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L-arginine, which we'll just refer to as arginine, is a conditionally essential amino acid. This means that some people sometimes need it, and most people usually don't.
Adding to the confusion, purveyors of arginine supplements typically try to persuade the healthy people who need the smallest amounts of arginine to take the most, and the people who really could benefit from high-dose arginine not to take enough. Let's begin to sort through the claims about arginine to get the truth of the matter by exploring the idea of a "conditionally essential" amino acid.
The human body makes proteins out of building blocks called amino acids. The synthesis of proteins requires having the right amino acids in the right order. Having just one amino acid out of thousands in a protein chain can change the function of the entire molecule. Every amino acid is essential for its position in a chain of amino acids that makes up a protein, but not every amino acid has to be obtained from the diet.
The human body cannot ever make isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. These essential amino acids always have to come from food or supplements.
The human body sometimes can make the amino acids alanine, asparagine, aspartate (or aspartic acid), citrulline, cysteine, glutamate (or glutamic acid), glutamine, glycine, histidine, ornithine, proline, serine, and tyrosine from the essential amino acids. These are the "non-essential" amino acids. If the essentials are not provided, however, the body cannot make the non-essentials, so, to add to the confusion in the nomenclature, nutritionists often refer to these amino acids as "conditionally essential."
If the adult human body gets more of the essential amino acids than it needs in their dietary forms, it can convert them into the other amino acids it needs. If there is a shortage of these amino acids, it may dissolve white blood cells or muscle tissue, breaking them down into needed components for critical repairs. And if there is an excess of an amino acid, the body can convert it into sugar.
And what about arginine? The body sometimes can make arginine, and sometimes it can't. Infants can't make arginine. Elderly people often don't make arginine. When a healthy adult body is not increasing muscle mass or repairing damaged tissues, it can make all the arginine it needs from essential amino acids. But if the body is building muscle or rebuilding injured tissues, a small amount of supplemental arginine can accelerate the process.
And there are cardiovascular conditions for which high doses of supplemental arginine practically work wonders. But how much is enough?
A typical Western diet provides from 3 to 6 grams of arginine per day, which is more than a healthy body needs for maintenance, and less than a healthy body sometimes needs for growth or repair. But the amount of arginine provided by the diet is not a whole lot less than the body needs even for growth and repair.
Researchers Douglas Paddon-Jones, Elisabet Borsheim and Robert R. Wolfe at the Shriner's Hospital for Children in Galveston, Texas in the USA report research finding that it only takes 1 gram (1,000 mg) of supplemental arginine with 1 gram (1,000 mg) of supplemental ornithine daily to enhance muscle building in athletes on a high-intensity strength-building program. (If you are concered about the nuances of absorption among the various arginine pyroglutamate, arginine alpha-ketoglutarate, arginine ethyl ester, and arginine hydrochloride supplements, just take 2 pills instead of 1, and you're covered.) If you are working out to build muscle, it only takes 1,000 mg of arginine a day, with 1,000 mg of ornithine a day, to enhance muscle growth.
Ornithine is included with arginine because the body tends to convert arginine into ornithine and citrulline, reducing the amount of arginine available to the muscles.
Arginine supplements are often recommended for athletes who have broken bones. Professor of nutrition and Canadian hockey team trainer Dr. John Berardi has recommended 7 grams of arginine, 7 grams of glutamine, and 1,500 mg of HMB (beta-hydroxy-beta-methybutyric acid) to support recovery from broken bones and torn ligaments.
On the other hand, it takes a lot more arginine in an athlete's stack to get any "NO2" effects. First a word about "NO2" effects. There actually aren't any. Arginine helps the body make NO, nitric oxide, a beneficial free radical, not NO2, nitrogen dioxide, a gas. NO helps arteries dilate for easier circulation of blood, lower blood pressure, and in both sexes, greater sexual response.
Nobel laureate Dr. Joseph Ignarro (you may see references in the literature to him as Louis J. Ignarro) reports that in his patients, it takes about 9 grams of supplemental arginine every day to be able to detect a change in the arginine concentration of blood plasma. Since NO is made by cells in the lining of blood vessels, you have to get a change in the arginine concentration of blood plasma to make a difference in the production of NO.
For arginine to act as a secretagogue for the release of growth hormone, the required dosages are even higher. Growth hormone, as you probably know:
Technically, high arginine levels inhibit the release of somatostatin, which ordinarily limits the release of growth hormone. But one study found that arginine supplementation could increase the nighttime release of growth hormone in men aged 20 to 35 by 60%.
There were two significant downsides to that study. One was that men aged 20 to 35 typically don't need additional growth hormone. Men and women aged 50 and up might. And the amount of arginine need to enhance production of growth hormone in young, healthy males was 250 mg per kg of body weight, or 1000 for every 4 pounds. A person who weighs 100 kg (220 pounds) would need to take at least twenty-five 1,000 mg capsules of arginine every night about an hour before bed to have any expectation of increased hormone production.
Can you get, for instance, 25,000 mg of arginine a day from your diet?
Arginine is found in "high-protein" foods. Shellfish and soy protein are especially rich in arginine. This amino acid is also found in beef, nuts, sesame seeds, peanuts, almonds, Brazil nuts, chicken (especially canned chicken, which has about 30% more arginine than fresh), halibut, and mayonnaise. There is more arginine in light meat than in dark meat. There is more arginine in animal foods than in plant foods, with the exception of Brazil nuts.
