What is nitric oxide?
Nitric oxide (NO) is a colourless gas that has been found to help dilate blood vessels and stimulate certain hormones such as insulin and human growth hormone. It has also been found to exert numerous effects on the kidneys, heart and vasculature. Reduced NO has been associated with aging, kidney, cardiovascular and metabolic disorders.
What has nitric oxide got to do with kidney health?
Research has found that the overall production of NO is actually decreased in CKD, this contributes to cardiovascular events and the further progression of kidney damage. Evidence from animal studies that experimentally induced chronic NO synthase (NOS) inhibition found it caused systemic and glomerular hypertension, glomerular ischemia, glomerulosclerosis, proteinuria and tubulointerstitial injury. NO in the kidney also promotes natriuresis and diuresis.
Nitric oxide supplementation has been shown to:
- Improve cardiac health
- Improves exercise performance
- Reduce blood pressure during pregnancy
- Reduce erectile dysfunction
- Improve the healing response
- Improve respiratory response
The two most prevalent NO supplements are L-arginine and L-citrulline. L-arginine and L-citrulline supplementation will help contribute to NO levels as L-arginine is involved in NO synthesis, in comparison, L-citrulline supplementation supports NO levels as L-arginine is involved in NO synthesis. L-citrulline acts as an L-arginine precursor which is converted to NO catalysed by NO synthase. Research supports the use of L-arginine supplementation in increasing respiratory response and enhancing exercise performance, in comparison L- citrulline with malate increases working capacity. NO stimulating supplements are usually a combination of amino acids, minerals, carbohydrates, creatine and vitamins.
Although NO supplementation has been used for decades, unfortunately, there is still little scientific evidence to support its health benefits.
Making a few changes in your diet provides a really easy way to boost your NO levels naturally. Adding these foods to your diet will not only boost NO levels but also promote better health!
Following are the 10 best foods to boost your NO levels;
- Meat- poultry and seafood
- Dark chocolate
- Leafy greens
- Citrus fruits
- Nuts and seeds
- Red wine
It is understood that supplements containing L-arginine and L-citrulline are considered to be safe, they may still have mild to moderate side effects such as:
- Stomach pain
It is suggested that smaller or divided doses may cause fewer side effects to the individual. Higher doses (>9 g/day) may increase the risk of gastrointestinal distress. Individual tolerance levels will differ greatly.
Nitric Oxide Side Effects
NO supplementation may have a higher risk of side effects in those with particular health concerns. These include cirrhosis, guanidinoacetate methyltransferase deficiency (GAMT) and low blood pressure. GAMT is a genetic condition where there is a lack of arginine to creatine converting enzyme. It is advised, people with GAMT do not take NO supplements.
Those who have liver scaring or cirrhosis should be careful taking NO as it may worsen liver function. Those with low blood pressure should cease NO supplementation prior to any surgery.
NO supplements may also interfere with certain medications such as blood pressure and diabetes medication. Therefore, individuals about to take a NO supplement will need to consult their healthcare practitioner prior to supplementation.
Nitric Oxide & Heart Health
Nitric oxide has been shown to have beneficial effects on heart health. These include:
- Reduced blood pressure
- Reduced arterial stiffness
- Improvement in blood flow in the carotid artery
Unfortunately, most of the studies are on animal models, so we require more human studies to back up these findings. NO has been shown to protect against the initiation and progression of atherosclerosis in many ways. NO produced from l-arginine plays a role in regulating endothelium-dependent vasodilation and prevents the adhesion of blood cells and platelets along the endothelial layer of blood vessels.
Nitric Oxide & Preeclampsia
Gestational hypertension (preeclampsia), is a complication in pregnancy that may lead to serious complications in the mother and baby. Women will experience high blood pressure and high levels of protein in the urine which will indicate kidney damage or other types of organ damage. Preeclampsia will usually occur after 20 weeks of pregnancy in women whose blood pressure had been in a healthy range previously. A 2005 paper reported women who took L-arginine supplements for a prolonged period had lower blood pressure than those who didn’t take the supplement. More studies are still required; however, the results are promising.
Nitric Oxide & Kidney Disease
Research has proposed endothelial dysfunction (ED), which is an early situation found in atherosclerosis, is the prime pathophysiological mechanism that provides the link between renal disease and the increased risk of CVD present in those with CKD. The reduced synthesis or decreased bioavailability of NO is one of the main mechanisms in the development of ED. Therefore, we can see how patients with CKD are at an increased risk of cardiovascular morbidity and mortality due to atherosclerosis. Results in a study reported in the Indian Journal of Nephrology showed that NO production is decreased in patients with renal failure. The decrease in NO production was seen to be due to decreased availability of arginine or due to an increased accumulation of asymmetric dimethyl arginine (ADMA), a potent competitive inhibitor of NOS. The study found both decreased levels of arginine as well as an increase in ADMA with a decrease in the production of NO levels.
The authors also concluded; increased ADMA levels are known to have a direct effect on increasing cardiovascular disease risk.
Nitric Oxide & Type 2 Diabetes
NO may be reduced in people with T2D, which leads to poor blood vessel health, which we know may eventually lead to health concerns such as high blood pressure, and kidney and heart disease. Research indicates supplements containing L-arginine may reduce insulin levels in patients without diabetes. Although L-arginine does not prevent the development of diabetes, it has been found to increase insulin sensitivity and improve blood sugar control. Once again, more research is required in this area for further evaluation.
So, there you have it!
NO is involved in many aspects of our health, it may be something worth considering. However, remember… making changes in your diet can help to increase your NO levels naturally. Eating a variety of fresh fruits and vegetables, nuts, seeds and sources of protein will optimize your levels of NO and promote overall better health.
I hope you found this article useful!
Till next time!