Interesting research on how PC's metabolites could potentially promote atherosclerosis.
Common Dietary Fat and Intestinal Microbes Linked to Heart Disease
http://www.scienceda...10406131814.htm
Posted 07 April 2011 - 12:19 AM
Posted 07 April 2011 - 12:46 AM
Posted 07 April 2011 - 02:47 AM
Posted 07 April 2011 - 02:55 AM
Posted 07 April 2011 - 03:31 AM
A known environmental risk factor for the development of CVD is a diet rich in lipids. A relationship between blood cholesterol and triglyceride levels and cardiovascular risk is well established.
Edited by Jay, 07 April 2011 - 03:36 AM.
Posted 07 April 2011 - 04:18 AM
I think the paper is a call for moderation, assuming their results hold up. We certainly don't want to eliminate choline. We just don't want way too much. We just had a thread regarding some ugly data on egg consumption.Eggs, liver, and animal fat are quite unlikely to cause CVD. We've been through all this before... Wholehealthsource, dailylipid, etc are great places to start for newbies. For those that have been around a while, not quite sure why you'd be so quick to turn on choline. I think many people have far too little of it.
Posted 07 April 2011 - 05:54 AM
Posted 07 April 2011 - 04:47 PM
Posted 07 April 2011 - 06:10 PM
Edited by Mortuorum, 07 April 2011 - 06:12 PM.
Posted 07 April 2011 - 06:52 PM
Edited by nameless, 07 April 2011 - 06:53 PM.
Posted 07 April 2011 - 06:55 PM
The clinical significance of TMA and TMNO may be related to their potential to form the carcinogen N-nitrosodimethylamine and their association with abnormal neurological symptoms observed in patients with ESRD [15]. Other studies have shown higher levels of N-nitrosodimethylamine in the gastrointestinal tract of patients with ESRD compared with healthy controls [16] and, therefore, its potential contribution to an increased incidence of cancer in ESRD patients [17] should be carefully examined. N-nitrosodimethylamine does not elicit its carcinogenic effects directly, but requires metabolic activation in the liver, particularly by the cytochrome P450 2E1 isoenzyme, to form highly reactive alkylating intermediates that have the ability to methylate target organ DNA [18]. Mildly acidic conditions are conducive to the formation of N-nitrosodimethylamine from TMA and TMNO and, therefore, the acidic conditions of the stomach provide the most likely site for its formation in the body [18]. Whether elevated plasma levels of TMA and TMNO translate to increased levels in gastric fluid is not known. However, compounds with similar structural properties to TMA and TMNO are excreted from blood to gastric fluid [19]. The presence of bacteria or chronic inflammation has also been highlighted in other research as favouring the formation of N-nitrosodimethylamine from TMA and TMNO, implying that other sites of the body have the potential to form this carcinogen [18]. In our study, the pre-dialysis plasma concentrations of TMA and TMNO were significantly greater than those in healthy subjects (P<0.00001 andP<0.0001, respectively). There was also a significant reduction (P<0.001) in the pre-dialysis plasma concentrations of these substances following a haemodialysis session. Whether the accumulation of TMA and TMNO in the interdialysis period is associated with adverse effects is not currently known.
Posted 07 April 2011 - 06:58 PM
Interesting... Some quick questions:
Would probiotics be a good or bad thing if this paper holds up?
I believe they more or less wrecked the mice's flora using antibiotics, and said mice didn't show increased atherosclerosis due to choline. So would taking probiotics worsen this? Or would certain strains of bacteria be protective?
And as Niner mentioned, if nothing else, it does lead to re-evaluation of some diets. And Vimmortal... some folks already had hesitations over its choline content to begin with. I can't see this paper helping much.
Posted 07 April 2011 - 08:23 PM
According to the study data as manifest, the healthier and more "normal" your intestinal flora is, that is what is required and optimal to facilitate this resultant pathological process. So, yes, probiotics, presuming they are of integrity and being assimilated properly, will bolster and enhance the dark contentions of this research.
Edited by rwac, 07 April 2011 - 08:24 PM.
Posted 07 April 2011 - 08:35 PM
According to the study data as manifest, the healthier and more "normal" your intestinal flora is, that is what is required and optimal to facilitate this resultant pathological process. So, yes, probiotics, presuming they are of integrity and being assimilated properly, will bolster and enhance the dark contentions of this research.
Well, for one thing, it's hard to argue that the intestinal flora of lab mice is "normal" in any sense of the word.
