You’ve heard it all your life: “Eat your greens.” But did you know that eating just one cup of leafy greens each day makes your brain an average of 11 years younger than someone who skips them?
Medical science has recently produced some of the most compelling evidence to-date encouraging us to eat those greens. New findings reveal that eating just one cup of leafy greens per day can take a whopping eleven years off a person’s cognitive age and delay or even prevent the anticipated decline in mental performance that often occurs as we age.
This information comes to light thanks to a branch study that was conducted as part of the ongoing Rush Memory and Aging Project, a longitudinal, epidemiological study of common chronic brain conditions that develop during advanced age. The Rush Project’s stated objective is “to identify the postmortem indices linking genetic and environmental risk factors to the development of Alzheimer’s disease (AD),” as well as to identify factors associated with the maintenance of cognitive health. The Rush Project, which started in 1997, was unique among previous studies of the aging brain, which often focused on specific population groups, due to the gender, race, and ethnic diversity of participants, as well as varying individual levels of educational attainment.
According to the branch study’s author, Dr. Martha Clare Morris, a nutritional epidemiologist at Rush, the researchers were looking for “effective strategies to prevent dementia,” as the nation’s oldest population groups swell in number and rates of dementia are seeing dramatic increases.
More than 1,000 elderly volunteers (mean age = 81 years) who were free from dementia, were selected from more than thirty residential facilities in the Chicago-metro area. Participants were given baseline evaluations and were subject to ongoing monitoring and examination. “Food frequency questionnaires” were given, assessing how often and in what quantities participants consumed greens such as kale, collards, lettuce, and spinach. Multiple cognitive tests were also performed for the purposes of analyzing changes to brain function, as well as identifying risk factors for Alzheimer’s disease. Diet, cognition, and memory skills were assessed annually for five years, with periodic follow-up taking place for an additional five years.
More Greens Means a Younger Brain
Researchers parsed the volunteers into one of five groups based on how much leafy green vegetables participants had consumed, from an average of slightly more than one serving (1.3 cups) per day on the high-end, to less-than-one (0.1 cup) serving per day on the low-end. You can probably guess which group experienced the least cognitive decline: the group that ate the most greens, of course!
While all participants suffered some decline in cognition and memory test scores over the ten-year follow-up period, the rate of decline was slowed by nearly two-thirds among the most voracious leafy greens eaters, imbuing them with significantly “younger” brains. Specifically, cognitive performance of those who rarely or never ate greens declined at a rate of 0.08 standardized units per year, while those eating at least 1 cup per day declined at a mere 0.03 units per year, saving them around 11 years of cognitive aging, according to Dr. Morris.
It is noteworthy to add that results remained valid after calculating for unrelated factors that can impact brain health, such as exercise, smoking, obesity, high blood pressure, and various social and dietary factors. Further research conducted by the group deduced that the neuroprotective properties of nutrients like phylloquinone, lutein, and folate, were the likely sources of the observed beneficial slow-down in brain aging.
Why Greens are a Fountain of Youth
Exactly what is it about greens that makes them a literal fountain of youth? One of the primary explanations is the exceptional nutritional profile of most dark, leafy greens which includes an array of vitamins and phytochemicals that are increasingly scarce in the modern diet and are vital to proper cellular functioning, as well a gene expression. Readers of GreenMedInfo may not be surprised to learn what medical science has been slow to acknowledge: poor quality, inadequate nutrition lies at the root of most of the “Top 10” killer diseases in the United States.
According to the Alzheimer’s Association, Alzheimer’s disease is the sixth-leading cause of death in the U.S. While the aforementioned brain-boosting benefits from eating leafy greens can help stave-off dementia and AD, the health benefits that leafy vegetables impart extends well beyond the brain. Phylloquinone, acknowledged by Rush University researchers in the dementia study as an important neuroprotective agent, plays the role of vitamin K1 in the body, which is required for blood coagulation and bone and vascular metabolism. Healthy blood flow and vasculature provide benefits throughout the body and perform vital roles in overall disease prevention. Green leafy vegetables and vegetable oil are the only major dietary sources of vitamin K for humans, with vegetable oil being a highly inferior source thanks to the prevalence of GMO canola (rapeseed) in modern vegetable oils.
