玉米黃質:健康益處和主要食物來源

What is zeaxanthin?

Zeaxanthin is a carotenoid found in the human eye. Two other carotenoids your eyes contain are lutein and meso-zeaxanthin.

Zeaxanthin is thought to be produced when your body breaks down other carotenoids, and you don't typically get it from your diet.

Carotenoids are fat-soluble antioxidant molecules that appear bright red, yellow, or orange. They are found in some algae, bacteria, fungi, plants, fruits and vegetables.

They are essential nutrients that you must get from your diet.

Of the 700 carotenoids found in nature, only about 20 are always present in the human body. Among them, zeaxanthin and lutein are mainly found in the human eye.

You can find zeaxanthin and lutein in a variety of fruits, vegetables, and animal products, such as egg yolks.

They belong to the class of carotenoid pigments called xanthophylls, which are abundant in plants and in the exposed structure of the human eye.

In scientific studies, zeaxanthin and lutein are often described together because of their overlapping functions in the eye and also because the body can convert lutein into zeaxanthin.

Zeaxanthin is concentrated in the center of the retina, while lutein is found in the peripheral areas of the retina. Together they form the macular pigment of the eye.

Both have antioxidant benefits, although zeaxanthin is the more potent antioxidant.

In humans, the most studied function of carotenoids is vision and their role in eye health and reducing the risk of eye disease.

Antioxidant and anti-inflammatory properties in eyes

Antioxidants protect the body from oxidative stress caused by highly reactive molecules called free radicals or oxidants. They reduce the levels of free radicals and inflammation in the body.

Excessive production of free radicals and chronic inflammation in the body are associated with the development of diseases such as:

Age-related macular degeneration (AMD)
Dementia Cancer Additionally, exposure to blue light waves has been shown to increase the production of free radicals and oxidative stress in the eyes, posing a potential threat to eye health.

Research shows that zeaxanthin reduces oxidative stress and damage to the eyes by absorbing blue light, thereby reducing inflammation and the risk of eye disease.

In fact, the most light-exposed layer of the eye contains about 75% zeaxanthin, which absorbs up to 90% of blue light to protect the retina from light-induced damage.

Reduce the risk of eye disease

Many studies show that zeaxanthin plays an important role in eye health throughout life. In particular, it is associated with a lower risk of age-related eye diseases, including AMD, cataracts, and glaucoma.

These eye diseases cause damage to the macula of the eye, the area responsible for fine vision. The macula is also where carotenoids, zeaxanthin and lutein are stored.

Cataracts, glaucoma, and diabetic retinopathy are all eye diseases caused by damage to the nerves in the eyes caused by long-term high blood sugar, which can occur in people with diabetes.

AMD is the leading cause of blindness in Americans over the age of 40.

The antioxidant properties of zeaxanthin help prevent oxidative stress, reduce eye inflammation, and protect the macula from damage.

Zeaxanthin also plays an important role in eye development during fetal development and optimal vision in early adulthood.

A diet rich in zeaxanthin and other antioxidants may increase the density of macular pigment and reduce the risk of eye disease.

May improve brain health and cognitive abilities in addition to

In addition to its role in vision, zeaxanthin is found in areas of the brain associated with cognition, motor coordination, and decision-making.

Compared to its benefits for the eyes, there is less research on the benefits of zeaxanthin for the brain.

Still, studies show that Alzheimer's patients with higher levels of zeaxanthin have lower mortality rates.

Other research suggests that taking 2 mg of zeaxanthin daily may not improve cognitive function in people with Alzheimer's disease.

It's unclear how this finding relates to dietary intake of zeaxanthin. Researchers estimate that the average daily intake of zeaxanthin in the United States is 1.3 mg, but may be as high as 25 mg in some South Pacific populations.

More research is needed on the relationship between zeaxanthin, cognition, and Alzheimer's disease.

UV protection and skin health

Zeaxanthin is found in large amounts in human skin.

In the eyes and skin, zeaxanthin absorbs harmful blue light waves and protects against oxidative stress caused by free radicals.

Many factors influence skin aging and sensitivity, including nutritional deficiencies and ultraviolet (UV) radiation from the sun.

Some symptoms of skin aging include:

  • dry or rough
  • wrinkle
  • lose elasticity
  • Discoloration

Research shows that zeaxanthin’s UV protection can improve signs of skin aging. People gain these benefits by eating a zeaxanthin-rich diet and using skin creams containing zeaxanthin and other antioxidants.

