L-Carnitine (Pt. 2)

L-Carnitine and the heart

As we have seen, the main job of L-carnitine is to transport fatty acids to the inner mitochondrial membrane where they are burned as fuel. A healthy heart obtains 60% of its fuel from fat, therefore, maximizing the burning of this fat is crucial for heart function.

The more advanced the heart disease is the harder it is to get oxygen, and the more blood congestion backing up into the lungs and tissues occurs. When this is the case, a thorough nutritional program can make a great difference. L-Carnitine, with the help of the ‘Heart and Body Extract’ and other nutrients that we will look at in following blogs, can be life altering.

Atherosclerosis sufferers with various degrees of congestive heart failure are the most compromised in their symptoms, all of which are related to a heart that is starved of oxygen, struggling to pump hard enough to keep the blood moving forward. Dr. Sinatra recalls how much improvement he saw when he combined L-carnitine with nutrients like CoQ10, D-Ribose and hawthorn for the most symptomatic of his patients. Hawthorn is one of the ingredients found in the ‘Heart and Body Extract’, making it a great addition to your heart protocol for its circulation enhancing properties. All of these nutrients can be used to treat any of the following heart conditions quite effectively.

L-Carnitine and angina

Angina is caused by insufficient supply of oxygen to the heart tissue due to blockages or spasms of the coronary arteries. Symptoms of angina are pressure, burning discomfort on the chest or pain from shoulder to shoulder or up into the neck, radiating into the back and left arm. Shortness of breath is also a sign because the body is trying to get more oxygen to compensate for the shortage. This symptom may be the only warning for someone with diabetes because their nerve endings have lost sensitivity. Other less typical signs of angina are throat tightness, soreness or pain in the jaw, a tooth, the back or the forearms.

Regardless of the cause, the source is always a lack of oxygen in the heart muscle, due to coronary arteries that have become blocked either from a build-up of inflammatory cholesterol plaque that progresses with age. As these blockages increase in size, they crowd the artery opening and limit the flow of oxygen to the heart muscle. This lack of oxygen leads to the symptoms, because lack of oxygen leads to energy depletion, which kills the cell, resulting in numbness and pain.

While the traditional treatment for angina works by reducing the workload of the heart and oxygen demand and can widen the arterial walls, these drugs can’t improve the oxygen demand ratio and do little to affect the energy imbalance. L-carnitine, on the contrary, can alleviate the symptoms of angina most effectively.

Many double-blinded placebo controlled research studies in the cardiovascular literature show the efficacy of L-carnitine and its cousin propionyl-L-carnitine (PLC) in treating angina and other cardiovascular disorders. PLC is taken into the myocardial cells more readily than other forms of carnitine. While acetyl-L-carnitine is taken up more widely by the brain.

As we have seen, L-carnitine enhances fatty acid metabolism and prevents the accumulation of toxic fatty acid metabolites inside the heart. In angina it improves overall oxygen use by the heart cells, allowing the heart to do more things with less oxygen.

L-carnitine was found to be helpful in angina and myocardial ischemia. Ischemia is defined as the lack of oxygenated blood flow to a tissue. When this happens it triggers other effects that compound the problem:

  1. Toxic levels of fatty acids and their metabolites start accumulating, which paralyze mitochondria.
  2. ATP levels crash.
  3. ATP breakdown products form and leave the cell, depleting the energy pool.

Studies have shown the effectiveness of L-Carnitine for all these conditions.

L-carnitine and myocardial infarction

Myocardial infarction is another term used to refer to a heart attack; infarction refers to tissue death. Dr. Sinatra explains that a heart attack can start when a clot coming from an artery plaque rupture site gets stuck in a coronary artery. Sometimes a clot can form somewhere else and it becomes stuck where it can not get through, creating a blocked artery. Another cause is a spasm that lasts so long that the blood congeals in an open area of circulation. In any case, it always results in an emergency, because without blood supply the heart muscle will die.

A lot of research has been done on the role of L-carnitine in heart attacks. In one study researchers tried to determine whether L-carnitine would protect the heart and micro-circulation against heart attack damage when given immediately during the acute phase of a heart attack. The results indicated that L-carnitine slows down the progression of a heart disease and limits its size.

Another study tried to determine whether propionyl-L-carnitine could improve exercise tolerance and physical function following a heart attack. They observed that 100 mg a day increased the level of total L-carnitine in both the blood serum and the heart muscle by 15-23%. Exercise capacity also increased by 3%, while in the group that didn’t receive L-carnitine it decreased by 16%.

In a third study researchers measured energy levels in the heart following a heart attack, the three different forms of L-carnitine were used in three different groups to check if there was a difference. All three forms markedly improved recovery of energy in the tissue, increasing energy levels for an hour. Acetyl-L-carnitine was even stronger in its early response, but did not keep the energy level as high as L-carnitine. Propionyl-L-carnitine didn’t provide very early recovery as compared with the other two forms but by the end the recovery was greater.

