We all know that green leafy vegetables are healthy. The advice to “eat your greens” has been around for decades. Such greens include spinach, kale, cabbage, Brussels sprouts, chard, arugula, collard greens, beet greens, bok choy and lettuce. Indeed, leafy greens are full of healthy nutrients – fiber, antioxidants, vitamins, minerals and other super healthy bioactives such as cancer-fighting glucosinolates in cabbage; nitrates from beet greens and arugula that can turn into nitric oxide and help with blood circulation; and syringic acid from Swiss chard that helps lower blood sugar levels (2). To add to this, in 2017, research was published from Rush University that described their discovery of new brain benefits from leafy green vegetables. (1)
This prospective study from Rush included 960 dementia-free participants aged 58 to 99 years of age from the Memory and Aging Project (a longitudinal, epidemiologic clinical-pathologic cohort study that began in 1997 and looked at common chronic conditions of aging and especially declines in cognitive and motor function and the risk of Alzheimer’s disease). Since earlier research suggested that green leafy vegetables might offer protection against cognitive decline, these researchers sought to examine this aspect more thoroughly. They investigated the relationship between losses in brain function and the primary nutrients and bioactives of which green leafy vegetables are a particularly rich source (nitrate, vitamin K (phylloquinone), folate (a B vitamin), lutein (a deep yellow pigment), alpha-tocopherol (Vitamin E) and the flavonoids beta-carotene and kaempferol). Participants were followed for up to ten years (an average of five years) after the original trial. The function of their brains was tested in five areas – episodic memory, working memory, semantic memory, visuospatial ability and perceptual speed. (1)
Study results showed that the daily consumption of green leafy vegetables was positively and significantly associated with a slower rate of decline on tests of memory and thinking skills. Those participants who ate 1 to 2 daily servings of green leafy vegetables appeared to have the brain function of a person eleven years younger compared to those who rarely or never consumed green leafy vegetables. The nutrients folate, phylloquinone and lutein were most strongly associated with a slower rate of cognitive decline and appeared to account for most of this protective relationship although higher intakes of all of the studied nutrients except for beta-carotene were individually associated with less decline in cognition. In addition, each of the nutrients linked to better preservation of the brain seemed to have an independent mechanism of action with the effects of all of them working together to protect the brain. (1)
This study is not the only science that has revealed brain benefits from leafy green vegetables. Two earlier large prospective studies both illustrated that eating green leafy vegetables, including spinach, kale, collard greens and lettuce, were strongly associated with conservation of brain performance (3,4). Other studies looking at folate and beta-carotene found links to better brain function during aging, although results were varied (5,6). Cognitive benefits were also discovered from higher dietary intake of phylloquinone among older adults. (7) In addition, higher lutein concentration in the blood has been significantly associated with decreased risk of dementia from all-causes and Alzheimer’s disease (8).
The amount of leafy green consumption required to have benefits in brain cognition is not large. Only ½ cup of cooked greens or 1 cup of raw greens are considered one daily serving of leafy greens (1). They can be used in a variety of ways – adding them to soups, stews or casseroles; mixing them up in smoothies; inserting them into sandwiches; or using them as the basis of a salad. Simply adding one or two servings of these healthy leaves to your daily food intake is an easy step to take but it offers the sizeable benefit of slowing age-related decline in brain function allowing your brain to hum along like a much younger version.
1 Morris, M.C., et al. Nutrients and bioactives in green leafy vegetables and cognitive decline. Neurology. 2017; 90: e214-e222.
3 Kang, J.H., Ascherio, A., Grodstein, F. Fruit and vegetable consumption and cognitive decline in aging women. Ann Neurol 2005; 57: 713–720.
4 Morris, M.C., Evans, D.A., Tangney, C.C., Bienias, J.L., Wilson, R.S. Associations of vegetable and fruit consumption with age-related cognitive change. Neurology 2006; 67: 1370–1376.
5 Luchsinger, J.A., Tang, M.X., Miller, .J, Green, R., Mayeux, R. Higher folate intake is related to lower risk of Alzheimer’s disease in the elderly. J Nutr Health Aging 2008 ;12: 648–650.
6 Corrada, M.M., Kawas, C.H., Hallfrisch, J., Muller, D., Brookmeyer, R. Reduced risk of Alzheimer’s disease with high folate intake: the Baltimore Longitudinal Study of Aging. Alzheimers Dement 2005; 1: 11–18.
7 Chouet, J., Ferland, G., Feart, C., et al. . Dietary vitamin K intake is associated with cognition and behaviour among geriatric patients: the CLIP Study. Nutrients 2015; 7: 6739–6750.
8 Feart, C., Letenneur, L., Helmer, C., et al. . Plasma carotenoids are inversely associated with dementia risk in an elderly French cohort. J Gerontol A Biol Sci Med Sci 2016; 71: 683–688.