It would be interesting to see if all strains of bacteria do this, or only specific strains.
Edited by Mortuorum, 07 April 2011 - 08:45 PM.
Posted 07 April 2011 - 09:05 PM
In which you and others have been corrected over and over again. Eggs drastically increase CVD in diabetics and may promote diabetes; some evidence suggests carcinogenic effects and overall effects on CVD are neutral-negative. They also worsen known risk factors and contain substances linked to diseases.Eggs, liver, and animal fat are quite unlikely to cause CVD. We've been through all this before... Wholehealthsource, dailylipid, etc are great places to start for newbies. For those that have been around a while, not quite sure why you'd be so quick to turn on choline. I think many people have far too little of it.
Edited by kismet, 07 April 2011 - 10:02 PM.
Posted 07 April 2011 - 09:29 PM
Posted 07 April 2011 - 09:36 PM
Edited by kismet, 07 April 2011 - 10:05 PM.
Posted 07 April 2011 - 09:56 PM
Posted 07 April 2011 - 10:32 PM
Edited by kismet, 07 April 2011 - 10:34 PM.
Posted 08 April 2011 - 05:52 AM
Posted 08 April 2011 - 01:16 PM
Edited by Jay, 08 April 2011 - 01:17 PM.
Posted 08 April 2011 - 02:31 PM
There is a huge difference between dietary folate from vegetables and supplementing with folate. See this study for instance.There are fist fulls of studies, in humans, some of them randommized placebo controlled trials, suggesting that folate and folic acid increase the risk of cancer. Yet, since folate is found in vegetables, many don't focus on this evidence. But, choline...
The problem with epidemiology is that there are too many confounding factors to see a cause and effect. An epidemiology study showing the dangers of egg intake could have many different explanations (such as oxycholesterol for instance).Now there is a study on dysbiotic mice and choline and we have a two page thread... Choline is of course found mainly in animal products... Since liver and other organs are out of fashion, human dietary intake of choline is primarily from eggs and coffee. And, people who ate the most choline just ate the most eggs, a dangerous thing to do if you believe your doctor... Paying attention to epidemiology where the variable goes against doctor's orders is not very reliable.
Now add in that serum cholilne is not so sensitive to dietary choline (in non-deficient people).
I don't see anyone but you jumping to this conclusion.What do we have left from this paper? More or less completely defective human evidence and a wierd mouse study... Yup, let's stop eating liver and eggs and start eating the low-fat chow...
Posted 08 April 2011 - 02:56 PM
There is a huge difference between dietary folate from vegetables and supplementing with folate. See this study for instance.
(the quote above from the NIH).Folate is a water-soluble B vitamin that occurs naturally in food. Folic acid is the synthetic form of folate that is found in supplements and added to fortified foods.
Posted 08 April 2011 - 04:03 PM
And this is after a very low choline diet (550 to 50mg/d for 42 days!):
"Of the 57 participants, 68% developed organ dysfunction when fed the low choline diet and this resolved when choline was added back to their diets. Plasma betaine concentrations decreased almost 50% in response to the low choline diet (from 60±3 to 32±2 nmol/ml; P<0.001) and choline concentrations decreased almost 30% (from 9.8±0.3 to 7.1±0.2 nmol/ml; P<0.001). These decreases were irrespective of whether or not subjects developed organ dysfunction on the low choline diet. Plasma phosphatidylcholine concentrations were 9% lower when subjects were fed the low choline diet (1691±41 vs. 1868±45 nmol/ml than when on baseline diet; P<0.001); those subjects who developed organ dysfunction on the low choline diet had a 3-fold greater decrease in phosphatidylcholine (–228±47 nmol/ml) than those who did not (–64±31 nmol/ml; P<0.029 by t test)."
http://www.fasebj.or.../20/9/1336.full
Exogenous choline hardly budges serum choline, which going by this recent paper would suggest that dietary choline only confers a small risk; consistent with the cohort studies. We do not have TMAO data unfortunately...
Posted 08 April 2011 - 04:32 PM
Thanks for mentioning that and for that informative link. It is true that the supplementation in the study I cited was mainly from folic acid intake as shown in this quote from the abstract:There is a huge difference between dietary folate from vegetables and supplementing with folate. See this study for instance.
