A 12-week study found evidence that overweight and obese adults who incorporate daily avocado consumption into their diets can improve their ability to focus.
 
The study, published in the International Journal of Psychophysiology, evaluated a cohort of 84 adults between the ages of 25 and 45 in a randomized controlled trial. The treatment group received a daily meal with fresh Hass avocado. Attention, inhibition, and serum lutein were assessed using Flanker, Oddball, and Nogo tasks, accompanied with an EEG recording.
 
Avocado consumption has been shown to improve retinal lutein accumulation and cognitive function. Though the benefits of avocado consumption have been studied in older adults and children, no research has been done on how avocados may benefit those with weight issues.
 
“Previous work has shown that individuals with overweight and obesity are at higher risk for cognitive decline and dementia in older age,” kinesiology and community health professor Naiman Khan, who led the study, said. “We are interested in whether dietary approaches may have benefits for cognitive health, especially in midlife.”
 
The three cognitive tests were performed at the beginning and end of the study. They found that the treatment group saw improved results in the Flanker task, which measures the ability to focus on tasks at hand in the face of distraction. However, there were no differences in the other two cognitive tests.
 
“It could be that nutrients in avocados have a specific action in the brain that supports the ability to do this task in particular, or they could be more beneficial for certain cognitive abilities over others,” Khan said. “It’s also possible that with a longer study or different tests, we could see other effects. Other studies have found broader effects in other populations, so it is interesting to see a more specific benefit for this population.”
 
While improvements in both serum lutein and accuracy in the Flanker tests were seen in the avocado treatment group, there was no correlation between the changes in lutein levels and cognitive changes.
 
“Avocados also are high in fiber and monounsaturated fats. It is possible that these other nutrients may have played a role in the cognitive effects we saw, but we focused on the lutein in our analyses,” Caitlyn Edwards, the first author of the study, said. “Future analyses may focus on other nutrients found in avocados, or avocado consumption’s impact on other measures such as weight status, inflammation and potential changes in the microbiome.”
 
Other dietary sources of lutein such as green leafy vegetables or eggs may also have similar potential cognitive and health benefits. The researchers said in a statement that the study shows that small dietary changes can have measurable impacts on cognitive performance, even when other health behaviors remain the same.
 
“Our mission is to give people options. There are multiple ways people can eat to optimize brain health,” Khan said. “What we’re learning is that avocados may be one of those fruits that may be neuroprotective in certain ways. This work provides some evidence behind one option people have from a plethora of healthful foods that we can consume.”