L-Ornithine is an amino acid that plays the lead in your urea cycle. Actually, it’s a weird one because unlike most amino acids you don’t need to eat anything specific to get it and your body doesn’t use it as a building block of protein, rather your body produces it to detoxify ammonia before your body excretes it (read – before you pee it out!). So what are the key benefits of L-Ornithine and how does it work?
Role in the Urea cycle
The amino acid ornithine is used in the urea cycle to break down ammonia into urea. Now the ammonia in your body is itself a product of the body breaking down proteins into amino acids or as a by-product of your digestion from your gut bacteria. The ammonia circulates through your body in your bloodstream, where, If you have too much ammonia, it can cause all kinds of nasty problems (think brain damage leading to coma or even death if left undiagnosed). The most common cause of too much ammonia is liver damage!
This is because the liver is where the body naturally produces ornithine by breaking down the essential amino acid arginine, so if the body can’t do it, then the natural Urea cycle gets interrupted. This process helps rid the body of excess nitrogen. Ornithine is produced by the liver from arginine, which is found in protein-rich foods like meat, dairy products, eggs, and fish.
What is the Urea Cycle
In the simplest terms, in humans, the urea cycle in liver cells converts ammonia into urea (a waste product) that the kidneys can then process for excretion (so you can pee it out!).
The urea cycle (or arginase pathway) is an important metabolic pathway in mammals that converts citrulline into ornithine, and then into arginine. Ornithine is converted back to citrulline by another enzyme called argininosuccinate synthetase. Citrulline is then recycled to produce ammonia via carbamoyl phosphate synthase. Arginine can be used for protein synthesis.
For the full technical detail of the Urea cycle, check out this great diagram.
Ornithine as a Supplement
Ever wondered what exactly the bodybuilding supplements and muscle gain supplements contain?
Well, often the two amino acids ornithine and arginine are paired together as the main ingredient. You might find Ornithine on the ingredients list by one of many names like L-ornithine, L-aspartate, OA (used informally), or ornithine-aspartate.
How does it work?
The amino acid L-ornithine has been shown to increase muscle mass and strength in rats by activating mTORC1 signalling (the protein complex responsible for growth) and inhibiting autophagy (a process that recycles damaged cells). It may also improve recovery after exercise by promoting protein synthesis.
A 2010 human study found that Arginine and Ornithine supplementation increased the growth hormone and insulin-like growth factor in athletes undertaking strength training, bonus if your goal is to build muscle!
Beneficial Effects of Ornithine Supplementation
There are several benefits of ornithine supplementation which have been reported in a number of studies, such as a reduction in fatigue, an increase in growth hormone, improved healing and reduced stress with improved sleep.
L-ornithine supplementation has been shown in controlled trials to reduce the feeling of fatigue (particularly in women!).
The study concluded that the results suggested that L-ornithine increased how efficiently your body can consume energy and remove the exercise waste products (the ammonia).
Because L-ornithine is so hard to get from food – the only way to get enough to promote the anti-fatigue effects is to take a nutrition supplement.
Increase Growth Hormone Levels
The Journal of Strength and Conditioning found that Ornithine and Arginine supplementation combined can elevate the growth hormone levels to improve athletic performance.
Ornithine and arginine have been suggested to improve both strength and power in male weightlifters. A 2010 study found that Arginine and Ornithine supplementation increased the growth hormone and insulin-like growth factor in athletes undertaking strength training.
Growth hormones are needed to build and maintain muscles during intensive physical training. It also helps deal with muscle loss that happens during the ageing process. As the body ages, the efficiency to synthesize proteins reduces and it can’t regenerate muscle tissue as strength and muscularity can start reducing rapidly. By helping to elevate growth hormone levels, it helps speed up the production of muscle tissue and delays the effects of ageing.
Although both arginine and ornithine are said to help protect and build muscle mass, the latter has been found to be twice as effective at perking up the growth hormone production as arginine. OA could even be the secret behind Wolverine’s healing power (Wolverine is a character in the movie X-Men. He can heal himself.)
Ornithine increases insulin and improves growth hormone levels. They are needed to build and maintain muscles during intensive physical training. It also helps deal with muscle loss that happens during the ageing process. As the body ages, the efficiency to synthesize proteins reduces and it can’t regenerate muscle tissue as strength and muscularity start reducing rapidly.
By helping to elevate growth hormone levels, it helps speed up the production of muscle tissue and delays the effects of ageing. Although both arginine and ornithine are said to help protect and build muscle mass, the latter has been found to be twice as effective at perking up the growth hormone production as arginine. So, if that (muscle building) is your purpose, you could eliminate arginine and concentrate more on ornithine. Since arginine is required to produce ornithine in the body, a basic intake of it should be maintained.
Healing From Trauma
But jokes aside, studies have found that a healthy level of ornithine can help the body to recover fast from trauma, burns and infections. Ornithine-aspartate has shown to have favourable effects in the treatment of rats suffering from brain abnormalities (hepatic encephalopathy) due to liver cirrhosis.
Stress Reduction and Sleep
L-ornithine supplementation has been shown in studies to reduce anger and increase perceived sleep quality among healthy volunteers in a double-blind clinical trial.
Adverse Effects of Ornithine
We know that the body itself produces OA. However, it is available in fish, meat, dairy, and eggs as well. There are meagre chances of a person suffering from OA deficiency (as it is produced by the body itself.). However certain conditions, like pregnancy, trauma, or malnutrition can lead to deficiency development. Pharmaceutical companies, like Esteem, Olympian Labs, Twinlab, Solaray, etc., do have a variety of ornithine supplements in the market. So, if you do suffer from arginine or OA deficiency, consult your doctor regarding these supplements, most especially if you are pregnant or under the age of 18 (do not administer any treatment or medication without consulting a doctor).
It is suggested that an intake of up to 10 grams of OA a day has minimal side effects. If the intake exceeds 10 grams a day gastrointestinal distress may occur – never any fun. Other than that OA is a pretty benign supplement.
They say “what ain’t broken, need not be fixed”. If you do not suffer from OA deficiency and have the urea cycle functioning smoothly, it’s probably best to refrain from the use of supplements. Your body is well-capable of fending for itself in this area. Don’t spoil it and make it dependent on medication. And even if you do see a requirement to opt for supplements, consult a doctor and take all your medical details into consideration before you begin having the supplements.
If you do go ahead with an Ornithine supplement, the side effects of high doses can include restlessness, nausea and diarrhoea.
So have you tried an Ornithine supplement? Let me know your experiences in the comments.