D-Ribose
- Is a 5 carbon monosaccharide [sugar]
- D-ribose is a part of the adenosine triphosphate molecule which is the energy currency of cells.
- The body can manufacture ribose from glucose in the Pentose Phosphate Pathway [PPP]--- this is a slow process which requires an enzyme called glucose-6-phosphate dehydrogenase (G- 6-PDH), an enzyme that is typically in short supply.
- The Pentose Phosphate Pathway is variable between organs and Glucose-6-phosphate dehydrogenase (G- 6-PDH) is an enzyme that has limited expression in the heart with significant delay in the production of ribose via glucose if there is injury to the heart12.
- Supplemental ribose by-passes this enzymatic step to rapidly replenish ATP levels in heart and muscle.
Energy from ATP
- When cells need energy, hydrolysis of ATP occurs to either ADP [adenosine diphosphate] or AMP [adenosine monophosphate]
Increasing ATP using Ribose
- Strenuously exercised muscle may have lowered levels of ATP by 20%1,2
- It may take 3 - 4 days to replenish these ATP levels1,2
- Supplementing with ribose can increase the store of ATP by up to 4 times3
D-ribose a 'Conditionally Essential' Nutrient?
- Human cells can manufacture D-ribose.
- However, when muscle has been stressed by injury or due to high energy demands, the cells may not be able to produce enough D-ribose for ATP production. In other words, the cells have trouble keeping up with the demand for this simple sugar.
- Some nutritional scientists thus classify D-ribose as “conditionally essential” --- the body needs D-ribose to be supplied in the diet in conditions of acute stress such as a heart attack, angina or heart failure or severe muscle stress and injury4.
D-ribose in heart disease
Numerous studies have shown increased ATP levels in heart muscle on supplementing with D-ribose5, 6,7,8,9,12.- A study published in the International Journal of Cardiology stated:
'Ribose, a pentose monosaccharide, has shown to replenish low myocardial energy levels, improving cardiac dysfunction following ischemia, and improving ventilation efficiency in patients with heart failure10.' - After a heart attack the loss of blood supply [ischaemia] and the reperfusion that follows is accompanied by a significant drop in ATP levels.
- Damaged heart muscle may in fact go into a 'hibernated' state awaiting a time when energy levels are high enough to allow the tissue to function normally again. An amazing study showed how D-ribose infusion may 'awaken' areas of ischaemic heart11.
Use in exercise
- D-ribose can be taken before, during or after high-intensity exercises.
- This will accelerate replenishment of ATP that can become depleted during intense exercise.
- This may help you prevent that muscle ache or marked tiredness felt after exercise.
Dosage
- 5 grams two to three times a day can be used for heart conditions or peripheral vascular disease.
- 5 grams pre and post-exercise can also be used to help supply and restore ATP levels.
What you should know
- D-ribose can mildly lower blood glucose levels.
- Care should thus be taken by insulin-dependent diabetics.
- Always discuss any supplementation with your doctor
- To offset the glucose lowering effect, you can take D-ribose with meals, or mixed into juice, milk, or added to fruit or cereals.