That's a bit apples and oranges. The study you linked supports the claim that folic acid supplements (which are synthetic) are problematic, but not necessarily supplementation of other forms of folate.(the quote above from the NIH).Folate is a water-soluble B vitamin that occurs naturally in food. Folic acid is the synthetic form of folate that is found in supplements and added to fortified foods.
Furthermore, although food folate intake was not significantly related to breast cancer risk, total folate intake, mainly from folic acid supplementation, significantly increased breast cancer risk by 32%.
Folate intake from food is not associated with any health risk.
Edited by aLurker, 08 April 2011 - 04:40 PM.
Posted 08 April 2011 - 07:09 PM
Posted 08 April 2011 - 09:25 PM
I'm not hysterically concerned with the plasma choline ORs, (although they are non-trivial) but note that the TMAO ORs are twice as big, and are pretty big numbers. That's a hard thing to ignore.I concur that a re-appraisal of choline is in order, but we must not get hysteric over the reported odds ratios for serum choline.
I think there's an explanatory role in the gut biota. We see little effect on CVD from dietary choline, but even there, the ORs are positive, though not significant. And that's with crappy FFQ data. When you look at plasma choline, you're getting better data, and you see a big jump in the ORs. This might represent differences in people's ability to transform PC to choline. Then consider that not everyone's gut flora is the same, and some are apparently more likely to convert choline to trimethylamine (TMA). The TMA is hepatically converted to TMAO, the putative ulitmate bad actor. There's probably some variation there, too. Each time we look further down the trasformation pathway, the ORs get worse.What does serum choline tell us about choline intake and how sensitive is it? this is a key question
since “there is no reliable blood biomarker for dietary intake of choline. As it is known from clinical settings, plasma concentrations of choline and betaine decrease when subjects are fed a low choline diet, but the amount of decrease is not highly correlated with susceptibility to develop organ dysfunction while on this diet”
The available cohort studies suggest a minimal risk from dietary choline if any.
"“During an average 14 years of follow-up (1987-2002), 1,072 incident CHD events were documented. Compared with the lowest quartile of intake, incident CHD risk was slightly and non-significantly higher in the highest quartile of choline and choline plus betaine, HR = 1.22 (0.91, 1.64) and HR = 1.14 (0.85, 1.53), controlling for age, sex, education, total energy intake, dietary intakes of folate, methionine and vitamin B6. No association was found between dietary choline intake and incident CHD when correcting for measurement error.”
BMC Cardiovasc Disord. 2007 Jul 13;7:20.
Usual choline and betaine dietary intake and incident coronary heart disease: the Atherosclerosis Risk in Communities (ARIC) study.
Bidulescu A, Chambless LE, Siega-Riz AM, Zeisel SH, Heiss G.
http://www.ncbi.nlm....79/?tool=pubmed
"During a median follow-up period of 97 months, 717 women were diagnosed with CVD. After adjustment, neither folate, nor betaine, nor choline intakes were associated with CVD (hazard ratios for highest versus lowest quartile were 1.23 (95% confidence interval 0.75; 2.01), 0.90 (0.69; 1.17), 1.04 (0.71; 1.53), respectively). In a subsample of the population, high folate and choline intakes were statistically significantly associated with lower homocysteine levels. High betaine intake was associated with slightly lower high-density lipoprotein (HDL)-cholesterol concentrations."
Classic inverted U, isn't it? We just need to sort out the parameters of the curve. But beyond that, I think the exciting messages are that a serum TMA or TMAO level would quickly tell you whether you had a problem or not. That should be simple to implement. Also, at the end of the paper, they mentioned the possibility of probiotic therapy. From their ref. 35, (Martin, F. P. et al. Probiotic modulation of symbiotic gut microbial–host metabolic interactions in a humanized microbiome mouse model. Mol. Syst. Biol. 4, 157 (2008).) they claim that probiotic supplementation can modulate TMAO levels. So get your gut microflora in the right shape and maybe you'll cut your risk of CVD and a growing list of other conditions.While zero choline as well as the ten-fold overdoses given to rats (and hyperlipid dieters?) will kill you, modest differences, e.g. 250mg vs 500mg, may involve only smallish trade-offs. Say, very, very small CVD risk vs neuro/cancer/inflamm. benefits. W/o all-cause mortality data it will probably remain guesswork.
Posted 09 April 2011 - 01:12 AM
Posted 09 April 2011 - 03:43 AM
Edited by Jay, 09 April 2011 - 03:47 AM.
Posted 09 April 2011 - 04:09 AM
0 members, 16 guests, 0 anonymous users