Is Protein a PCa Risk Factor?

[pjoshea13]

New study below [1].

The jounal is Complementary Therapies in Medicine, which is new to me. It became full access this year & some might like to browse through recent issues [2].

The study is a meta-analysis.

Bottom line: protein from whatever source - animal, plant or total - was not a statistically significant risk factor. Exception: dairy, but only above 30 g/day.

The Abstract is a little confusing to me:

"... positive association was seen among men who consumed ≥30 gr/day of dairy protein, such that a 20g/d increase in dairy protein intake (equal to 2.5 cups milk or yogurt) was associated with a 10% higher risk of prostate cancer" So, 20g or 30g?

{Note that a cup of whole milk has 8g protein. 2.5 cups milk = 20g.}

With advanced PCa, IGF-I (a growth factor found in dairy products, but also manufactured by the body) is associated with progression. One way to reduce IGF-I production is to limit total protein intake.

Mayo: "The recommended dietary allowance to prevent deficiency for an average sedentary adult is 0.8 grams per kilogram of body weight" So, by limiting protein to 0.7 grams per kilogram of body weight, say, we might lower IGF-I. The body will not invest in growth if the availability of adequate protein is 'iffy'. One might achieve this, I suppose, by by having a few low-protein days between protein binges. A nice porterhouse steak might be a suitable reward. Note that in these scenarios, the source of protein hardy matters, IMO.

-Patrick

[1] pubmed.ncbi.nlm.nih.gov/358...

{full text: reader.elsevier.com/reader/...

Review Complement Ther Med. 2022 Jul 9;102851. doi: 10.1016/j.ctim.2022.102851.Online ahead of print.

Dietary protein intake and prostate cancer risk in adults: a systematic review and dose-response meta-analysis of prospective cohort studies

Meshari A Al-Zahrani 1, Mohammad Ahmad 2, Mohammad Alkhamees 3, Ahmed Aljuhayman 3, Saleh Binsaleh 4, Raed Almannie 4, Rahul Tiwari 5Affiliations expandPMID: 35820576 DOI: 10.1016/j.ctim.2022.102851Abstract

Objective: This study aimed to conduct a comprehensive systematic review and dose-response meta-analysis to summarize available findings on the associations between dietary protein intake and prostate cancer risk as well as the dose-response associations of total, animal, plant, and dairy protein intake with prostate cancer risk.

Methods: This study followed the 2020 PRISMA guideline. We conducted a systematic search in the online databases of PubMed, Scopus, ISI Web of Science, and Google Scholar to detect eligible prospective studies published to October 2021 that assessed total, animal, plant, and dairy protein intake in relation to prostate cancer risk.

Results: Overall, 12 articles containing prospective studies with a total sample size of 388,062 individuals and 30,165 cases of prostate cancer were included. The overall relative risks (RRs) of prostate cancer, comparing the highest and lowest intakes of total, animal, plant, and dairy protein intake, were 0.99 (95% CI: 92-1.07, I2=12.8%), 0.99 (95% CI: 95-1.04, I2=0), 1.01 (95% CI: 96-1.06, I2=0), and 1.08 (95% CI: 1.00-1.16, I2=38.1%), respectively, indicating a significant positive association for dairy protein intake (P=0.04) and non-significant associations for other protein types. However, this positive association was seen among men who consumed ≥30 gr/day of dairy protein, such that a 20g/d increase in dairy protein intake (equal to 2.5 cups milk or yogurt) was associated with a 10% higher risk of prostate cancer (Pooled RR: 1.10, 95% CI: 1.02 to 1.20, I2 = 42.5%). Such dose-response association was not seen for total, animal, and plant protein intake.

Conclusion: Overall, dairy protein intake may increase the risk of prostate cancer in men who consumed >30 gr/day of dairy protein. Larger, well-designed studies are still required to further evaluation of this association.

Keywords: Dairy; Diet; Meta-analysis; Prostate cancer; Protein.

Copyright © 2022 The Authors. Published by Elsevier Ltd.. All rights reserved.Conflict of interest statement

Conflicts of interest The authors declare no conflicts of interest.

[2] sciencedirect.com/journal/c...

