A recent study conducted by researchers from the University of Georgia suggests that incorporating colorful fruits and vegetables into the diet of athletes may enhance their visual range. This research underscores the significance of nutrition in the training regimen of top athletes.
In the publication titled "Exercise and Sport Sciences Reviews," researchers from the University of Georgia (UGA), namely Billy R. Hammond and Lisa Renzi-Hammond, explore the role of macular pigments in enhancing eye health and functional vision. These macular pigments, which accumulate in the retina, have been found to contribute significantly to improving visual function.
The findings build upon previous studies conducted by Hammond and Renzi-Hammond at UGA, which have demonstrated that the consumption of specific foods such as dark leafy greens, as well as yellow and orange vegetables, can lead to improved eye and brain health. These foods are rich in lutein and zeaxanthin, the plant compounds responsible for the beneficial effects observed in the studies.
"A lot of the research into macular lutein and zeaxanthin has focused on health benefits, but from a functional perspective, higher concentrations of these plant pigments improve many aspects of visual and cognitive ability. In this paper, we discuss their ability to improve vision in the far distance or visual range," said lead author Jack Harth, a doctoral candidate in UGA's College of Public Health.
Visual range, which refers to an individual's ability to perceive distant targets with clarity, holds significant importance for elite athletes across various sports.
One contributing factor to the diminishing clarity and increased blurriness of objects as they move farther away from our eyes is the impact of blue light.
"From a center fielder's perspective, if that ball's coming up in the air, it will be seen against a background of bright blue sky, or against a gray background if it's a cloudy day. Either way, the target is obscured by atmospheric interference coming into that path of the light," said Harth.
According to Harth, while athletes often employ eye black or wear blue blocker sunglasses to mitigate the effects of blue light, incorporating a diet rich in lutein and zeaxanthin can enhance the eye's natural defense against blue light exposure.
When lutein and zeaxanthin are consumed, they accumulate as yellow pigments in the retina, acting as a protective filter that prevents blue light from entering the eye.
Earlier research conducted in the 1980s focused on evaluating the visual range capabilities of pilots, while more recent studies by Hammond and Renzi-Hammond have investigated the relationship between macular pigment density (the amount of yellow pigment in the retina) and various aspects of eye health and functional vision assessments.
"In a long series of studies, we have shown that increasing amounts of lutein and zeaxanthin in the retina and brain decrease glare disability and discomfort and improve chromatic contrast and visual-motor reaction time, and supplementing these compounds facilitates executive functions like problem-solving and memory. All of these tasks are particularly important for athletes," said corresponding author Billy R. Hammond, a professor of psychology in the Behavior and Brain Sciences Program at UGA's Franklin College of Arts and Sciences.
According to Harth, this paper serves the purpose of updating the research on the connections between macular pigment and functional vision, while also exploring the implications of the evidence in terms of enhancing athletic performance.
"We're at a point where we can say we've seen visual range differences in pilots that match the differences found in modeling, and now, we've also seen it in laboratory tests, and a future goal would be to actually bring people outside and to measure their ability to see contrast over distance through real blue haze and in outdoor environments," said Harth.
Before diving into a kale-eating spree with hopes of enhancing your athletic performance, it's important to consider individual differences, as highlighted by the expert. The absorption and utilization of lutein and zeaxanthin can vary among individuals, and it may take a considerable amount of time before any noticeable improvements occur, if they occur at all.
Nevertheless, the authors emphasize that the broader health advantages associated with increased consumption of lutein and zeaxanthin alone are compelling reasons to incorporate more colorful foods into your diet.
"We have data from modeling and empirical studies showing that higher macular pigment in your retina will improve your ability to see over distance. The application for athletes is clear," said Harth.
Jacob B. Harth et al, A Dietary Strategy for Optimizing the Visual Range of Athletes, Exercise and Sport Sciences Reviews (2023). DOI: 10.1249/JES.0000000000000318