“Extending people’s cognitive functioning is an important public health challenge,” said researcher May A. Beydoun, Ph.D. “Antioxidants may help protect the brain from oxidative stress, which can cause cell damage. Further studies are needed to test whether adding these antioxidants can help protect the brain from dementia.”
How antioxidants affect brain health
The researchers had over 7,200 people who were at least 45 years old involved in the study. The team took baseline vitals -- including a blood test, a physical exam, and a cognitive assessment -- at the start of the study. The researchers then tracked the participants' health outcomes over the course of 16 years.
The study showed that participants who had the highest levels of three antioxidants – lutein, zeaxanthin, and beta-cryptoxanthin – had a lower risk of developing dementia. Each 15.4 micromoles/liter increase of lutein and zeaxanthin was linked with a 7% lower risk of dementia. Similarly, each 8.6 micromoles/liter increase of beta-cryptoxanthin was linked with a 14% lower risk of dementia.
The researchers explained that lutein and zeaxanthin can be found in broccoli, kale, spinach, and other leafy, green vegetables. On the other hand, beta-cryptoxanthin can be found in fruits, like persimmons, oranges, tangerines, and papayas.
While the researchers hope to do more work in this area to better understand why this link between antioxidants and dementia risk exists, these findings highlight the cognitive benefits of having higher antioxidant levels.
“It’s important to note that the effect of these antioxidants on the risk of dementia was reduced somewhat when we took into account other factors such as education, income, and physical activity, so it’s possible that those factors may help explain the relationship between antioxidant levels and dementia,” Dr. Beydoun said.