Vitamin Trader - Healthy Discounts on Quality Vitamins

In addition to their structural role, amino acids are involved in many biochemical functions that are essential to life. Each person has a distinct pattern of amino acid makeup that fluctuates with health and illness. The range of requirements may differ by as much as sevenfold for a particular amino acid.1 Providing the body with a deficient amino acid or tilting the balance can influence various systems in the body. Thus, supplements of single as well as combination amino acids have many therapeutic applications. Single amino acids such as lysine or tyrosine can be isolated and taken in a disproportionately large dose to produce a pharmacological effect. In the case of tryptophan, supplements have been used clinically for treating depression, anxiety, pain, insomnia, migraine and carbohydrate craving.

While some neurotransmitters have an excitatory effect on the nervous system, others, such as serotonin, produce an inhibitory effect that soothes, calms and gives rise to feelings of contentment. Some serotonin is converted by the pineal gland into melatonin, the hormone that helps determine our sleep/wake cycle. Specifically, serotonin deficiency has been implicated in depression, uncontrollable appetite, obsessive-compulsive disorder, autism, bulimia, social phobias, premenstrual syndrome, anxiety and panic, migraines, schizophrenia and extreme violence. 2

Studies during the early 1980s by Richard Wurtman of the Massachusetts Institute of Technology, in Cambridge, showed that serotonin concentration in the brain is directly related to dietary intake of tryptophan. This was the first accepted demonstration that a single amino acid derived from the diet is capable of affecting neuronal biochemistry.3

Popular as they may be, these drugs have not been without serious complications. In September 1997, manufacturers of the weight-reduction drug ReduxTM and its close chemical cousin fenfluramine (an agent that comprises half of the drug mix popularly known as fen/phen) recalled the product when it was discovered that as many as 30 percent of patients using it could develop heart valve abnormalities.4 Before the drugs were even approved, both manufacturers and FDA were aware of other possible adverse effects such as primary pulmonary hypertension, a potentially fatal lung condition.

The FDA tryptophan ban may be forcing people to take dangerous and expensive drugs to achieve the same results as the amino acid. Fortunately, the ban does not apply to the recently introduced 5-HTP and has had the unforeseen benefit of spurring a closer examination of the extensive tryptophan research. A recent statistic shows there are nearly 5,000 papers referencing 5-HTP that can be accessed via the Internet.5

In one study, 5-HTP was compared to fluvoxamine, an SSRI.7 In a double-blind, multi-center study by Swiss and German psychiatric researchers, subjects diagnosed with depression were given either 100 mg of 5-HTP three times per day or 150 mg of fluvoxamine three times per day. The subjects were evaluated at zero, two, four and six weeks using standard depression rating scales. They were also asked to evaluate how well they felt. Beginning at week two and continuing through week six, both treatment groups experienced a significant and nearly equal reduction in depression. At week four, 15 of 36 patients treated with 5-HTP and 18 of 33 patients treated with fluvoxamine had improved by at least 50 percent, according to evaluation scores. When the numbers were totaled, researchers found the mean percentage improvement from baseline to the final assessment was greater for the patients treated with 5-HTP. Although not statistically significant, the number of treatment failures was higher (17 percent) in the fluvoxamine group than in the 5-HTP group (6 percent). Adverse side effects from both treatments were rare and generally mild, usually occurring during the first few days of treatment and then disappearing.
Although tryptophan may have antidepressant properties, there is more data available to suggest 5-HTP is efficacious in treating depressed patients. In one study, researchers administered 5-HTP (50 to 300 mg) to 107 patients with endogenous depression and found that 74 patients (69 percent) were either cured or showed marked improvement.8 (A 50 mg capsule of 5-HTP is generally regarded as the equivalent of 500 mg L-tryptophan.)

It has been reported that 5-HTP treatment is statistically superior to placebo in treating a small number of patients with endogenous depression.9 However, researchers recommend additional placebo-controlled investigations of 5-HTP and depression in which larger numbers of subjects are studied for at least six weeks.10

Prior to this 1989 study, another study provided evidence that the high quantity of carbohydrate-rich snacks frequently consumed by obese people can be diminished by treatments aimed at either enhancing serotonin release (fenfluramine) or increasing its synthesis (tryptophan).12

Serotonin's inhibitory functions in the brain prevent excess nervous stimulation at night so sleep can occur. Serotonin also is a growth hormone releaser. Growth hormone, which normally reaches peak levels during sleep, is crucial for growth and repair as well as stimulation of the immune system. These growth hormone peaks are frequently absent or smaller in elderly and obese people.13

People formerly took tryptophan as a sleep aid. It appears 5-HTP produces similar effects. A French study found that 100 mg of 5-HTP resulted in significant improvement in people described as "mildly insomniac."14

Because of competition among amino acids, dietary protein intake should be adequate, especially if larger doses of 5-HTP are taken. However, persons taking prescription drugs, particularly to alter mood or induce weight loss, should be extremely cautious. It is likely that 5-HTP potentiates the effects of such medications. Combining 5-HTP with other drugs should be done only with the consent and supervision of a physician. There also are some medical conditions in which serotonin or tryptophan metabolites become elevated. The effect of 5-HTP on fetuses and in pregnant women has not been studied; therefore, its use during pregnancy is contraindicated. Since 5-HTP may cause drowsiness, it should not be used while driving a car or operating heavy machinery.

Ken Babal, C.N., is a consulting nutritionist and a member of the board of directors for the Society of Certified Nutritionists. Babal is the author of the recently released book Maitake: King Of Mushrooms (Keats Good Health Guide, 1997).