Amino Acids: Do They Really Stack Up?
Amino Acids: Do They Really Stack Up?
By Catherine Guthrie
Amino acid supplements used to be the stuff of gym rats: ordinary Joes yearning for IncredibleHulk-like physiques, who gobbled down the protein precursors like candy. Today amino acidsare not only sold alongside vitamins, they also appear on grocery store shelves in the form of"functional foods." The amino acid taurine, for example, puts the pep in Red Bull, an energydrink popular among college students. And baby boomers nibble on HeartBars, nutritional barsboasting arginine, an amino acid purported to lower cholesterol and tame hypertension. Betweensupplements and food additives, the market for amino acids in the United States is climbing at asteady 5 percent a year with sales expected to near $600 million by 2004.
Some people swear by them. Dan Delaney, a 34-year-old computer programmer in Louisville,Kentucky, takes them for insomnia. "The quality of my sleep has improved exponentially with5HTP," says Delaney, who can barely remember a time when sleep was an effortless affair.Between long workdays and helping to care for two young sons, he spent many a night in bedticking off to-do lists and stewing over various worries. When sleep finally came, it was thickand leaden, leaving him groggy in the morning. But once Delaney began taking 5HTP, which heread about in a diet book, he started having deep and restful slumber, and feeling refreshed bymorning. "Working with your body's own biochemistry just makes sense," he says.
Indeed, considering the critical role amino acids play in the body, it's tempting to think thattossing one or two into your daily supplement mix won't hurt. But some practitioners think thatmay be overdoing it. Taking too many amino acids, they say, or even too much of a single one,can create a biological imbalance, hindering the body's ability to build protein, fight disease, andabsorb vitamins and minerals.
Even proponents agree there's a right way and a wrong way to use amino acids. Mostrecommend a targeted strategy. "I don't see any reason to take them for prolonged periods," saysRay Sahelian, a general practitioner and nutritionist in Marina Del Rey, California, and author ofMind Boosters and Natural Sex Boosters. "But people with specific medical conditions canbenefit from taking amino acids temporarily to ease symptoms."
So, when can amino acid supplements help? And how do we take them without throwing awrench into our biochemistry? First of all, it helps to know why they're so important--and whythere's so much conflicting opinion about whether you even need them at all.
Amino acids are most often described as building blocks of protein. Better yet, picture an erectorset with 20 distinct pieces, each with its own specific shape. Imagine how many hundreds ofstructures you could build just by combining those pieces in different ways. By stringing togetherthe different aminos, the body constructs roughly 50,000 unique proteins, which are responsiblefor a jaw-dropping 75 percent of your body mass--everything from a strand of hair on your scalpto the nerve endings in your pinkie toe. Indeed, every single organ, tooth, and bone in your bodydepends on amino acids to stay healthy.
The human body is ingeniously designed to keep its stock of amino acids full. Of the 20 the bodyneeds, the liver manufactures 11. These are called nonessential--not because they aren'timportant but because the body churns them out on its own. The other nine, known as essentialamino acids, are gleaned from plant and animal proteins in our diet--and some people take themas supplements.
So what are the odds that your diet is lacking one of the essential nine? Not high, say manymedical experts. They point to America's love of meat and dairy as evidence that we're gettingenough. Even vegetarians, if they eat eggs, and vegans, if they eat soy, take in loads of the stuff."If you eat a basically healthy diet, it's difficult to be deficient in amino acids," says CynthiaSass, a spokesperson for the American Dietetic Association.
Still, even in the land of plenty, amino acid deficiencies do occur. Those who tend to fall shortare people who undereat--the critically ill, crash dieters, and extreme athletes who eat too littleand overtrain--and those with digestive problems such as irritable bowel syndrome andulcerative colitis, which can inhibit amino acid absorption. Signs of deficiency include fatigue, aweakened immune system, and injuries that refuse to heal. But Sass still thinks the best approachis to eat more protein rather than rely on supplements. "Even in rare cases when a health problemmight lead to a deficiency," she says, "it's not so easy to tell which amino acid might be lacking."
Some practitioners, though, think supplements are a good idea not only for people with signs of adeficit but for some healthier types as well. In some cases, they view single amino acids as viablealternatives to prescription drugs, especially for certain tenacious conditions. Sahelianencourages his patients to try a short course of amino acid supplements to increase sex drive(arginine), boost the immune system (glutamine), and induce sleep (5HTP). Others have usedarginine to treat hypertension and taurine for congestive heart failure.
