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Enhancing Cardiac Energy with Ribose

May 2007

By Stephen T. Sinatra, MD, and James C. Roberts, MD

The Rise of D-ribose

Until 1944, D-ribose was thought to be primarily a structural component of DNA and RNA with little physiological significance. But a series of studies, culminating in 1957, revealed that this sugar molecule played an intermediate role in an important metabolic reaction called the pentose phosphate pathway. This reaction is central to energy synthesis, the production of genetic material, and for providing substances used by certain tissues to make fatty acids and hormones.

The D-ribose connection to cardiac function was made by the physiologist Heinz-Gerd Zimmer at the University of Munich. In 1973, he reported that energy-starved hearts could recover faster if D-ribose was given prior to, or immediately following, ischemia (oxygen deprivation). Five years later, he reported the same effect in skeletal muscle and also showed for the first time that the energy-draining effects of drugs that make the heart beat more strongly (inotropic agents) could be lessened if D-ribose was given along with the drug. Zimmer and his research colleagues later proved that D-ribose was the limiting element in energy recovery in ischemic tissue and that energy synthesis could not occur without it.

Zimmer’s research sparked a flurry of research on humans, rats, rabbits, guinea pigs, dogs, and even turkeys, all with similar results. D-ribose administration significantly improved energy recovery in ischemic, hypoxic, or cardiomyopathic hearts and skeletal muscle, and it improved functional performance of the tissue. In addition, studies with several common heart drugs—those used even today—showed that D-ribose administration did not negatively affect (and in many cases helped) the action of the drug on the heart.

The most significant findings of the studies underscored the dramatic effect that D-ribose administration played in both energy restoration and the return of normal diastolic cardiac function. A clinical study from Zimmer’s group in Munich in 1992 showed that D-ribose administration to patients with severe, stable coronary artery disease increased exercise tolerance and delayed the onset of moderate angina. Since this groundbreaking study in coronary artery disease, the benefits of D-ribose have been reported for cardiac surgery recovery, heart failure and neuromuscular disease treatment, restoration of energy to stressed skeletal muscle, and control of free-radical formation in oxygen-deprived tissue.

Several notable papers were published in 2003. One study showed that D-ribose improved diastolic functional performance of the heart, increased exercise tolerance, and significantly improved the quality of life of patients. Researchers have even extended their sights to healthy hearts and bodies and documented benefit from D-ribose supplements to improve athletic performance.

Research continues here and abroad. Yet, despite the powerful scientific evidence, very few US physicians have even heard of D-ribose outside of their first-year medical school biochemistry class, and fewer still recommend it to patients. We lucky ones who are familiar with it have the wonderful gratification of seeing it help our patients on a regular basis.

Our Recommendations

Supplemental D-ribose absorbs easily and quickly through the gut and into the bloodstream. About 97% gets through.

How much D-ribose do you need? That question can only be answered with another question, “What do you want it to do for you?

Studies have shown that any amount of D-ribose you give to energy-starved cells gives them an energy boost. At the University of Missouri, researcher Ronald Terjung has shown that even very small doses (the equivalent of about 500 mg) of D-ribose increase energy salvage in muscles by more than 100%. Larger doses increase the production of energy compounds by 340-430%, depending on the type of muscle tested, and improve the salvage of energy compounds by up to 650%. Most amazing is that when muscles are supplemented with D-ribose, they continue to add to their energy stores even while they actively work! Until this study was reported, it was thought that muscle energy stores were only refilled in muscles at rest.

An adequate dose of D-ribose usually results in symptom improvement very quickly—sometimes within a few days. If the initial response is poor, the dose should be increased until the patient feels relief. Logically, the sickest patients stand to gain the most.

Patients with arterial and heart disease who chronically choke off oxygen delivery to their tissues need to take a higher dosage simply to allow enough of it to work its way through the clogged vessels into the energy-parched portions of the heart. We start those patients at higher dosages and monitor their progress. With progress, the dosage can be reduced to the lowest possible point at which good energy and quality of life are maintained.

Those patients must take D-ribose every day. Missing even one or two days will negatively impact cellular energy, which will show up as weakness and fatigue.

We don’t know the optimal level for every patient or every pathological condition, but we can make some recommendations as dosage starting points:

  • 5 grams (if using a powder, two teaspoons) daily for cardiovascular prevention, for athletes on maintenance, and for healthy people doing strenuous activity
  • 10-15 grams daily for most patients with heart failure, other forms of ischemic cardiovascular disease, or peripheral vascular disease, for individuals recovering from heart surgery or heart attack, for treatment of stable angina, and for athletes working out in chronic bouts of high-intensity exercise
  • 15-30 grams daily for patients with advanced heart failure, dilated cardiomyopathy, or frequent angina, for individuals awaiting heart transplant, and for people with fibromyalgia or neuromuscular disease.

Start at the upper level of each range for patients with heart or peripheral vascular disease. We recommend that daily doses up to 10 grams be taken as two 5-gram doses with morning and evening meals or just before and just after exercise or activity. Larger doses (15 grams per day or more) should be taken in three or sometimes even four smaller doses of about 5 grams each. Daily doses in excess of 30 grams are seldom needed. Most heart patients will stabilize at about 10 grams per day.

Once a patient responds with a reduction in symptoms, the dosage may be gradually reduced until a maintenance level is reached. Sometimes patients well maintained at a certain dose may require an increase due to changes in their activity level or changes in their cardiac drug therapy, such as the addition or deletion of beta blockers or calcium channel blockers. It cannot be overemphasized that patients must continue on D-ribose therapy, or relapses will almost certainly occur. D-ribose is quickly absorbed and leaves the blood rapidly. Therefore, assessing blood levels of D-ribose is not helpful, in addition to being very costly.


The toxicology and safety of D-ribose have been exhaustively studied. The supplement is 100% safe when taken as directed. Thousands of patients have taken D-ribose at dosages up to 60 grams per day with minimal side effects. However, even though there are no known contraindications of D-ribose therapy, we recommend that pregnant women, nursing mothers, and very young children refrain from taking D-ribose simply because there is not enough research on its use in these populations.

D-ribose can actually lower blood glucose levels; therefore, insulin-dependent diabetics should check with their physicians before starting on the supplement.

Reported side effects are minimal and infrequent. Patients may experience light-headedness if they take a large dosage (10 grams or more) on a completely empty stomach. Take D-ribose with meals, or at least mixed into juice, milk, or fruit, to offset the blood-glucose-lowering effect.

There are no known adverse drug or nutritional interactions associated with D-ribose use.

Excerpted from Reverse Heart Disease Now by Stephen T. Sinatra, MD, and James C. Roberts, MD (John Wiley & Sons, Inc., Hoboken, New Jersey, 2007).