New research points to benefits of flavonoids and cognitive wellbeing.
In recent weeks, there have been even more study findings that highlight the importance of dietary influences and the effects on cognitive health.
In recent weeks, there have been even more study findings that highlight the importance of dietary influences and the effects on cognitive health. We know we are in the midst of a tremendous rise of neurodegenerative diseases such as Alzheimer’s, Parkinson’s disease, amyotrophic lateral sclerosis (ALS), Huntington’s disease, and other often serious conditions. Although clinical presentations vary with each disease, they all share a common thread of “cellular stress response,” which includes neuroinflammation, oxidative stress, proteotoxicity, and endoplasmic reticulum (ER)-stress. So, what are the potential causes and how can we combat this situation to better protect our brain health?
Additionally, there are numerous other factors, such as the increasing toxicity of our environment caused by the use of heavy metals, pesticides, chemicals, and more, that all have contributed to a surge in the number of patients with neurodegenerative disease. Since many brain-related disorders strike primarily in mid- to late-life, the incidence was expected to soar as the population ages, so even before COVID we anticipated a likely rise in the incidence of these conditions. But, the numbers are extremely concerning for clinicians and patients alike.
In fact, one of my latest blogs looks closely at the current data and questions whether we may indeed have a new form of Alzheimer’s with which to contend.
Commensurately, other research has shown findings have shown a close correlation between COVID-19 and neurodegenerative characteristics bringing the potential role of COVID-19 in the future development of neurodegenerative diseases into the spotlight. Lingering viral fragments and in particular spike protein are driving many of the pathological mechanisms that may impact the development of these illnesses; note that spike protein may linger both post infection and post vaccine.
“Intellectual” nourishment: a closer look at flavonoids.
But, there are things we can do to counter some of these negative factors. A recently published article describes the value of flavonoids, which are readily available, naturally occurring phytonutrients found in abundance in fruits and vegetables, and have been well documented for various health-promoting effects. You also may be familiar with flavonols, which are simply a subclass of the flavonoid family of phytonutrients.
Flavonoids exert multiple neuroprotective actions within the brain, such as protection of neurons from neurotoxins and suppression of neuron-inflammation, thereby improving memory, learning, and overall cognitive function.
The study, “Association of Dietary Intake of Flavonols with Changes in Global Cognition and Several Cognitive Abilities,” was conducted using 961 participants (60-100 years) of the Rush Memory and Aging Project, which is a prospective cohort of community-dwelling Chicagoans of retirement communities and senior public housing who were followed by researchers for an average of 6.9 years.
The average age of subjects was 81 with no signs of dementia. Each patient was asked to complete a food questionnaire each year for seven years. In addition, the participants underwent annual cognitive and memory tests and were quizzed on their time spent being physically and mentally active. People were divided into groups based on their daily intake of flavonols. The lowest intake was about 5 milligrams a day; the highest 15 milligrams a day — equal to about a cup of dark leafy greens. For comparison, the average flavonol intake in US adults is about 16 to 20 milligrams per day, according to the study.
The study looked at the impact of the four major flavonols — kaempferol, quercetin, myricetin, and isorhamnetin — on the rate of cognitive decline over the seven year period. While scientists found no positive effect with dietary isorhamnetin, the other three flavonols did show significant promise.
The greatest impact was found with kaempferol: people who ate the highest amounts of foods with kaempferol showed a 0.4 units per decade slower rate of cognitive decline compared with those who ate the fewest, according to the study.
Good sources of kaempferol are:
Next up was myricetin; people who consumed the most foods with myricetin had a 0.3 units per decade slower rate of cognitive decline compared with the lowest consuming group. Good sources include:
People who ate the most foods with quercetin showed a 0.2 units per decade slower rate of cognitive decline. Good dietary sources are:
The results of this study suggest that “dietary intakes of total flavonoids constituents may be associated with slower decline in global cognition and multiple cognitive abilities with older age.”
The USDA provides a helpful chart that features the flavonoid content of many fruits and vegetables at: https://www.ars.usda.gov/ARSUserFiles/80400525/Articles/AICR03_VegFlav.pd
More research points to more reasons to eat well for our brain’s sake!
We have previously written about the role of flavonoids and studies that attest to their value in cognitive health. And in other recent research conducted with nearly 11,000 subjects of the Brazilian Longitudinal Study of Adult Health, findings noted that higher consumption of ultra-processed foods was associated with a higher rate of global and executive function decline after a median follow-up of eight years. Ultra-processed food, like chips, microwave meals, many breakfast cereals, candy, soft drinks, and more, really should be called “thoughtless food” because of its potentially negative effect on our thinking abilities.
Food really is medicine! So, while we know that in our very busy lives it can be hard to totally avoid eating convenience foods, it’s truly important that we try to choose whole, fresh food whenever possible to give our bodies and our brains the very best chance at optimal health.
Remember the wise words of Hippocrates who said “let food be thy medicine, and let medicine be thy food.” If you have questions regarding dietary options that are suitable for your particular needs be sure to consult your physician or nutritionist for guidance. And please check back soon for our follow-up blog that will look at flavonoids in even more detail!
In hope and healing,
Dr. Suzanne Gazda
Gazda, S. Do we have a new form of Alzheimer’s disease in the making? (2022)
Li, C., Liu, J., Lin, J. et al. COVID-19 and risk of neurodegenerative disorders: A Mendelian randomization study. Transl Psychiatry 12, 283 (2022). https://doi.org/10.1038/s41398-022-02052-3
Holland, Thomas Monroe et al "Association of Dietary Intake of Flavonols With Changes in Global Cognition and Several Cognitive Abilities." Neurology (2022): 10.1212/WNL.0000000000201541. Web. 08 Dec. 2022.
Dr. Suzanne Gazda, Integrative Neurology