Does Carnitine Increase Heart Disease Risk?

Written by Dr. Steve Chaney on . Posted in Food and Health, Issues, Supplements and Health

Carnitine: Dr. Jekyl or Mr. Hyde?

Author: Dr. Stephen Chaney

Heart HealthIt’s both interesting and confusing when one Journal article appears talking about the dangers of a particular supplement and just a couple of weeks later another article appears talking about the benefits of that same supplement – especially when the conclusions of both articles are misrepresented in the media.

But that’s exactly what has just occurred with the supplement L-carnitine. Media reports of the first article trumpeted the headline “Cleveland Clinic study links L-carnitine to increased risk of heart disease”. Media reports of the second article featured the headline “Mayo Clinic review links L-carnitine to multiple health heart benefits”. As you might suspect, neither headline was completely accurate. So let me help you sort out the confusion about L-carnitine and heart health

What is Carnitine?

But first let me give you a little bit of background about L-carnitine. L-Carnitine is an essential part of the transport system that allows fatty acids to enter the mitochondria where they can be oxidized and generate energy. So it is an essential nutrient for any cell that has mitochondria and utilizes fatty acids as an energy source.

L-carnitine is particularly important for muscle cells, and the hardest working muscle cells in our body are those that pump blood through our hearts. So when we think of L-carnitine we should think of heart health first.

But that doesn’t mean that L-carnitine is an essential nutrient. In fact, our bodies generally make all of the L-carnitine that we need. There are some metabolic diseases that can prevent us from making L-carnitine or utilizing L-carnitine efficiently. People with those diseases benefit from L-carnitine supplementation, but those diseases are exceedingly rare.

There is some evidence that supplemental L-carnitine may be of benefit in individuals suffering from congestive heart failure and other diseases characterized by weakened heart muscles. Other than that there is little evidence that supplemental L-carnitine is beneficial for healthy individuals.

Does Carnitine Increase Heart Disease Risk?

fatty steakLet’s look at the first study (Koeth et al, Nature Medicine, doi:10.1038/nm.3145, April 7, 2013) – the one that purportedly linked L-carnitine to increase risk of heart disease. The authors were trying to gain a better understanding of the well-established link between red meat consumption and cardiovascular disease risk. The classical explanation of this link has been the saturated fat and cholesterol content of the red meat.

However, several recent studies have questioned whether saturated fat and cholesterol actually increase the risk of cardiovascular disease (see last week’s article “Are Saturated Fats Good For You?”)

Since red meat is also high in L-carnitine, the authors hypothesized that it might be the L-carnitine or a metabolite of the L-carnitine that was associated with increased risk of heart disease in people consuming red meat.

The authors honed in on a metabolite of L-carnitine called trimethylamine-N-oxide or TMAO that is produced by bacteria in the intestine and had been previously shown to accelerate atherosclerosis in mice. They developed what they called an L-carnitine challenge. Basically, they gave their subjects an 8 ounce sirloin steak, which contains about 180 mg of L-carnitine, and measured levels of L-carnitine and TMAO in the blood one hour later and the urine 24 hours later. [I’m guessing they didn’t have much trouble finding volunteers for that study.]

When the subjects were omnivores (meaning meat eaters) they found a significant increase in both L-carnitine and TMAO in their blood and urine following the L-carnitine challenge. When they put the same subjects on broad-spectrum antibiotics for a week to wipe out their intestinal bacteria and repeated the L-carnitine challenge, they found an increase in L-carnitine but no increase in TMAO. This simply confirmed that the intestinal bacteria were required for the conversion of L-carnitine to TMAO.

Finally, because previous studies have shown that omnivores and vegetarians have very different populations of intestinal bacteria, they repeated their L-carnitine challenge in a group of vegans and found that consumption of the same 8 ounce sirloin steak by the vegans did not result in any significant increase in TMAO in either their blood or urine.

Armed with this information, the authors measured L-carnitine and TMAO concentrations in the fasting blood of 2595 patients undergoing cardiac evaluation in the Cleveland Clinic. They used an established protocol to assess the three-year risk for major adverse cardiac events in the patients they examined. They observed a significant association between L-carnitine levels and cardiovascular event risks, but only in subjects who also had high blood levels of TMAO.

Now it’s time to compare what the headlines said to what the study actually showed. The headlines said “L-carnitine linked to increased risk of heart disease”. What the study actually showed was that there were two things that were required to increase the risk of heart disease – L-carnitine and a population of intestinal bacteria that converted the L-carnitine to TMAO.

The major source of L-carnitine in the American diet is red meat, and habitual red meat consumption is required to support a population of intestinal bacteria that is capable of converting L-carnitine to TMAO. So the headlines should have read “red meat consumption linked to increased risk of heart disease”. But, of course, that’s old news. It doesn’t sell subscriptions.

Does Carnitine Decrease Heart Disease Risk?

Heart AttackThe second study (DiNicolantonio et al, Mayo Clinic Proceedings, dx.doi.org/10.1016/j.mayocp.2013.02.007) was a meta-analysis. It reviewed 13 clinical studies involving 3629 people who had already had heart attacks and were given L-carnitine or a placebo after the heart attack.

In evaluating the results of this study it is useful to remember that a heart attack generally kills some of the heart muscle and weakens some of the surviving heart muscle. When the data from all of the studies was combined the authors reported a 27% reduction in all cause mortality, a 65% reduction in arrhythmias, and a 40% reduction in angina. However, there was no reduction in a second heart attack or the development of heart failure.

