什麼是L-酪胺酸?

What is L-tyrosine?

L-tyrosine is an amino acid found in the diet that is metabolized to produce catecholamines such as dopamine (DA) and norepinephrine (NE). L-tyrosine is also used in the production of thyroid hormone. L-Tyrosine is often taken as a supplement to help increase the levels of catecholamines that are consumed during stressful or challenging conditions. It is used as a free form amino acid supplement, often alone or as part of a weight loss or pre-workout supplement.

What are the main benefits of L-Tyrosine?

The primary benefit of L-tyrosine is related to its ability to replenish catecholamine levels in the brain, which can be depleted during stressful conditions. Multiple studies have shown that L-tyrosine helps prevent cognitive decline under stressful, cognitively demanding conditions. Although L-tyrosine supplementation has not been shown to improve memory under resting conditions, L-tyrosine supplementation has been shown to alleviate memory decline under acute stress conditions. Overall, moderate doses of L-tyrosine appear to be safe and well-tolerated, with one 2-week human trial using a dose of 2,500 mg delivered three times daily for two weeks, and another Trials have used single doses up to 150 mg/kg body weight (approximately 10,000 mg for a 68 kg/150 lb individual), with no adverse effects.

What are the main disadvantages of L-tyrosine?

Although L-tyrosine has shown beneficial effects in some studies, its record of efficacy is mixed, with some studies failing to observe positive effects on cognition. This may be explained in part by the fact that L-tyrosine only increases catecholamine synthesis when catecholamine levels are depleted, thus limiting efficacy to sufficiently stressful or challenging conditions. Efficacy may also vary between individuals, as highlighted by one study that found that L-tyrosine's effects on cognitive function become detrimental as we age. People with hyperthyroidism or those taking levodopa or monoamine oxidase inhibitors may also have contraindications to L-tyrosine supplementation. If this happens to you, consult your doctor before supplementing with L-tyrosine.

How does L-tyrosine work?

L-tyrosine is used in the body to produce catecholamines, dopamine (DA), and norepinephrine (NE), which may be depleted under conditions of stress or cognitive challenge. After supplementation, L-tyrosine levels in the blood peak after one to two hours and remain elevated for up to eight hours. L-tyrosine then crosses the blood-brain barrier, is absorbed by brain cells, and is converted into DA in a series of enzymatic reactions. DA can be converted into NE through the action of another enzyme. L-tyrosine's ability to enhance catecholamine synthesis only in actively firing neurons may explain its ability to reverse the effects of neurotransmitter depletion during stress.

Should You Try L-Tyrosine Supplements? Check out its benefits and side effects

With so many different supplements claiming to improve sleep, boost the immune system, and improve heart health (just to name a few), it can be hard to know which ones might work and which ones won't.

L-tyrosine, for example, has gained widespread attention for its ability to help relieve stress and improve memory. But does this non-essential amino acid, also known as tyrosine, really live up to the hype?

As a non-essential amino acid, your body naturally produces L-tyrosine. It is used as a building block of proteins. It is made from an essential amino acid called phenylalanine.

So, what does L-tyrosine do?

In addition to building protein, L-tyrosine helps your body produce enzymes, thyroid hormones, and melanin, and aids in communication between nerve cells.

Although L-tyrosine is produced naturally in the body, you can also get it from certain foods, such as cheese, cured or smoked meats, soy products, avocados, and nuts.

So, do we still need it as a supplement?

L-Tyrosine Benefits

What is L-tyrosine used for? While the benefits of L-tyrosine may help relieve stress and depression, more research is needed to fully understand the role this amino acid plays in our bodies.

May be helpful in stressful situations

Who hasn’t been stressed? When we are stressed, we may have difficulty thinking clearly, retaining information, and concentrating.

Research is investigating whether L-tyrosine can help improve mental performance in stressful situations in humans.

In one example, participants who took a test measuring cognitive flexibility performed better when taking L-tyrosine supplements than when taking a placebo. Another study showed that working memory improved after taking L-tyrosine in people engaged in highly mental tasks.

L-tyrosine has not been shown to improve memory under resting conditions. It has been shown to alleviate memory loss under stressful conditions. The stress factor is the key. If you are stressed, your neurotransmitters are depleted, and therefore, your L-tyrosine levels may be lower.

May help relieve depression

One in six people will be affected by depression in their lifetime. While we don't know exactly why someone experiences depression, one belief is that it has to do with an imbalance in the brain's chemicals and its neurotransmitters like serotonin and dopamine.

L-tyrosine increases neurotransmitters in the brain, making it a possible treatment for depression.

It's important to know that early studies have had mixed results. One study showed that L-tyrosine did not have any antidepressant effects, while another study showed that individuals with low dopamine levels saw significant benefits when supplementing with L-tyrosine.

Until there is more conclusive research, L-tyrosine supplements are not recommended for treating depression.

May help patients with phenylketonuria

Phenylketonuria (PKU) is a rare genetic disorder caused by a defect in the gene that plays a role in producing phenylalanine hydroxylase, an enzyme. This special enzyme is used to make L-tyrosine.

