It's common to reconsider diet following a cancer diagnosis. Perhaps give up foods touted as pro-cancer & load up on those thought to be protective. As though what we should have been eating before, is what we should be eating henceforth.
But what if the cancer likes the new diet?
It's widely accepted that free radicals in the body, being inherently unstable, may cause DNA damage (& therefore cancer) & that antioxidants from a diet rich in non-starchy vegetables may provide sufficient antioxidants to counter those free radicals.
I have known two men who hoped to coax their PCa cells back to normalcy via a "healthy" diet. The idea being that the cells would somehow become better differentiated & less dangerous. Meanwhile, BigPharma takes the opposite approach. Cancer treatments generally involve the generation of reactive oxygen species [ROS]. Antioxidants in the diet might water down the therapeutic ROS effect.
We bring into PCa, dietary baggage that cannot automatically be assumed to be useful. Unfortunately, dietary advice from the gurus is often just more of the same. Did Dean Ornish make any changes to his standard 10% fat vegan diet for his PCa clinical trial? The diet is supposed to be perfect for all circumstances. Perhaps he had doubts, though, since he slipped in a little fish oil, but otherwise changed nothing. Vegans quite rightly were angry with him.
PCa has an extraordinary wide phytochemical literature (mostly polyphenols). These chemicals have protective roles in plant life. There are two common features: (i) they inhibit NF-kB (nuclear factor-kappaB), the chronically-activated cell survival protein complex, & (ii) they are antioxidants.
But why might an antioxidant be found useful against cancer? Invariably, the phytochemicals only became effective in studies at levels where ROS was induced. At high levels, an antioxidant may become a pro-oxidant.
I often see some variation of the following statement:
"Pretreatment with N-acetylcysteine (NAC) inhibited both ******-induced ROS generation and growth inhibition."
NAC itself can become pro-oxidant at very high levels, but it is generally a reliable ROS scavenger. Thus, if we take a pharmacological dose of polyphenols, in order to encourage ROS, we should stay away from NAC. (I'm also wary of alpha lipoic acid [ALA]. ALA is a very fine supplement for those without cancer, but might undermine ROS-related therapy.)
I dredged up a number of PCa-phytochemical studies, below, to make the point that we need pro-oxidant doses. It isn't an exhaustive sample, however.
[A] Apigenin, a flavone.
[A0] Source: "parsley, celery, celeriac, and chamomile". Supplement from grapefruit.
[A1] "Apigenin generated reactive oxygen species, a loss of mitochondrial Bcl-2 expression ..."
[A2] "Apigenin at these doses resulted in ROS generation, which was accompanied by rapid glutathione depletion, disruption of mitochondrial membrane potential, cytosolic release of cytochrome c, and apoptosis."
[Ca] Capsaicin
[Ca0] Source: chili peppers.
[Ca1] "The results showed that capsaicin induced prostate cancer cell death in a time- and concentration-dependent manner" in LNCaP and PC-3 cells.
"Furthermore, we found that capsaicin triggered ROS generation in cells, while the levels of ROS decreased with N-acetyl-cysteine (NAC) ... Co-treatment of cells with NAC and capsaicin abrogated the effects of capsaicin on autophagy and cell death."
[Ch] Chrysin. A flavone.
[Ch0] Source: propolis. Supplement: passionflower. Bioperine for bioavailability.
[Ch1] "chrysin induced apoptosis of cells evidenced by DNA fragmentation and increasing the population of both DU145 and PC-3 cells in the sub-G1 phase of the cell cycle. In addition, chrysin reduced expression of proliferating cell nuclear antigen in the prostate cancer cell lines compared to untreated prostate cancer cells. Moreover, chrysin induced loss of mitochondria membrane potential (MMP), while increasing production of reactive oxygen species (ROS) and lipid peroxidation in a dose-dependent manner."
[Cu] Curcumin.
[Cu1] "curcumin induced ER {endoplasmic reticulum} stress by triggering ROS generation, which was supported by the finding that treating cells with the antioxidant NAC alleviated curcumin-mediated ER stress and vacuolation-mediated death. An in vivo PC-3M orthotopic prostate cancer model revealed that curcumin reduced tumor growth by inducing ROS production followed by vacuolation-mediated cell death. Overall, our results indicated that curcumin acts as an inducer of ROS production, which leads to nonapoptotic and nonautophagic cell death via increased ER stress.
[Cu2] A curcumin analog (WZ35).
