Peut aider à protéger le cerveaux
des effets négatifs du stress
- Supports performance during prolonged, high-stress work
- Enhances cognitive function and alertness during multitasking and sleep deprivation
- AOR offers a potent and effective daily dose
L-Tyrosine is an amino acid found in wheat germ, oats, dairy products, pork and poultry. It is a precursor for the neurotransmitters epinephrine, norepinephrine, and dopamine, which are all essential for mood, cognitive function and central nervous system function. The most prevalent usage for supplemental L-tyrosine appears to be the enhancement of cognitive function and alertness under conditions of environmental stress such as sleep deprivation, multi-tasking in the workplace, and functioning at high altitudes and/or cold temperatures. It is noteworthy to mention that a high percentage of the studies done on L-tyrosine are conducted by the military looking to enhance focus and attention in their personnel. Clinical trials with L-tyrosine have also been conducted with respect to attention deficit disorder (ADD) with good results. L-Tyrosine is also used by the body to make thyroid hormones as well as melanin, the skin and hair pigment.L-Tyrosine is ideal for those who are required to work long hours under stressful conditions, those whose lifestyles or work require a high degree of multitasking, those who experience prolonged physical and mental stress, students, and those who have difficulty concentrating such as in ADD.
Serving Size: 1 Capsule
Amount Per Serving
% Daily Value
Non-medicinal ingredients: none
Sleep DeprivationMilitary life is one of the few areas of employment in modern society where the work is meant to be as physically and as psychologically taxing on its employees as possible. Soldiers are meant to function under conditions that are often unnaturally stressful, and none more so than those imposed on the pilots of the United States Marine Corps. In a study conducted at the U.S. Naval Aerospace Medical Research Laboratory in Pensacola, Florida, 20 such marine aviators (all males, aged 21-27) volunteered to help determine if tyrosine can improve alertness during periods of sleep deprivation. After being deprived of sleep for 24 hours, the marines taking tyrosine scored markedly higher and made significantly fewer errors in their standardized tests which measured their hand-eye coordination, memory capacity, and comprehensive skills.High Altitudes and Cold WeatherHypoxia is the condition whereupon the body’s tissues are deprived of oxygen. This can take place in high altitudes (due to thin air) and extremely cold temperatures (due to constricting arteries). High altitude exposure causes hypobaric hypoxia, and additional exposure to extremely cold temperatures can further exacerbate this cognitive impairment. The bottom biological line is that acutely stressful situations (such as, but not limited to – hypoxia) can deplete brain norepinephrine and dopamine levels, thus disrupting behaviour and performance.Human studies with tyrosine have been impressive. A series of clinical trials were conducted by the U.S. Army Research Institute of Environmental Medicine in Natick, Montana among soldiers operating at mountainous altitudes of 15,300 feet. They revealed that “tyrosine significantly mitigated many of the decrements in symptoms, mood, and performance induced by [hypobaric hypoxia], including functions believed to be regulated by catecholaminergic neurons such as vigilance, alertness, and anxiety.”The United States Air Force, for its part, commissioned a study investigating the effectiveness of tyrosine on acute cardiovascular stress. Using a method designed to simulate gravitational stress (orthostasis), subjects who were given tyrosine experienced stabilized pulse pressures and increased central nervous system activity.Animal Studies: Better Performance Under StressExtensive animal studies have revealed some very interesting revelations about tyrosine. In a series of trials, laboratory rats that were pre-treated with tyrosine were subjected to the Porsolt swim test, which is when the rats are placed in an escape-proof tank filled with freezing water. The amount of time that the rats were immobilized by the freezing water was then measured. It was found that the rats that were pre-treated with tyrosine had their immobility time reduced significantly, so much so in fact that the performance levels of these animals matched those that were not exposed to cold-induced stress.Another type of test called the Morris water maze tested spatial learning and memory in laboratory rats exposed to a simulated height of 19,500 feet for 8 hours. The decrements in performance among the tyrosine-treated animals were only marginal, where as the non-treated animals’ decline in performance was considerable.ADDADD or Attention Deficit Disorder (sometimes referred to as attention deficit hyperactivity disorder, or ADHD) can be defined as a persistent pattern of inattention, hyperactivity, and impulsivity, occurring more frequently and severely than is typical in individuals at a comparable level of development. As expected, many diagnoses occur among schoolchildren, and there appears to be some connection between this disorder and the maintenance of adequate levels of certain amino acids, especially phenylalanine, tyrosine, tryptophan, histidine, and isoleucine. In fact, recent data suggest that children with phenylketonuria (PKU) may have an increased prevalence of attentional dysfunction.The results from studies conducted with tyrosine with specific regard to ADD have been mixed, with their beneficial role being limited to a temporary one. In one noted clinical trial, 12 adults with ADD supplemented with tyrosine for 8 weeks. After 2 weeks, 8 of these subjects showed “marked to moderate” improvements, but after 6 weeks these particular subjects developed tolerance against tyrosine supplementation. The temporary improvements experienced by these subjects, however, leaves open the potential usage of tyrosine in cases of ADD that are of a transient type. Dosage and SafetyMost of the successful human trials with tyrosine, especially those conducted by the U.S. military, used doses of 100-150 milligrams for every kilogram of bodyweight. This would equate to 8-12 grams of tyrosine for a 175 pound subject, and no discernibly adverse side effects were noted.
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