T Nation

LNA Leads to Prostate Cancer?

Hey people, what do you think of this article?


Although the article isn’t unequivocal, the author (industry vets will recognize the name) discusses a few studies showing a possible relationship between the consumption of plant-derived alpha-linolenic acid (i.e., flax seed products) and an increase in prostate cancer.

Would be interested in a discussion about this including science-minded responses.

Is there a link? “Possibly” is about all you can say.

There’s no doubt that you can process even the best foods and make them unhealthy. I am always wary of that whenever I read another study. This one is interesting because it tries to summarize a lot of studies. By its own admission, some studies show a link, others don’t.

I’ve seen this scribbed in several places - even some magazines. I always read it, but am never satisfied with the “conclusions”.

One of the first suspicions I have in relation to the link with flax seeds is whether they used seeds that were treated with pesticides (which ones; how much, etc.). There’s the first wild-card that most studies seem to ignore.

Another thought is that flax seeds are actually hard to break-down if chewed as seeds (most just come out the other end “untouched”). We can fix that on an industrial scale by processing them (grinding them up). In any studies involving flax - who processed the seeds? How careful are they with the product? (Flax oil will rapidly oxidize, and oxidized oil is very toxic - carcinogenic - a good reason to NOT buy flax oil, in my opinion). These are some of the major questions that always go unanswered in these types of publications - a bit like the latest on Vitamin E.

Until there’s a reliable source of date, from which true conclusions can be drawn, this comes down to a judgement call only on our parts.

I personally will continue to use flax seed and other sources of LNA. I grind my own organic flax seeds, and I use them immediately to minimize oxidation. Will I die of prostate cancer? I hope not, but I guess someone can email me when I’m dead so I can tell you what killed me…

Interesting topic.



  1. Keep in mind that too many omega 6 fatty acids has been linked to cancer.

  2. This data has been around, but it is unlclear what the source of LNA is. I don’t think flax oil.

  3. Fish oil as a source of omega 3s is…a safer bet anyway since no one can tell you reliably how much…forget if it is EPA or DHA that gets made in your body after ingesting flax oil i.e. what % gets converted.

The Monk and Wizlon,
Yes, there are a few studies suggesting this association but

a.) an association is not cause-and-effect evidence, as you may know, and

b.) other data suggest no relationship between linolenic acid intake and prostate cancer.

A thorough Medline search will corroborate this “mixed data” conclusion as one views multiple studies.

But you have a good point. I, myself, am concerned enough to limit my flax to 2 Tbsp. of freshly ground flax seeds (~2.5 g linolenate) about four days per week.

[quote]ScottL wrote:

  1. Keep in mind that too many omega 6 fatty acids has been linked to cancer.

So I guess this could suggest that flax users actually follow poor eating habits? Comparing two studies, Will Brink suggested in his supplement e-book (I lost the e-book so I’m going by memory here) that the reason why flax may not convert to epa/dha for certain people is because they’re diets contain too much omega-6’s. He theorized a high 6-3 ratio cancelled the conversion.

So could it be the reason people w/ prostate cancer received no benefit from flax is because they weren’t eating more omega-3s such as green leafy vegetables, deep-water fish, and grass-fed meat and eggs? They just assumed the flax would cover them.