Dementia, a decline in memory and cognitive function, is one of the most feared aspects of aging. But those who reported eating their vegetables seem to be more successful in staving it off.
Researchers at Rush University and Tufts University studied 1,000 people and found that those who reported eating one to two daily servings of green leafy vegetables, such as kale, lettuce or spinach, had slower rates of cognitive decline.
The new research was published today in the journal Neurology.
Study participants completed food frequency questionnaires, which asked how often they ate certain foods in the past year. The researchers then estimated the levels of nutrients consumed by each participant based on their responses.
The people in the study also underwent yearly testing of their memory and cognitive function.
The group of participants who ate the most servings of leafy greens per day (an average of only 1.3 servings daily) had slower cognitive decline than those who ate fewer leafy greens, researchers found. Statistically, the effect was similar to being 11 years younger.
The findings suggest this benefit is likely from important nutrients found in these vegetables, such as folate, lutein and nitrate, which were also associated with slower cognitive decline, Dr. Martha Clare Morris, lead author of the study and author of a new book “Diet for the MIND: The Latest Science on What to Eat to Prevent Alzheimer’s and Cognitive Decline,” said.
This may be because the nutrients protect against inflammation, stress and damaging changes in the brain, as has been reported in prior studies, according to the researchers.
The design of the study could only show an association, not that eating these vegetables actually causes the lower rates of dementia. Additionally, much of the data is based off the reports of study participants, a possible source of bias or inaccuracy because few people can say for sure how many kale salads they ate in the past year.
Still, the findings are promising, according to one expert not involved in the research.
“A healthy diet is good for your body,” Dr. Gayatri Devi, a neurologist specializing in memory disorders at Lenox Hill Hospital in New York City and author of the recently released book “The Spectrum of Hope: An Optimistic and New Approach to Alzheimer’s Disease and Other Dementias.”
Devi said she thinks the protective effects of leafy greens stem more from an overall healthy diet.
“It keeps your arteries clean, reduces the risk for heart disease, reduces the risk for diabetes, and all that is good for your brain,” she said.
Morris and her team attempted to control for other factors that can contribute for brain health including heart conditions, physical activity, mentally stimulating activities “like reading books and doing crosswords” and other factors. But the contribution from these other factors is “always a concern in observational studies and can never be fully ruled out,” she noted.
Both Devi and Morris recommend against taking supplements of the studied nutrients and advocate for incorporating leafy greens instead. “It’s just so much easier and safer to get them from nature,” Devi said.
So should you eat a bowl of lettuce every day to prevent dementia? Maybe. These findings suggest that greens might help keep your mind sharper.
Plus, eating an extra cup of spinach every day probably isn’t going to hurt you. “There aren’t any drawbacks,” Morris said.