Men hoping for monster muscles used to be the only people who routinely used amino acid supplements. But not any more. Today, these protein precursors are popping up all over the place. The amino acid taurine puts the pep in Red Bull energy drinks. And baby boomers nosh on nutritional bars boasting arginine, an amino acid that helps lower cholesterol and tame hypertension. Read more about derivatives of amino acids

Yes, supplemental amino acids have come a long way from bodybuilding. Can they help give your health a boost? It’s possible, but only if you take them properly.

Protein Precursors

Amino acids are most often described as the building blocks of protein. By stringing together the different aminos, the body constructs roughly 50,000 unique proteins, which are responsible for a jaw-dropping 75 percent of your body mass – everything from a strand of hair on your scalp to the nerve endings in your pinkie. Indeed, every single organ, tooth and bone in your body depends on amino acids to stay healthy.

The human body is ingeniously designed to keep its stock of amino acids full. Of the 20 the body needs, the liver manufactures 11. These are called nonessential amino acids – not because they aren’t important, but because the body churns them out on its own. The other nine, known as essential amino acids, are gleaned from plant and animal proteins in our diet – and some people take them as supplements.

So, what are the odds that your diet is lacking one of the essential nine? Because of the role meat and dairy play in the standard American diet, most of us don’t experience a deficiency. Still, even in the land of plenty, amino acid deficiencies do occur. Those who tend to fall short are people who under eat – the critically ill, crash dieters, extreme athletes who eat too little and exercise too much, and sometimes the elderly. Those with digestive problems, such as irritable bowel syndrome and ulcerative colitis, can also be at risk, since these conditions inhibit amino acid absorption. Signs of deficiency include fatigue, a weakened immune system, and injuries that refuse to heal.

The Supplement Controversy

So, should you supplement? It could give you an edge, even if you aren’t deficient. For instance, a short course of arginine can increase your sex drive. Glutamine can boost the immune system. And 5HTP can help you sleep. Others have used arginine to treat hypertension and taurine for congestive heart failure.

The importance of amino acids to brain function makes these nutrients of particular interest to practitioners who deal with mental disorders. While the majority of amino acids make protein, a few work in the brain as neurotransmitters. Single amino acid supplements, such as taurine and 5HTP, can also be extremely helpful for people with mild to moderate anxiety.

Just don’t go overboard. Overloading the body with one amino acid can crowd out one or more of the remaining 19. A special molecule carries amino acids from the gut to the liver. That molecule is like a bus with only so many seats. Put in too many of any one “passenger” and there is less room for the others. Without ready pools of all 20 amino acids, the body isn’t able to create the proteins needed to keep things running smoothly. Indeed, a deficiency of one amino acid may force the body to tear down muscle protein to glean enough amino acids for basic metabolic functions – a condition called negative nitrogen balance. Signs of a long-term imbalance include weight-loss and muscle wasting. More severe symptoms of a protein deficit include depression, digestive ills, and growth problems.

If you want to try supplemental amino acids, it’s best to work with a nutritionist or integrative physician experienced in their use. And bear in mind several precautions. Many experts recommend alternating two months on, two months off, to avoid developing an imbalance. Food inhibits absorption, so wait at least an hour between taking an amino acid and eating. And always follow recommended dosages unless otherwise instructed, since several amino acids, including aspartic acid, glutamic acid and homocysteine, are toxic when taken in large quantities.

Amino Acid 411

Here’s the scoop on five popular amino acid supplements that have shown promise either in scientific studies or clinical practice.

Arginine: This amino acid is most often associated with heart health. It raises blood levels of nitric oxide (a compound that expands blood vessels), keeps arteries pliable, and enhances blood flow. Three small trials have found that taking supplemental arginine improved symptoms of congestive heart failure. Other studies suggest it may reduce cholesterol, and also lower blood pressure in those with mild hypertension. For heart disease, take 2,000 to 3,000 mg. per day.

Taking supplemental arginine can also perk up your sex life. In one study of 50 men with erectile problems, half swallowed 5,000 mg. of arginine daily while their counterparts took a placebo. Six weeks later, a greater number of men in the amino acid group than in the placebo group reported enhanced “sexual performance.” In a similar study of postmenopausal women with lackluster libidos, those taking 6,000 mg. of arginine noted a greater improvement in sexual response than their counterparts taking the dummy pills. To boost your love life, take 5,000 mg. an hour before sexual activity no more than once a week.

5HTP: Made from the seeds of the griffonia plant, 5HTP is used as a weight-loss aid and mood lifter, as well as a sleep inducer. Research on this amino acid is still in its infancy; in two recent reviews of more than 200 clinical studies, researchers concluded that the lack of quality trials made it impossible to support or refute 5HTP-related claims. But it may be worth a try, if you don’t want to use prescription antidepressants or sleep aids. Take up to 50 mg. daily for depression; for insomnia, take the same amount, but at night.

GABA: The body generates GABA, or gamma-aminobutyric acid, from another amino acid called glutamic acid. It works by muffling neuronal activity in the brain and soothing frazzled nerve cells. For anxiety, take 1,000 to 2,000 mg. daily.