November 6, 2006
Older men and women who ate plenty of vegetables tended to have less memory decline than those who shunned their salad and broccoli, researchers report. Fruit did not appear to have the same protective effect. The findings appeared in Neurology, the scientific journal of the American Academy of Neurology.
Doctors at Rush University Medical Center in Chicago followed 3,718 seniors, aged 65 and up, living in the Chicago area. All were given extensive survey about the foods they ate, including lists of 28 vegetables and 14 fruits, as well as any vitamin pills they were taking. They were also given several detailed exams to measure memory and attention at the start of the study, then again three and six years later.
"Compared to people who consumed less than one serving of vegetables a day, people who ate at least 2.8 servings of vegetables a day saw their rate of cognitive change slow by roughly 40 percent," said study author Martha Clare Morris, ScD. "This decrease is equivalent to about five years of younger age."
Of the different types of vegetables consumed by participants, green leafy vegetables had the strongest association to slowing the rate of cognitive decline. The study also found the older the person, the greater the slowdown in the rate of cognitive decline if that person consumed more than two servings of vegetables a day.
Surprisingly, the study found fruit consumption was not associated with cognitive change. "This was unanticipated and raises several questions," said Morris. "It may be due to vegetables containing high amounts of vitamin E, which helps lower the risk of cognitive decline. Vegetables, but not fruits, are also typically consumed with added fats such as salad dressings, and fats increase the absorption of vitamin E. Still, further study is required to understand why fruit is not associated with cognitive change."
All the study participants had some memory loss as they grew older. But those who ate the most vegetables, three to four servings a day, had the slowest rate of decline in memory and attention.
The findings are consistent with other studies that show that eating a heart-healthy diet, including plenty of vegetables, is good for the brain. Vegetables are high in antioxidants and other nutrients that can protect the brain and nervous system. In other studies, fruit has also shown protective effects on memory. More study is needed to determine why fruit did not offer protection to this group of seniors, and how diet may affect aging. In addition, this study did not address older people who are already suffering from Alzheimer's disease.
Ready to eat more veggies? Here are some of those listed in the study survey:
- Lettuce/tossed salad
- Greens (kale, collards, etc.)
- Cole slaw
- Lima beans
- Sweet pottatos
- Summer squash
To learn more about ways to protect your mental acuity and keep the brain young, visit www.ALZinfo.org.
M.C. Morris, ScD; D.A. Evans, MD; C.C. Tangney, PhD; et al: "Association of Vegetable and Fruit Consumption with Age-Related Cognitive Chance." Neurology, October 24, 2006, Volume 67, pages 1370-1376.