The importance of amino acids to brain function makes the nutrients of particular interest topractitioners who deal with mental disorders. While the majority of amino acids make protein, afew work in the brain as neurotransmitters. Jay Lombard, an assistant clinical professor ofneurology at Cornell Medical School in New York, uses some for patients who spurn traditionaldrug therapy. "Single amino acid supplements, such as taurine and 5HTP, can be extremelyhelpful for people with mild to moderate problems like anxiety and insomnia," he says.
But nagging questions remain. On top of the fact that scientific evidence of the benefits of aminoacid supplementation is in short supply--and long-term analysis of side effects doesn'texist--physicians worry that consumers lack the know-how to determine accurate dosage."Swallowing an amino acid supplement is not the same as taking a multivitamin," says JamesDillard, assistant clinical professor at Columbia University's College of Physicians and Surgeonsand author of The Chronic Pain Solution. "It's a medical intervention. Whether you've gotinsomnia or heart disease, you need the advice of a professional, not the guy in the health foodstore."
The concern is not unfounded. Overloading the body with one amino acid can crowd out one ormore of the remaining 19. A special molecule carries amino acids from the gut to the liver,explains Phil Harvey, a nutritional biochemist and chief science officer of the NationalNutritional Foods Association, based in Newport Beach, California. "That molecule is like a buswith only so many seats. Put in too many of any one 'passenger,' and there is less room for theothers," he says. Without ready pools of all 20 amino acids, the body isn't able to create proteinsneeded to keep things running smoothly. Indeed, a deficiency of one amino acid may force thebody to tear down muscle protein to glean enough aminos for basic metabolic functions--acondition called negative nitrogen balance. Signs of a long-term imbalance include weight lossand muscle wasting. More severe symptoms of a protein deficit include depression, digestive ills,and growth problems.
Here's the scoop on six popular amino acid supplements that have shown promise either inscientific studies or clinical practice. Even with these, you should always consult a physician or anaturopath before trying one. And bear in mind several precautions. Many experts recommendalternating two months on, two months off, to avoid developing an imbalance. Food inhibitsabsorption, so wait at least an hour between taking an amino acid and eating. And always followrecommended dosages unless otherwise instructed, since several amino acids, including asparticacid, glutamic acid, and homocysteine, are toxic when taken in large quantities.
Protecting Hearts and Perking Up Libido
This amino acid is most often associated with heart health. It raises blood levels of nitric oxide, acompound that expands blood vessels, keeps arteries pliable, and enhances blood flow. Threesmall trials have found that taking supplemental arginine improved symptoms of congestive heartfailure; other preliminary studies suggest it may reduce cholesterol, and also lower bloodpressure in those with mild hypertension.
Hoping to cash in on Americans' ailing hearts, one company has marketed an arginine-lacednutritional bar. But the HeartBar, packed with 3 grams of arginine, has failed to live up to itsname. In a study published last March in the American Heart Journal, researchers divided 47high-cholesterol patients into two groups. One gobbled two HeartBars a day for two weeks; theother ate placebo bars. At the end of the study, neither group saw any change in their cholesterolnumbers.
Some researchers are experimenting with arginine as an alternative to Viagra for treatingimpotence in men and sexual dysfunction in women. In one study of 50 men with erectionproblems, half swallowed 5 grams of arginine daily while their counterparts took a dummy pill.Six weeks later, a greater number of men in the amino acid group than in the placebo groupreported enhanced "sexual performance." In a similar study of postmenopausal women withlackluster libidos, those taking 6 grams of arginine noted a greater improvement in sexualresponse than their counterparts on placebos.
Dosage: For heart disease, take 2 to 3 grams per day. For sexual performance, take 5 to 10 gramsan hour before activity no more than once a week.
Cautions: Heart disease is a serious condition that shouldn't be treated solely with an amino acid.If you have cardiac disease, consult with your doctor before adding any supplement to your diet.People with kidney disease or cancer should steer clear of arginine; raising nitric oxide levels canbe dangerous for these conditions. Also, arginine may trigger outbreaks in people with herpes.
Easing Insomnia and Depression
Until 1989, the amino acid tryptophan was considered helpful in treating insomnia and milddepression, but the popular supplement was banned in the United States after it was linked to alife-threatening blood disorder. Experts eventually traced the problem to contamination duringmanufacturing, but the supplement has yet to come back into favor with the Food and DrugAdministration.
Many consider 5HTP, which is derived partly from tryptophan, to be the next best thing. Madefrom the seeds of the griffonia plant, 5HTP is used as a weight loss aid and mood lifter as well asa sleep inducer. Research on the amino acid is still in its infancy--in two recent reviews of morethan 200 clinical studies, researchers concluded that the lack of quality trials made it impossibleto support or refute 5HTP-related claims--but it may be worth a try if you don't want to useprescription antidepressants or sleep aids.
