Researchers from Rush University Medical Centre (IL, USA) have demonstrated a link between eating leafy green vegetables and improved brain health with age.
The study, published in Neurology, enrolled 960 individuals with an average age of 81. The participants did not have dementia and were observed for 4.7 years on average, during which time they completed questionnaires and underwent yearly cognitive examinations.
The survey asked how often participants ate any of three leafy green vegetables; spinach, kale and lettuce, and were then divided into five groups based upon how often they ate these. Individuals in the highest consuming group ate approximately 1.3 servings per day, with the lowest group only eating 0.1 servings daily.
Whilst overall thinking and memory test scores declined for the cohort over the trial period, at a rate of 0.08 standardized units per year, there were marked differences between the highest and lowest salad consuming groups. Those who ate leafy greens the most frequently exhibited a rate of cognitive decline which was 0.05 standardized units slower compared with those in the lowest consuming group. The difference is equal to being 11 years younger in comparison.
Additional factors such as smoking, physical activity and blood pressure were accounted for, adding validity to the findings. However, the study may be limited by the fact that all participants were elderly and Caucasian, hence further studies would need to examine more diverse age and ethnicity ranges.
Despite this limitation, there is a clear association observed between consumption of leafy greens and reduced cognitive decline, a discovery which renews hope that neurodegeneration can, at least partially, be supressed, as summarized by study author Martha Clare Morris (Rush University Medical Centre): “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.”