Another reason to eat well: A new study shows that eating certain fruits and vegetables, as well as chocolate, can slow cognitive decline in old age. The study investigated the effects of foods containing flavonol, which occurs naturally in certain plants.
Flavonol is one of six types of flavonoids, bioactive compounds found in foods that benefit the body through their antioxidant and anti-inflammatory properties.
According to the new study, from the Rush Institute for Healthy Aging at Rush University Medical Center in Chicago and published online Nov. 22 in Neurology, older people who ate or drank more flavonoid-rich foods experienced a slower decline in memory.
To explore the benefits of the flavonol, researchers followed 961 participants in the Rush Memory and Aging Project, a group of Chicago residents whose average age was 81, for an average of seven years.
They measured how the participants’ flavonol intake affected their memory by testing their global cognition, episodic memory, semantic memory, visuospatial ability, perceptual speed and working memory.
Participants took annual standardized tests to measure these cognitive functions and also completed food frequency questionnaires.
The American Academy of Neurology (publisher of the journal Neurology) reported that after researchers adjusted for other factors that can affect the rate of memory decline (such as age, gender, and smoking), they found that the cognitive scores of people who had the a highest flavonol intakes decreased at a rate of 0.4 units per decade more slowly than people who had the lowest intakes.
In other words, individuals who ate the highest level of flavonols (an average of about seven servings of dark leafy greens per week) had a 32% lower rate of cognitive decline compared to the group who ate the least amount of flavonols. , author of the study. Dr. Thomas M. Holland told The Epoch Times.
“It is exciting that our study shows that making specific dietary choices can lead to a slower rate of cognitive decline,” Holland said in a statement. “Something as simple as eating more fruits and vegetables and drinking more tea is an easy way for people to play an active role in maintaining brain health.”
Holland’s work adds to the growing body of evidence showing that “what we eat matters, and a diet rich in fruits and vegetables is critical for cognitive and physical functioning,” he said.
International Findings
Another research group, this one in Iran, called a diet of flavonoid-rich foods “a promising nutraceutical approach against life-shortening diseases.”
Flavonoids “help prevent premature aging and decline in brain function, which is linked to Alzheimer’s disease and dementia,” the researchers wrote in a review article published in the Iranian Journal of Basic Medical Sciences.
“Degenerative diseases and premature aging are closely related to the oxidative stress produced by free radicals in the body,” they wrote.
So it makes sense that foods that reduce oxidative stress and neutralize damaging free radicals, i.e. antioxidant foods, fight disease and slow aging.
After reviewing the evidence, the Iranian group called flavonoid-rich foods “the superfoods of the millennium.”
In Greece, researchers examining the effects of flavonoids on brain health found that flavonoids “increase cognitive function at the behavioral level and attenuate cognitive decline promoted by brain disorders.” Their article in the journal Biomedicine & Pharmacotherapy stated that flavonoids “appear to have the ability to prevent or even reverse cognitive deficits through various mechanisms.”
They noted that around 5,000 flavonoids have been identified so far and can be divided into six groups: flavones, isoflavones, flavanones, flavonols, flavanols (also called flavan-3-ols), and anthocyanidins.
Foods With Flavonoids, Flavonols
The American Institute for Cancer Research has a list of flavonoid-rich foods on its site Flavonoids in Your Food: Here’s where to get them, featuring:
- Vegetables including onions, broccoli, asparagus, celery, leafy greens, kale, and tomatoes
- Herbs and spices including parsley and oregano
- Fruits including citrus fruits, berries, grapes, cherries, and peaches
- Beverages including black tea, green tea, white tea, and soy milk
- Chocolate
- Tofu
The Linus Pauling Institute Micronutrient Information Center at Oregon State University features a more detailed list of dietary sources of flavonoids on its website. Foods listed as high in flavonol (the compound studied in the new Chicago study) include blueberries, broccoli, green peppers, black-eyed peas (black-eyed peas), kale, red onion, parsley, arugula (arugula), chives, spinach, and tea. and cress.
Organic, Responsibly Farmed Food May Be Better
According to the Mayo Clinic and other sources, organic foods may have more flavonoids than conventionally grown foods.
A meta-analysis of 343 peer-reviewed publications that appeared in the British Journal of Nutrition in 2014 reported that flavonol concentrations in organic crops were 50% higher than in conventional crops. This adds to the finding that pesticide residues were four times higher on non-organic crops.
Six-year research published in 2017 in the American Chemical Society’s Journal of Agricultural and Food Chemistry found that flavonoid levels and antioxidant activity in onions grown in organic soil were higher than in conventional onions.
Interestingly, the researchers also found that climatic conditions, including temperature and rainfall, also influence flavonoid content, regardless of whether the food is grown organically.
Holland also noted that several factors determine the concentration of flavonoids in foods, whether they are grown organically or conventionally. Sun exposure, soil composition, harvest time, and even altitude can all have an effect.
“There is a lot of variability regarding food,” she said, explaining that sun exposure is vital.
If non-organic crops are properly positioned for maximum sun exposure, they can have similar flavonoid concentrations to organic crops, he said, so growing technique is important.
It’s never too early – or too late
More good news on flavonoids and cognition: It’s never too early or too late to start making healthy lifestyle changes, especially when it comes to diet, according to Holland.
“We know that changes in the brain, that is, the accumulation of amyloid plaques and hyperphosphorylated tau protein or neurofibrillary tangles, begin 10 to 20 years before the onset of easily detectable clinical signs and symptoms of cognitive changes. This means that people can have Alzheimer’s neuropathology 10 to 20 years before cognitive impairment is clinically detected.”
This means that waiting until symptoms appear is not the most sensible course of action when dietary improvements can have a significant impact on dementia risk. One more reason to eat well and enjoy the benefits of natural food.
