by Laura-OMS » Thu Jun 08, 2017 1:52 pm
Message from one of our doctors:
I have reviewed the medical literature and could find no evidence for Flaxseed oil causing inappropriately low testosterone levels in males.
In my literature search I found 1 small pilot study that showed flaxseed supplementation reduced free testosterone in men with prostate cancer ( a pathological state - Prostate cancer is a testosterone dependent cancer).
Of note in this trial the testosterone was lowered (as was the free androgen index(FAI) - a measure of the available testosterone) but remained well within normal reference range (as did the FAI)
congruent to this:
Flaxseed supplementation has been shown to be protective for prostate cancer - interesting RCT here:
(Flaxseed supplementation (not dietary fat restriction) reduces prostate cancer proliferation rates in men presurgery.)
(Prostate Cancer , diet and hormones is covered very well in Prof Colin Campbell's "TheChina Study" - do read this).
In fact the 1 study in men without prostate cancer found the opposite. Men following a Vegan diet and supplementing with Flaxseed oil increased their Testosterone:
"There was a pre-post intervention increase in testosterone for men (111.0 Â± 121.13 ng/dL, P < .05)."
Of reassurance is this study ( ) which found, "
In summary, we found that omega-3 fatty acids may be positively associated with testicular function as indicated by testicular volume whereas intake of omega-6 fatty acids and trans fatty acids appear to be negatively related to it. Some of these findings, most notably those for omega-3 and trans fats, are in agreement with animal experimental data as well as preclinical and clinical data
The authors of this paper noted:
"there is little consistency in the relation between omega-3 PUFA intake and reproductive hormones among men,27,28,29,30"
"experimental models also showed a positive effect of omega-3 PUFAs on male reproductive health.55,56"
There is a case report showing that it reduces testosterone in women with PCOS (who again have inappropriately high testosterone levels).
Interestingly a diet rich in flaxseed oil had no effect on testosterone levels in postmenopausal women :
Serum concentrations of androstenedione, estrone, sex hormone-binding globulin, progesterone, testosterone, free testosterone, "dehydroepiandrosterone, and dehydroepiandrosterone sulfate were not altered with flaxseed feeding."
In summary I could find no detrimental effects on supplementing with Flaxseed oil and no risk of it causing an abnormally low Testosterone levels. Indeed there is good evidence that following a vegan diet and supplementing with flaxseed oil results in increased Testosterone levels. It will also be protective against Cancers, including Prostate Cancer (and Cardiovascular disease).