If you search PubMed for <prostate iodine> you will get over 1,500 hits. Unfortunately, most are related to Iodine-125-brachytherapy. In fact, I haven't found any study that links iodine deficiency to PCa.
Yet Dr. Brownstein is adamant that PCa is one of a long list of diseases where deficiency increases risk.
I became interested in iodine after I was made aware of intense interest on some of the BCa groups. The breast-iodine literature goes back fifty years.
I discovered that the prostate readily takes up iodine - so perhaps it has a protective role?
Some time in 2006, my son told me of a test for deficiency. You paint some iodine on a small patch of inner arm before bedtime. If it has disappeared before morning, you need to keep doing it until the area remains stained. It isn't good advice, but that's what I did.
Earlier that year, I had gone to a hand surgeon, since I couldn't straighten a finger in my right hand & the condition was rapidly getting worse. He diagnosed Dupuytren's contracture. It's on Dr. Brownstein's list.
Over the period of my arm-painting experiment, my symptoms began to reverse. The surgeon had told me that there was nothing to be done. The situation would progress. Surgery was not likely to help. He seemed almost amused by "the Viking disease".
As with PCa, it is difficult to get evidence that iodine deficiency is related to Dupuytren's contracture. I continued painting for a while, during which the reversal occurred at about the same rate as during its appearance. The thickening of connective tissue in my palm had almost disappeared when I first went to my integrative medicine doc. He told me to switch to Iodoral [1] - more expensive but safer.
Iodine, for most people, is only associated with the thyroid. Iodized salt all but eliminated the U.S. goiter problem almost a century ago. If a deficiency were to be related to, both, thyroid cancer & PCa, that might show up in the secondary cancer data.
[2] (2015) "Coupling of Prostate and Thyroid Cancer Diagnoses in the United States"
The authors seem to have set out to disprove linkage:
"Prostate and thyroid cancers represent two of the most overdiagnosed tumors in the U.S. Hypothesizing that patients diagnosed with one of these malignancies were more likely to be diagnosed with the other, we examined the coupling of diagnoses of prostate and thyroid cancer in a large U.S. administrative dataset."
Blame the patient?
"Patients with thyroid cancer were much more likely {+28%} to be diagnosed with prostate cancer than patients in the SEER control group ..."
"Similarly, the observed incidence of thyroid cancer was significantly higher {+30%} in patients with CAP when compared with SEER controls ..."
"In the absence of a known biological link between these tumors, these data suggest that diagnosis patterns for prostate and thyroid malignancies are linked."
Rather than contemplate a "biological link", the data was dismissed as perhaps being an artifact of inappropriate patient/doctor screening behavior.
I'm not saying that that the authors are wrong, but it seems that my PCa developed at a time when iodine intake was suboptimal.
[3] (2014) "Incidence of second malignancies for prostate cancer."
Cretinism (due to iodine deficiency) was not uncommon in the alpine regions of Europe, where there is little iodine in the soils. The Swiss were the first to iodize salt. Unlike the U.S., Switzerland is not particularly known for PCa over-screening.
For men with PCa in the Canton of Zurich, the risk factor for thyroid cancer was 2.89.
[4] (2015) "Risk of Second Primary Cancer among Prostate Cancer Patients in Korea"
Korea has a low PCa incidence rate & no mass overscreening:
"men with prostate cancer have a 25% lower risk of developing {a second primary cancer} in Korea, but a higher risk {"significant increases in the risk"} of developing subsequent bladder and thyroid cancers"
[5] Peyronie's Disease. Very similar in cause to Dupuytren's Contracture. A build up of connective tissue in the penis leads to curvature that can interfere with sexual activity. It is on Dr. Brownstein's list.
I can't seem to find the Johns Hopkins paper which first reported penile problems after prostatectomy that seemed similar to Peyronies. The concern was that the operation was perhaps somehow causing these problems. From my perspective, if a significant subset of men with PCa have poor iodine status, urologists might note a greater incidence of Peyronie's emerging before or after surgery. In the latter instance, the patient might be inclined to blame the surgery.
[5a] (2010) "Peyronie's disease following radical prostatectomy: incidence and predictors."
"Men presenting with sexual dysfunction after RP {radical prostatectomy} have higher PD {Peyronie's disease} incidence then the general population."
The authors end by mumbling on about whether "RP has a causative role in the pathogenesis of PD." Without the hypothesis that iodine deficiency is a risk factor for PCa & PD, one would not look for a more direct relationship than the surgery.
[5b] (2004) "Subjective and objective analysis of the prevalence of Peyronie's disease in a population of men presenting for prostate cancer screening."
Out of 534 men presenting for PCa screening, a "total of 48 patients were found to have a palpable penile plaque on physical examination for a prevalence rate of 8.9%."
"The mean age of men with Peyronie's disease was 68.2 years compared to a mean of 61.8 years in men without Peyronie's disease ..."
Unfortunately, while the study found Peyronie's to be more common than expected, it did not investigate any connection with PCa (why would the team have expected one without the iodine hypothesis?)
[6] (2013) "Uptake and antitumoral effects of iodine and 6-iodolactone in differentiated and undifferentiated human prostate cancer cell lines."
"Non-cancerous (RWPE-1) and cancerous (LNCaP, DU-145) cells, as well as nude mice xenotransplanted with DU-145 cells were used as cancer models."
"All three cell lines take up both forms of iodine." "In the three cell lines both forms of iodine activated the intrinsic apoptotic pathway "
"Iodine supplementation impaired growth of the DU-145 tumor in nude mice."
...
Regardless of any possible role in PCa, iodine insufficiency needs to be corrected. LEF called deficiency an epidemic in 2008 [7].
I have mentioned Dr. Brownstein a few times. He wrote "Iodine : Why You Need It, Why You Can't Live Without It" [8]. I haven't read it, but probably should.
-Patrick
[1] swansonvitamins.com/optimox...
[2] ncbi.nlm.nih.gov/pmc/articl...
[3] journals.plos.org/plosone/a...
[4] journals.plos.org/plosone/a...
[5a] ncbi.nlm.nih.gov/pubmed/205...
[5b] ncbi.nlm.nih.gov/pubmed/151...
[6] ncbi.nlm.nih.gov/pubmed/225...
[7] lifeextension.com/magazine/...
[8] amazon.com/Iodine-Need-Cant...
