D-Ribose in cardiovascular disease

The heart could be said to be the most metabolically active organ in the body, requiring a large volume of oxygenated blood flow to continually supply its tremendous demand for ATP. Oxygen deprivation due to heart disease or stress depletes energy from the heart and will quickly empty the heart’s energy reserves. The good news is that the heart is also the most responsive organ to supplementation. D-Ribose is particularly effective in this respect and the reason why it shows such promise in treating heart patients. D-Ribose increases the energy pool and promotes the metabolic health of the tissue (1). Medical and scientific literature has repeatedly confirmed that D-Ribose can be effective in treating patients with congestive heart failure, coronary artery disease, angina, ischemic cardiomyopathies and for those recovering from cardiac intervention such as aortic valve repair, coronary artery bypass graft surgery and angioplasty.

D-Ribose in congestive heart failure

Hearts with congestive heart failure are severely energy depleted, in many occasions up to 30%. Because the loss of energy is progressive, it is not evident until there is severe failure. Congestive heart failure is also characterized by the loss of the more efficient energy pathway in favor of the less efficient, which causes:

1. Stress in the heart
2. Ventricular pump failure caused by diastolic dysfunction
3. Thickening of ventricular walls

Because D-Ribose supports the heart’s ability to preserve and rebuild its energy pool, it helps provide the heart with the energy it needs to do its job. D-Ribose also helps reduce free radical formation by salvaging ATP breakdown products. Both of these actions are critical for congestive heart failure patients in which low energy output, free radical stress and cardiac arrhythmia dominate.

The effectiveness of D-Ribose in treating congestive heart failure was proven in a study done in 2003 reported in the ‘European Journal of Heart Failure’. In this study D-Ribose supplementation resulted in a highly significant improvement in:

1. Atrial contribution to left ventricular filling: More blood was able to flow into the relaxed ventricle, making it possible for more blood to pump to the rest of the body.
2. Reduced left atrial dimension: Less back-up of blood that is associated with congestion.
3. Greater flow rate across the valve separating the left atrium and the left ventricle: More blood flow to the ventricle.
4. Ventricle relaxation, which allows it to fill more easily and reduces diastolic dysfunction.

This study showed that D-Ribose supplementation improved diastolic heart function (less shortness of breath), quality of life and exercise capacity in coronary artery disease and congestive heart failure in 90% of patients.

D-Ribose in coronary artery disease

Vascular disease has a profound effect on energy metabolism, with a reduction of as much as 40% in patients with chronic cardiac ischemia. Heart attacks or surgery can deplete the energy pool even further, by 50% or more. Since normal heart function requires large amounts of energy and since the energy stores of the heart are limited to sustain only a few seconds of contraction, supplementation is key.

In myocardial ischemia there is a severe and chronic depletion of the energy stores due to inadequate oxygenated blood flow that can take up to ten days to rebuild. Even when normal circulation is restored through surgery, this can lead to extended post-ischemic heart dysfunction. This energy strain depletes ATP and it is ironically exacerbated when blood flow is restored. The new blood flow pulls these energy substrates out of the cell leaving it energy deprived. Dr. Sinatra has seen how many patients who have surgery to open their coronary arteries get actually worse for up to two weeks after the surgery. These patients become very fatigued, and during this time of recovery, the lack of energy reserves puts them at great risk.

On the other hand, those patients that are not candidates for this kind of surgery, remain in a chronic stage of energy depletion   and their heart function worsens progressively to congestive heart failure if the energy metabolism does not improve. “Restoration of the energy pool ….can only be accomplished through the pathway of energy metabolism regulated by the availability of D-Ribose” (1). This reduces fatigue, increases exercise tolerance and enhances quality of life. All this information was first reported in a 1992 study published by the British medical journal ‘The Lancet’. The subjects in this study had chronic coronary artery disease in at least one main coronary artery and a history of angina induced by normal daily activities. Three of them had had heart attacks. These patients were randomly given either D-Ribose or a placebo of glucose for three days. The group that were given D-Ribose performed significantly better when compared to baseline tests, while there was no improvement in the group that was given glucose. The conclusion of this study was clear: D-Ribose supplementation effectively increased cardiac energy metabolism in only three days, controlled the onset of angina and improved exercise tolerance in chronically diseased patients.

Another study from the University of Minnesota showed that D-Ribose is valuable after a heart attack. The study was conducted in animals because it was too invasive to be done in humans. After four weeks of treatment with D-Ribose, animals showed better heart function than those given a placebo. This study showed that by increasing the energy level of the heart, the heart muscle could function better and be less affected by the stress of a heart attack.

Another study showed that D-Ribose also helps reduce the development of pulmonary hypertension in ischemic hearts. The study showed that D-Ribose significantly reduced the development of heart failure on the right side of the heart, allowing the heart to pump blood to the lungs more easily.

D-Ribose in Peripheral vascular disease

Peripheral vascular disease (PVD) results from arterial clogging, especially in the arteries feeding blood to the legs. It leads to severe leg pain even with mild exercise. The same pain that patients with congestive heart failure feel due to the heart being unable to pump blood out to the extremities.

