Fruit & PCa

Lifestyle changes are reportedly common following a PCa diagnosis, including a "healthier" diet. I suspect that most would not seek expert advice, because we all "know" what is healthier: more fruits & vegetable, less meat, less fat, more whole grains, & so on. Ask one's doctor for dietary advice, & the familiar boilerplate wording will likely be trotted out. & I almost forgot "drink 8 glasses of water every day".

The Harvard Medical School churns out inoffensive publications, offering health advice. Here is something from March [1]:

"Can adopting a healthier diet help fight prostate cancer? That’s a question men newly diagnosed with prostate cancer often ask their doctors."

"Several studies have shown that in countries where men eat a typical “Western” diet containing a large amount of meat, the incidence of prostate cancer, especially aggressive prostate cancer, is higher than in countries where plant-based foods are a primary part of the diet. Unfortunately, these studies weren’t designed to prove cause and effect. So for now, definitive answers about prostate cancer and diet aren’t yet in — although researchers are actively studying this topic."

"Investigators have launched a federally funded national study to see whether a diet that’s higher in plant-based foods and lower in animal-based foods than the typical Western diet will help control tumor growth in men with early-stage prostate cancer."

"Participants in the Men’s Eating and Living (MEAL) study will try to eat nine servings of fruits and vegetables daily — significantly more than the three to four servings consumed each day by the typical American man — as well as two servings of whole grains and one serving of beans or other legumes."

& so on.

Why am I disgusted? The MEAL intervention study [2] began in January 2011 (so it isn't news) & ends in June next year. Intermediate findings have not been published. & yet, the Harvard people seem to be promoting the diet. Why? Presumably because the diet seems so healthy. LOL

A sample menu is provided [1]. In addition to the 3 meals, we get 3 snacks. More food than I could eat in a day, but without the snacks, how could we get our quota of fruit?

The MEALS study involves men on active surveillance, & you can't safely extrapolate findings from that kind of study to metastatic disease.

What we do have (in PubMed) is a bunch of epidemiological studies that looked at fruit & PCa risk, & an intervention study, like MEALS, in men without PCa [5]:

[3] (2000) "No associations were found between fruit intake and prostate cancer risk."

[4] (2000) "Intake ... of fruits was not related to risk"

[5] (2002) "Dietary intervention over a 4-year period with reduced fat and increased consumption of fruits, vegetables, and fiber has no impact on serum PSA levels in men. The study also offers no evidence that this dietary intervention over a 4-year period affects the incidence of prostate cancer during the 4 years."

[6] (2004) "No significant associations between fruit ... consumption and prostate cancer risk were observed." Huge study: 130,544 men in 7 countries

[7] (2004) This study identified 3 dietary patterns:

"prostate cancer risk was not associated with the vegetable-fruit or red meat-starch pattern, but higher intake of the Southern pattern showed a reduction in risk"

"although the red meat-starch pattern was not associated with prostate cancer, intermediate intake of the vegetable-fruit pattern showed a slight elevation of risk [RR, 1.5 ...]"

[8] (2008) (Australian) "A decreased prostate cancer risk was observed with increasing intakes of vitamin C-rich vegetables, including bell peppers and broccoli. Fruit, other vegetables and vitamin A intakes did not appear to be strong factors in the development of prostate cancer in this study."

[9] (2010) (Japanese) "no association was observed for intake of either fruits or vegetables (total or any subtype) with localized or advanced prostate cancer"

[10] (2014) (European) "no clear indication that the risk for prostate cancer is related to intakes of ... fruit"

Another big study: 150,000 men in eight European countries.

No doubt the gurus will continue to advise us that fruits belong in a PCa diet, but a null effect on PCa risk doesn't give me much hope for the MEALS study, or for any effect on metastatic PCa.

A common problem with epidemiological dietary studies is a lack of nuance. Corn oil & lard becomes "fats"; strawberries & bananas are "fruits", & so on. Can't I find something good to say about fruit? Yes - but very little:

[11] (1995) Giovannucci's study that began the lycopene industry. Most seemed to ignore the reference to strawberries. Rich in fisetin.

Pomegranate studies look interesting, but whole pomegranates aren't likely to show up in epidemiological or intervention studies. The two Pantuck studies are inconsistent:

[12] (2006) Juice. "Mean PSA doubling time significantly increased with treatment from a mean of 15 months at baseline to 54 months posttreatment"

[13] (2015) Extract. A PSADT "increase from 12.9 months at baseline to 14.5 months". The placebo group did better.

