This is a follow-on from my Fred Kummerow post - in response to some questions.
Flaxseed contains two elements that might affect PCa progression: lignans that might impede it & alpha-linolenic acid [ALA] that might accelerate it.
A tablespoon of flaxseed oil contails a lot of ALA with little or none of the lignans. A tablespoon of flaxseed hulls contains a lot of lignans without the ALA. What is the net effect of a tablespoon of seeds? One shouldn't expect a lot of lignans or a lot of ALA, so does it matter that many men I knew a dozen years ago were devoted to the breakfast ritual of grinding the seeds?
Wendy Demark-Wahnefried at Duke became interested in the effect of whole flaxseed over 20 years ago. Unfortunately, she also felt that a low-fat diet might also be useful. In 2001 she published the results of a pilot study [1] involving 25 men scheduled for prostatectomy. 30 grams of flaxseed coupled with a 20%-fat diet for 21-77 days (34 average).
"... significant decreases were observed in total serum cholesterol (201 ... mg/dL to 174 ... mg/dL), total testosterone (422 ... ng/dL to 360 ... ng/dL), and free androgen index (36.3% ... to 29.3% ...)"
"The baseline and follow-up levels of prostate-specific antigen were 8.1 ... ng/mL and 8.5 ... ng/mL, respectively, for the entire sample ...; however, among men with Gleason sums of 6 or less (n = 19), the PSA values were 7.1 ... ng/mL and 6.4 ... ng/mL ..."
Perhaps, since she measured T, she thought that a reduction would be a good thing? Men with PCa are not noted for elevated T. A 62 point drop brought average T down to the hypogonadism cutoff. Was she aiming for lite-castration?
Average PSA went up by 5% during the short intervention. However, it went down in the Gleason 6 or under cases.
Notice Wendy's sleight of hand. There were only 6 men with Gleason 7 or over, & yet they drove up PSA for the entire group by 5% even as the 19 other men saw a 10% drop. A rough calculation suggests that the 6 had an average PSA of 11, rising to 15. I can't rely on my math these days, but those men experienced significant increases (or at least one of them did! LOL)
There seems to be two responses to the intervention, rather like the Finasteride & Dutasteride PCa prevention studies - a benefit for Gleason 6, but an apparent stimulation of more serious cancer.
From my perspective, the added variable of the low-fat diet adds a couple of complications: (i) an increase in insulin levels associated with high-carb diets & (ii) by reducing total fat, there is less linoleic acid to counter the ALA - i.e. while there might not have been a lot of ALA, it would have more influence with a low-fat diet.
Three years later (2004) [2], another pilot study paper. Perhaps a continuation, with a 6 month intervention. Gleason scores not mentioned in the Abstract, so not much to be gleaned.
In 2008, the results of a Phase II clinical trial [3].
"Flaxseed Supplementation (not Dietary Fat Restriction) Reduces Prostate Cancer Proliferation Rates in Men Presurgery"
This time, 161 men in 4 arms (with/without flax, with/without low-fat diet).
"Proliferation rates were significantly lower ... among men assigned to the flaxseed arms."
"Data on PSA and biopsy Gleason sum suggested that most participants had earlier-stage disease, with roughly two-thirds having biopsy Gleason sums ≤6."
{GS <6:1%, =6:63%, =3+4:24%, =4+3:6%, >7:4%}
"In contrast to our previous studies ... we did not observe differences in PSA change between the study arms. Curiously, all study arms experienced significant decreases in both PSA and testosterone during the presurgical period."
Who knows what men might use in the month leading up to surgery?
"Our initial premise, that flaxseed exerts its effects through androgen and IGF pathways was unsupported ..."
"An unexpected finding of this study was despite the fact that ALA intakes were significantly higher among flaxseed-supplemented men, we did not find any evidence that this translated into higher levels of ALA in the erythrocytes or prostatic tissue."
"... the down-regulation of Ki-67, a candidate surrogate for cell proliferation, in the flaxseed-treated arms is highly suggestive of an anti-carcinogenic effect on prostate cancer cells in vivo."
This was the study that turned a lot of men onto flaxseed. Wendy even suggested that there was an omega-3 benefit of ALA, i.e. conversion to EPA/DHA. But in 2012, she redeemed herself with:
"Prostatic alpha-linolenic acid (ALA) is positively associated with aggressive prostate cancer" [4]
"We found that while flaxseed supplementation resulted in significantly higher levels of ALA in the diet, this consumption did not translate into higher prostatic levels of ALA. This was an important finding because in additional analyses, prostatic ALA was associated with significantly higher PSA and tumor proliferation rates."
I suspect that it had little effect on men with PCa. Too complicated to make the news.
The study confirms that ALA in prostatic cells is dangerous.
The problem with the earlier studies was the assumption that ALA intake levels correlated to PCa levels. Fatty acids are complicated. With a decent level of linoleic acid, ALA will be prevented from entering PCa cells at high levels. Who knew that corn oil could be protective? The men who were on the low-fat diet might have been at a disadvantage, but they were not instructed regarding fats to use or avoid.
...
Bottom line: don't mess with ALA in any form. Flaxseed lignans are the presumed cause of the protection reported by Wendy, although it's not clear if benefit might vary by Gleason. Here is what I use:
flaxpremiumgold.com/Flax-Hu...
Shop around - prices vary.
... apologies to Wendy for using her first name, but Demark-Wahnefried is a bit daunting.
-Patrick
[1] ncbi.nlm.nih.gov/pubmed/114...
[2] ncbi.nlm.nih.gov/pubmed/151...
Flaxseed
Flaxseed oil, Omega-3's and lignans - good or bad with PCa?
PSA is increasing with Docetaxel, what should we do now ? 