Low levels of L-tyrosine can lead to mental health disorders. Whether L-tyrosine supplementation helps relieve PKU symptoms has yet to be determined, as studies have shown no improvement when taking L-tyrosine supplements.

L-tyrosine side effects

L-tyrosine supplements are considered generally safe by the U.S. Food and Drug Administration (FDA), but they may interact with certain medications, such as:

  • Thyroid hormone.
  • Monoamine oxidase inhibitors (MAOIs).
  • Levodopa (L-dopa).

It's important to remember that supplements are not regulated by the FDA. So make sure you do your homework on the brand to see if there are other additives added.

Is L-Tyrosine Right for You?

Most people will not benefit from taking L-tyrosine supplements. It's best to discuss with your healthcare provider whether taking an L-tyrosine supplement is right for you.

You can find L-tyrosine supplements as part of a sports supplement package. As for how much to take .

Review

All comments are moderated before being published

HealthyPIG Magazine

View all
皮質醇管理:如何控制皮質醇?我們能夠自行管理或調節劑量嗎?

皮質醇管理:如何控制皮質醇?我們能夠自行管理或調節劑量嗎?

皮質醇是一種在壓力反應中發揮重要作用的激素,適量的皮質醇可以幫助我們應對壓力和維持健康。然而,過量或長期的高皮質醇水平可能會對身體帶來負面影響。以下我們將探討如何控制和管理皮質醇,包括自然方法、藥物干預、以及測量皮質醇的方式。 1. 自然方法調節皮質醇 壓力管理技術:研究顯示,冥想、深呼吸...
皮質醇是什麼?它如何影響我們的身體與日常生活?

皮質醇是什麼?它如何影響我們的身體與日常生活?

皮質醇(Cortisol)是一種由腎上腺分泌的激素,通常被稱為「壓力荷爾蒙」。它的主要功能是幫助身體應對壓力情境,並且在多種生理過程中扮演重要角色。皮質醇的釋放受腦部下丘腦-垂體-腎上腺軸(HPA軸)控制,這是一個調節人體反應於壓力的系統。 皮質醇對身體的影響 當我們處於壓力下時,皮質...
為什麼我們在緊張時總是忍不住吃零食?科學解密壓力性飲食行為

為什麼我們在緊張時總是忍不住吃零食?科學解密壓力性飲食行為

當人們感到緊張或壓力時,經常會無意識地吃零食,這種行為主要涉及大腦的多巴胺系統、情緒反應以及身體的生理需求。以下是背後的幾個主要原因: 壓力荷爾蒙的影響:壓力會觸發皮質醇的釋放,這種壓力激素會引發人們對高糖和高脂肪食物的渴望。這些食物能帶來短暫的愉悅感,因為它們能刺激大腦分泌多巴胺,讓人感...
光學治療濕疹 - 全面總結

光學治療濕疹 - 全面總結

簡介 光療使用光波來治療某些皮膚問題。皮膚會暴露於紫外線 (UV) 光下一段設定的時間。光療利用人造的紫外線光源,紫外線也來自陽光。當與一種叫做甲氧補骨脂素的藥物一起使用時,這個程序稱為 PUVA 光療。 紫外線光能夠抑制皮膚中的免疫系統細胞,對於因免疫系統過度反應引起的皮膚問題有幫助。可以使...
什麼是「操縱者」?

什麼是「操縱者」?

操縱者,也可以說成「擅用手段的人」,「心機重的人」。操縱者利用欺騙、影響或者其他形式的心理操控來控制或影響他人,以達到自己的目標。他們的行為通常包含使用隱蔽、間接或偷偷摸摸的手法來獲得他們想要的東西,往往是以犧牲他人為代價。以下是一些常見的特徵和手段: 欺騙: 他們可能會說謊或扭曲事實來誤...
什麼是肌肉抽搐?你需要去看醫生嗎?

什麼是肌肉抽搐?你需要去看醫生嗎?

肌肉抽搐,也稱為肌束顫動,是指身體各部分出現不自主的肌肉收縮。以下是肌肉抽搐的原因、症狀及管理方法的詳細介紹: 肌肉抽搐的原因 壓力和焦慮 高水平的壓力和焦慮會導致肌肉緊張和抽搐。身體對壓力的反應會觸發神經系統,導致肌肉不自主地收縮。 疲勞 過度使用或劇烈運動後的肌肉疲勞會導致肌...
蘋果與牙齒健康:保護牙齒的小技巧

Apples and Dental Health: Tips to Protect Your Teeth

Apples are widely loved for their rich nutritional content and refreshing taste. However, apples' acidic and sugary content may also have an impact...
蘋果籽的毒性:它們真的有毒嗎?

Apple Seed Toxicity: Are They Really Poisonous?

Apple seeds contain cyanogenic glycosides, compounds that break down in the body to produce cyanide, which has raised concerns about the toxicity o...
有機蘋果與傳統蘋果:哪個更健康?

Organic apples vs. conventional apples: Which one is healthier?

Apple is one of the common fruits in our daily life, but when choosing, many people are confused whether to choose organic apples or traditional ap...