Milk and prostate cancer recurrence - Prostate Cancer N...

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Milk and prostate cancer recurrence


I thought I might ask the brains-trust on this board about something that my research has thrown up. Quite a few studies show a correlation between PCa recurrence and progression and consumption of dairy products. There are sometimes differences between whether it shows high fat products are the problem, or any dairy, but there's a reasonably consistent, if not absolutely determined connection. So, on the safety first principle, I've dropped dairy, and moved to soy (which has some evidence of a good effect).

What do people think? Are soy flat whites (or lattes) a step too far?

32 Replies

The studies are not consistent. In fact, they are remarkably inconsistent. What about the studies that say it has no effect?

"With the exception of whole milk, our results suggest that milk and dairy intake after a prostate cancer diagnosis is not associated with an increased risk of lethal prostate cancer."

"Total dairy product consumption was not statistically significantly associated with risk of any prostate cancer or stratified by disease severity. "

"The RRs of advanced prostate cancer were reported as ranging from 0.92 to 1.33 for dairy products, 1.09 (95% CI: 0.86, 1.38) for milk and 1.18 (95% CI: 1.00, 1.41) for cheese consumption. Finally, for prostate cancer mortality, the RRs were reported as 1.11 (95% CI: 0.97, 1.27) for dairy products, 1.38 (95% CI: 0.49–3.86) for milk (from 1 to 1.38 if whole, low-fat, and skim milk categories were considered separately), and 1.17 (95% CI: 0.75, 1.81) for cheese consumption. "

Ergo, no statistically significant associations for men with advanced prostate cancer.

I'm not saying that these or any studies you or I looked at are useful. In fact, I'm saying the opposite - ALL of the observational studies you or I have looked at are quite useless. They do not come up to the level of evidence needed to make a decision. Lacking evidence, the best approach is moderation. You don't want to be in the highest quartile of dairy consumption, but neither do you want to radically exclude a good source of protein and nutrients and flavor.

It is also incorrect that soy is good for you.

"This study revealed that dietary intake of isoflavones was associated with an elevated risk of advanced prostate cancer"

Again, I'm not saying it's bad. I'm just saying the quality of the evidence does not support making radical dietary changes.

I feel the paper you referred to is a bit thin - reads like a typical enthusiast lost in the joy of statistics. Dietary intake of isoflavones was based on just one questionaire at the start of the study which encompassed results from 11 years. The amounts of the different foods consumed is assumed and not measured. Fair enough - every study has its limits, and the results as composed are valid within the asumptions made. However if this result was realistic, then men from eastern countries, who consume 10 times the amount of soy and its biproducts than those on a western diet, would be expected to develop much more prostate cancer than those on a western diet. They dont!. In fact a study in 1981 showed japanese men on eastern based diets show way less than half the incidence of PC than similar men on a western diet. (Doll and Peto, 1981).

So we need to be careful with conclusions, and I agree with Allen that the quality of the evidence needs to be looked at - and also the quantity of studies for and against weighed and ranked according to thier relevance. So far I feel that Soya products (particularly genistein) have the potential to moderate PC development. But like all of these things - a little every day will be preferable to consuming supplements. I use about 30gm roasted soya beans each day as a snack.

I tried to be clear, but perhaps you missed my point - what I'm saying is that ALL such retrospective, observational studies - pro AND con - do not rise to a level of evidence that one should make health decisions based on them.

Your epidemiological analysis is even worse. Can you imagine how many differences there are between men living in Japan and men living in the US? Soy consumption is just one rather small difference. To pick on that as a causative factor is absurd. That is why epidemiological studies are considered to be among the lowest levels of evidence.

Quantity of evidence is NOT a factor. 100 times zero is still zero. Only the quality of evidence matters. That's why we always look for GRADE A Level 1 evidence - once we have that all other studies are thrown out the window. Your "feelings" have nothing to do with whether it is true or not.

You may be interested in learning more about "levels of evidence" before deciding whether some study is useful.

Fair enough - but I suspect that it practically impossible to monitor, let alone control all the elements of a diet in enough people in a clinical trial to meet the standards for clinical trials etc. So we end up by throwing out any ideas based on nutrition for lack of GRADE A Level 1 evidence.

So, based on your criteria - then I agree with you. There are too many variables to control.