So perhaps the headlines describing this study were a little closer to being on target, but they failed to mention that these effects were only seen in people who had already suffered a heart attack and had weakened heart muscles. They also failed to mention that there was no decreased risk of a second heart attack or congestive heart failure.

The Bottom Line:

1)     The first study should be considered preliminary. It needs to be confirmed by other studies. If it is true, it is not ground breaking. It merely gives us a fuller understanding of why red meat consumption may be linked to increased risk of heart disease and gives you yet another reason to minimize red meat consumption.

The study does raise the possibility that use of L-carnitine supplements may increase your risk of heart disease if you eat red meat on a regular basis, and that this same risk may not be associated with L-carnitine supplementation if you are a vegan. But the study did not directly test that hypothesis, and much more research is required before I would give it any weight.

2)     The second study suggests that if you have already had a heart attack, you may want to consult with your physician about whether L-carnitine supplementation might be of benefit. Once again, this study is not ground breaking. We already knew that L-carnitine supplementation was helpful for people with weakened heart muscle. This study merely confirmed that.

Contrary to what the headlines suggested, this study provides no guidance about whether L-carnitine supplementation has any heart health benefits in people without pre-existing heart disease – and the bulk of existing literature suggests that it does not.

3)     Finally, I realize that the major use of L-carnitine in the US market is in sports supplements purported to increase strength and endurance. The literature on that is decidedly mixed, but that’s another subject for another time.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

Tags: , , ,

Trackback from your site.

Comments (2)

  • Linda Dietz

    |

    Thank you once again for clearing up the confusing messages we receive from the press-usually on slow news days! Then hearing from the expert doctors on these shows further confuses the issues.

    Your well written and clear articles are such a blessing to us — so helpful to have your articles to send when someone has questions we can’t answer as well as you.

    Reply

Leave a comment

Recent Videos From Dr. Steve Chaney

READ THE ARTICLE
READ THE ARTICLE

Latest Article

Epsom Salt Bath for Sore Muscles!

Posted November 21, 2017 by Dr. Steve Chaney

Epsom Salt – An Inexpensive “Miracle Cure”

Author: Julie Donnelly, LMT – The Pain Relief Expert

Editor: Dr. Steve Chaney

 

epsom salt bath for sore musclesAn Epsom Salt bath for sore muscles is an old remedy that until recently has been overlooked by modern medicine. For hundreds of years people have used Epsom salt baths for relieving sore muscles, healing cuts, drawing out inflammation, and treating colds.  To many people this has long been a miracle cure, the first “go-to” for pain relief. Research has proven why Epsom Salt works so well, and how to use it so you benefit the most.

Why An Epsom Salt Bath for Sore Muscles Works

Epsom Salt is a combination of magnesium and sulfate. When you are under stress – and who doesn’t have stress in their life – your body becomes depleted in magnesium. Magnesium is a key component in a mood-elevating chemical of the brain called serotonin. Serotonin creates relaxation and a feeling of calm, so it reduces stress, helps you sleep better, improves your ability to concentrate, and lessens the tension of irritability.  It is also a component in the production of ATP (adenosine triphosphate), which produces energy for the cells.

The magnesium in Epsom Salt regulates the activity of over 325 enzymes, helps prevent hardening of the arteries, and is beneficial for muscle and nerve function.  Sulfates improve the absorption of nutrients and flushes toxins out of the body.  All of this is why an Epsom salt bath for sore muscles works.

Massage and Epsom Salt – a “Marriage Made in Heaven!”

Every month I explain how massaging one area of your body will help eliminate or reduce pain. My book (see below) teaches many self-treatments for a long list of aches and pains. Massage has been proven to help with:

  • Joint pain
  • Stiffness
  • Muscle aches
  • Fibromyalgia
  • Insomnia
  • Sports injuries
  • TMJ
  • Headaches
  • and much, much more!

Massage will also force toxins out of your muscles and improve circulation.  Epsom Salt baths are beneficial after a massage because it will remove the toxins out of the body. In the past I had heard that a 15-minute bath was sufficient, but that has changed.  Recently I read an article that explained it takes 40 minutes of soaking to make the transfer complete. Toxins are drawn out and magnesium enters into the body

Self-Massage is Convenient and Easy-to-Do

It’s wonderful to go to a qualified massage therapist and relax while the spasms are worked out of your muscles. However, if you have a stressful job or you love to exercise, you can’t go to a therapist as frequently as you should.  That’s where self-massage becomes a life-saver.

pain free living book coverBefore relaxing in your Epsom salt bath, do the techniques demonstrated in my book, “Treat Yourself to Pain-Free Living” to release the spasms that are causing joint and muscle pain.

As you untie the “knots,” you are releasing toxins into your blood stream and lymphatic system.  A relaxing, 40-minute soak in a tub of comfortably hot water and 2 cups of Epsom Salt will eliminate the toxins from your body.

Life is more stressful than ever before, and you deserve a relaxing break.  Massage and Epsom Salt baths are the perfect beginning to a restful night’s sleep!  Plus, the benefits of both massage and Epsom Salt will improve your health and vitality.

Wishing you well,

Julie Donnelly

 

About The Author

julie donnelly

Julie Donnelly is a Deep Muscle Massage Therapist with 20 years of experience specializing in the treatment of chronic joint pain and sports injuries. She has worked extensively with elite athletes and patients who have been unsuccessful at finding relief through the more conventional therapies.

She has been widely published, both on – and off – line, in magazines, newsletters, and newspapers around the country. She is also often chosen to speak at national conventions, medical schools, and health facilities nationwide.

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

UA-43257393-1