Older men and women who ate a serving a day of green, leafy vegetables had a slower rate of decline on tests of memory and thinking skills than people who rarely ate such greens. Those who ate leafy greens showed brains that were, on average, the equivalent of 11 years younger than those who shunned these vegetables.
“Adding a daily serving of green, leafy vegetables to your diet may be a simple way to foster your brain health,” said Martha Clare Morris of Rush University Medical Center in Chicago, the study’s lead author. “Projections show sharp increases in the percentage of people with dementia as the oldest age groups continue to grow in number, so effective strategies to prevent dementia are critical.”
For the study, in the journal Neurology, researchers looked at 960 men and women who ranged in age from 58 to 99. Their average age was 81. None had dementia, and they were followed for almost five years.
Study participants completed questionnaires about how often and how much they ate of three leafy greens: spinach (a serving was considered to be a half cup of cooked spinach); kale, collards or similar greens (a half cup cooked); and lettuce (one cup of raw salad).
They also underwent tests of thinking and memory skills yearly over the five-year study period.
The participants were divided into five groups based on how often they ate leafy greens. Those in the in the top serving group ate an average of about 1.3 servings a day. Those in the lowest serving group ate, on average, 0.1 servings a day.
Over all, the researchers calculated that those who regularly ate leafy greens showed less decline in thinking and memory abilities over the years. The brains of those who ate one to two servings a day, the researchers estimated, resembled the brains of those who were 11 years younger compared to the brains of those who rarely or never ate leafy greens.
The researchers controlled for other factors that could affect brain health, such as smoking, high blood pressure, obesity, education level and the amount of exercise and mentally stimulating activities. Still, eating leafy greens was tied to better brain health.
Dr. Morris noted that the study does not prove that eating green, leafy vegetables slows brain aging; it only shows an association between eating leafy greens and better brain health.
Earlier studies have shown that eating lots of vegetables, and particularly leafy greens like spinach, kale, collars and lettuce, may be good for the brain. Leafy greens are rich in nutrients like folate (a B vitamin), lutein and beta-carotene that may have protective effects against dementia.
Vegetables, including leafy greens, are also a key component of the heart-healthy Mediterranean diet, which also appears to provide benefits for the brain.
“The addition of a daily serving of green leafy vegetables to one’s diet may be a simple way to contribute to brain health,” the authors conclude.
By www.ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Marc Flajolet, Ph.D., Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Martha Clare Morris, ScD, Yamin Wang, PhD, Lisa L. Barnes, et al: “Nutrients and Bioactives in Green Leafy Vegetables and Cognitive Decline.” Neurology, Dec. 20, 2017