First, let me be clear that I don't discredit the superiority of fish oil as the best source of EPA and DHA. We agree on that. My response should have read "In this case, I prefer flax oil over fish oil."

I would recommend, however, that one obtain the omega-3's from fish itself rather than rely on a supplement. My preference for flax oil was primarily for someone who is attempting to add omega-3's without actually consuming fish itself.

In other words, if someone simply wanted to add omega-3's to their diet for the health benefits, oily fish would be a superb choice. In Jane's case, she wanted to add a calorically dense source, so in my opinion, flax oil would be preferable to fish oil.

Here are some articles that support the health benefits of flax oil/ALA and the conversion of ALA to EPA. There actually isn't good evidence at this time to support the conversion of ALA to DHA. Regardless, ALA has been shown to provide significant improvements to one's health.

Supplementing Lactating Women With Flaxseed Oil Does Not Increase Docosahexaenoic Acid in Their Milk

Francois CA, Connor SL, Bolewicz LC, Connor WE
Am J Clin Nutr. 2003;77:226-233

Background: Flaxseed oil is a rich source of 18:3n-3 (alpha-linolenic acid, or ALA), which is ultimately converted to 22:6n-3 (docosahexaenoic acid, or DHA), a fatty acid important for the development of the infant brain and retina.
Objective: The objective of this study was to determine the effect of flaxseed oil supplementation on the breast-milk, plasma, and erythrocyte contents of DHA and other n-3 fatty acids in lactating women.
Design: Seven women took 20 g flaxseed oil (10.7 g ALA) daily for 4 wk. Breast-milk and blood samples were collected weekly before, during, and after supplementation and were analyzed for fatty acid composition.
Results: Breast milk, plasma, and erythrocyte ALA increased significantly over time (P < 0.001) and after 2 and 4 wk of supplementation (P < 0.05). Over time, 20:5n-3 (eicosapentaenoic acid, or EPA) increased significantly in breast milk (P = 0.004) and in plasma (P < 0.001). In addition, plasma EPA increased significantly (P < 0.05) after 2 and 4 wk of supplementation. There were significant increases over time in breast-milk 22:5n-3 (docosapentaenoic acid, or DPA) (P < 0.02), plasma DPA (P < 0.001), and erythrocyte DPA (P < 0.01). No significant changes were observed in breast-milk, plasma, or erythrocyte DHA contents after flaxseed oil supplementation.
Conclusions: Dietary flaxseed oil increased the breast-milk, plasma, and erythrocyte contents of the n-3 fatty acids ALA, EPA, and DPA but had no effect on breast-milk, plasma, or erythrocyte DHA contents.

J Nutr. 2006; 136(1):83-7 (ISSN: 0022-3166)

Harper CR; Edwards MJ; DeFilippis AP; DeFilipis AP; Jacobson TA
Department of Medicine, Office of Health Promotion and Disease Prevention, Emory University, Atlanta, GA, USA. charper@emory.edu

Alpha-linolenic acid (ALA) is a major dietary (n-3) fatty acid. ALA is converted to longer-chain (n-3) PUFA, such as eicosapentaenoic acid (EPA) and possibly docosahexaenoic acid (DHA). EPA and DHA are fish-based (n-3) fatty acids that have proven cardioprotective properties. We studied the effect of daily supplementation with 3 g of ALA on the plasma concentration of long-chain (n-3) fatty acids in a predominantly African-American population with chronic illness. In a randomized, double-blind trial, 56 participants were given 3 g ALA/d from flaxseed oil capsules (n = 31) or olive oil placebo capsules (n = 25). Plasma EPA levels at 12 wk in the flaxseed oil group increased by 60%, from 24.09 +/- 16.71 to 38.56 +/- 28.92 micromol/L (P = 0.004), whereas no change occurred in the olive oil group. Plasma docosapentaenoic acid (DPA) levels in the flaxseed oil group increased by 25% from 19.94 +/- 9.22 to 27.03 +/- 17.17 micromol/L (P = 0.03) with no change in the olive oil group. Plasma DHA levels did not change in either group. This study demonstrates the efficacy of the conversion of ALA to EPA and DPA in a minority population with chronic disease. ALA may be an alternative to fish oil; however, additional clinical trials with ALA are warranted.

Omega-3-rich Flaxseeds Protect Bone Health

Alpha linolenic acid, the omega-3 fat found in flaxseed and walnuts, promotes bone health by helping to prevent excessive bone turnover-when consumption of foods rich in this omega-3 fat results in a lower ratio of omega-6 to omega-3 fats in the diet.(Griel AE, Kris-Etherton PM, et al. Nutrition Journal)

The researchers also found that omega-3s from nuts, seeds, and vegetable oils-such as walnuts and flaxseed-had just as much impact on blood pressure as omega-3s from fish.

Flaxseed Provides Comparable Cholesterol-Lowering Benefits to Statin Drugs

In a study involving 40 patients with high cholesterol (greater than 240 mg/dL), daily consumption of 20 grams of ground flaxseed was compared to taking a statin drug. After 60 days, significant reductions were seen in total cholesterol, LDL cholesterol, triglycerides and the ratio of total to HDL cholesterol-in both groups. Those receiving flaxseed did just as well as those given statin drugs!

The Benefits of Flaxseed

WHFoods: Flaxseeds