Increased lutein intakes may improve night vision in drivers

A daily supplementation with lutein may improve visual performance and help with tasks such as driving at night, suggests a study from China.

In this randomized controlled trial, 120 healthy participants who had spent an average of 10 hours per day driving over the course of the two years before the beginning of the study received either a daily dose of lutein (20 milli-grams) or a placebo for one year (1). The participants’ visual acuity, serum lutein concentrations, macular pigment optical density (MPOD), and visual performance were measured at regular intervals during the study. The study results showed that the lutein group had a significant increase in serum lutein levels and central MPOD, while no such changes were recorded in the placebo group. In addition, significant increases in contrast and glare sensitivity, especially in the mesopic condition (nighttime light level), were measured. Moreover, the lutein group showed a trend towards improved visual acuity, but this did not demonstrate significant differences.

Based on the findings, the researchers concluded that a supplementation with lutein may improve driving at night as well as other spatial discrimination tasks carried out under low illumination. Although the results did not support a direct link between supplementation and changes in visual acuity, they provided evidence that increased intakes of lutein could significantly improve visual performance and vision-related quality of life when ambient illumination is low.

The carotenoids lutein and zeaxanthin are vital for eye health. Both are found in high concentrations in the macula. They are the only carotenoids capable of filtering the harmful blue light that can damage cells in the eye, the rods and the cones. The cones are used for vision in well-lit conditions (photopic vision), whereas the eye switches over to the rods for seeing under very low level light (scotopic vision). At many nighttime levels (mesopic vision), a combination of rods and cones is used.

1. Yao Y. et al. Lutein supplementation improves visual performance in Chinese drivers: 1-year randomized, double-blind, placebo- controlled study. Nutrition. Published online April 2013.