WHAT IS ZEAXANTHIN?
Zeaxanthin is a carotenoid and phytonutrient (health boosting, plant based chemical compounds which are not classed as essential nutrients) that can be found in green leafy vegetables. In this article I will be taking a deeper look at zeaxanthin and its potential health benefits in the human body.
WHAT IS THE HISTORY OF ZEAXANTHIN?
Apart from being found in plant based foods, zeaxanthin can be found in the macula lutea (an oval shaped, highly pigmented yellow spot close to the centre of the retina of the human eye). The macula lutea was first described in 1782 but zeaxanthin was not identified as part of the macula lutea until 1985 when Bone & Laundrum made the breakthrough. Since this discovery, interest in dietary zeaxanthin and its potential effects on the eyes has increased dramatically.
WHAT ARE THE HEALTH BENEFITS OF ZEAXANTHIN?
Zeaxanthin is a potent antioxidant that can protect your body’s cells from dangerous free radicals (harmful by-products of oxygen based reactions).
As discussed, above there is also a great deal of interest in the potential health boosting properties of zeaxanthin when it comes to the eyes. A number of observational studies suggest that consuming high levels of this carotenoid can prevent age related macular degeneration and prevent cataracts (clouding on the lenses of the eyes). However, these studies on their own are not enough to confirm the health benefits of zeaxanthin and further studies are needed to determine whether it actually does boost the eyes.
HOW MUCH ZEAXANTHIN DO YOU NEED?
Zeaxanthin is not classed as an essential nutrient so no official recommended daily allowance (RDA) has been established. However, a number of studies suggest consuming between 6 milligrams (mg) and 10mg of this nutrient each day to maintain optimal health.
WHICH FOODS CONTAIN ZEAXANTHIN?
Green leafy vegetables such as broccoli, kale and spinach are the best food source of zeaxanthin. However, it can also be sourced from other fruits, vegetables and egg yolks. The table below lists some of the top food sources of zeaxanthin:
|FOOD||MG OF ZEAXANTHIN PER 100 GRAMS (G)|
|Collard Greens||Between 0.1mg and 2mg.|
|Kale||Between 4.4mg and 8mg.|
|Spinach||Between 2.4mg and 5.1mg.|
|Turnip Greens||Between 2mg and 4.9mg.|
WHAT ARE THE SYMPTOMS OF CONSUMING TOO MUCH ZEAXANTHIN?
Currently there are no reported overdose symptoms associated with zeaxanthin. However, no studies have been done into the long term effect of zeaxanthin supplementation so it is best to stick to natural food sources until more research is available.
WHAT ARE THE SYMPTOMS OF FAILING TO CONSUME ENOUGH ZEAXANTHIN?
Zeaxanthin is not classed as an essential nutrient so no deficiency symptoms have been established. Some people have suggested that long term deficiency of this nutrient can lead to eye problems and macular degeneration but no studies have been done to confirm this.
There is still a lot more to learn about the role of zeaxanthin in the human body. However, the available evidence suggests that it has an important role to play in healthy vision. So make sure you are including plenty of green leafy vegetables in your diet to take full advantage of this phytonutrient.
Foods That Contain Zeaxanthin (Livestrong)
List of Phytochemicals in Food (Wikipedia)
Zeaxanthin And Lutein – The Macular Pigments And A Review Of Their Role In Eye Health (Douglas Labs)