Nutritional science knows of no better source of arginine than sea lion livers, a 200-calorie serving providing nearly 5 grams of arginine. Sea lion livers, of course, are not a practical food outside of eastern Siberia and western Alaska. They're usually eaten raw, by the way.
A 200-calorie serving of soy protein isolate, which is a lot to add to a shake, provides about 4 grams of arginine. A 200-calorie serving of steamed shrimp also provides about 4 grams of arginine. That's the equivalent of about 200 grams/half a pound of steamed shrimp. A pound (approximately 450 grams) of ready-to-cook turkey breast yields about 3 grams of arginine.
Or looking at it a different way, it would be reasonable to assume that you can get the arginine you need for supporting increased growth hormone levels by cooking and eating 8-1/3 pounds (about 3500 grams) of turkey breast every day. The problem with this is that only about 90% of arginine is digested from food, which means you would need 9 pounds (a little under 4 kilos), and only about 50% of the arginine that is digested is accepted by the liver, which means you would need to start with 18 pounds (a little under 9 kilos) of turkey just to get the arginine. Prefer a vegan approach? Then eat eight 10-oz packages of spinach.
There are no diets that include eating a whole turkey or eight packages of spinach every day. To get more than about 6 grams of arginine a day, it's essential to supplement. But it really doesn't make a lot of difference which kind of arginine you take.
The arginine used to make the familiar, 1000 mg capsules is arginine hydrochloride, also known as arginine HCl. For most applications, this is the kind of arginine I'd recommend. There are theoretical advantages to other arginine formulas:
I think that most bodybuilders max out on the benefits of taking arginine at two capsules of arginine HCl. If you really want to boost growth hormone, try an eat-stop-eat program. Fasting increases growth hormone release (to protect muscle tissue) many times more than taking arginine. Or if you take citrulline to prevent soreness, taking one or two capsules of arginine may extend citrulline's effects. But the people who really can benefit tremendously from arginine supplements are people who have peripheral arterial disease. ( More about L-Arginine and Bodybuilding. )
What is peripheral arterial disease, also known as PAD?
If you have PAD, you probably first notice something is wrong by looking at your toes. The skin on your toes may peel as if they had been sunburned, even when they haven't been out in the sun. You might develop "blood blisters" under your toenails or on the sides of your feet. Eventually the tissue heals over. The skin on your legs may look "rusty" and then dry out and crack. And at some point it may hurt, a lot, to run or even to walk.
PAD occurs when the linings of the arteries don't make enough NO (nitric oxide). Strictly speaking, the arteries don't convert arginine into NO. They use arginine to make an enzyme called endothelial NO synthase, which enables them to release NO. The release of nitric oxide doesn't just "relax" the arteries. It also prevents platelets from sticking together. This prevents clotting and "no-flow" situations, but it also prevents high blood viscosity and "low-flow" situations.
Increased production of NO keeps white blood cells from adhering to the linings of blood vessels. When white blood cells do not attach themselves to the linings of blood vessels, they do not transform cholesterol into hardened, artery-clogging plaques. The provision of arginine keeps the cells lining arteries from undergoing apoptosis, a series of changes sometimes called "cellular suicide." And arginine also helps normalize the pH of the blood, reduces the production of harmful free radicals of oxygen, and acts as an angiotensin converting enzyme inhibitor (like the blood pressure medication lisinopril, only without the side effect of dry cough).
Who is most likely to benefit from taking supplemental arginine to treat or prevent PAD?
How much arginine should people who have PAD or who are at risk of PAD take? Dr. Joseph Ignarro, UCLA scientist who won his Nobel Prize for his work in the role of arginine in vascular health, says that it takes at least 9 grams a day to make a difference in bloodstream arginine concentrations. Lower amounts of arginine may help muscle growth, but they won't change NO synthesis. Up to 30 grams of arginine a day may make a difference, although this amount can cause stomach upset.
If you have PAD, and you see improvement in your legs, you may be inclined to tolerate a little stomach upset. However, some people should not take arginine supplements at all.
What kind of arginine should you take for cardiovascular conditions? I am skeptical of the benefits of of arginine powders. They taste bad, and they don't really make any difference for muscle growth. If you simply cannot take 20 capsules a day, then I would use 20 grams of arginine ethyl ester in beverages as the manufacturer suggests on the label. It won't taste good, but it will be easy to swallow.
Otherwise, I recommend arginine HCl (arginine hydrochloride) capsules. They are inexpensive. They are easy to store, and they work. You don't need to spend a lot of extra money to get a high dose of potentially beneficial arginine. Always work with your doctor on any supplement program, discussing all medical concerns with your physician in person before you start.
Q. I have been taking a supplement that contains 500 mg of arginine, pcynogenol, and hawthorn berries for heart support. Is this a good combination?
A. It would depend on the amount of pcynogenol. That is not enough arginine to make a difference. Sometimes manufacturers add ingredients that have no direct health benefit for marketing or patent protection. It could be that the arginine is just "there" to distinguish the product from a competitor's, or to prevent a claim of patent infringement.
Q. Will arginine help enlarge my penis?
A. I have no direct information on this. It is possiblethat erections might be firmer.
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