Other potential health benefits

Zeaxanthin may also provide a range of other health benefits, including:

Can protect kidney health. Low levels of the lutein carotenoids, including zeaxanthin, are associated with an increased risk of kidney disease. Eating the zeaxanthin found in egg yolks may also provide antioxidant benefits to people with chronic kidney disease.
Can treat liver disease. Zeagin dipalmitate, extracted from goji berries, appears to protect the liver by reducing inflammation and helping to prevent liver scarring caused by liver disease. Scientists are exploring it as a potential treatment.
Improve communication within cells. Zeaxanthin and carotenoids may play a role in intercellular communication and homeostasis, the balanced physical and chemical state required for good health. More research is needed in this area.
So far, scientists have explored most of zea yellow's benefits for vision and eye health.

main food sources

Zeaxanthin occurs naturally in a variety of fruits and vegetables. Dark leafy green vegetables are rich in zeaxanthin.

Scientific information often lists foods containing zeaxanthin and lutein as one category, rather than listing them separately. This may be because lutein can be converted into the carotenoid meso-zeaxanthin in the eye, but also because zeaxanthin is low in the human diet.

Zeaxanthin is the main carotenoid in wolfberry. Fruits and seeds are rich sources.

Corn, egg yolks, and breast milk are other bioavailable sources, meaning your body can easily absorb the zeaxanthin in these foods.

Here is a list of other foods rich in zeaxanthin and lutein, including the amount of each per 100 grams:

  • Raw spinach: 12.2 mg
  • Raw pistachios: 2.9 mg
  • Raw green peas: 2.5 mg
  • Lettuce, raw: 2.3 mg
  • Zucchini, cooked: 2.3 mg
  • Brussels sprouts, boiled: 1.2 mg
  • Raw broccoli: 1.4 mg
  • Pumpkin, cooked: 1.0 mg
  • Cooked asparagus: 0.8 mg
  • Raw carrots: 0.3 mg

Currently, there is no recommended daily intake of zeaxanthin. However, intake of at least 2 mg appears to provide some health benefits.

Research shows that when people consume 5-6 mg of zeaxanthin per day, the risk of AMD is lowest and cataract growth slows.

Through diet alone, you can get 5-10 mg of zeaxanthin and lutein from a variety of whole foods, including orange peppers, corn, and eggs.

There are currently few studies examining its effects in other parts of the body.

Zeaxanthin Supplements

Zeaxanthin-containing supplements and eye health supplements are becoming more and more popular.

Studies show that taking zeaxanthin increases the density of macular pigment in the eyes.

One study had people take zeaxanthin supplements for 6 to 24 months. Studies have found that 36-95% of humans have increased macular pigment density. Interestingly, this reaction varies from person to person.

potential risks

Although scientific findings are inconclusive, zeaxanthin appears to be generally safe.

Taking lutein (including zeaxanthin) at higher doses may cause some concern, but more research is needed.

Other studies estimate that a daily intake of 0.34 mg per pound of body weight (0.75 mg per kilogram) may be safe. For a person weighing 154 pounds (70 kilograms), this is equivalent to 53 milligrams of zeaxanthin.

High levels are often difficult to absorb through diet alone. The average daily intake of zeaxanthin through diet is only 1.3 mg.

generalize

Zeaxanthin is an important molecule in the eyes and is essential for protecting the eyes from damage throughout life. It is fat-soluble and a member of the carotenoid family.

One of three carotenoids found in the human eye that absorb harmful blue light, it has antioxidant and anti-inflammatory properties that may reduce the risk of age-related macular degeneration, glaucoma, cataracts and diabetic retinopathy.

You can get it in your diet by eating a variety of whole foods and taking supplements.

There is no recommended daily intake for zeaxanthin. Scientists need to do more research to find a safe and beneficial dose for humans.

Scientists need to do more research to determine what doses of zeaxanthin supplements are safe and beneficial.

Higher macular pigment density is associated with a lower risk of AMD.

Review

All comments are moderated before being published

HealthyPIG Magazine

View all
成年後懷疑自己有注意力不足過動症(ADHD),應該接受診斷嗎?

成年後懷疑自己有注意力不足過動症(ADHD),應該接受診斷嗎?

在過去,注意力不足過動症(Attention-Deficit/Hyperactivity Disorder, ADHD)多被視為「小孩的病」,很多成年人小時候從未被評估或診斷。直到近年社會對心理健康重視度提升,許多成人才開始懷疑,自己長期以來的專注困難、健忘、衝動或時間管理不良,可能與 ADHD 有關。這種「晚發現」的情況相當普遍,也引發了問題:成年後是否值得接受 ADHD 診斷?

