From improved eyesight to better heart health, eating a colorful array of fruits and veggies has a lot of benefits. And new research shows that this healthy habit can protect your brain against cognitive illnesses such as dementia and Alzheimer’s disease, too.
A study conducted by the Virginia Tech Carilion School of Medicine reveals that dietary antioxidants found in colorful plant-based foods such as lutein, zeaxanthin, and vitamin E can have a substantial impact on cognitive functions and the risk of dementia or Alzheimer’s disease.
Published in the June 2023 issue of the Journal of Alzheimer’s Disease, the study discovered that the brain levels of dietary lutein, zeaxanthin, lycopene, and vitamin E in Alzheimer’s patients were half those in normal brains.
“This study, for the first time, demonstrates deficits in important dietary antioxidants in Alzheimer’s brains,” C. Kathleen Dorey, a professor in the Department of Basic Science Education at the medical school, said in a statement.
“These results are consistent with large population studies that found risk for Alzheimer’s disease was significantly lower in those who ate diets rich in carotenoids, or had high levels of lutein and zeaxanthin in their blood, or accumulated in their retina as macular pigment,” Dorey said.
Eating colorful foods increased dietary levels of lutein and zeaxanthin, which were found to be strongly connected to enhanced cognitive functions and a reduced risk for dementia or Alzheimer’s disease.
“Not only that, but we believe eating carotenoid-rich diets will help keep brains in top condition at all ages,” Dorey said.
Colorful plant foods and brain function
Carotenoids, the antioxidants found in colorful plants, are especially crucial for the brain, as they prevent oxidative damage. Lutein is abundant in vegetables like kale and spinach, while zeaxanthin is highest in corn and orange peppers.
The study illustrates how brains with Alzheimer’s neuropathology have significantly lower levels of lutein, zeaxanthin, and lycopene. Concentrations of these elements were half in Alzheimer’s-afflicted brains compared to age-matched brains without the disease’s pathology.
This adds to the growing evidence that a greater dietary intake of carotenoids may slow cognitive decline both before and possibly after a diagnosis of Alzheimer’s disease.
The new evidence from the study may pave the way for preventative measures, such as recommendations for increased intake of colorful plant foods, against Alzheimer’s.
“Recent advances in new therapies for Alzheimer’s disease show exciting promise,” Dorey said. “I’d be thrilled if our data motivated people to keep their brains in optimum condition with a colorful diet with abundant carotenoids and regular exercise. Available studies suggest this may also reduce risk for dementia.”
The Rush University Memory and Aging Project (RUMAP)—which has observed 1,000 Chicagoans for more than a decade—further supported the study’s findings by revealing that those following the MIND diet had a reduced risk for Alzheimer’s disease. This diet focuses on antioxidant-rich foods such as fresh fruits, vegetables, nuts, whole grains, legumes, and specific brain-boosting foods like leafy greens and berries.
Notably, RUMAP found that people who consumed the highest amount of carotenoids or lutein/zeaxanthin during the project period had a 50-percent lower risk for Alzheimer’s disease.
While the MIND Diet was developed to help older adults maintain cognitive function, research presented at the recent Nutrition 2023—the prestigious annual meeting of the American Society for Nutrition—showed that the plant-forward diet is also effective in optimizing brain health for children, helping improve focus.
Processed meat and cognitive health
Conversely, a diet high in processed foods and animal products has been shown to negatively affect cognitive health. One study recently published in JAMA Neurology reveals that consuming ultra-processed foods (UPFs), including processed meats, is associated with an increased risk of cognitive decline.
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The multicenter study observed 10,775 participants in Brazil and found that individuals whose daily diet consisted of over 19.9 percent UPFs experienced a 28 percent faster rate of global cognitive decline. Younger participants were more likely to experience cognitive decline compared to older individuals consuming similar levels of UPFs.
This finding aligns with previous research highlighting the increased risk of colorectal cancer among men consuming UPFs, particularly processed meats and dairy products.
The studies collectively stress the crucial role of dietary choices in protecting brain health and preventing cognitive decline. The link between UPFs and cognitive decline underscores the importance of whole, plant-based foods, including those rich in carotenoids, in preserving mental health.