Consumption of one fresh avocado per day may lead to improved cognitive function in healthy older adults, according to research published in the open access journal Nutrients. This benefit is thought to be due to an increase in lutein levels in the eyes and in the brain. Lutein is a carotenoid found in fruits and vegetables that may act as an anti-inflammatory and antioxidant.
The researchers tracked 40 healthy adults over the age of 50 who were told to incorporate one medium avocado a day into their diet for 6 months. A control group was instructed to eat either one medium potato or one cup of chickpeas, which provided equal amounts of calories, but a negligible amount of lutein and monounsaturated fats. Compared to those in the control group, those who ate avocado were found to have a 25% increase in lutein levels in the eyes and experienced progressive improvement on tests that evaluated memory, processing speed and attention levels. The research was conducted at Tufts University and supported by the Hass Avocado Board.
This study also revealed that lutein levels in the eye more than doubled in subjects that consumed fresh avocados when compared to those that consumed a supplement. The data for the lutein supplement came from a previous study conducted by the lead researcher of this avocado study.
Together, these results indicate that consumption of fresh avocado is an effective way to increase lutein levels in the eyes and brain. Further research will focus on whether these cognitive benefits are seen at one-third the serving, which is the current recommended serving size of avocado.