It used to be fashionable for American researchers to look to Japan for the dietary 'reason' for low PCa rates. Was it the green tea? Or soy products - 10.7 kilos per person annually? etc, etc.
I recall seeing studies that found that male soy eaters had lower testosterone [T]. Clearly, lower T was the answer! LOL.
Soybeans contain phytates, lectins & trypsin inhibitors and are not considered to be nutritious in their natural state. However, thanks to the ingenuity of the food industry, supermarkets are now full of non-traditional soy-based food products that are consumed as meat substitutes.
But now we have a study from Japan that associates soy with an increased risk of PCa death.
"During 16.9 years follow-up, we registered 221 deaths from prostate cancer.
"Isoflavones and soy products intake was associated with an increased risk of prostate cancer death, with multivariate HRQ5 vs. Q1=1.39 ... for isoflavones and multivariate HRQ5 vs. Q1=1.76 ... for soy food."
Note: "HRQ5 vs. Q1" is the relative risk of being in the fifth quintile (highest) versus the first quintile (lowest) of intake. (A 76% increase in PCa mortality risk for soy food!)
I have mentioned in old posts that genistein has been found to be biphasic in BCa & PCa studies. Essentially, growth-promoting at physiological doses (from diet) & growth-resistant at pharmaceutical doses.
IMO it is not prudent to eat soy foods.
However, there are many studies that suggest that high-dose genistein might be protective. IMO, one should think in term of the dosage given for:
1 Epidemiology and Prevention Group, Center for Public Health Sciences, National Cancer Center, Tokyo, Japan.
PMID: 32968784 DOI: 10.1093/ije/dyaa177
Abstract
Background: Although many epidemiological studies have reported the preventive effects of soy products and isoflavones on prostate cancer, our previous studies reported that the association between soy and isoflavones and prostate cancer incidence differed according to stage. It is more important to identify modifiable risk factors related to lethal prostate cancer. Here, we investigated the association between soy, soy products and isoflavones intake and prostate cancer mortality, in a prospective study in Japan.
Methods: We conducted a population-based prospective study in 43 580 Japanese men with no history of cancer or cardiovascular disease (aged 45-74 years). Participants completed a validated questionnaire which included 138 food items. We followed participants from 1995 to 2016. Hazard ratios (HRs) and 95% confidence intervals (CIs) of prostate cancer mortality were calculated according to quintiles of soy products and isoflavones intake, using Cox hazard proportional hazards regression.
Results: During 16.9 years follow-up, we registered 221 deaths from prostate cancer. Isoflavones and soy products intake was associated with an increased risk of prostate cancer death, with multivariate HRQ5 vs. Q1=1.39, 95% CI = 0.87-2.20, p for trend = 0.04 for isoflavones and multivariate HRQ5 vs. Q1=1.76, 95% CI = 1.10-2.82, p for trend = 0.04 for soy food.
Conclusions: Our study suggested that high intake of soy and isoflavones might increase the risk of prostate cancer mortality.
Keywords: JPHC Study; Soy; isoflavone; prospective; prostate cancer death.
At this point, I have no confidence that my PCa cells express ERbeta - the target of phytoestrogens. But I downed a ton of LEF's Ultra Soy in the first dozen years or so. Plus a lot of other things. I only expected incremental benefit from any one of them, but thought that the increments might add up to something.
My original post on genistein was 4 years ago. Two responded. Big-Rich was closing in on 20 years since diagnosis when he stopped posting 2 years ago. Dr_WHO also went silent 2 years back - he had a rare aggressive form of PCa.
Same study. In that Japanese population, I doubt that the men would be using genistein supplements to any extent. While intake would presumably be much higher than in the 'Western' diet, levels would not be in the pharmaceutical eange offered by LEF's Ultra Soy. IMO
As I recall, soy is a double-edge sword... on one hand it helps sensitize PCa to radiation, on the other, it raises estrogen levels, which is a precursor to T -> DHT and thus increased PCa progression. During radiation, I ate soy beans (edamame), but then stopped all soy due to risk of gynecomastia while on ADT and possibly progression.
FWIW, last summer on a low-cal, low-protein keto diet my PSA went from 20 to 13 in 3 mos. Then, in the fall, I went off keto, upped calories and protein, and added LOTS of soy milk and flax seed... my PSA went from 13 to 26 in 3 mos. Seems related, to me. (No meds of any kind, until PSA hit 30 after another 3 mos of NO soy and NO flax.)
Here's a paragraph taken from MD Anderson about the goodness of Soy-based food:
Soy might lower the risk of other cancers
Soybeans, soy nuts and edamame all contain fiber. And a diet high in fiber may lower your risks for several cancers, including colorectal cancer.
