Is it possible to get too much omega-3? How do the omega-3s from various sources compare? Nutrition Diva helps sort it all out for you.
All Omega-3s Are Not the Same
Flax and fish are not interchangable sources of omega-3s.
However, as you may know, omega-3 is not one nutrient but a whole family of fatty acids. Certain members of the family, such as EPA and DHA, which are the omega-3s found in fish, are much more biologically active than other forms, such as ALA, which is the type you get from flaxeed. While your body does have the ability to convert ALA into EPA and DHA, this conversion is not terribly efficient. So, to answer one part of Ben's question, flax-enriched flour and fish oil are not interchangable sources of omega-3s.
See also: Fish Oil and Omega-3s
Furthermore, the Adequate Intake refers to ALA, the least active form of omega-3. Meanwhile, most of the research on the health benefits of omega-3s focuses on EPA and DHA. The average American gets about 150mg of EPA and DHA (combined) per day. Yet a review of the scientific literature suggests that most people should aim for about twice that much, or 300mg per day. Those with (or at risk of) cardiovascular disease would benefit from more, up to 1,000mg per day. So, to answer another part of Ben's question, I don't think it's overkill for him to take his fish oil capsule on days when he is also cooking with flax-enriched flour--seeing as the flour contains no EPA or DHA.
Finally, let's tackle the third part of Ben's question:
Can You Get Too Much Omega-3?
The Institute of Medicine declined to set an upper limit for omega-3s because they say that "There is no known level at which adverse effects may occur." Then again, these guys seem somewhat oblivious to the research on EPA and DHA. Do we want to take their word on this?
As you know from previous Nutrition Diva episodes, I do think it's possible to overdo a good thing. For example, one of the reasons that fish oil reduces the risk of heart disease is that it has an anti-coagulating, or blood-thinning, effect. Excessive intake of fish oil, especially in combination with blood-thinning drugs could potentially cause problems. If you've ever been scheduled for surgery, for example, your surgeon may have asked you to stop taking any fish oil supplements several days prior to surgery, in order to reduce the risk of uncontrolled bleeding.
See also: Broccoli and Blood Thinners
And just a few weeks ago, I reviewed some research suggesting that high intakes of fish oil might increase a man's risk of prostate cancer. As I discussed in that episode, I don't think that most men need to completely stop eating fish or taking fish oil. For most guys, the benefit to your heart probably outweighs the risk. But it's another good reminder of the virtues of balance and moderation.
See also: Does the Omega Ratio Matter?
How Much Is Too Much?
There are a few situations where high dose fish oil is medically appropriate. But these are not do-it-yourself scenarios. Unless your doctor is monitoring you closely, I recommend limiting fish oil supplementation to a combined 1,000mg of EPA and DHA per day. And while I don't think it's overkill to have both fish oil and flax flour on the same day, I do think it makes sense to skip the fish oil pills on days when fish is on the menu!
I think there's less potential for harm from high intakes of ALA, which is the kind of omega-3 in the special flour Ben found. Nonetheless, there are good reasons to take it easy on baked goods and other flour-based foods--even when they're high in omega-3!
See also: The Truth About Whole Grains
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