Zeaxanthin is a crucial carotenoid molecule that resides within the cells of your eyes. This potent antioxidant is associated with numerous health benefits, including a reduced risk of age-related cataracts, macular degeneration, and glaucoma.
This comprehensive article will explore zeaxanthin, its benefits, and potential risks. We will also delve into the top food sources of zeaxanthin and provide information about zeaxanthin supplements.
What Is Zeaxanthin?
Zeaxanthin is a carotenoid present in the human eye, along with two other carotenoids: lutein and meso-zeaxanthin. Meso-zeaxanthin is believed to be synthesized by the body from other carotenoids and is not typically obtained through the diet.
Carotenoids are fat-soluble, antioxidant compounds that exhibit vibrant red, yellow, or orange colors. They are found in various organisms such as algae, bacteria, fungi, plants, fruits, and vegetables. These essential nutrients must be obtained from the diet.
Out of the approximately 700 carotenoids discovered in nature, only about 20 have been consistently identified in the human body. Zeaxanthin and lutein are primarily concentrated in the human eye.
Zeaxanthin and lutein can be found in a diverse range of fruits, vegetables, and animal products like egg yolks. They belong to the xanthophylls, a class of pigments within the carotenoid family. These compounds are present in high concentrations in light-exposed structures found in both plants and the human eye.
Zeaxanthin and lutein are often discussed together in scientific studies due to their overlapping functions in the eye, as well as the body's ability to convert lutein into zeaxanthin.
Zeaxanthin is primarily concentrated in the central part of the retina, while lutein is more abundant in the peripheral regions. Together, they form the macular pigment, which plays a critical role in eye health.
Antioxidant And Anti-inflammatory Properties
Antioxidants shield the body from oxidative stress caused by highly reactive molecules known as free radicals or oxidants. They help reduce the levels of free radicals and inflammation in the body.
Excessive production of free radicals and chronic inflammation is linked to the development of various diseases, including age-related macular degeneration (AMD), dementia, and even cancer.
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.
Studies have demonstrated that zeaxanthin absorbs blue light, reducing oxidative stress and damage in the eye. This, in turn, alleviates inflammation and lowers the risk of eye diseases.
In fact, the most light-exposed layers of the eye contain approximately 75% zeaxanthin, which absorbs up to 90% of blue light, protecting the retina from light-induced harm.
Reduced Risk Of Eye Disease
Numerous studies have highlighted the crucial role zeaxanthin plays in eye health. It is particularly associated with a decreased risk of age-related eye conditions, including AMD, cataracts, and glaucoma.
These eye conditions often result in damage to the macula, which is responsible for detailed vision. The macula is also where zeaxanthin and lutein are stored.
Cataracts, glaucoma, and diabetic retinopathy are all eye conditions caused by nerve damage in the eyes due to sustained high blood sugar levels, commonly seen in individuals with diabetes.
AMD is the leading cause of blindness in people over 40 years old in the United States.
Zeaxanthin's antioxidant properties help prevent oxidative stress, reduce inflammation, and protect the macula from damage.
Additionally, zeaxanthin plays a vital role in eye development during fetal development and optimal vision in young adulthood.
A diet rich in zeaxanthin and other antioxidants may enhance the density of the macular pigment and is associated with a lower risk of eye diseases.
Potential Impact On Brain Health And Cognition
Beyond its role in vision, zeaxanthin is also present in regions of the brain associated with cognition, decision-making, and movement coordination.
Although research on the benefits of zeaxanthin for the brain is not as extensive as for the eyes, studies have indicated that individuals with Alzheimer's disease who have higher levels of zeaxanthin exhibit a lower mortality rate from the condition.
However, other studies suggest that taking a daily dose of 2 mg of zeaxanthin does not improve cognitive function in people with Alzheimer's disease.
The relationship between dietary intake of zeaxanthin and cognitive function requires further investigation. Researchers estimate that the average daily zeaxanthin intake in the United States is 1.3 mg but may reach as high as 25 mg in certain South Pacific populations.
More research is needed to elucidate the connection between zeaxanthin, cognition, and Alzheimer's disease.
UV Protection And Skin Health
Zeaxanthin is found in significant amounts in human skin. Similar to its role in the eyes, zeaxanthin absorbs harmful blue light waves and protects against oxidative stress caused by free radicals.