The study I mentioned takes japanese families who have one or more members who have moved to Hawaii - and compares the rates of various cancers in a certain period of years. So it is quite definitely telling us something about lifestyle and the effect on cancer development. Nutrition is important. And, as you say, before anyone considers they have found the perfect supplement to help them, they should look at the details. Dosage is important. Too much of one factor can give adverse effects.

For nutrition studies we have to use invitro studies (isoflavins added to human PC cells in a petri dish), and animal studies (use of rats, mice and rabbits etc) where the precise diet can be controlled over a sufficient time to give a result. These may give indications, but not GRADE A Level 1 evidence I think.

I actually believe that if we could sort out all the relevant factors involved, that we can keep cancer at bay purely with the use of the right blend of foods - but thats just a belief so far. I have only my own body to experiment on in 3 month periods (PSA readings) so I will never be sure untill I know how many years I have lived when I die.

Stoneartist wrote >>> " ...I actually believe that if we could sort out all the relevant factors involved, that we can keep cancer at bay purely with the use of the right blend of foods - but thats just a belief so far. I have only my own body to experiment on in 3 month periods (PSA readings) so I will never be sure untill I know how many years I have lived when I die."

My PCa detour in life began 6 years ago later this month at almost 65yo AND in excellent health eating a healthy diet >>>

GL10(confined right half) some 6/7 left side, IMMEDIATE bilateral orchie, Hemi Cryoablation right half, 7 months later Focal left spot + injection of Opd+Key+Yer into right side then 1 month later Cypionate every other week = MY EXPERIMENT

LIFE CONTINUES, just bicycled 121 miles Saturday 'CAUSE it was the FULL MOON even after having skipped a "T" injection so "T" was clinically lower double digits where normally it is 500/600ng/dL . Had SUGARS during ride and after -- just because it was GOOD.

Could be having METS growing undetected as I type BUTT Life doesn't suck right now.

Thanks for the detailed history - how has PSA varied in your PCa time?

Have prostate so still ups 'n downs. 2018 had a double/double up so Axumin and a few spots 6/7 in left and again cryo'd. IF that's all for life, haven't a problem --- only time will tell.

I took a long look at the genetic report of my specific neuroendocrine cancer and decided food will have zero direct effect on the caner. There's simply too many broken genes that control cellular growth and they're stuck in an infinite loop of growth, ignoring all external signals. That may not be true of less aggressive cancers, but to suggest that all cancers can be controlled by diet is fallacy.

That said, UCSF has "saturated fat" on its list of foods to avoids, which would include full fat dairy, and is attempting to perform higher quality, prospective trials to test out its recommendations.

There's also many indirect effects diet and lifestyle can have on survival, for example, exercise can increase circulation and drive treatment deeper into tumors. Anything that helps bone marrow recover after a chemo infusion will also help the body withstand more treatment. Thus my advice is usually to achieve a healthy weight first (weather it's gaining or losing, in my case I'm trying to gain), and then try to eat healthier foods after achieving that weight.

There was a pretty good attempt. It is called the MEAL trial:

It is widely considered to be the best trial on diet ever done for prostate cancer. If you're interested, here are more details of it:

You continue to ignore all the variables of just living in Japan. There are differences in the soil, in species of foods, of micronutrients that get into the food, the balance of vegetables and proteins, the social effects on the immune system, the medicines used, etc.

Lab/bench studies are considered Level 5 evidence - the lowest of any. Do you actually believe that anything that is true of mice is true of humans? Everything works in mice! Mouse and lab studies are ONLY used to rule things OUT, never to rule things in.

Here's a guide showing the levels of evidence and GRADE system:

(I've tried to share this with some people on this forum, but sadly, they are so set on believing mouse studies predict for humans, that they ignore it)

As for self-experimentation, how do you know what would have happened if you had done something differently? That's why God invented randomized control groups. Also, PSA is not a good surrogate endpoint. We are moving towards using as a surrogate endpoint the development of new metastases. metastasis

Thanks - that looks interesting, though no results that suggest even vegetable diatery fokus has no beneficial effects. But as you say about the japan study - and indeed with all studies on diet - it is very difficult to control what other factors are involved. Too many variables!!

But with nutrition we are in a different situation - we have to eat something - so the choice is between a and b, with no grade A evidence to distinguish between them.

