, the body must convert it into EPA and DHA, a process that is unreliable and inefficient - perhaps as inefficient as 10:1, according to some studies. The American Heart Association does not recommend ALA for people at risk for heart disease.
For more information on which species of fish are safe to eat in your area, please contact your local state chapter of the United States Department of Agriculture.