Thanks for sharing your findings. - very informative!
A few questions:
- I am also AG in the rs2987983. How worse is GG compared to AG in this case?
- Is AA variation in the rs5275 polymorphism mentioned in the second study good then?
- I am AG in Rs2236225 so how that compares to being AA or GG?
- I am also TT in rs7946 - what recommendation have you found to act against this mutation? Also increased choline intake?
Thank you for your feedback.
- I am also AG in the rs2987983. How worse is GG compared to AG in this case?
I do not know. As far as I can understand, the study differentiates only for TT and the carriers of the C allele, so meaning both CT and CC without further differentiation. CT is the case relevant for both of us thought, so why bothering? We both carry the allele for which isoflavones are protective at a specific dose. Key is “…For isoflavonoids, we found no overall association with risk of prostate cancer (Table III). However, when we stratified by nucleotide sequence in the SNP (-13950 T/C), risk decreased monotonically with increasing intake of isoflavonoids among TC/CC carriers, whereas no reduction in risk was seen for TT carriers…”.
When you take 1 as reference for TT you go down to 0.63 (for 116 mcg/day intake) which makes the -37% decrease in risk I mentioned in my post.
Isoflavone intake and OR for PCa.png.jpg 236.56KB
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http://www.ncbi.nlm....pubmed/16921512
- Is AA variation in the rs5275 polymorphism mentioned in the second study good then?
I do not think so. I think the protective allele for prostate cancer when taking salmon-type fish is the C (or G in 23andMe conventions: if confused with these conventions I find useful this link: http://www.snpedia.c...php/Orientation). But there seems to be no benefit if you do not have the variant. The study says:
“…Among subjects who were heterozygous or homozygous for the variant allele C of the SNP (+6365 T/C), high intake of salmon-type fish was associated with a significantly decreased relative risk of prostate cancer. Following multivariate adjustment, risk of prostate cancer was 72% lower among men who ate salmon-type fish once or more per week, when compared with men who never ate salmontype fish, whereas we found no significant association with salmon-type fish intake among subjects homozygous for the more common allele (T)…”
- I am AG in Rs2236225 so how that compares to being AA or GG?
I guess simply you have less risk that me (AA) of being choline deficient at parity of other conditions, the risk allele hinting to requiring more choline being A.
- I am also TT in rs7946 - what recommendation have you found to act against this mutation? Also increased choline intake?
I would guess so and, as I have mutations in the BHMT too, the geneticgenie report recommends so. But there are no simple replies and here I think is the challenge of this emerging science, which can be overwhelmingly complex without use of more education and advances in AI and computing. I really refrain to jump too quickly to conclusions. The issue looks confounded because of interactions with other possible mutation and folate status. There is some race differences too (Caucasian, Hispanic and African-American descent), see: http://www.snpedia.c...ndex.php/Rs7946. The study says (full text at http://www.ncbi.nlm....les/PMC1256033/): “ … The requirement for choline (from diet or from PEMT synthesis) is spared, in part, by the availability of methyl groups from 1-carbon metabolism (via methyltetrahydrofolate) (42). It is possible that the PEMT SNP we describe will interact with other commonly known SNPs in humans. For example, the thermolabile variant (677C→T) of 5,10-methylenetetrahydrofolate reductase (MTHFR, E.C. 1.5.1.20) occurs in 15–30% of humans (43). We found that mice in which MTHFR was deleted develop fatty liver that resolves when mice are fed the choline metabolite betaine (43). These mice require more choline or betaine because homocysteine remethylation to methionine, in the absence of 1-carbon units via the folate pathway shifts to a pathway that uses choline as a precursor. Homocysteine can be remethylated to methionine by methionine synthase, using 5-methylfolate which is supplied by MTHFR (43). Alternatively, betaine:homocysteine methyltransferase (BHMT, EC 2.1.1.5) catalyzes a methyl transfer from betaine to homocysteine (43). When 5-methylfolate is not available, more betaine is required. Thus, humans who have diminished capacity to synthesize choline moiety via PEMT activity, and who have diminished capacity to form 5-methylfolate will have difficulty producing increased betaine from choline when it is needed for homocysteine methylation…”
Edited by albedo, 21 November 2015 - 02:57 PM.