-Patrick

[1] health.harvard.edu/cancer/c...

[2] clinicaltrials.gov/ct2/show...’s+Eating+and+Living%22&rank=1

[3] jnci.oxfordjournals.org/con...

[4] cebp.aacrjournals.org/conte...

[5] ncbi.nlm.nih.gov/pubmed/122...

[6] ncbi.nlm.nih.gov/pubmed/147...

[7] cebp.aacrjournals.org/conte...

[8] ncbi.nlm.nih.gov/pubmed/175...

[9] ncbi.nlm.nih.gov/pubmed/200...

[10] ncbi.nlm.nih.gov/pubmed/245...

[11] ncbi.nlm.nih.gov/pubmed/747...

[12] ncbi.nlm.nih.gov/pubmed/168...

[13] ncbi.nlm.nih.gov/pubmed/261...

19 Replies

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  • how about the old saying ... further study is needed

  • Patrick, I'm in a state of shock. Someone gave me a Physicians Committee for Responsible Medicine newsletter when I was diagnosed, in 2003, with an article on PC & diet. I knew they were animal rights folks, but I thought they had a good basis for advising against meat, fowl & dairy. They didn't mention fish, so I kept eating that. Later, others advised me against sugar (except in fruits) & foods that convert quickly to sugar, & against white rice. Do you think there are research findings to support this, or at least that Asians in Asia get less PC than we do, & guys in Mediterranean countries also do better?

    Of course, if there is a basis for giving various things up, then we need to eat what's left, right? Whether or not it provably helps, if other foods provably increase risk? At worst, fruits, veggies, whole grains & fish keep us fed without doing harm, right? At least if the produce & grains are organic? Did any of the studies use organic foods?

    For those of us who are eager to do what we can to extend our lives, what should we eat?

  • I'm with Neal on this one and follow a similar diet too. And it doesn't do any harm for sure.

  • Don't eat anything that Monsanto is involved in. There is no one best diet for everyone but the story that was peddled to us 30 years or so ago that fat was bad led to many thousands of grossly overweight Americans. Fat does not make us fat.

  • Neal (& Roger),

    When I was diagnosed 12 years ago, there wasn't much in the way of PCa-specific diet/supplement advice. There was Roger Mason's little book, supposedly based on PubMed papers, but with too many of his own beliefs to make it useful. For instance, he was against nightshade produce, which ruled out tomatoes (& therefore lycopene), as well as peppers, eggplant & potatoes.

    So I decided that I would retrace his steps for each vitamin, mineral, plant extract, fat type, etc. My idea was that some things that were good for normal cells might help malignant cells. Perhaps it was best to withhold useful nutrients that made the cancer thrive?

    This goes against the idea that some have, that the clock can be reset. That correcting the diet might make cancer cells "better differentiated".

    As the years went by, I came across people who insisted that some foods were good & some bad, & there was no room for debate. Fruits & vegetables would seem to be the least controversial of food categories (it should be two). However, while the case for vegetables is mixed but generally positive, no case can be made that fruits (as a category) are helpful against PCa.

    But is there a case against fruit? I think that it all depends on the type & quantity of micronutrients & the mix & quantity of sugars. Glucose is glucose, regardless of the source. Sweet cheries are 6.5% glucose. I'll eat some when they are in season, but not in great quantity. The glucose in cherries is free to enter the blood very quickly. The idea that, as a whole fruit, digestion has to break down the cell walls to release the sugars, makes no sense. You chew on a ripe cherry & get a mouthful of sweet juice. That's why we like them.

    What is useful here is a table of glycemic load [GL] data. Unlike glycemic index, the GL tells you the glycemic effect of a serving. One cup of prunes has a GL of 34.2, whereas a cup of strawberries is 3.6. One could, perhaps should, restrict oneself to GL<10. Pineapple would be out (1 cup = 11.9), whereas a medium apple is 6.2. Or one could cut back on portion size.

    In contrast, looking at vegetables, cruciferous veg has a GL of zero per serving, while a cup of corn is an amazing 61.5. One might restore insulin sensitivity very quickly by limiting carbs to the non-starchy types.

    ...

    Regarding organic foods, we are unlikely to see an epidemiological study, I believe.

    Considering the amount of water that lettuce, say, takes up while growing, it would be prudent to be concerned about antinutrients that might be taken up with that water. I think that there are a lot of urban backyard gardeners who are unaware of how much lead might have been deposited in the soli before leaded gasoline was phased out.