哪些職業對健康影響最大?科學與現實的分析

哪些職業對健康影響最大?科學與現實的分析

在現代社會中,工作佔據了人們生命中相當大的一部分。然而,不同職業對健康的風險並不相同。一些工作性質或環境,會顯著增加慢性病、心理壓力、甚至縮短壽命的風險。以下從科學研究與醫學角度,探討幾類對健康損害較大的職業,並附上相關統計數據。

電擊槍的機制與對人體健康影響

電擊槍的機制與對人體健康影響

在現代執法中,警察常使用所謂「非致命性武器」(less-lethal weapons),其中最廣為人知的便是 電擊槍(Taser)。電擊槍的設計初衷是提供一種介於徒手制服與槍械之間的選擇,藉由暫時性電擊使嫌疑人失去行動能力,以降低致命暴力發生的風險。然而,電擊槍並非完全無害,背後涉及的電流機制與人體生理反應值得深入探討。

PD-(L)1/VEGF「三抗」:腫瘤免疫治療新方向

PD-(L)1/VEGF「三抗」:腫瘤免疫治療新方向

腫瘤治療的新挑戰 近十年來,免疫檢查點抑制劑(Immune Checkpoint Inhibitors, ICIs)改變咗癌症治療格局。當中 PD-1/PD-L1 抑制劑 已經成為多種腫瘤的一線或二線療法,而 VEGF 抑制劑 亦係抗血管生成治療嘅核心藥物。然而,臨床數據顯示,雖然 PD-(L...
疲勞駕駛的健康風險與新科技防護:REMONY 裝置的認證分析

疲勞駕駛的健康風險與新科技防護:REMONY 裝置的認證分析

疲勞駕駛一直是全球道路安全的重要議題。許多人將疲勞視為「只是累了」,但科學研究表明,當人處於極度疲倦時,大腦功能下降的程度可與酒精中毒相當。不僅如此,長時間駕駛還會對身體健康造成慢性負擔。隨著科技發展,越來越多可穿戴裝置被設計用來協助監測疲勞狀態,其中,日本 Medirom 公司開發的 REMONY 裝置近日獲得國土交通省(MLIT)認證,成為市場矚目的焦點。本文將先探討疲勞駕駛的健康風險,然後客觀分析 REMONY 裝置的技術特點與潛力。

腳跟為何會變黃乾裂?成因與護理全攻略

腳跟為何會變黃乾裂?成因與護理全攻略

腳跟皮膚為何容易出現問題? 腳跟係身體承受最大壓力嘅部位之一。每日行走、站立,腳跟長期摩擦同受壓,如果缺乏適當護理,就會導致角質層過度增厚、乾燥同龜裂。當角質層愈厚,皮膚顏色會慢慢變得偏黃,甚至暗啡。 造成腳跟黃、裂、脫皮的常見原因 角質層增厚長期行走或穿硬底鞋,令腳跟角質層積聚過多,顏色...
Wi-Fi 會唔會對人體有害?科學研究同日常生活影響全解析

Wi-Fi 會唔會對人體有害?科學研究同日常生活影響全解析

Wi-Fi 幾乎已經變成日常生活不可或缺嘅一部分。無論係屋企、公司、學校,甚至咖啡店同巴士,都有無線網絡覆蓋。但好多讀者都會擔心:「成日浸喺 Wi-Fi 入面,會唔會慢慢影響身體健康?會唔會致癌?會唔會令我失眠或者精神差?」 今篇文章會由淺入深,帶大家了解 Wi-Fi 嘅電磁波特性、科學研究結...
長時間保持一個姿勢,點解會痛、僵硬、麻痺?|久坐對身體嘅危害

長時間保持一個姿勢,點解會痛、僵硬、麻痺?|久坐對身體嘅危害

好多人每日要長時間坐喺辦公室、電腦前面,或者瞓覺時維持同一個姿勢。結果往往出現腰酸背痛、手腳麻痺,甚至覺得關節「鎖住」郁唔到。久坐傷身腳麻痺點解長時間坐姿影響健康,都係大家經常搜尋嘅問題。今次我哋就一齊睇下背後原因。

癌症如何擴散:從一個器官走到另一個器官的旅程

癌症如何擴散:從一個器官走到另一個器官的旅程

癌症最令人畏懼的地方,不單在於原發腫瘤本身,而是它能夠 轉移(Metastasis) —— 由原本的器官擴散至身體其他部位。事實上,大多數癌症致命的原因,並非來自腫瘤的「原居地」,而是因為它在其他重要器官(如腦、肝、骨、肺)形成了新的腫瘤。