Studies among prostate cancer survivors indicate that eating soy foods may lower PSA levels. Among men in various stages of prostate cancer, those who consumed soy milk or isolated soy isoflavones saw their PSA levels rise at a slower rate. The effect was stronger in some men than others, making it unclear whether genetics or metabolism made a difference in lowering PSA levels.
Myth: Soy’s isoflavones act like estrogen in the body, raising the risk of cancer
How we got it wrong:
Failure to understand the differences between estrogen and isoflavones (natural plant compounds found in soy foods) led to many false assumptions. Isoflavones have a similar chemical structure to human estrogen, but they bind to the body’s estrogen receptors differently and function differently.
Facts:
Scientists have now found that rodents metabolize isoflavones differently than humans. So earlier studies in which soy isoflavones promoted the growth of estrogen receptor-positive (ER+) breast cancer in mice relate to much higher blood levels than what would result from humans consuming soy foods.
Different kinds of estrogen receptors are present in different parts of the body. Activation of some receptors seems to promote cell growth. But studies suggest that isoflavones more often bind to estrogen receptors with other effects, potentially acting as a tumor suppressor.
In studies of isolated cells, isoflavones can “turn on” genes that slow growth of cancer cells and stimulate their self-destruction (the process called “apoptosis”). These compounds may also support the body’s antioxidant defenses and DNA repair, which would help protect against cancer.
Soy protein powder or soy isoflavone supplements show no effect on markers of breast cancer risk such as hormone levels, markers of breast cell growth, or breast density, in randomized controlled clinical trials. And likewise, such studies show no effect on prostate-specific antigen (PSA) levels or hormones related to the risk of prostate cancer.
Population studies don’t link soy consumption with increased risk of any cancer, and limited evidence shows soy possibly protecting against lung cancer in people who have never smoked tobacco, and either no effect or decreased risk of prostate cancer. Observational studies also link moderate soy consumption (one to two servings a day) with lower breast cancer risk in Asia, where soy foods are commonly consumed throughout life.
Emerging research links soy food consumption with a greater variety of health-promoting bacteria in the gut microbiome.
Myth: After a diagnosis of breast or prostate cancer, be sure to avoid soy foods
How we got it wrong:
Avoidance messages mainly stemmed from the misunderstanding about potential effects of “phytoestrogens” and hormone-sensitive cancers, and we didn’t have good data from research with cancer survivors. But now studies of survivors of breast and prostate cancer show no harmful effects, and potential for soy foods playing a beneficial role as part of a healthy diet.
Facts:
Consistent findings from several population studies demonstrate that there is no increased risk for breast cancer survivors who consume soy foods. In fact, limited evidence shows potential for greater overall survival, and perhaps decreased recurrence, among women (including those who had ER+ cancer) who include moderate amounts of soy.
Among men with prostate cancer preparing for or following prostate surgery, or following a “watchful waiting” approach after diagnosis, supplements of soy protein or isoflavones for periods ranging from 6 weeks to 2 years have shown either no effect or a decrease in progression of prostate cancer. Although benefit was unclear, none of these controlled clinical trials showed an increased risk associated with soy or isoflavone consumption.
A link to overall survival may reflect a role for soy foods in eating habits to benefit heart health, which takes on added importance for many cancer survivors. Studies show a 4 to 6 percent drop in LDL cholesterol (particularly among people with elevated levels) and potential to reduce blood pressure in people with hypertension by promoting relaxation of blood vessels. These effects are linked with daily soy food consumption that are achievable, but well beyond occasional use.
soy and cancer myths, Soy and Cancer: Myths and Misconceptions
Myth: Whole soybeans are ok, but any processing makes soy foods an unhealthy choice
How we got it wrong:
Some people fear that more processed soy foods concentrate isoflavones to dramatically high levels that could pose cancer risk. Others fear whether that processing removes all elements of soy that make it healthful. You can find soy ranging from minimally processed (like steamed edamame), to traditional soy foods that are moderately processed (think of tofu and soymilk) to isolated components used as ingredients (such as soy protein isolate in cereal and bars, and soy fiber added to bread).
Facts:
Soy protein isolate powder and textured soy protein don’t contain any more isoflavones than an equal portion of plainly roasted soybeans. Some forms of isolated soy protein lose as much as 80 to 90 percent of isoflavones in processing.
Moreover, these components of soy are not consumed on their own, but as an ingredient. As a result, isoflavone content of veggie burgers, bars and high-protein cereal with added soy protein ranges from dramatically less to a little less than in what is considered a standard serving of soy food (for example, a half-cup serving of tofu).
To allow more precise control, clinical trials with soy have often used isolated soy protein or isoflavones. However, soy contains a variety of nutrients, phytochemicals and dietary fiber that may contribute to health. Although isolated isoflavone supplements sometimes provide amounts far beyond what has long been safely consumed in traditional Asian diets, this is not an issue when consuming up to three servings a day of even processed soy foods.