    Regarding rice, are you aware that Gerber (baby food) no longer offers a brown rice option? & that Gerber was forced to switch to more expensive Californian rice which has lower arsenic levels?

    "... it’s not just arsenic and cadmium, which are present in soil both as naturally occurring elements and as industrial byproducts. Recent studies have shown that rice is custom-built to pull a number of metals from the soil, among them mercury and even tungsten. The findings have led to a new push by scientists and growers to make the grain less susceptible to metal contamination." [1]

    "The highest levels often occur in brown rice, because elements like arsenic accumulate in bran and husk, which are polished off in the processing of white rice. The Department of Agriculture estimates that on average arsenic levels are 10 times as high in rice bran as in polished rice." [1]

    Regarding foods that convert quickly to sugar, the answer is fat!. The most dangerous diet in terms of triglycerides (a sign of glucose spikes), is the Dean Ornish 10%-fat vegan diet.

    Unwittingly, in my early search for healthy foods, I thought oat groats cooked in water might be a good breakfast choice - no sweetener, milk or cream. Whole grain oats take a while to cook, but they taste good. Anyway, about 20 minutes after eating them (nothing else) I would have an urgent need to urinate. The urine would be totally clear & feel hot. One of the tricks the body uses to dump a sudden surge of glucose. I realized that whole grains can be digested quite quickly. & even if digestion were to take an hour, there would still be that surge.

    With fat at 30% or higher, there is a slow release of glucose into the blood.

    Fat, of course, has been demonized. It began with saturated fat, but strangely grew to include any fat.

    A week ago, the British National Obesity Forum released an astonishing report [2]. Note that 24.5% of British adults are now obese.

    "The report says the low-fat and low-cholesterol message, which has been official policy in the UK since 1983, was based on “flawed science” and had resulted in an increased consumption of junk food and carbohydrates."

    "The authors call for a return to “whole foods” such as meat, fish and dairy, as well as high-fat healthy foods like avocados."

    "The report, which has provoked a broad backlash among the scientific community, also argues that saturated fat does not cause heart disease while full fat dairy products such as milk, yoghurt and cheese, can actually protect the heart."

    12 years ago, no-one was making such claims when I was sifting through studies. Bias is easy to recognize in studies, since it affects study design. PCa studies on diet seemed to assume that fat was detrimental.

    It was a relief to me when I read Nina Teicholz's "The Big Fat Surprise: Why Butter, Meat and Cheese Belong in a Healthy Diet" [3]. She is a phenomenal researcher & had to cover an amazing amount of ground - over 60 years of the influence of Ancel Keys. Government money thrown at him & his disciples. The silencing of alternative views. The creation of the vegetable oils industry & its influence on what we eat. & most of all - bad science caused by bias. It's a great read if you value substance.

    -Patrick

    [1] well.blogs.nytimes.com/2014...

    [2] telegraph.co.uk/news/2016/0...

    [3] amazon.com/Big-Fat-Surprise...

  • Patrick, thank you VERY much for all the info. Questions:

    1. What distinctions, if any, do you make now between a healthy diet for people in general & a healthy diet for someone with advanced prostate cancer?

    2. Have you read Integrative Oncology (2nd Ed. 2014, Oxford), Donald Abrams , MD & Andrew Weil, MD, editors? It has chapters by professors of medicine, etc., including Diet & Cancer, Nutritional Interventions in Cancer, Botanicals, & various alternative medicine approaches. The chapters I've read, such as the ones I listed & Cannabinoids & Cancer, are research based. If you haven't read it, I wonder if you'd be interested in looking at it & seeing whether it provides you with information of use to you & to us.

    3. Any further suggestions you may have on what to eat or avoid, & what supplements appear to be worth taking, would be most welcome I'm sure to many of us. To the extent that you're willing to collect this information into a summary or a list, perhaps 1 on food & 1 on supplements, you'd be providing us with posts of wonderful practical value.

    Thank you very much, again.

    Neal

  • No medical group will ever promote healthy eating- anything that could possibly cut into profits for Big Pharma is off the table. This isn't just for prostate cancer- it's for anything. Look what they did to Coconut Oil for 20-30 years- did you ever see unhealthy looking Phillipinos or Pacific Islanders? People whose diet included a lot of coconut oil and meat. Asking a Doctor about healthy eating is like asking a Sumo wrestler how to lose weight.

  • Why do people assume that medical groups and physicians will lie for "big pharma"? There are plenty of men here reading this that are physicians. Why in the world would they lie? Why in the world would they not want information to get out to protect their sons and men they love?

