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New study links L-carnitine in red meat to heart disease

April 17, 2013

About the Author

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Daniel Pendick, Former Executive Editor, Harvard Men's Health Watch

Daniel Pendick is a former executive editor of Harvard Men’s Health Watch. He previously served as editor and chief writer for the Cleveland Clinic Men’s Health Advisor and Mt. Sinai School of Medicine’s Focus On Healthy … See Full Bio
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June 15, 2013

This article was at least decent until this crap:

“Cattle farming has devastating environmental effects, including production of greenhouse gases, water pollution, and deforestation. “Health effects in humans aside, red meat consumption is clearly bad for the health of our planet,” says Mozaffarian.”

This is more opinion than science. Not that I’m an expert, but there have been so many studies that find contrary results. Pretty bold statement to say that red meat consumption is bad for the health of our planet.

June 11, 2013

Question… Is this study performed with commercial beef? Meaning beef sold in your typical grocery store? I wonder what the results would be for someone whose diet is primarily organic and consumes grass fed beef with no hormones, pesticides, herbicides etc. is the bacteria from the farming process and in the meat already before it becomes part of the intestinal flora? This study is interesting but I think more specifications need to be looked at to determine if its the processing that is the true culprit. People have been eating red meat for thousands of years. The prevelance of heart disease occurs more now than in our paleo ancestors… Why?? This I think is the question that remains unanswered in scientific articles. It’s a no touch zone because the commercial farming industry would fail if the truth (although already known theoretically, yes an oxymoron I know) was proven.

June 9, 2013

What if the meat is well dried by smoke will it stil contian L carnitine

Nalliah Thayabharan
June 6, 2013

Meat is very environmentally unfriendly now. Large proportion of agricultural land is used to grow feed for livestock rather than food for people. In terms of food security, that’s not the greatest way to go. Livestock are also breeding grounds for disease epidemics such as various influenza strains.

James Alsop
May 28, 2013

See “Six Reasons to Eat Less Red Meat”
Nutrition Action Health Letter June 2013
Bottom Line: (But do study the research data therein)
Eat as little red and processed meat as possible.
Replace red meats with beans, lintels, soy-based veggie meats. (Love it when alternatives are recommended)
Don’t take carnitne, lecithin, or choline supplements.

Gasp! This person has been taking L-carnitine for years.

May 23, 2013

Shocked to know that..

May 9, 2013

So, the body builders with high blood pressure who take these supplements?

Joao S. de Queiroz
May 7, 2013

Once again, like the tobacco industry — an effort to muddle things. When are we going to learn that reductionist hypothetic- deductive studies that try to attribute a causal linkage between one factor (carnitine) and the result of a complex process (heat disease) are a waste of money. There is ample evidence world wide based on statistical associations that lead us to conclude — eating significant amounts of red meat is bad for you. We should not wait to know exactly “why” that is to change behavior —

John Lerch
May 3, 2013

It would seem to be a simple experiment to see if culturing bacteria with carnitine and various preservatives in meat might lead to greater production of TMAO

April 26, 2013

Moderators, can you please delete my previous post on THIS article? I meant to post it on a more recent article. Sorry about that. I had two tabs open and posted on the wrong one.

Thank you,


Lisa Jackson
April 22, 2013

Hi friends i have read lot of stuff about red meat effect on heart and found that it really lead to heat attack.

K. Gabriel
May 1, 2013

Gee, Lisa, would you like to document some of your ‘research’?

Sue w
May 25, 2013

Depends on whether it is factory farmed, loader with antibiotics, herbicides and pesticides. We need a prescription for antibiotics!

Heart Fit Clinic
April 21, 2013

This does confuse a lot of things. I think a great study that was posted in circulation March 2010 compared 3 different diets; low fat, Mediterranean diet, and low carb diet. This study showed a decreases in arterial wall thickness through carotid ultrasound and showed that diet can reverse heart disease.
The common thread is that all these diets focused on reducing blood pressure, and decrease body weight and waist circumference. What is also mentioned that all these diets contained natural foods that are not processed.
You can make a big difference in your heart health focusing on a diet that you can maintain long term focusing on foods that will lower inflammation and that are not processed. Nutrition containing natural foods we know works best on arterial health reducing the chance of heart attacks and strokes.

Diamond Fernandes
April 21, 2013

Interesting post. Yes the research is conflicting, however l-carnitine has been shown to improve heart health. I think the more natural the food we eat the better it is. This is evident in the case of processed vs un-processed (natural) meats). At the end of the day it is important to follow a natural diet high in natural fiber, and vegetables.

April 20, 2013

It’s frustrating to see conflicting scientific studies. The reason I started taking the L-Carnitine with alpha-lipoic acid supplement is because the study by Bruce Ames showed that these chemicals (in combination) actually improved health in rats and increased their longevity. Having been taking the supplement on and off, I noticed a difference (and yes, I realize it might be just a placebo effect or spurious relationship). Regardless, I want to keep taking the supplement, but this news is troubling.

I’d greatly appreciate it if somebody can answer the following though: the article says “In studies in mice, TMAO has been shown to cause atherosclerosis, the disease process that leads to cholesterol-clogged arteries. We know that clogged coronary arteries can lead to heart attacks.” Question: Do clogged arteries strongly correlate with the levels of LDL or total cholesterol? I’m an athlete with good diet habbits and (relevant) genes, so my cholesterol levels are pretty good. Does this mean that I don’t have high risk of clogging arteries or does presence of TMAO clog the arteries regardless of what the cholesterol levels are? You can see where I’m going with this.

Thank you !

Price Weston
April 18, 2013

The human study part of this had N=6. If someone came out with a study saying supplement x had significant benefits, do you think it would get all this media attention? See the well researched paleo responses.

shawn Johnson
April 18, 2013

This study does not take into account that many vegetables raise the TMAO much higher than red meat does. Perhaps L-carnitine is not the problem.

See this article:

“He points out that red meat is only one of many foods that increases TMAO when eaten, and cites data from a 1999 study that evaluated TMAO excretion following consumption of 46 different foods, which shows that red meat generated no more TMAO than fruits and vegetables. In fact, some veggies, such as peas, cauliflower and carrots generated more TMAO than beef did! Still, none of the foods generated TMAO at levels that were statistically different from the control. (Similarly, there was no statistically significant difference between different kinds of meats, compared to the control.)”

healthy old man
April 18, 2013

I’ve been taking L-carnitine (as Acetyl-L-carnitine) supplements for years. At my physical earlier this month my BP was 102/62, which suggests my 69-year-old arteries aren’t being blocked. I am a vegetarian … perhaps something else in red meat is needed for carnitine to be a problem?

Dan Pendick
April 18, 2013

The Nature Medicine research suggest that vegetarians may not have the mix of gut flora to convert L-carnitine into TMAO, the substance implicated in atherosclerosis. But this is only one study–albeit a very well conducted study–so it’s too early to make any conclusions about what you should and should not eat.

fire proof door
April 18, 2013

Does that mean that having L carnitine drinks can cause heart disease? I thought it helps your metabolism at pace!

david jackson
April 18, 2013

Yes its raises the metabolic rate and the rate of early of death….I am no never eating red meat ever again.But isn’t carnitine in pork too?

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