Numerous factors contribute to skin aging and sensitivities, including nutritional deficiencies and exposure to ultraviolet (UV) radiation from sunlight.
Symptoms of skin aging may include dryness, roughness, wrinkles, loss of elasticity, and discoloration.
Studies suggest that zeaxanthin's UV protection may improve the signs of skin aging. People have experienced these benefits both by consuming a diet rich in zeaxanthin and by applying skin creams containing zeaxanthin and other antioxidants.
Other Potential Health Benefits
Zeaxanthin may offer additional health benefits, including:
- Liver Disease: Zeaxanthin dipalmitate derived from goji berries appears to protect the liver by reducing inflammation and preventing the formation of liver scars, which are underlying factors in liver disease. Scientists are exploring its potential as a therapeutic drug.
- Kidney Health: Low levels of xanthophyll carotenoids, such as zeaxanthin, are associated with an increased risk of kidney disease. Consuming zeaxanthin from sources like egg yolks may provide antioxidant benefits for individuals with chronic kidney disease.
- Improved Cell Communication: Zeaxanthin and other carotenoids may contribute to cell-to-cell communication and overall bodily homeostasis, which is essential for good health. Further research is needed in this area.
While scientists have extensively studied the benefits of zeaxanthin for vision and eye health, research investigating its impact on other areas of the body is currently limited.
Zeaxanthin Rich Food Sources
Zeaxanthin naturally occurs in a wide variety of fruits and vegetables, with dark leafy green vegetables being particularly rich sources.
Scientific sources often list zeaxanthin- and lutein-containing foods together, as lutein can be converted into the carotenoid meso-zeaxanthin in the eye. Additionally, the average dietary intake of zeaxanthin is often low.
Goji berries contain the highest concentration of zeaxanthin among fruits and seeds.
Other bioavailable sources of zeaxanthin include corn, egg yolks, and human milk, where zeaxanthin is readily absorbed by the body.
Here is a list of foods rich in zeaxanthin and lutein, along with the amounts per 100 grams:
- Green peas, raw: 2.5 mg
- Spinach, raw: 12.2 mg
- Pistachios, raw: 2.9 mg
- Asparagus, boiled: 0.8 mg
- Summer squash, boiled: 2.3 mg
- Pumpkin, boiled: 1.0 mg
- Broccoli, raw: 1.4 mg
- Romaine lettuce, raw: 2.3 mg
- Brussels sprouts, boiled: 1.2 mg
- Carrots, raw: 0.3 mg
Currently, there is no official daily recommended intake for zeaxanthin. However, an intake of at least 2 mg per day has shown some health benefits.
Research indicates that individuals who consume 5-6 mg of zeaxanthin per day have the lowest risk of AMD and slower cataract growth.
By consuming a varied diet of whole foods, including orange bell pepper, corn, and eggs, individuals can potentially obtain 5-10 mg of zeaxanthin and lutein combined.
Zeaxanthin Supplements
The popularity of zeaxanthin-containing supplements and eye health supplements is on the rise.
Studies have demonstrated that taking zeaxanthin supplements can increase the density of the macular pigment in the eye. In one study, individuals taking zeaxanthin supplements for 6-24 months experienced an increased density of macular pigment, ranging from 36% to 95%. However, the response varied significantly among individuals.
A higher macular pigment density is associated with a lower risk of AMD.
Potential Risks
Zeaxanthin appears to be generally safe, although conclusive scientific findings are still pending.
Concerns have been raised about taking xanthophylls (including zeaxanthin) at higher dosages, but more research is needed to establish any potential risks.
Some studies suggest that a daily intake of 0.34 mg per pound (0.75 mg per kg) of body weight may be safe. For instance, a person weighing 154 pounds (70 kg) might safely consume up to 53 mg of zeaxanthin.
However, it is generally challenging to reach high levels of zeaxanthin through diet alone, as the average daily zeaxanthin intake is only around 1.3 mg.
Further research is necessary to determine the safe and beneficial dosages of zeaxanthin supplements for humans.
Conclusion
Zeaxanthin is a vital molecule in your eyes, essential for safeguarding them against damage throughout your life. As a fat-soluble compound belonging to the carotenoid family, it plays a crucial role in eye health.