"we found that WZ35 treatment for 30 min significantly induced reactive oxygen species (ROS) production in PC-3 cells. Co-treatment with the ROS scavenger NAC completely abrogated the induction of WZ35 on cell apoptosis, ER stress activation, and cell cycle arrest, indicating an upstream role of ROS generation in mediating the anti-cancer effect of WZ35."
[Ga] Gallic acid.
[Ga0] Source: Indian gooseberry. There is some in tea leaves.
[Ga1] "Gallic acid (GA) is a natural polyphenol, and we tested its in-vitro cytotoxicity after 24 h in prostate cancer LNCaP cells." "Increased intracellular ROS levels with GA were reduced by N-acetyl-L-cysteine (NAC) and L-glutathione (GSH). Cells were protected against GA cytotoxicity when pretreated with increasing levels of superoxide dismutase/catalase mixture, NAC, or GSH for 3 h"
[Ge] Genistein. An isoflavone & phytoestrogen.
[Ge0] Source: soy. LEF product.
[Ge1] Genistein was added to Doxorubicin Hydrochloride to amplify oxidative damage.
[P] Phenethyl isothiocyanate (PEITC)
[P0] Source: some cruciferous vegetables, but particularly watercress.
[P1] "PEITC significantly inhibited DU145 cell proliferation in a dose-dependent manner and induced the cell arrest at G2-M phase." "Moreover, an antioxidant reagent, N-acetyl-L-cysteine (NAC) which suppresses reactive oxygen species (ROS) generation, reversed the early inhibitory effects of PEITC on cell proliferation"
[S] Sulforaphane.
[S0] Source: Source: some cruciferous vegetables. BroccoMax.
[S1] "Sulforaphane-induced apoptosis in PC-3 cells correlated with the generation of intracellular reactive oxygen species (ROS), collapse of mitochondrial membrane potential" "The quenching of ROS generation with antioxidant N-acetyl-L-cysteine conferred significant protection against sulforaphane-induced ROS generation"
[NAC]
"Discordant results in preclinical and clinical trials have raised questions over the effectiveness of antioxidants in prostate cancer chemoprevention. Results from the large-scale Selenium and Vitamin E Cancer Prevention Trial (SELECT) showed that antioxidants failed to prevent, and in some cases promoted, prostate cancer formation in men without a history of the disease."
"{We treated} Nkx3.1 mutant mice with the antioxidant N-acetylcysteine (NAC) for 13 weeks post-weaning. Surprisingly, while NAC treatment decreased ROS levels in Nkx3.1 mutant mouse prostates, it failed to reduce prostatic epithelial hyperplasia/dysplasia. Rather, NAC treatment increased epithelial cell proliferation and promoted the expression of a pro-proliferative gene signature."
[X] Drugs.
[XC] Cabazitaxel [Jevtana]
[XC1] "Cabazitaxel showed significantly higher cytotoxic efficacy than docetaxel in human CRPC cells, accompanied by elevated ROS production"
"To investigate whether cabazitaxel-mediated cell death was caused by the ROS generation induced by cabazitaxel, we treated CRPC cells in the presence of antioxidant NAC. NAC reduced the cytotoxic effect induced by cabazitaxel."
-Patrick
[A0] swansonvitamins.com/swanson...
[A1] ncbi.nlm.nih.gov/pubmed/154...
[A2] ncbi.nlm.nih.gov/pubmed/183...
[Ca0] swansonvitamins.com/natures...
[Ca1] ncbi.nlm.nih.gov/pubmed/266...
[Ch0] swansonvitamins.com/swanson...
[Ch1] ncbi.nlm.nih.gov/pubmed/?te...
[Cu1] ncbi.nlm.nih.gov/pubmed/260...
[Cu2] ncbi.nlm.nih.gov/pubmed/265...
[Ga0] swansonvitamins.com/swanson...
[Ga1] ncbi.nlm.nih.gov/pubmed/225...
[Ge0] lifeextension.com/Vitamins-...
[Ge1] ncbi.nlm.nih.gov/pubmed/294...
[NAC] ncbi.nlm.nih.gov/pubmed/230...
[P] en.wikipedia.org/wiki/Phene...
[P1] ncbi.nlm.nih.gov/pubmed/194...
[S] Sulforaphane.
[S0] swansonvitamins.com/jarrow-...
[S1] ncbi.nlm.nih.gov/pubmed/189...