    My husband is a physician with metastatic prostate cancer. He worked so hard his whole life to put himself through college and medical school. We paid back student loans until we were in our 40's all the while my husband went to work each day saving lives. None of our kids went into medicine because he told them it has to be a passion because there are easier ways to make money.

    Don't continue to spread misinformation that somehow we won't get good research because it is all being hidden to benefit pharmaceutical companies. There is a reason there are government funded and private funded studies.

    Sorry for the rant. I see a once healthy, happy man who who worked in the system. He still believes in scientific medicine and is open to acupuncture, diet or anything else we can read about and try.

  • Hi RA-MA,

    I think that there are two perceptions about physicians:

    a) that medical school devotes a minimal number of hours to dietary issues

    b) that big pharma is a major source of drug education

    & so, for example, a doctor might not know about the role of vitamin K2 in bone health (or boron, for example), but would have up-to-date info on the latest bisphosphonate.

    At 65, my wife had an arterial calcium scan. Non-invasive & inexpensive, but not covered by insurance. Our doctor was willing to write the prescription, but asked her is she was willing to act on the results. A good question. The scan came back with zero calcification in & out of the heart. He said it was "unheard of" in someone her age.

    An earlier bone scane revealed normal bone density, whereas one done 15 years earlier had shown mild osteoporosis.

    More recently, she has been treated for a solitary plasmacytoma & has osteopenia. He told her that he could prescribe something, but he knew that she could reverse the condition.

    A couple of years ago, at my annual medical, he warned me that a study had found an increase in CVD events in men who used testosterone. I knew more about that study than he did, so he gave me his email & I sent him a couple of papers on the flawed study.

    He's a great guy. Has been our doctor for 11 years. Is open to discussion. He knows more about many, many things than I do, but he can't be up to speed in some of the areas that concern me.

    & his advice on saturated fat & cholesterol was probably dated when he received it. That's not a criticism. As a patient, one has to know the limits of a doctor's knowledge.

    My urologist is another great guy. Asked me to send him papers that I thought important. "But keep it brief!" I have acess to over 40 journals & no day job. How could he possibly keep up?

    A few years ago he was off to lunch with a pharma guy, to learn more about Xtandi. The realities of life. I'm OK with it - the patient must be a participant (or his spouse, partner, etc.)

    -Patrick

  • All of that is very true. Plus each specialty can't be a specialist in every other area as well.

    What bothers me is the notion that big pharma is buying off doctors so the information they provide should be suspect because somehow they are withholding vital information for the sake of "big pharma". That's different than not knowing information.

  • I don't expect my doctors to be nutritionists, or to have expertise in integrative/alternative medicine. I'm a Kaiser member & generally satisfied with my health care there. However, I wish they had some integrative medicine specialists, so I wouldn't have to go outside the plan & pay for this. Also, I did expect Kaiser's nutritionists to know something about cancer & diet, but they don't say or do anything differently for cancer patients, either in inpatient care or outpatient consultation. However, after reading what Patrick has to say, that makes more sense.

  • I adopted a vegan diet after my PCa diagnosis in July 2012 (Gleason 9 with metastasis to bladder and pelvic lymph nodes). I had external beam radiation and was on ADT for 26 months. Right now I am off all cancer meds and seem to be in a temporary remission (PSA steady at 0.1).

    Have no idea if the diet (and lots of exercise) have helped, but, hey, my cholesterol level dropped 36 points!

  • Hi smroush,

    How would you term your vegan diet in terms of fat?

    - low ~10%

    - high ~30% or higher

    - intermediate

    Your cholesterol dropped 36 points, so you presumably had a lipid panel recently. What were your HDL & triglycerides?

    Yes, I know, very nosey, but it would help me get a more nuance view of the vegan option.

    Best, -Patrick

  • I don't track my fat intake, but I try to keep it somewhat low, so I guess I would term it low to intermediate.

    HDL was 82 and triclycerides 53. (LDL was 91 and cholesterol was 184.)

    Steve

  • Steve,

    Those are great numbers. Actually, I'm only interested in the HDL:triglyceride ratio. 1:1 is a good target I feel, & you have done much better.

    I doubt anyone could acheive that on a very low fat Ornish-style diet.

    What fats do you use for cooking? Other sources, such as nuts?

    Any concerns about not being able to use marine omega-3 fatty acids?

