Tumor growth, in mice, slowed by diet restrictions

[kreg001]

Not a cure but an interesting take on cancer and diet. Caloric restriction for mice with pancreatic cancer tumors slowed tumor growth. Upon investigation researchers identified lower availability of lipids, necessary for cell membranes, as the reason. It appears cancer cells can’t manufacture lipids and rely upon circulation for them.

news.mit.edu/2021/how-diet-...

[pjoshea13]

Just checked & PubMed has 555 hits for <prostate "IGF-I">.

IGF-I is insulin-like growth factor-I. It is usually elevated in PCa, and binding proteins (such as IGFBP3), which reduce IGF-I bio-availability are often down-regulated.

If we restrict protein, rather than calories, the body will respond by limiting IGF-I production. The aim is to restrict the essential amino acids used to build protein. Vegans do not eat preformed protein, so are able to selectively restrict a single amino acid. We have had posts on this.

The linked article says:

"While both of these diets reduce the amount of sugar available to tumors ..."

As many here know, PCa cells do not start out with an appetite for glucose (why do these articles always say "sugar"? - the fate of all carb is to become glucose.) A fluorodeoxyglucose (FDG)-PET scan is not used to diagnose PCa.

"the researchers found that only the calorically restricted diet reduced the availability of fatty acids, and this was linked to a slowdown in tumor growth."

Some might conclude that it is important to lower the intake of fatty acids, but with a low-fat high-carb ratio:

"Excess carbohydrates in the body are converted to palmitic acid. Palmitic acid is the first fatty acid produced during fatty acid synthesis and is the precursor to longer fatty acids. As a consequence, palmitic acid is a major body component of animals. In humans, one analysis found it to make up 21–30% (molar) of human depot fat" [1]

I suppose the key word is "excess". With calorie restriction, will the body stop making palmitic acid? Some of its metabolites are provisionally essential. Possibly not a good long-term approach.

Maybe a stretch to expect a mouse panreatic cancer study to translate into benefit for men with advanced PCa.

Dr. Myers ran into some heated responses to his dietary advice. It's common for men with PCa to adopt a new diet - and belief in the diet is often as strong as religious belief. Myers advocates the Mediterranean diet & adopted it in the absence of proof that it improved PCa outcome. In fact, he adopted it well before the results of the PREDIMED trial proved that the diet was heart-healthy (important for men with PCa).

But a restrictive diet of some sort might have more impact. To some of us, severe dietary restriction has all of the appeal of religious self-flaggelation.

-Patrick

[1] en.wikipedia.org/wiki/Palmi...

[kreg001 in reply to pjoshea13]

Agreed. I like to eat and the authors make it clear there’s no cure. I found it interesting because blocking lipids is not unheard of.

[Tall_Allen]

Unfortunately, what works in mice does NOT work in humans.

[kreg001 in reply to Tall_Allen]

Not always. But, cell metabolism is cell metabolism and blocking lipids is not unheard of.

[Tall_Allen in reply to kreg001]

95+% of what works in mice has no effect in humans. Mice are bred to react to treatment, so they can be used as screeners. It is also untrue that "cell metabolism is cell metabolism." There are no clinical data that show that blocking lipids has any effect. In fact, if prostate cancer cells are deprived of lipids (their preferred nutrient), they simply switch to another nutrient or break down benign cells to feed.

Caloric deprivation has been tried in primates - it doesn't work:

"Caloric restriction (CR) initiated at older ages did not increase survival relative to Controls...This suggests that the effects of CR in a long-lived animal are complex and likely dependent on a variety of environmental, nutritional, and genetic factors.

ncbi.nlm.nih.gov/pmc/articl...

[kreg001 in reply to Tall_Allen]

No argument. It was, I thought, an interesting article in my MIT Daily feed.Thought I’d share. That’s all. No crusade. I remember how longevity was increased by keeping rats at the edge of starvation but rat puberty was also delayed. Long time ago. Lot of interesting things in biology.

[Hidden]

The issue all of these mouse studies run into is a mouse metabolism and and human metabolism are not the same...it is why many studies on mice show great results but do not translate into the same results in humans. It's understandable that many on this site are looking for Hail Mary treatments. IMHO, most should stick to evidence based treatments and take a smattering of supplements....anything else is wishful thinking and a complete waste of money.

[kreg001 in reply to Hidden]

The authors make it clear there’s no cure in their findings. But blocking lipids is not unheard of.

[Hidden in reply to kreg001]

Unheard of and a evidence based treatments are not the same. There have been studies on statins for men with prostate cancer...if it did what it was suppose to do, the discussion would be over now...but it isn't . Hey, take whatever you want...but no one should ever complain about the cost of SOC treatments when some spend $500+/month on supplements with unproven results.

[noahware in reply to Hidden]

Last time I checked, caloric restriction was a way to SAVE money, not spend more of it. That was my experience, anyway... especially when I reduced the calories from Chianti Classicos, Imperial IPAs, and single malt Scotches!

But the article is really just "food" for thought, as the authors point out: "Although this study showed that calorie restriction has beneficial effects in mice, the researchers say they do not recommend that cancer patients follow a calorie-restricted diet, which is difficult to maintain and can have harmful side effects. However, they believe that cancer cells’ dependence on the availability of unsaturated fatty acids could be exploited to develop drugs that might help slow tumor growth."

[Hidden in reply to noahware]

As someone who practices 16:8 IF, I understand the the theory. What I was stating is that a mouse metabolism is so much different than ours that any observations are really meaningless. A mouse metabolism is roughly 7 times greater than a human. A 16:8 IF on a mouse will have a much different result than on me.

My supplements comment was a general comment about the decision to spend 100s a month on supplements based on mouse studies. I find that unwise.

[CharlieBC in reply to Hidden]

TomTom, I just finished a 4 day fast, and will transition to a 16:8 (maybe 18:6). I am sure my weight, beer belly and lifestyle opened the door to PCa. My primary goal is to lower my BMI, lose weight and hopefully make my body a little more hostile to PCa, while still using Xtandi. Next PSA in December. Anything eye-opening, I'll report it.

[Hidden in reply to CharlieBC]

Be careful when fasting when on ADT...it's already difficult to maintain muscle...fasting will definitely cause muscle loss...you'll need to workout extra hard (heavier weights) to regain any muscle loss. Good Luck.

I just finished my nearly 2.5 years of ADT. My next psa and T draw is January 14, 2022. I am waiting until my T begins to rise before I start a fasting program....lets see...if a mouse metabolism is roughly 7x that of human...I believe that equates 1 day of mouse fasting to 7 days of human fasting...NO? How many are willing to engage in that?

[CharlieBC in reply to Hidden]

Thanks.

[Hidden]

Here's an article about animal models in prostate cancer research.

cancerres.aacrjournals.org/...

[j-o-h-n]

Eat the mice..... Freeze the tails and use them for toothpicks.....

Good Luck, Good Health and Good Humor.

j-o-h-n Friday 10/22/2021 11:25 PM DST