A serving of green, leafy vegetables a day - such as spinach, kale or lettuce - has been linked to a younger brain, a new study has revealed.
People who ate at least one serving a day had a slower rate of decline on tests of memory and thinking skills than those who rarely ate the vegetables.
The difference between them was the equivalent of being 11 years younger in age, study author Martha Clare Morris, from Rush University Medical Centre in Chicago, said.
The study involved 960 people with an average age of 81 who did not have dementia and were followed for almost five years.
The participants completed a questionnaire about how often they ate certain foods and had their thinking and memory skills tested every year during that time.
The questionnaire asked how often and how many servings people ate of three green, leafy vegetables: spinach, with a serving being a half cup of cooked spinach; kale/collards/greens, half a cup and cooked; and lettuce salad, with a serving of one cup raw.
The participants were divided into five groups based on how often they ate green, leafy vegetables. The people in the top serving group ate an average of 1.3 servings per day, while those in the lowest serving group ate on average 0.1 servings per day.
The participants’ scores on the thinking and memory tests declined over time. Over 10 years of follow-up, the rate of decline for those who ate the most
leafy greens was slower than the rate for those who ate the least leafy
greens. This difference was equivalent to being 11 years younger in age.
The results remained valid after accounting for other factors that could affect brain health such as smoking, high blood pressure, obesity, education level and amount of physical and cognitive activities.
Morris noted that the study cannot rule out other possible reasons for the link between vegetable intake and brain ageing. Additionally, the results may not apply to younger adults and people of colour, as the majority of adults surveyed were older and white.
She concluded: “Adding a daily serving of green, leafy vegetables to your diet may be a simple way to foster your brain health.
“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.”