Posted on 04/08/2011 1:19:41 PM PDT by decimon
How specific digestive tract microbes react to a dietary lipid increases risk of heart attack, stroke and death
A new pathway has been discovered that links a common dietary lipid and intestinal microflora with an increased risk of heart disease, according to a Cleveland Clinic study published in the latest issue of Nature.
The study shows that people who eat a diet containing a common nutrient found in animal products (such as eggs, liver and other meats, cheese and other diary products, fish, shellfish) are not predisposed to cardiovascular disease solely on their genetic make-up, but rather, how the micro-organisms that live in our digestive tracts metabolize a specific lipid -- phosphatidyl choline (also called lecithin). Lecithin and its metabolite, choline, are also found in many commercial baked goods, dietary supplements, and even children's vitamins.
The study examined clinical data from 1,875 patients who were referred for cardiac evaluation, as well as plasma samples from mice. When fed to mice, lecithin and choline were converted to a heart disease-forming product by the intestinal microbes, which promoted fatty plaque deposits to form within arteries (atherosclerosis); in humans, higher blood levels of choline and the heart disease forming microorganism products are strongly associated with increased cardiovascular disease risk.
"When two people both eat a similar diet but one gets heart disease and the other doesn't, we currently think the cardiac disease develops because of their genetic differences; but our studies show that is only a part of the equation," said Stanley Hazen, M.D., Ph.D., Staff in Lerner Research Institute's Department of Cell Biology and the Heart and Vascular Institute's Department of Cardiovascular Medicine and Section Head of Preventive Cardiology & Rehabilitation at Cleveland Clinic, and senior author of the study. "Actually, differences in gut flora metabolism of the diet from one person to another appear to have a big effect on whether one develops heart disease. Gut flora is a filter for our largest environmental exposure – what we eat."
Dr. Hazen added, "Another remarkable finding is that choline – a natural semi-essential vitamin – when taken in excess, promoted atherosclerotic heart disease. Over the past few years we have seen a huge increase in the addition of choline into multi-vitamins - even in those marketed to our children - yet it is this same substance that our study shows the gut flora can convert into something that has a direct, negative impact on heart disease risk by forming an atherosclerosis-causing by-product."
In studies of more than 2,000 subjects altogether, blood levels of three metabolites of the dietary lipid lecithin were shown to strongly predict risk for cardiovascular disease: choline (a B-complex vitamin), trimethylamine N-oxide (TMAO, a product that requires gut flora to be produced and is derived from the choline group of the lipid) and betaine (a metabolite of choline).
"The studies identify TMAO as a blood test that can be used in subjects to see who is especially at risk for cardiac disease, and in need of more strict dietary intervention to lower their cardiac risk," Dr. Hazen said.
Healthy amounts of choline, betaine and TMAO are found in many fruits, vegetables and fish. These three metabolites are commonly marketed as direct-to-consumer supplements, supposedly offering increased brain health, weight loss and/or muscle growth.
These compounds also are commonly used as feed additives for cattle, poultry or fish because they may make muscle grow faster; whether muscle from such livestock have higher levels of these compounds remains unknown.
"Knowing that gut flora generates a pro-atherosclerotic metabolite from a common dietary lipid opens up new opportunities for improved diagnostics, prevention and treatment of heart disease," Dr. Hazen said. "These studies suggest we can intelligently design a heart healthy yogurt or other form of probiotic for preventing heart disease in the future. It also appears there is a need for considering the risk vs. benefits of some commonly used supplements."
Is there such a thing as farm raised:
salmon
tuna
sardines
Seems to me these species are not farmable.
I’d like to know which strains of gut flora are good and which are bad. Are the ones in Dannon yogurt the good ones?
Those are supposed to be some of the good ones. I've read that there are hundreds of good ones and that getting a handle on just what they all do will be quite a task. Maybe it's enough to know that replenishing the good ones helps to crowd out the bad ones.
"These studies suggest we can intelligently design a heart healthy yogurt or other form of probiotic for preventing heart disease in the future. It also appears there is a need for considering the risk vs. benefits of some commonly used supplements."
The first is that gut bugs matter, though it's hard to tell if what matters is what kind they are or how much of them you have. The second conclusion is that excessive choline and other subtances can be turned into plaque-causing compounds by gut bugs, with less emphasis on the bugs' particular kind or quantity.