Similar energy depletion occurs in leg muscles during PVD, in congestive heart failure and in coronary artery disease. In all three cases oxygen deprivation leads to a depletion of the tissue energy pool because an adequate volume of oxygenated blood cannot be supplied to the heart muscle. This energy depletion disrupts the normal function of the muscle, leading to fatigue, soreness, and stiffness that can become so severe that patients cannot stand and walk.

D-Ribose has been shown both in human and animal studies to greatly accelerate energy synthesis in skeletal muscle. By accelerating energy synthesis muscles are better equipped to keep up with the energy demand, improve their physiology and reduce pain. While D-Ribose supplementation will not increase blood flow to the tissues, it allows muscles to manage the balance between energy supply and demand more effectively.

Myocardial protection and recovery in cardiac surgery

There are three major cardiac interventions that have to do with restoring blood flow to the heart:

1. Traditional coronary artery bypass graft (CABG) surgery: During this kind of cardiac surgery, the body’s temperature is lowered to decrease metabolism and reduce cardiac energy loss. The body’s blood supply is then rerouted to the bypass pump so the heart can be stopped for surgery, while the body continues to receive oxygenated blood from the pump.
2. “Off pump” CABG: During ‘off pump’ procedures, on the contrary, the body is cooled, but the blood is not rerouted to the bypass pump and the heart is not stopped. This is also called ‘beating heart surgery’ and it places less metabolic strain on the heart, muscles and brain.
3. Percutaneous transluminal coronary angioplasty (PTCA): PTCA is a procedure where a balloon is placed into the clogged artery and expanded, which breaks apart the plaque and eliminates the clog. While the balloon is expanded, blood flow stops to a portion of the heart and an ischemic event is the immediate result. This ischemic event, although short, also stressed cardiac energy metabolism to the limit.

All these three interventions cause the heart to become ischemic and put it under extreme metabolic stress. All of them also provide an immediate restoration of highly oxygenated blood to the heart which can cause some issues.

There have been numerous animal and human studies that researched the role of D-Ribose in protecting the heart during surgery and helping it recover after cardiac intervention. Some research has shown that bathing the stopped heart in a solution with D-Ribose preserves energy metabolites and slows the energy drain during traditional CABG surgery. Other studies have shown that the metabolic state of the heart prior to surgery is the main factor affecting functional cardiac recovery following the procedure and that the preservation of the energy pool in the heart before surgery is crucial for a successful outcome. Still other studies have shown that keeping donor hearts for transplant bathed in a D-Ribose solution can be an effective way to preserve the tissue energy pool and promote cardiac function following transplant.

Giving patients D-Ribose before and after cardiac intervention has proven very effective. In one study, giving it intravenously to patients following aortic valve repair enhanced cardiac recovery. Other studies show that giving energy to the heart before surgery improves the surgical outcome and helps the heart pump blood more easily and completely following the surgical intervention.

Reperfusion

It is defined as the restoration of blood flow to the heart. In this technique, massive amounts of oxygen-rich blood flow into regions of the heart that previously had been deficient. Reperfusion can happen spontaneously if an arterial clog or blood clot breaks away from the vessel wall or it can be done surgically when a surgeon ‘replumbs’ the heart during CABG, opens a clogged vessel , or when a clog-buster agent is used to dissolve away the clots.

There is a downside to reperfusion, when this fresh supply of oxygenated blood is delivered under high-oxygen tension, it brings an excessive amount of oxygen to the previously starved tissue. All this oxygen must be broken down by the cells, creating inevitable and harmful byproducts called ‘reactive oxygen species’ (ROS). What is more, the increased flow of blood that comes with reperfusion washes huge amounts of energy substrates away from the cell and some of these energy metabolic byproducts contribute to free-radical formation in the presence of too much oxygen.

This process can place so much oxidative stress on the tissue being rescued that causes a condition called ‘reperfusion injury’. D-Ribose can counter-balance this harmful effect because it helps control free radical formation by salvaging some of the energy substrates before they can be washed away, not allowing them to escape the cell.

Adverse reactions

When taken as directed, D-Ribose has been proven to be safe. However, because there is not enough published data on pregnant women, nursing mothers and very young children, Dr. Sinatra recommends these populations to refrain from taking D-Ribose.

Also, because D-Ribose lowers blood sugar levels temporarily, insulin dependent diabetics should have their blood sugar monitored so they do not accidentally overdose with insulin.

On an empty stomach, D-Ribose can cause minor light-headedness in a large dose (10 mg.), therefore, it is best taken with food.

Summing up

Because the heart is in such a need for energy, D-Ribose, together with a heart healthy diet and the products you can find in the ‘Healthy Hearts Club’, can make a great difference in energy levels, as we have seen. This is especially important in the case of heart disease, which depletes energy in heart cells.

References:

(1) Sinatra, Stephen T. The Sinatra Solution: Metabolic Cardiology. Laguna Beach, CA: Basic Health, 2011. 145-177. Print.