The human body naturally follows a circadian rhythm—we’re awake during the day, and asleep at night. Blue light has a particular wavelength which is beneficial during daylight hours as it increases attention and mood—it wakes the body up. However, it is also harmful because it has the highest energy wavelength of visible light, and as Dr Melina Culver, Director of Scientific Affairs at OmniActive Health Technologies, explains, this energy can penetrate to the back of the eye and cause damage.
The biggest issue in this digital age is the level of blue light exposure from digital device use. The proliferation of electronics with screens that emit blue light, as well as energy efficient lighting, increase exposure, particularly in the evenings when the body should be preparing to sleep.
Dr Culver stresses there are different types of blue light, differentiated by the amount of energy they contain, and some blue light is beneficial. Higher energy blue light is a concern; primarily due to the amount of blue light we are exposed to each day and because of its potential to negatively impact vision. Much of the high energy blue light is focused on a specific area at the back of the eye, the macular, which is responsible for sharpness, clarity of vision and provides the best colour perception. Absorbing the energy from the blue light causes increased free radical formation and oxidative stress which has a cumulative effect and manifests as headaches, eye strain and fatigue, Dr Culver explains. She warns, it could even lead to a progressive loss of vision in the long term.
This degeneration is known as age-related macular degeneration and is a gradual loss in visual function—but it’s not inevitable, Dr Culver explains. With the right diet and supplementation, it’s possible to maintain healthy eyesight for a lifetime.
Carotenoids are a class of compounds responsible for the orange and yellow pigments in fruits and vegetables. There are hundreds of carotenoids found in nature, but only three are found in the eye: lutein and the two zeaxanthin isomers. All three are preferentially deposited in the macular hence macular carotenoids. Macular carotenoids play an important role in the protection of the macular and the body cannot synthesise these compounds, so dietary supplementation is essential.
Dr Culver explains macular carotenoids are very good at absorbing high energy blue light and act as potent antioxidants. They’re analogous to sunglasses worn to protect the eyes from UV light, she adds, only these protect the most sensitive areas of the eye, the regions of the eye responsible for vision. Without macular carotenoids, the hundreds of millions of photoreceptor cells would degenerate from the constant exposure.
These compounds not only protect the eye, but play a functional role as well, improving markers of visual function including contrast sensitivity, photo-stress recovery, and glare performance. Their importance rivals any vitamin for visual function, Dr Culver continues.
Most people do not get enough lutein and zeaxanthin in their diet alone, presumably because of the Western diet’s common lack of sufficient fruit and vegetables. Dr Culver says supplementation can fill that deficiency—she recommends looking for a supplement that has a complete formula: all three macular carotenoids in a 5:1 ratio of lutein to zeaxanthin as is naturally found in the diet. Daily supplementation of 10 to 20g of macular carotenoids significantly increases the thickness of the macular in as little as eight weeks, which can lead to great improvements in visual performance. Supplementation also helps with sleep quality, Dr Culver adds, especially in people with high levels of digital device use and so, may offset the effect of looking at your smartphone at night.
OmniActive issued an overview of the B.L.U.E (Blue Light User Exposure) Study which showed that macular carotenoid supplementation has beneficial effects on ocular health and performance, sleep quality, eye-strain and fatigue during long-duration exposure to blue light-emitting digital screens.
For the full interview, check out the Vitafoods Insights podcast here.