Dosage: Up to 50 milligrams daily for depression; for insomnia, take the same amount, but atnight.
Cautions: Don't mix 5HTP with prescription antidepressants. High doses of 5HTP (more than 50milligrams per day) may cause nausea, stomach cramps, and decreased sex drive.
The body generates GABA, or gamma-aminobutyric acid, from another amino acid calledglutamic acid. It works by muffling neuronal activity in the brain and soothing frazzled nervecells.
However, the notion that GABA's brain-pacifying powers can be instigated by tossing back asupplement is contested. At the crux of the debate is whether or not GABA supplements elbowpast the blood-brain barrier, the body's shield that protects the brain from blood-borne diseasesand toxins. Studies are lacking, but Sahelian sees enough improvement in his patients to suggestthat people with anxiety issues should consider it.
Dosage: For anxiety, 1 to 2 grams daily.
Cautions: Side effects from too much GABA include increased anxiety, shortness of breath, andtingling in the hands and feet.
This nonessential amino acid is credited with building, repairing, and maintaining the body'sthousands of muscles. However, new research shows that sports enthusiasts who use it may bewasting their money. Two trials found no difference between the muscle mass of athletes whogulped glutamine and those who abstained.
That's not to say no one can benefit from the amino acid. In addition to fortifying muscles,glutamine is used by white blood cells that help the immune system ward off disease. A fewsmall studies show that supplementing with glutamine may help prevent the post-race infectionsthat plague professional athletes. Another promising application is for HIV patients; studies haveshown that those taking glutamine supplements were better able to maintain a healthy weight.
Dosage: To prevent post-exercise infection, take 1.5 to 6 grams daily. If you have HIV, consultyour physician before adding glutamine supplements to your routine.
Cautions: Don't take glutamine if you are sensitive to MSG (monosodium glutamate) because thebody metabolizes the amino acid into glutamate. Also, be aware that high doses of glutaminemay interfere with anti-seizure drugs, such as those taken to control epilepsy.
Taurine helps shore up cell membranes in body parts with multiple neuronal connections, such asthe brain and heart. For years, scientists noticed a correlation between lagging levels of taurineand heart attack deaths. As a result, in Japan, where much of the research originates, cardiologistsregularly give heart attack victims up to 6 grams of taurine a day to buttress wounded heartmuscles. Taurine supplements also appear to mellow symptoms of congestive heart failure(CHF). However, experts are calling for more research before the amino acid can be sanctionedas a routine treatment.
A more common use for taurine is perking up sleep-deprived students and groggy office workers.In a review of three studies of Red Bull Energy Drink, which relies partially on taurine to delivera jolt, researchers found Red Bull drinkers had quicker reaction times, longer attention spans, andbetter short-term memories than those who consumed ersatz brews.
Dosage: For an energy boost, 1.5 grams a day; for heart health, up to 6 grams a day.
Cautions: Too much taurine may cause diarrhea and peptic ulcers.
Promoting Weight Loss and Enhancing Memory
There seems to be some confusion about whether or not carnitine is technically an amino acid.But it looks and acts enough like one that it is often lumped in with the aminos for discussion'ssake. It's gleaned primarily from meat and dairy foods and is best known as a fat catalyst,meaning it hauls molecules from the body's fat stores to cells looking for energy to burn.
Carnitine has long piqued researchers' interest as both a weight loss enhancer and staminabooster, particularly in patients suffering from long-term ailments. The National Center forComplementary and Alternative Medicine is currently studying whether or not carnitine canboost energy levels of patients undergoing treatment for cancer.
Carnitine also holds promise as a memory enhancer, especially when paired with acetic acid, asubstance that resembles a brain chemical used for memory. Numerous studies show that theduo, called acetyl-L-carnitine or ALCAR, eases symptoms of early Alzheimer's disease,especially in patients under 65.
Dosage: If you're looking to boost memory, try 500 milligrams of either L-carnitine oracetyl-L-carnitine twice a day; people with early Alzheimer's disease can take up to 1,500 mg aday.
Cautions: At the store, you may see the supplement sold as D-carnitine or DL-carnitine, but mostexperts recommend L-carnitine; it's the closest match to what your body makes, so it's safer andmore easily absorbed. Acetyl-L-carnitine is also fine, but you'll pay a lot more for it.
Reprinted from Alternative Medicine Magazine, via the Jarrow Formulas Website, ScientificReading Room, Article Library. Go to www.jarrow.com for more information.