4Ever Fit L-Tyrosine 500mg, 90 Capsules - Sport Nutrition Depot Canada

4Ever Fit L-Tyrosine 500mg, 90 Capsules

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About L-Tyrosine

L-Tyrosine is an amino acid. Your body uses it to produce
· dopamine
· norepinephrine (noradrenaline)
· epinephrine (adrenaline)

These are some of the main neurotransmitters in the brain. Attention deficit disorder can be caused by not enough dopamine or norepinephrine. Low levels of tyrosine, therefore, can result in ADD.
What happens in this case is that the neo-cortex of the brain basically shuts down. This is the part of the brain that allows you to pay attention. Without enough dopamine and norepinephrine, all the effort in the world won't help much.

That is why tyrosine is important. More tyrosine means more dopamine and norepinephrine. As a result, the neo-cortex can now function properly, and you can pay attention.

L-Tyrosine can also be helpful for people with
· chronic fatigue
· narcolepsy
· anxiety
· depression
· low sex drive
· allergies
· headaches1

L-tyrosine aids in the functions of the adrenal, thyroid and pituitary glands. It is converted into thyroid hormone, or thyroxin "which plays an important role in controlling metabolic rate, skin health, mental health, and growth rate. Tyrosine is specifically used to treat depression because it is a precursor for those neurotransmitters that are responsible for transmitting nerve impulses and essential for preventing depression."2
Amino acids are the 20 building blocks of protein. Some amino acids are essential, and others are non-essential. Essential means that your body cannot produce them and so you must get them from your diet. Non-essential amino acids can be produced by your body from the essential amino acids.

L-Tyrosine is a non-essential amino acid for most people, because your body can produce it from phenylalanine. (Some people have a genetic disease called phenylketonuria, or PKU, which prevents their bodies from converting phenylalanine into tyrosine.)

Amino acids come in two forms, L- and D-, which are mirror images of each other. The L- form is found in food, and is generally the form used in our bodies.
You can get some tyrosine in your diet, from such foods as
· fish
· poultry
· almonds
· avocados
· bananas
· dairy products
· lima beans
· pumpkin seeds
· sesame seeds3
Although tyrosine can be produced in our bodies, the question is whether you have enough tyrosine in your body to produce sufficient quantities of neurotransmitters.
People who have ADD/ADHD, that is, inattentive or hyperactive ADD, may wish to take extra tyrosine, either from their diet or in the form of supplements, to increase their dopamine and norepinephrine.

Who Should Avoid Taking Tyrosine?
Before discussing how much tyrosine to take, you must be aware that tyrosine must be avoided if you are taking
· monoamine oxidase (MAO) inhibitors
· tricyclic anti-depressants
· serotonin re-uptake inhibitors (SSRIs) such as Prozac
Also avoid tyrosine if you are taking other pharmaceutical drugs used to treat mental or emotional conditions, such as depression.
Avoid tyrosine if you have high blood pressure, muscular dystrophy or cancer, especially malignant melanoma.
Avoid tyrosine if you are subject to heart palpitations.
If you have a thyroid condition, such as hypo-thyroidism, don't take tyrosine without first consulting your doctor.
If you have glaucoma, discuss the use of tyrosine with your doctor. Tyrosine is a stimulant (since it produces dopamine), and other stimulant drugs, such as Ritalin, are not to be taken if you have glaucoma.
Dosages and Side Effects.

According to Dr. Ray Sahelian, M.D., if you are taking supplemental tyrosine, you should start with 50 mg and slowly work your way up to higher levels. Observe very carefully what effects it is having, beneficial or otherwise. Discontinue if it causes irritation, anxiety or digestive problems.4

Dr. Sahelian warns to be careful of your dosage of tyrosine if you are taking other stimulants. The effects of stimulants can be cumulative. He mentions DMAE, CDP-choline, pantothenic acid, methyl donors, ALC, CoQ10, DHEA, pregnenolone, St. John's wort, and ginseng.5
Tyrosine supplements should be taken either on an empty stomach, with water, or with carbohydrate meals. This is so it doesn't have to compete for absorption with other amino acids, from protein food.
According to Leon Chaitow, N.D., D.O.,

"A high protein meal will increase blood and brain tyrosine to a degree but not enough to affect neurotransmitter synthesis greatly."6

"Tyrosine has been found to be most effective when there exists a deficiency state. Patients who have previously responded to amphetamines may respond well to tyrosine therapy."7

"small doses of tyrosine are more effective in increasing brain levels of neurotransmitters than large doses. Although blood and brain levels of tyrosine will increase with large doses, there appears to be an inhibition of the enzyme tyrosine hydroxylase which converts tyrosine to neurotransmitters, when large amounts of tyrosine are present."8
The Life Extension Foundation (LEF) suggests a daily dosage of L-Tyrosine of from 500 mg to 1500 mg, to fight depression.9 Presumably, in recommending such dosages, they are thinking of adults, not children.

The editors of The Natural Pharmacy point out that clinical studies in which tyrosine was used for a variety of conditions involved dosages of up to 7 grams (7000 mg). They add that it is unclear if such large dosages are necessary.10

LEF points out that clinical studies in which blood levels of subjects were raised to three times the level of controls were not accompanied by any evidence of side effects.11
According to The Natural Pharmacy,

"Tyrosine is not generally associated with side effects. Vitamin B6, folic acid and copper are necessary for conversion of tyrosine into neurotransmitters."12
Contrast that with the side effect profiles of pharmacological stimulants, not to mention their cost, and L-Tyrosine looks like a safe, natural and cost-conscious alternative.

References:
1. Prescription for Nutritional Healing, third edition, by Phyllis Balch, CNC, and James F. Balch, M.D., Avery, 2000, pp. 51-2.
2. Disease Prevention and Treatment, third edition, Melanie Segala, ed., published by the Life Extension Foundation, 2000, p. 536.
3. Balch, p. 52.
4. Mind Boosters, by Dr. Ray Sahelian, M.D., St. Martin's Griffin, 2000, pp. 142-3.
5. Sahelian, p. 142.
6. Thorson's Guide to Amino Acids, by Leon Chaitow, Thorson's, 1991, pp. 73-4.
7. Chaitow, p. 74.
8. Chaitow, p. 74.
9. Segala, p. 235.
10. The Natural Pharmacy, by Schuyler Lininger et al., Healthnotes Inc., 1999, p. 335.
11. Segala, p. 537.
12. Lininger et al., p. 335.