Do you happen to know if yogurt contains a particular strain of gut bugs, or is it a blend? I know you can buy pro-biotic capsules. I wonder if those have a select blend of the good ones.
That might vary by brand but it's listed on the yogurt container. Wikipedia does a better job of this than I can: http://en.wikipedia.org/wiki/Probiotic
Salmon and tuna are indeed farmed. Buy wild.
Then, of course, you have the studies that show the exact opposite effect.
http://www.ncbi.nlm.nih.gov/pubmed/18983488
http://www.ncbi.nlm.nih.gov/pubmed/18983488
Maybe. Can't tell. How does that refute the dose-dependent results of this study?
Thanks, good info there. Some wikipedia pages are really good, and that is one of them.
Well, it’s not the exact opposite. But it points out the anti-inflammatory effects of serum lecithin.
It’s pretty well determined by now that the primary correlation is between CRP (C Reactive protein, an indicator of inflammation) and the formation of arteriosclerotic lesions.
Heart disease is not caused by what you do eat. It’s caused by what is missing from your diet. Linus Pauling proved that and won a Nobel prize in the process.
Slightly more than half of all people who suffer sudden cardiac dilemmas have normal or lower than normal cholesterol.
I guess I’ll stick with sardines and kipper snacks then. I really like fresh salmon and fresh tuna though.
"I'm reading this as saying it is the amount of choline determining what the gut bugs do with it."
This article is written quite poorly and no particular metabolites of choline, TMAO, or betaine that are implicitly referenced are given. The blood conc. of these molecules is only used to indicate the probability of developing CVD. Choline metabolism by gut bugs isn't determined by choline concenttration though. This article is claiming it's the type of bug that produced the bad metabolic end products. The article abstract just says the following about excess choline...
From the Abstract: "Suppression of intestinal microflora in atherosclerosis-prone mice inhibited dietary-choline-enhanced atherosclerosis."
I don't know what you're arguing for or against.
"I don't know what you're arguing for or against."
I'm saying this article is junk. This article says, "...and supplementation with choline or TMAO promoted atherosclerosis.", but that's not supported by the article's abstract. The article's abstract says that without the metabolic action of the gut bugs on these substances, there is no effect on CVD by choline, TMAO, or betaine. Take a look at the quote given in the link in my last post and the link to the abstract for the article itself.
That quote I gave in post #34 is from the abstract, not the article.
From the abstract: "...and supplementation with choline or TMAO promoted atherosclerosis."
For anyone not familiar with the term macrophage, it's a type of white blood cell. It's part of the innate immune system. This diet and some gut flora elicits inflammation. Here's the abstract:
Gut flora metabolism of phosphatidylcholine promotes cardiovascular disease
Metabolomics studies hold promise for the discovery of pathways linked to disease processes. Cardiovascular disease (CVD) represents the leading cause of death and morbidity worldwide. Here we used a metabolomics approach to generate unbiased small-molecule metabolic profiles in plasma that predict risk for CVD. Three metabolites of the dietary lipid phosphatidylcholine—choline, trimethylamine N-oxide (TMAO) and betaine—were identified and then shown to predict risk for CVD in an independent large clinical cohort. Dietary supplementation of mice with choline, TMAO or betaine promoted upregulation of multiple macrophage scavenger receptors linked to atherosclerosis, and supplementation with choline or TMAO promoted atherosclerosis. Studies using germ-free mice confirmed a critical role for dietary choline and gut flora in TMAO production, augmented macrophage cholesterol accumulation and foam cell formation. Suppression of intestinal microflora in atherosclerosis-prone mice inhibited dietary-choline-enhanced atherosclerosis. Genetic variations controlling expression of flavin monooxygenases, an enzymatic source of TMAO, segregated with atherosclerosis in hyperlipidaemic mice. Discovery of a relationship between gut-flora-dependent metabolism of dietary phosphatidylcholine and CVD pathogenesis provides opportunities for the development of new diagnostic tests and therapeutic approaches for atherosclerotic heart disease.
Regulation of macrophage function in inflammation and atherosclerosis FReebie
From WebMD:
--snip--
"A certain form of phosphatidylcholine (polyunsaturated phosphatidylcholine) might provide protection against liver fibrosis and liver damage caused by drinking alcohol, although the exact mechanisms are not completely understood."
So phosphatidylcholine itself refers to a variety of molecules depending upon what fatty acids were used in its synthesis.
This is a tap dance.
This nonsense was demolished by Ottobani over a decade ago.
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