Then we have to use other rules. Given the choice of eating foods which contain elements which can be shown to attack cancer cells in vitrio, and in animal reaearch, or eating foods which have been shown to have negative - or zero effects on cancer cells in vitrio, and in animal reaearch, then there is a greater intrinsic probabality that the former has a better chance of limiting cancer development than the latter.

Its not proof - but, as I say - you have to eat something.

That is not the case. Maintaining health is a much better way of slowing cancer than relying on specific foodstuffs that seemed to help mice. Lab studies showed a beneficial effect of Vitamin E. However, in clinical trials it was shown to cause prostate cancer in humans.

Its not a case of relying on specific foodstuffs - but a case of which foodstuffs to choose. Yes there are exceptions - just as there are dosage problems if people go bananas on one food because they think it will help. And we surely need to understand the underlying biological mechanism. There has been a good deal research on this.

But even this is complex. You will have to consider the bio-uptake in the body, the effects of different cooking methods and temperatures, the effects of dosage etc. Its not easy - and we are a long way from being able to carry out clinical phase III trials in this arena - primarily due to control and monitoring problems

I still maintain that the probability that a food which has been demonstrated to restrain human cancer cells in the petri dish, and in rats/mice etc will also exhibit a similar response in humans, is higher than for a food which has not shown these effets. Even though I lack grade A evidence for this.

I sense that you have no time for these nutrition ideas - but surely you can agree to the essence of the above?

What food, for example, has been shown to restrain prostate cancer in a petri dish or in rats/mice?

Great question TA - i had to read a bit since I dont have these things at my fongertips like you do. But its an important theme so I started a new post regarding this

Currumpaw in reply to Tall_Allen

Hey T_A!

As for observational studies, the world class health of our own US of A "Blue Zone" people, the Seventh Day Adventists, shouldn't be discounted so readily. Their lifestyle and dietary habits are what has made them a "Blue Zone" people.

An "observational study" I might make would be to avoid a neighborhood or a night club that makes the news because of shootings and stabbings! Just observational though!

You posted some good links! It does seem to be the fat in dairy that is the culprit. Interesting that whey protein is shown to inhibit cancer.


Whey Protein Supplementation Improves Nutritional Status ...


For those that are vegans Solgars Brewers Yeast is a good source for the amino acids and some of the vegan protein powders also have the amino acids.


Tall_Allen in reply to Currumpaw

Observational studies are done as a first signal. They often have conflicting results because they are plagued by selection bias. That is , those that consume dairy in the fifth quintile are different in many ways from those that consume dairy in the first quintile. Since there is no established harm in consuming dairy products, it does not follow that any ingredient in dairy is the "culprit." Because you believe it is true, does not make it true.

Currumpaw in reply to Tall_Allen

Hey T_A!

I know about the "when you wish upon a star" thing and Shirley MacLaine.

I scanned the links you posted. Dairy fats was mentioned as the "suspected" culprit.

I'm still not going to that night club! Or any others like it!


Stevemart in reply to Tall_Allen

Tall Allen—Related to this, I am just finishing 30 doses of IMRT and 6 months of Lupron for a Gleason 4+3 and am looking ahead to my life and what I should do. When I look at lots of literature I find, as you mention, that much of it is pretty sketchy in having any real data. It seems like the general guidelines for life in general apply, i.e:

—Exercise and control your weight

—Eat a diet with a fair amount of fruit, vegetables and fish and limit red meat

—Coffee and green tea are generally good

—Probably makes sense to take a multivitamin and maybe some extra vitamin D but most of the other supplements appear to be more marketing than anything

—Limit alcohol

Does that fit with your thinking? Am I missing anything?



Sandy752 in reply to Stevemart

Like you my Gleason is 4 +3 (with 10 of 12 samples cancerous). I had 40 radiation treatments which failed to cure me. I just started my 8th year on Lupron (latest PSA .22). I do all the things you listed but also take calcium.)

Tall_Allen in reply to Sandy752

If your blood calcium levels are low, by all means, supplement. Otherwise, don't:

Calcium supplementation may also have negative effects on cardiovascular health.

Sandy752 in reply to Tall_Allen

Thanks. I will have my blood calcium levels tested. A while ago now but I thought one of the doctors suggested calcium would help maintain bone density levels and that Vitamin D should be taken when taking calcium. They often come in the same pill.