All this information helps us conclude that all three forms of L-carnitine protect the heart against the intracellular damage associated with the buildup of lactic acid that normally happens during heart attacks. Heart patients that were given any of the forms of L-carnitine were able to withstand four induced heart attacks in succession.

In yet another study, researchers observed that L-carnitine was able to reduce infarct size, limiting tissue damage. There was also a reduction of ischemic arrhythmias and heart enlargement as well as the number of deaths.

Another study from the ‘Journal of the American College of Cardiology’ confirmed that supplementing with L-carnitine after an acute heart attack had a beneficial effect on the preservation of the left ventricle, where most heart attacks happen, by preventing an increase in heart size. Increased left ventricle during the first year of a heart attack is a very good predictor of future adverse cardiac events according to Dr. Sinatra.

L-Carnitine and congestive heart failure

In congestive heart failure the heart cannot contract with enough force to pump blood around the body. This is the reason for the congestion through the body: ankles, lungs and heart. One of the ways to help the heart is to supplement the diet with nutrients that strengthen heart contractions and help the heart fully relax so it can fill up again. L-carnitine is one of them.

One of the major problems with congestive heart failure is the scar tissue present after repeated heart attacks, which limits muscle function. Another side effect is a heart muscle that is stretched out, dilated and enlarged due to long standing high blood pressure. In any case, the research shows that in patients with end stage congestive heart failure and donor hearts, concentrations of L-carnitine in heart muscle was significantly lower and it correlated with ejection fraction. Ejection fraction measures the amount of blood volume pumped from the heart with each heartbeat. In congestive heart failure ejection fraction is reduced sometimes to 10-15%. Research showed that this condition made patients lose L-carnitine from the heart itself, creating a deficiency. This is evidence that a diseased heart has difficulty holding on to its L-carnitine. Conclusions of these studies showed that supplementation with L-carnitine was able to reverse this deadly trend. Advantages included improvement in arterial blood pressure, cholesterol levels, rhythm disorders and signs of congestive heart failure, but above all a reduction in mortality. Dr. Sinatra, working with his patients, has observed less shortness of breath, less fatigue, less ankle swelling, more energy, better sleep and increased appetite.

L-carnitine and peripheral vascular disease

Also known as intermittent claudication, peripheral vascular disease is a condition that mimics angina but the pain occurs in the calf instead of the heart. It is characterized by poor circulation in the legs with obstructed blood flow in a large artery, such as the femoral, due to loss of energy in the muscle tissue of the leg. It may happen after a bypass operation and the pain is due to reduced oxygen delivery to the legs, which encourages increased production of free radicals. Both angina and peripheral vascular disease share the fact that the pain can occur with normal everyday activities like walking. L-carnitine works for this condition as well as for angina, because it can help maximize cellular energy production if blood flow is compromised.

Research showed that propionyl-L-carnitine supplementation could increase exercise tolerance and reduce the pain associated with physical activity. Walking time increased by 54%, in walking time, distance and speed, muscle strength increased, pain was reduced and resulted in higher quality of life.

Cardiac arrhythmia

Two of the most frequent types of arrhythmia are ‘premature ventricular contractions’ (PVCs) and ‘premature arterial contractions’ (PACs). Both of these start with an early beat followed by a pause, often described as a palpitation. This pause is actually allowing more blood to enter the heart so that the next contraction feels more pronounced, creating a sensation like the heart is palpitating. These two conditions usually happen due to the accumulation of fatty acid metabolites that weaken the contraction of the heart and make the sufferer more vulnerable to irregular heartbeats, eventually injuring heart tissue, and interrupting electrical transmission of impulses. Supplementing with L-carnitine can help the heart keep the beat energetically. Research has shown that L-carnitine assists the body in free fatty acid metabolism and high grade ventricular arrhythmia. Dr. Sinatra also recommends to add magnesium, potassium, calcium and hawthorn berry, fish oil, CoQ10 and D-ribose as adjunct therapy.

Concluding, research has shown repeatedly the remarkable properties of L-carnitine in treating various heart disorders. Taken together with other nutrients like the ones present in the ‘Heart and Body Extract’ can add to its benefits and make a complete health protocol.


Sinatra, Stephen T. The Sinatra Solution: Metabolic Cardiology. Laguna Beach, CA: Basic Health, 2011. 101-143. Print.