[Brocktree]

Thank you pjoshea13 for your time and faithfulness in keeping me/us informed. You and Nal are treasures

[Hidden]

Very interesting. Thanks!

[Teufelshunde]

From my reading this is risk of developing PC initially, so we assume that it is equally as bad or worse from a progression standpoint?

[pjoshea13 in reply to Teufelshunde]

Protein is needed for tumor growth. With adequate protein there will be IGF-I. the "GF" stands for "growth factor". Beware of any names with "GF" in them.

... [VEGF] Vascular endothelial growth factor

... [TGF...] Transforming growth factor ...

... [EGF] Epidermal growth factor

... etc.

Protein was not generally found to be a risk factor for occurrence. But milk protein (at significant levels) was. Milk contains IGF-1. Identical to the IGF-I in human milk. Babies drink a food that not only contains all of the buiding blocks for rapid growth, but also the GF to stimulate growth.

My theory about milk drinkers is that the milk doesn't actually cause PCa, but if PCa occurs it can take off rapidly because of the stimulation of IGF-I.

-Patrick

[Teufelshunde in reply to pjoshea13]

Thanks Patrick for that. I do use 2 tbsp of half and half per day. >1 protein so I feel I am ok with this now. Before PC, drank a gallon of milk every 10 days, with the eggs, and cheese.

[Currumpaw in reply to pjoshea13]

Nice post! Thanks once again.

I think your hypothesis that there is no risk with many foods--the processed, nitrate and nitrite laden foods and such excluded--if there isn't an active cancer-- is correct. That is my belief also.

Every so often there is an article about someone who has eaten exclusively at a fast food chain with no apparent ill effects. The last one I read was about a man in his 60's who has eaten Big Macs every day since he was a teenager. In addition to that he has saved the packaging!!?? Note the punctuation--I have no idea how think about that. He must be fun at Thanksgiving dinners don't you think?

It was easy to find some info.

"Grandfather Donald Gorske (pictured) has been eating two Big Macs a day since 1972. Guinness World Records Gorkse has meticulously filed away every burger receipt since 1972 along with the burger packaging, which he flattens down and stores in boxes by the year."

This man has eaten 32,340 Big Macs since 1972 - Newsweek

newsweek.com/man-eats-two-b...

newsweek.com/man-eats-two-b...

If McDonalds ever changes their "secret sauce" or whatever such as only serving Big Macs on whole wheat buns I can possibly see a melt down such as in the Judge Wopner scene in Rain Man.

Currumpaw

[akaipop3ps in reply to pjoshea13]

How is plain, non fat yogurt, figured into this protein (from milk) issue?

[andy_diggs]

The protein topic is a complex and nuanced one and I still don't think there is a clear answer. After my RP in early 2021 I hit 59 kg @ 180 cm tall. My goal post op was/is to build as much muscle as possible to build my reserves, so I consume a decent amount of protein. I am sure it will be stimulating igf-1 and mTor, but I also workout 5 days a week, so the mTor and IGF-1 have a "target" so to speak in that my body is actively building muscle. I try and consume clean protein, both animal and plant, but I don't consume dairy or eggs. I also do a 36 hour fast once per week to keep my insulin sensitivity up (Sunday night to Tuesday morning) and give my digestive system a chance to clear and rest. The rest of the week I pretty much go for it. I have put on about 4kg of muscle over that time and intend ramping up the protein over the next 12 months if my PSA stays below detectable limits . My target is 70kg by Christmas 2023 while keeping body fat below 10%. Protein may stimulate IGF-1, but increase muscle mass improves your insulin sensitivity as well as a host of other longevity benefits.

[London441]

Sugar, and simple carbohydrates in general are damaging enough to confound profoundly attempts to evaluate the possible harm of protein. In even simpler terms, too much food and not enough movement is the most serious issue in the developed world by such a large margin it’s a luxury to be able to ponder this. Great info but most should beware of putting cart before horse. Most of us are simply too fat and deconditioned as the primary consideration.

[j-o-h-n]

If it were it would be called "Contein"....

Good Luck, Good Health and Good Humor.

j-o-h-n Thursday 07/14/2022 7:53 PM DST