Tall_Allen in reply to Sandy752

That is the old way of thinking. More recent and better evidence is that excess Vitamin D actually robs calcium from bones. Neither should be supplemented unless blood levels are low:

Stevemart in reply to Sandy752

That sucks about the failure but glad the Lupron is keeping the PSA low. I am hoping for the best and will be glad to get off Lupron though I didn't have crazy side affects when I compare them to many. It naturally wiped out the sex life and I have a lot less endurance in exercise but I haven't had any of the mood swings or hot flashes. Good luck

Tall_Allen in reply to Stevemart

In general, if you eat to be heart-healthy, you'll be OK. Remember that cardiovascular disease is 20 x the killer of older men than prostate cancer.

The only things on your list I would definitely not do is take multivitamins. They often contain ingredients known to be harmful (like Vitamin E) or that are known to interfere with PSA tests (like biotin). Get all your nutrients from foods. Variety is essential. We and our microbiomes evolved to be omnivores, and are healthiest when we don't try to outsmart evolution.

If you get outside for at least 15 minutes each day (difficult now, I know), there is no reason to take extra Vitamin D. (it can rob bones of calcium) Let blood tests be your guide if you need to supplement anything.

No reason to limit alcohol that I know of, as long as you consume it moderately.

In general, I am against depriving oneself of anything that diminishes one's enjoyment of life. You've had cancer - be good to yourself.

Stevemart in reply to Tall_Allen

Thanks much and I am with you about enjoying life. I live in New Mexico so am getting plenty of sun and will skip the multivitamin.

Beware of studies sponsored by the dairy industry.

Currumpaw in reply to Magnus1964

Well said Magnus1964!

Like giving the fox a security guard's uniform and telling him his assignment is the chicken coop!

Ahh! The humor in the cartoons of our youth! I can almost hear Mel Blanc's voice as my mind conjures up a picture of the fox with a sly look upon his face!


A LOT is incompletely known about diet. What we do know is there is an ASSOCIATION between diet and at least some cancers. There are some proposed (GUESSES at) the molecular chain of events but these are largely unconfirmed.

I think your "safety first" attitude is appropriate particularly since there are directions to take with lower risk vs others. From an overall dietary standpoint, my best GUESS is the diets of the longest lived areas of the world (Blue Zones .... several books are available) would be worth exploring.

Remember, PIN (Prostate Intraepithelial Neoplasia), an abnormal finding, is seen in about 50% of the male population by age 30. Because PIN occurs so early in life, diet from the point of Prostate Cancer (PCa) diagnosis MIGHT only have small effect overall ..... NOT that you would not want this effect, but diet at this point MIGHT be a smaller factor vs from birth.

If I were beginning to look for dietary help (not solutions .... with existing PCa we are likely well past dietary "solutions") I would look globally at diet rather than just certain elements of diet (I would look at elements too but not JUST elements). This might involve a large change in diet for a small/negligible effect, but personally, I will take whatever POSSIBLE (not necessarily certain) advantages I might be able to get.

IMO, diet probably influences PCa but, in many instances, we do not definitely know the specifics.

If I were starting out on dietary help I would investigate the work done on the "Blue Zones" AND remember that even those in the Blue Zones get sick & die with some of these deaths at a much younger age .... so, while diet might provide measurable advantages for a population, diet is not foolproof for the individual ..... but I would take whatever I might be able to get.

Just some opinions ..... yours may differ.

I haven’t read all the various studies but my take away is eat a heart healthy diet and don’t worry about every single ingredient. No one single food element be it dairy or cranberry or tree nuts is going to make or break someone’s health.

My 3 cents...

Eggs come up as consistently bad for PCA, in the studies I have seen.

Dairy spikes IGF-1, so should likely be limited.


I put more faith in actual lab studies than epidemiological retrospective studies of diet where variations of competing factors and population vary widely. Casein appears to be a risk factor for reoccurrence...

α-Casein and total casein did not affect the proliferations of RWPE1, HEK293, A459, SNU484, MCF7, HEK293, or RWPE1 cells. However, PC3 cells treated with 1 mg/mL of α-casein and casein showed increased proliferation (228% and 166%, respectively), and the proliferation of LNCaP cells was also enhanced by 134% and 142%, respectively.

Chocolate chip ice cream (two scoops).....

Good Luck, Good Health and Good Humor.

j-o-h-n Sunday 03/14/2021 7:38 PM DST

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