L-carnitine (Pt. 1)

We have seen how good circulation is essential to deliver the nutrients our cells need to produce energy. The heart in particular is so metabolically active that it requires a constant supply of energy to pump 60 to 100 times a minute everyday for years. By improving circulation, the ‘Heart and Body Extract’ ensures that the nutrients in the food we consume reach the cell where they can be turned into energy the heart can use. In the words of Dr. Stephen Sinatra, “Our heart muscle is one of the most responsive organs in the body for targeted nutritional supplementation” (1).

In this blog, we will look at a nutrient that is essential to make this conversion from food to energy. We are talking about L-carnitine, a vitamin like nutrient that, while it doesn’t have a direct effect on blood flow, it can help maximize cellular energy production. Together, the ‘Heart and Body Extract’ and L-carnitine can be considered a powerful combination that can benefit our heart health greatly, as we will see. First, we will look at how the body converts our food into energy. Then, we will discuss the different conditions in which L-carnitine has been found to be helpful.

How does the cell convert nutrients into energy?

When it comes to heart health, energy metabolism is critical. Both the food we consume and oxygen are essential for the production of energy. Our food choices should be have this principle in mind. After all, we do not eat only for the sake of pleasure, but to provide the building blocks our body needs to thrive. It is important then to understand how the body converts food and oxygen into energy.

Energy metabolism occurs via three metabolic pathways:

  1. The glycolytic pathway
  2. The krebs cycle
  3. The Electron transport chain of oxidative phosphorylation

All of these are extremely important for cellular health. In the glycolytic pathway, glucose, a simple sugar made by the body from carbohydrates, becomes the body’s main source of energy. However,

glucose only provides short bursts of energy and cannot keep the cell working for long periods of time. Only three molecules of ATP are formed this way. What is more, under conditions of oxygen deprivation, like is the case of ischemic heart disease, the energy that is produced from glucose turns into lactic acid quickly, increasing acid levels in the cell. This can cause cellular stress and a burning sensation in heart muscles like is the case of angina. This form of energy, though important, is not the preferred source of energy for the heart.

Via the other two metabolic pathways, the body can obtain great amounts of energy from fatty acids. When oxygen is present, fatty acids become the preferred energy fuel, producing an astounding 129 molecules of ATP. The burning of fats contributes to 60-70% the heart’s energy. And this is when L-carnitine comes into play, because L-carnitine is the only nutrient that can transport fatty acids across the inner membrane of the mitochondria to begin a process called ‘beta-oxidation’. Without it the body could not metabolize fats, and the heart would suffer for lack of energy.

It is in the krebs cycle that fatty acid metabolism occurs. First, electrons from fatty acids are removed, the electrons then travel through the electron transport chain and make ATP. The energy taken from the electrons is used to attach inorganic phosphate to ATP in order to reform it; oxygen is required for this pathway to function. Co-enzyme A also helps to move energy substrates into the mitochondria by binding to fatty acids and other molecules, thus helping them be transported across lipid membranes.

The importance of oxygen is vital, without it, like is the case of ischemia (lack of oxygenated blood flow to the tissue), or hypoxia (oxygen deprivation to the cell) the recycling of energy slows down and this causes ATP to be used faster than it can be replaced.

What is L-carnitine?

L-carnitine is a vitamin-like nutrient, which means that it can be obtained through diet and it is made by the body too. The word ‘carnitine’ comes from the latin word ‘carnis’ which means ‘meat’. L-Carnitine, therefore, is mainly found in protein. The highest sources are mutton, lamb, beef, other red meat and pork in that order. The quantities in plants are rather low, 90% lower than in meat, so vegetarians may show a higher deficiency of this nutrient. Plants also are low in the other nutrients that are needed to metabolize L-carnitine, methionine and lysine. It is important then for vegetarians to supplement with these nutrients. It is also significant that its production slows down with age, so it is important to obtain it through supplementation as we age.

Biosynthesis of L-carnitine

L-carnitine is derived from two amino acids, lysine and methionine. The body synthesizes these via a series of metabolic reactions involving these two amino acids together with niacin, vitamin B 6, vitamin C and iron.

To make L-carnitine, the body goes through different steps and needs the following nutrients to synthesize it: the amino acids L-methionine and L-lysine , vitamin C, B 6, niacin, and iron. Without these nutrients L-carnitine will not be synthesized properly, thereby the importance of obtaining these from the diet. Apart from this, L-carnitine is produced in the kidneys and liver.

Functions of L-carnitine

Generally speaking, L-carnitine helps maximize efficient metabolic activity by mobilizing ATP and promoting better use of oxygen. The main function of L-carnitine is to facilitate the transport of long-chain fatty acids across the inner mitochondrial membrane to begin the process called ‘beta-oxidation’. Most importantly, L-carnitine is the only carrier that can do this, so its presence in the cell is an absolute requirement for heart health. Energy recycling, like the one we explained in the manufacturing of ATP, is dependent directly on the amount of L-carnitine available in the cell accelerating energy metabolism.