    Thanks, -Patrick

  • I devised my own diet based on what I learned (some of which is questionable, based on what Patrick is telling us). I describe my diet as vegan plus fish & eggs, minus sugar & white rice). More recently, I'm "not eating white"--breads, pastas. Nuts give me diarrhea, but I eat seeds.

    I put fresh-ground organic flax seeds in my daily organic oatmeal, & use non-GMO soy milk. Based on a recommendation by a nutritionist who presented at a cancer center, I put a cup of organic blueberries in the oatmeal, using frozen blueberries for cost & avaiability reasons. I even throw in some organic brown rice, cooked with a tablespoon of extra virgin olive oil per cup of rice.

    This is also a good diet for cholesterol. I feel healthy. I eat lots of spicy Thai, Chinese, Indian & other Asian foods, & plenty of cooked tomato sauces. So my food isn't boring & I don't feel deprived.

  • For cooking the fats are usually extra virgin olive oil. Lots of other foods I eat have a fair amount of fat, including nuts and veggie patties and veggie sausages (and just a bit of dark chocolate daily - I'm just not self disciplined enough to avoid that!).

    The marine omega-3 are a conundrum - some sources say they are good and others scream no animal protein. I stick to vegan pretty consistently. I do use a couple of tablespoons of ground flax meal each day for the short chain omega 3s and lignans. (My wife and I are driving from Michigan to Wyoming for a few weeks in September; I expect the vegan diet to be a real challenge... Might have to compromise and have some seafood...)

  • Steve,

    There is a type of vegan who will come up with a clever explanation why his diet is not, in fact, deficient in EPA, DHA, B12, etc.

    For omega-3, the argument is that ALA (alpha linolenic acid) is converted in the body to EPA/DHA. This does not happen to any great degree in the body, according to studies, but this has been disputed on some vegan sites.

    [1] "Conversion of alpha-linolenic acid to eicosapentaenoic acid is limited in men and further transformation to docosahexaenoic acid is very low." "Overall, alpha-linolenic acid appears to be a limited source of longer-chain n-3 fatty acids in man and so adequate intakes of preformed n-3 polyunsaturated fatty acids, in particular docosahexaenoic acid, may be important for maintaining optimal tissue function."

    [2] "Studies generally agree that whole body conversion of 18:3n-3 {ALA} to 22:6n-3 {DHA} is below 5% in humans"

    [3] is a good overview

    It would interest me know how the situation changed when EPA/DHA from algae [4] became available. It is a product clearly aimed at vegans & other vegetarians - but supposedly not, in fact, needed by them. LOL

    Dr. Myers was so disturbed by patients saying that they used flaxseed, that he wrote a little book. I haven't seen it, but the PCa literature associates ALA with aggressive disease:

    [5] Giovannucci (1993):

    "Saturated fat, monounsaturated fat, and alpha-linolenic acid, but not linoleic acid, were associated with advanced prostate cancer risk; only the association with alpha-linolenic acid persisted when saturated fat, monounsaturated fat, linoleic acid, and alpha-linolenic acid were modeled simultaneously (multivariate RR = 3.43 ...)"

    But wait, said the fans of ALA - a lot of the ALA was animal ALA - flaxseed oil is different! LOL

    [6] Giovannucci (1994):

    "The association of alpha-linolenic acid levels with prostate cancer was greater among men with low linoleic acid and reduced meat intake."

    "The effects of dietary alpha-linolenic acid, particularly from vegetable sources, warrant further study."

    & this is the irony. Men who avoided polyunsaturated vegetable oils high in linoleic acid [LA] (an omega-6) were particularly at risk if they had a bottle of flaxseed oil in the fridge. I was one of those guys. Oddly, the "evil" LA protects against the "good" ALA".

    One thing to ponder on. Flaxseed oil is very unstable. It is sold in health stores under refrigeration. When opened, there will be oxidation even if refrigerated. & in the body?

    -Patrick

    [1] ncbi.nlm.nih.gov/pubmed/150...

    [2] researchgate.net/publicatio...

    [3] ihpmagazine.com/the-metabol...

    [4] nordicnaturals.com/en/Produ...

    [5] ncbi.nlm.nih.gov/pubmed/810...

    [6] ncbi.nlm.nih.gov/pubmed/815...

  • If you're not a vegan for moral/philosophical reasons but as a way to live longer with prostate cancer, why not have fish & fish oil, & eggs too if you like? Aren't the people screaming no animal protein saying that out of conviction, not PC diet design? Fish are generally healthier than seafood, but I eat both. Enjoy your trip!

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