Zeaxanthin, along with lutein, absorbs harmful blue light and provides antioxidant and anti-inflammatory benefits that reduce the risk of age-related macular degeneration, glaucoma, cataracts, and diabetic retinopathy.
This carotenoid can be obtained through a varied diet, incorporating a wide range of whole foods, or by using supplements.
While no official daily recommended intake for zeaxanthin has been established, researchers are working to determine safe and beneficial dosages for humans through further investigation.
References:- Lutein and Zeaxanthin-Food Sources, Bioavailability and Dietary Variety in Age-Related Macular Degeneration Protection; Authors: Bronwyn Eisenhauer and Sharon Natoli; PMID: 28208784, PMCID: PMC5331551.
- The Pharmacological Effects of Lutein and Zeaxanthin on Visual Disorders and Cognition Diseases; Authors: Yu-Ping Jia and Lei Sun; PMID: 28425969, PMCID: PMC6154331.
- Lutein and Zeaxanthin Isomers in Eye Health and Disease; Author: Julie Mares; PMCID: PMC5611842, NIHMSID: NIHMS867278, PMID: 27431371.
- Zeaxanthin and Lutein: Photoprotectors, Anti-Inflammatories, and Brain Food; Authors: Barbara Demmig-Adams and Marina López-Pozo; PMID: 32784397, PMCID: PMC7464891.
- Lutein, zeaxanthin, and meso-zeaxanthin: The basic and clinical science underlying carotenoid-based nutritional interventions against ocular disease; Authors: Paul S Bernstein and Binxing Li; PMID: 26541886, PMCID: PMC4698241.
- Carotenoids: biochemistry, pharmacology and treatment; Alireza Milani and Marzieh Basirnejad; PMCID: PMC5429337, PMID: 27638711.
- Carotenoids: From Plants to Food and Feed Industries; Authors: Panagiota Langi and Sotirios Kiokias; PMID: 30109624.
- Antioxidant Phytochemicals for the Prevention and Treatment of Chronic Diseases; Yu-Jie Zhang and Ren-You Gan; PMID: 26633317, PMCID: PMC6331972.
- Evolution of the Knowledge of Free Radicals and Other Oxidants; Authors: Sergio Di Meo and Paola Venditti; PMID: 32411336, PMCID: PMC7201853.
- Chronic Inflammation; Authors: Roma Pahwa, Amandeep Goyal, Ishwarlal Jialal.
- Why is Zeaxanthin the Most Concentrated Xanthophyll in the Central Fovea?; Justyna Widomska and John Paul SanGiovanni; PMID: 32392888, PMCID: PMC7284714.
- Effect of Dietary Supplementation With Lutein, Zeaxanthin, and ω-3 on Macular Pigment: A Randomized Clinical Trial; Authors: Jean-François Korobelnik and Marie-Bénédicte Rougier; PMID: 28973076, PMCID: PMC5710391.
- The global state of cataract blindness; Cameron M Lee and Natalie A Afshari; PMID: 27820750.
- The pathophysiology and treatment of glaucoma: a review; Authors: Robert N Weinreb and Tin Aung; PMID: 24825645, PMCID: PMC4523637.
- The pathology associated with diabetic retinopathy; Authors: Judith Lechner and Olivia E O'Leary; PMID: 28412095.
- AGE-RELATED MACULAR DEGENERATION; Authors: Andreea Gheorghe, Labib Mahdi; PMID: 26978865, PMCID: PMC5712933.
- Age-related macular degeneration; Authors: Paul Mitchell and Gerald Liew; PMID: 30303083.
- Role of lutein and zeaxanthin in visual and cognitive function throughout the lifespan; Authors: Elizabeth J Johnson; PMID: 25109868.
- Serum lycopene, lutein and zeaxanthin, and the risk of Alzheimer's disease mortality in older adults; Authors: Jin-young Min, Kyoung-bok Min; PMID: 24247062.
- Nutritional Intervention to Prevent Alzheimer's Disease: Potential Benefits of Xanthophyll Carotenoids and Omega-3 Fatty Acids Combined; Authors: John M Nolan and Riona Mulcahy; PMID: 29945352.
- Effect of Omega-3 Fatty Acids, Lutein/Zeaxanthin, or Other Nutrient Supplementation on Cognitive Function: The AREDS2 Randomized Clinical Trial; Authors: Emily Y Chew and Traci E Clemons; PMID: 26305649, PMCID: PMC5369607.
