Thinking Green: The Surprising Cognitive Benefits of Leafy Vegetables
Martha Clare Morris, the researcher who established the benefits of the MIND diet, is a personal hero of mine. In part, this is because of the remarkable – and surprising – findings she reported in the Journal of Neurology in 2018. This study shed new light on how nutrient-rich leafy green vegetables can significantly impact cognitive decline.
This prospective cohort study followed 960 participants aged 58 to 99, part of the Rush Memory and Aging Project in Chicago. Researchers assessed their cognitive function and dietary habits over several years. Participants completed annual cognitive tests and food frequency questionnaires, which provided data on their average daily servings of green leafy vegetables. The cohort was divided into quintiles based on their intake, with the lowest quintile consuming only 8% of a serving per day and the highest consuming 1.3 servings per day.
The results were astonishing. The difference in cognitive decline between the lowest and highest quintile was equivalent to 11 years. In other words, individuals in the highest quintile, consuming 1.3 servings of leafy greens daily, had cognitive abilities comparable to those 11 years younger than individuals in the lowest quintile. Their brains were aging slower. Researchers controlled for various factors like education, physical activity, and other dietary habits, yet the effect remained significant.
In other words, individuals in the highest quintile, consuming 1.3 servings of leafy greens daily, had cognitive abilities comparable to those 11 years younger than individuals eating only 8% of a serving.
Their brains were aging slower.
To put this into perspective, a serving of leafy greens could be half a cup of cooked spinach or a cup of raw salad greens. Achieving the highest quintile’s intake is as simple as adding a cup of spinach to a smoothie and having a small side salad daily. This small dietary change can lead to significant cognitive benefits.
Supporting these findings, a 2005 study by Dr. King and colleagues, part of the Nurse’s Health Study, showed similar trends. Women who consumed the most green leafy vegetables experienced slower cognitive decline compared to those who consumed the least. While the effect size was smaller (1-2 years), it still underscored the cognitive benefits of leafy greens.
Another study by Dr. Morris in 2006, involving a more diverse group of 3,718 older adults, found that higher vegetable consumption, particularly leafy greens, was associated with slower cognitive decline. The decrease in rate for persons who consumed greater than two vegetable servings per day was equivalent to about 5 years of younger age. Of the different types of vegetables, green leafy vegetables had the strongest association. These findings reinforce the idea that leafy greens are indeed brain food, contributing to better cognitive health.
Incorporating leafy greens into your daily diet can have profound effects on your cognitive function, potentially slowing down the natural decline associated with aging. While this isn’t medical advice, it’s a powerful reminder of simple daily practices that support our brain health. By adding leafy greens to our meals, we can promote a healthier, more resilient mind.
If you want to learn more you can tune into my podcast, The Well Nurtured Brain, Season 1 Episode 5 – Thinking Green: The Surprising Benefits of Leafy Vegetables. Available on Spotify and Apple Podcasts.
- Nutrients and bioactives in green leafy vegetables and cognitive decline: Prospective study. Morris MC, Wang Y, Barnes LL, Bennett DA, Dawson-Hughes B, Booth SL. Neurology. 2018 Jan 16;90(3):e214-e222.
- Associations of vegetable and fruit consumption with age-related cognitive change. Morris MC, Evans DA, Tangney CC, Bienias JL, Wilson RS. Neurology. 2006 Oct 24;67(8):1370-6.
- .Fruit and vegetable consumption and cognitive decline in aging women. Kang JH, Ascherio A, Grodstein F. Ann Neurol. 2005 May;57(5):713-20.
