Fish Oil and Prostate Cancer (Part 1)

Fish-OilIt is often suggested that Prostate cancer is the male equivalent of Breast cancer. There are some striking similarities. Both are hormonally driven and both occur with increasing frequency as a person ages. As you will also see, the mechanisms by which Fish Oil prevents and improves the outcomes in this type of cancer are also very similar to how it works in Breast cancer.

One of the things that distinguishes men from women is the presence of an enzyme in the skin and other areas of the body called 5 alpha reductase. This is the enzyme that converts Testosterone into its more potent but less desirable androgenic cousin Dihydroxytestosterone or DHT for our purposes. Women do not have this enzyme at least in any meaningful amounts. As a man ages the enzymatic activity of 5 alpha reductase seems to increase and converts more Testosterone into DHT. Additionally this happens while men are making less Testosterone in general (aging!).

Another enzyme that seems to become more active as a man ages is the enzyme Aromatize which changes DHT into estrogen. This coupled with declining levels of Testosterone leads to a situation where some men in their 50’s actually have as much or more estrogen floating around as Testosterone. Couple this with declining levels of Growth Hormone and you can see why the stereotypical middle aged male has a gut, increased body fat and decreased muscle tone.

This situation makes men mentally flabby as well!

Now comes the interesting part with regards to Prostate Cancer. For years it was taught (and a surprising number of doctors still think) that high levels of Testosterone lead to Prostate cancer and male Breast cancer. This was one of the warnings used to dissuade would be bodybuilders from using anabolic steroids.

Then it was found that the men who entered their 60’s and 70’s with the highest natural testosterone levels had the least amount of prostate cancer. In a sense the implication was that Testosterone therapy might actually PREVENT Prostate cancer. At this moment the Urologists in the crowd are having steam come out of their ears.  This is not what they want to hear!

In truth it is much more complex than that, but I had to have a little fun and ruffle a few feathers.

Here’s how we think it actually works:

Much like estrogen in women, the relative or in some cases absolute excess of estrogen in men seems to promote the Prostate Cancer.  This explains why men with high testosterone (naturally high) seem not to get prostate cancer and men with low testosterone do. Generally the ones with high testosterone have maintained a higher ratio of testosterone to estrogen than men whose testosterone has fallen and the other enzymatic pathways have become dominant. Some health gurus have twisted these facts to blame other sources such as diets, soy xenoextrogens (estrogens from outside sources like animals and plants added to our food stuffs) and of course medicines.

There is some truth to this especially with pickled foods. But let’s set the record straight on soy. If you go back to “The Truth About Soy” email of last week you will see that at least in the case of soy, it blocks estrogens effects.


P.S. This is continued in Part 2. Click here.


Regulation of gene expression and inhibition of experimental prostate cancer bone metastasis by dietary genistein.


For example, the expression of various metalloproteinases (MMPs) in PC3 bone tumors was inhibited by genistein treatment, whereas osteoprotegerin was upregulated. MMP immunostaining and transfection experiments also demonstrated that MMP-9 expression was inhibited in PC3 cells in vitro and PC3 bone tumors in vivo after genistein treatment. These results, particularly the in vivo results, demonstrate that dietary genistein may inhibit prostate cancer bone metastasis by regulating metastasis-related genes. Genistein may thus be a promising agent for the prevention and/or treatment of prostate cancer.

So what about the gurus that say that soy causes you to become feminized?  Well, they should know better.  I think they actually do but are sacrificing truth and accuracy for copy that stirs up their readers.  This to me is a bigger crime than ignorance!  Here is another reference:
Soy isoflavones in the treatment of prostate cancer.

Hussain M, Banerjee M, Sarkar FH, Djuric Z, Pollak MN, Doerge D, Fontana J, Chinni S, Davis J, Forman J, Wood DP, Kucuk O.

1 thought on “Fish Oil and Prostate Cancer (Part 1)”

  1. Pingback: Fish Oil and Prostate Cancer (Part 2) | Dr Dave Unleashed Blog

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