Another function of L-carnitine is the removal of ammonia, and lactic acid from our tissues which have shown to have negative effects in the brain and heart. For this reason L-carnitine is recommended after strenuous exercise. Exercise can lead to high levels of lactic acid in the body, and L-carnitine can help the body clear high levels of lactic acid from tissues and blood.

L-carnitine is also an antioxidant and free radical scavenger and has the ability to chelate iron.


L-carnitine is the most available and least expensive of all forms. However, because the free form of L-carnitine is very unstable, it makes it not suitable for tablets or capsules. This has led to research to find ways to make it more stable. Several forms have been synthesized: fumarate, tartrate, citrate, lactate and amino carnitines (new molecules with specific amino acids attached to L-carnitine molecules). Between the fumarate and the tartrate versions, the former appears to be absorbed better than the latter. L-carnitine fumarate has a 58% content of L-carnitine and 42% of fumaric. Both of these compounds are naturally occurring substances in living organisms.

A newer version of the L-carnitine is the amino-carnitines, they are the result of bonding certain amino-acids like glycine, arginine, lysine, and taurine with L-carnitine derivatives. These combinations have been found to increase L-carnitine’s metabolic performance. The resulting molecule is being called amino-carnitine. Combining L-carnitine with these amino-acids provides an interesting synergistic effect on how much of each nutrient is made available, making both more readily used by the body.

Two of these amino-carnitines are acetyl-L-carnitine arginate and acetyl-L-carnitine taurinate. These amino-carnitine combinations are effective because, in general terms, when our bodies are low on L-carnitine they are also low on its amino-acid precursors. Since these precursors are also essential they must be obtained from the diet. In addition, they help us synthesize L-carnitine.

Another reason why these new forms of L-carnitine are so effective is that they have similar properties, therefore they can get better results when bonded together. Arginine taken with L-carnitine aids in the delivery of L-carnitine to ischemic regions of the heart and muscles. The amino-carnitines also work together with D-ribose. The combinations enhance each of the nutrients properties and assist in energy recycling in heart cells. This makes them suitable for heart disease, peripheral vascular disease, diabetes, fibromyalgia and chronic fatigue. For athletes it can also be beneficial because they increase exercise capacity by reducing muscle fatigue, increasing recovery and overall energy.

A specific form of L-carnitine known as propionyl-L-carnitine (PLC) is an L-carnitine derivative that along with the base L-carnitine and acetyl-L-carnitine forms a component of the body’s L-carnitine pool. A dietary version of this PLC is called Glycine-Propionyl-L-Carnitine (or GlycoCarn). It has been shown to be a powerful vasodilator, improving the blood supply to the heart, muscles and other tissues. In some studies it was shown that this form of L-carnitine is rapidly taken up by heart, muscle, kidney and other tissue and what is not needed is secreted through urine.

In a study done with 42 subjects, results showed that supplementation with GPLC helped muscles retain L-carnitine during and after physical activity, as well as the levels of nitric oxide (a powerful vasodilator).


Dr. Sinatra recommends 3,000 mg of GPLC a day, or 500-1000 mg capsules three times a day, between meals. This dosage of GPLC showed to reduce oxidative damage (free radical stress) and triglyceride levels, while increasing nitric oxide levels.

Why carnitine deficiency?

Although L-carnitine is found throughout the diet and is synthesized by the body, it is very common to find deficiencies in this very important nutrient. Deficiencies can be caused by genetic defects, poor diet, co-factor deficiencies of vitamin B 6, folic acid, iron, niacin and vitamin C, liver or kidney disease, and use of some drugs, especially the anti-convulsants.

People with deficiencies can have symptoms like muscle fatigue, muscle cramps, and muscle pain following exercise, also, muscle disease, or cardio-myopathy. This can be seen under the microscope in the presence of fat deposition and abnormal mitochondria in the cells because that is where L-carnitine has its greatest efficacy. Renal failure is also associated with deficiencies, severe malnutrition, and liver cirrhosis and of course, heart disease. Dr. Sinatra believes L-carnitine offers its most greatest use for the heart.

Concluding, “L-carnitine is a heart and muscle specific supplement that must be considered if you have any cardiac or vascular conditions” (1). Together with its derivative, propionyl-L-carnitine , L-carnitine is a key nutrient for the heart. These co-factors not only enhance free fatty acid metabolism but also reduce the intra-cellular buildup of toxic metabolites, particularly where the heart muscle is not getting enough oxygen.

In what follows, we will look at how L-carnitine can improve different heart conditions that have to do with energy metabolism malfunctions.


(1) Sinatra, Stephen T. The Sinatra Solution: Metabolic Cardiology. Laguna Beach, CA: Basic Health, 2011. 101-143. Print.