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Zeaxanthin: Health Benefits And Rich Food Sources
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.