- Nutraceuticals: A Review; Skylar A Souyoul and Katharine P Saussy; PMID: 29411317, PMCID: PMC5825326.
- The protective effect of zeaxanthin on human limbal and conjunctival epithelial cells against UV-induced cell death and oxidative stress; Authors: Yue Huang, Chun Shi; PMID: 30918802, PMCID: PMC6423392.
- Zeaxanthin-based dietary supplement and topical serum improve hydration and reduce wrinkle count in female subjects; Author: Steve Schwartz and Emily Frank; PMID: 27312122.
- The Benefits and Risks of Certain Dietary Carotenoids that Exhibit both Anti- and Pro-Oxidative Mechanisms-A Comprehensive Review; Author: Homer S Black and Fritz Boehm; PMID: 32210038, PMCID: PMC7139534.
- Serum xanthophyll carotenoids are associated with estimated glomerular filtration rate in an aged cohort; Authors: Declan Browne, Michael A Williams; PMID: 31745176, PMCID: PMC6864050.
- Egg Intake in Chronic Kidney Disease; Authors: Dina A Tallman, Sharmela Sahathevan; PMID: 30544535, PMCID: PMC6315879.
- Zeaxanthin Dipalmitate in the Treatment of Liver Disease; Authors: Nisma Lena Bahaji Azami, Mingyu Sun; PMID: 31531108, PMCID: PMC6721266.
- An evidence-based update on the pharmacological activities and possible molecular targets of Lycium barbarum polysaccharides; Jiang Cheng, Zhi-Wei Zhou; PMCID: PMC4277126, PMID: 25552899.
- Top 10 Foods Highest in Lutein and Zeaxanthin; Author: Daisy Whitbread; My Food Data.
- Effect of lutein and zeaxanthin on macular pigment and visual function in patients with early age-related macular degeneration; Authors: Le Ma, Shao-Fang Yan; PMID: 22858124.
- Secondary Analyses of the Effects of Lutein/Zeaxanthin on Age-Related Macular Degeneration Progression AREDS2 Report No.3; Authors: Emily Y. Chew and Traci E. Clemons; PMCID: PMC4636082, NIHMSID: NIHMS720274, PMID: 24310343.
- Lutein + zeaxanthin and omega-3 fatty acids for age-related macular degeneration: the Age-Related Eye Disease Study 2 (AREDS2) randomized clinical trial; PMID: 23644932.
- Crystalline Maculopathy Associated with High-Dose Lutein Supplementation; Authors: Rene Y. Choi, Susan C. Chortkoff; PMCID: PMC5906391, NIHMSID: NIHMS955303, PMID: 27787539.
- An innovative approach to the determination of safety for a dietary ingredient derived from a new source: case study using a crystalline lutein product; Authors: C L Kruger, M Murphy; PMID: 12176081.
- Safety assessment of lutein and zeaxanthin (Lutemax 2020): subchronic toxicity and mutagenicity studies; Authors: R Ravikrishnan, Shraddha Rusia; PMID: 21872637.
- Dietary Sources of Lutein and Zeaxanthin Carotenoids and Their Role in Eye Health; Author: El-Sayed M. Abdel-Aal; PMCID: PMC3705341, PMID: 23571649.
- The Pharmacological Effects of Lutein and Zeaxanthin on Visual Disorders and Cognition Diseases; Yu-Ping Jia, Lei Sun; PMCID: PMC6154331, PMID: 28425969.
- Carotenoids as a Source of Antioxidants in the Diet; Authors: Ana Augusta Odorissi Xavier, Antonio Pérez-Gálvez; PMID: 27485230.
- Distribution of lutein, zeaxanthin, and related geometrical isomers in fruit, vegetables, wheat, and pasta products; Authors: Julia M Humphries, Frederick Khachik; PMID: 12590476.
- Xanthophyll (lutein, zeaxanthin) content in fruits, vegetables and corn and egg products; Authors: Alisa Perry, Helen Rasmussen; Received 12 June 2007, Revised 28 May 2008, Accepted 20 July 2008, Available online 12 August 2008.
- Fruits and vegetables that are sources for lutein and zeaxanthin: the macular pigment in human eyes; Authors: O. Sommerburg, J. Keunen; PMCID: PMC1722697, PMID: 9828775.