Another top-ten killer, cardiovascular disease, is attributed to one out of every four deaths in the United States. Multiple studies have linked vascular disease to a decreased level of nitric oxide, an important molecule that is produced by the body when nitrates, prevalent in plant foods, are consumed. According to health researchers, maintaining adequate levels of nitric oxide in the body protects arteries and blood vessels, and can even reverse existing arterial damage. Nitric oxide helps maintain the contractility (ability of the heart muscle to contract) and health of vascular smooth muscle cells.
Nitric oxide, in the form of nitrate, occurs at naturally high levels in leafy greens. Vegetables high in nitrate include celery, cress, chervil, lettuce, beetroot, spinach, and arugula. A 2015 meta-analysis found that daily intake of green leafy vegetables produced a nearly 20% reduction in risk for incidence of several types of cardiovascular disease. Eating adequate greens can therefore be a key strategy to ensuring a strong, vital heartbeat into the elder years. A high blood nitrate count provides yet another anti-aging benefit: it greatly enhances our cells’ ability to utilize energy, creating a more efficient metabolism that effectively extends lifespan.
Greens have been clinically shown to benefit patients facing “the Big C”—cancer, the second-leading killer in the U.S. after cardiovascular disease. While some doctors will recommend up to 3 cups of fruits and vegetables per day as part of a cancer-preventive strategy, a 2015 study found that neither citrus fruits nor cruciferous vegetables had the impact on bladder cancer risk that was observed with green leafy vegetables. Risk of bladder cancer went down with every serving size increase (0.2 c) each day, proving that you don’t have to eat a lot to get BIG benefits. Brassica vegetables contain glucosinolates, responsible for the pungency we taste in greens and horseradish, which have been credited with reducing prostate cancer risk. Greens such as bok choy, cabbage, and mustard and collard greens are excellent sources of glucosinolates, whose metabolic breakdown products protect DNA from damage.
Diabetes takes the third spot for highest mortality rate in the United States, after a recent study attributed a significantly higher percentage of deaths to the disease than had previously been acknowledged. Mustard greens have been widely studied, especially in India and countries that more openly acknowledge the power of nutrition to abate disease. They have been shown to prevent the development of insulin resistance in rats being fed a high-fructose diet, improve kidney function in diabetic rats, as well as possessing multiple blood sugar-lowering effects.
Greens also contain the molecule chlorophyll, which has been found to increase the efficiency of energy production within our mitochondria, effectively allowing us to harvest the energy of the sun like plants and convert it into metabolic energy.
If you want to add more reasons to the list of why you should be heaping greens onto your plate, there are more than 85 abstracts on GMI analyzing the potent and varied health benefits of green leafy vegetables. Consume them raw—in the case of tender lettuces, or saute them, as with kale, spinach, and mustard or collard greens. A light steaming has been shown to unlock their virtues, and even improve digestion and assimilation. Just get those greens into your diet each day, and enjoy your very own fountain of youth—for many years to come!
 Morris MC, et al. Nutrients and bioactives in green leafy vegetables and cognitive decline. Neurology. 2017 90:e214-e222. Research supported by NIA grants R01 AG031553 and R01 AG17917.
 Bennett DA, et al. The Rush Memory and Aging Project: study design and baseline characteristics of the study cohort. Neuroepidemiology. 2005;25(4):163-75. Epub 2005 Aug 15.
 Alan R Kristal, Johanna W Lampe.Brassica vegetables and prostate cancer risk: a review of the epidemiological evidence. Nutr Cancer. 2002;42(1):1-9. PMID: 12235639