Archive for the ‘Omega-3s’ Category

Flaxseed Absorption

Tuesday, September 29th, 2009

I just updated the High ALA Sources of with the following info from a study in the September issue of the European Journal of Clinical Nutrition:

“There is some evidence that people 45 and older do not absorb the oil from ground flaxseeds as well as from flaxseed oil.2 The one study indicating this was only for four weeks and using 6 g of ALA per day. With smaller amounts and for longer periods, the difference might be negligible, but that hasn’t been tested.”

What does this mean? If you are age 45 or older, you might want to get your ALA from flaxseed oil, rather than ground flaxseed. Or you might want to wait until more research determines whether this study is applicable to a more typical situation of eating less ALA but on a more consistent basis.

2. Patenaude A, Rodriguez-Leyva D, Edel AL, Dibrov E, Dupasquier CM, Austria JA, Richard MN, Chahine MN, Malcolmson LJ, Pierce GN. Bioavailability of alpha-linolenic acid from flaxseed diets as a function of the age of the subject. Eur J Clin Nutr. 2009 Sep;63(9):1123-9.

Omega-3s and Prostate Cancer

Wednesday, May 27th, 2009

Alpha-linolenic acid (ALA) is the main omega-3 fatty acid found in plant foods, and it is found in large amounts in flax seeds. A number of studies have found a link between ALA and prostate cancer, but others have not. Until recently, the best review of the literature claimed that ALA does not cause prostate cancer. I thought its logic was sound, but it came from the Flax Council of Canada.

Now a new meta-analysis says that ALA does not cause prostate cancer. The abstract states:

When examined by study type (ie, retrospective compared with prospective or dietary ALA compared with tissue concentration) or by decade of publication, only the 6 studies examining blood or tissue ALA concentrations revealed a statistically significant association. With the exception of these studies, there was significant heterogeneity and evidence of publication bias. After adjustment for publication bias, there was no association between ALA and prostate cancer (RR: 0.96; 95% CI: 0.79, 1.17).

I’ve updated the article Omega-3 Fatty Acid Recommendations for Vegetarians with this information.

How much omega-3?

Monday, February 23rd, 2009


My wife and I aren’t all that into flaxseed oil. If we eat a 1/4 cup of walnuts (or some other amount) every day as well as Deva’s Omega-3 DHA (200 mg DHA), will that substitute sufficiently for the nutritional values of flaxseed?


Below and here are my omega-3 recommendations. You only need 3 halves of walnuts if you are taking DHA.

Daily Recommendations

1. 200 – 300 mg DHA.

2. Do not prepare food with oils high in omega-6 (corn, soy, safflower, sunflower, “vegetable,” sesame oil). Instead, use low omega-6 oils like olive, avocado, peanut, or canola. Only cook canola under low heat and for short periods.

3. Add 0.5 g of uncooked ALA to your diet daily (see chart). This would be the equivalent of:

1/5 oz English* walnuts (3 halves)
1/4 tsp of flaxseed oil
1 tsp of canola oil
1 tsp ground flaxseeds

*English walnuts are the typical walnuts for sale in grocery stores. They are distinct from black walnuts.