On the other hand, don’t let a “health halo” lead you to think that adding soy protein to a low-nutrient, sugar-laden bar or drink turns it into health food. Isolated soy protein doesn’t provide the dietary fiber or complete range of nutrients found in common soy foods.
Although isolated soy protein or fiber can contribute to a food and does not pose risk, neither turn a low-nutrient, sugar-or sodium-laden bar, drink or convenience food into a portion of health food. Several recent studies report connections between extensive use of ultra-processed foods and increased calorie consumption, weight gain, and possibly increased cancer risk. However, these studies group together a wide range of foods, including some that are far less healthful than others.
Bottom line
A range of soy foods are available to make plant-focused eating habits easy, delicious and nutritious. For now, there is no reason to steer clear of soy foods and let outdated myths about soy foods keep you from enjoying them as part of a healthy diet. There is also no reason to consider them must-haves if you prefer not to include them in your diet.
Dr Myers put me on lef soy isoflavones to try to eventually help reverse PTEN hyper methylation; been on it for years, still undetectable—- was he in error?
The way I see it is we either eat meat or soy. There is far more evidence that meat of every type can lead to cancer and cancer progression. I will take my chances with the vegan and soy route.
I drank soy protein for a few weeks and it did cause my Lupron hot flashes to abate. The problem is soy protein is loaded with purines so it gave me gout. Apple cider vinegar flushes with 1/4 teaspoon of celery seeds every day for a week cleared the gout.
I'm so confused. I upped my soy consumption base on Ornish's protocol for his early stage non metatastic PCa study:
"Ornish Prostate Protocol
Experimental group patients were prescribed an intensive lifestyle program that included:
1) vegan diet supplemented with
2) soy (1 daily serving of tofu plus 58 gm of a fortified soy protein powdered beverage),
3) fish oil (3 gm daily),
4) vitamin E (400 IU daily),
5) selenium (200 mcg daily)
6) C (2 gm daily)
7) moderate aerobic exercise (walking 30 minutes 6 days weekly)
8) stress management techniques (gentle yoga based stretching, breathing, meditation, imagery and progressive relaxation for a total of 60 minutes daily)
9) participation in a 1-hour support group once weekly to enhance adherence to the intervention.10
The diet was predominantly:
fruits, vegetables, whole grains (complex carbohydrates), legumes and soy products, low in simple carbohydrates
with approximately 10% of calories from fat.11
The diet is intensive but palatable and practical. In earlier studies most patients were able to adhere to this diet for at least 5 years.10 –13 "
All the experimental group improved, all in the control group got worse.
Wish I knew what to do. For now, I try to follow the above, along with a few additional suppliments.
The Ornish study elicited a collective yawn from the group I was in at the time.
Ornish included men with Gleason score 3+3 & at least one man with <6.
The benefit was modest (to say the least).
The average triglycerides at baseline were high & the increased during the intervention. This is common on an Ornish diet - only 10% fat.
The ratio of triglycerides to HDL cholesterol - a surrogate used to assess insulin resistance - went the wrong way. This is to be expected on a low-fat high-carb diet, since glucose levels spike with every meal. Complex carbs delay the spike but do not prevent it. Only fat can smooth out the rate that glucose enters the blood.
Dr. Greger makes a big thing about this study, even though Ornish described it as "vegan with fish oil". Elsewhere, Ornish got a lot of flak from vegans.
I used to preferentially eat almonds. But now they seem a little passe when I look at the latest research (paper in link is 2008 but there are many studies more current).
wstein, my diet is currently rolling back PSA. Gleason 4 + 3 biopsy, 3 + 3 pathology with a PSADT of seven months. I'm using a vegan plus a little "wild caught" seafood, no fast carbs and limiting dietary iron. Breakfast is key, have to get it right (low insulin response). I have 52 ultrasensitive PSA readings over the last 7 1/2 years. My last PSA was 0.243 and my PSA in late 2018 was 0.525. I'm using (organic) soy every day (about 1 serving). I removed soy for three months and the diet crashed.
More info can be found by searching "prostate cancer diet" on healthUnlocked".
I do use it but sometines I just can't swallow another 5 caps.
The big thing about DIM, to my mind, is that it encourages estradiol to be metabolized down the 'good' path (2-hydroxyestrone pathway, rather than the cancer-promoting 16-hydroxyestrone pathway). The presence of genistein, I assume, would have no effect on that.
For those on ADT who have basement-level estradiol, DIM may be less important, but Nalakrats is the go-to guy on DIM, having been in touch with Zeligs (the formulator) long before most of us were diagnosed.
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Mushroom consumption and reduced prostate cancer incidence - A cohort study from Japan
